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Biochemistry, Genetics and Molecular Biology » "Milk Protein", book edited by Walter L. Hurley, ISBN 978-953-51-0743-9, Published: September 12, 2012 under CC BY 3.0 license. © The Author(s).

Chapter 2

Milk Derived Peptides with Immune Stimulating Antiviral Properties

By Haiyan Sun and Håvard Jenssen
DOI: 10.5772/50158

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The traditional direct antiviral mechanismes of selected milk proteins. Several proteins are characterized to interact directly with cell surface heparan sulphate, like lactoferrin (1) and lactoperoxidase. Casein species like -casein (3) and s2-casein (4) are despite high cationic character on their surface not described to interact with heparan sulphate, and the latter in stead been demonstated to interact with the virus pareticle. Anionic milk proteins like -lactalbumine (5) and -lactoglobuline (6) are also illustrated to interact directly with the virus particle, thus preventing host receptor interaction.
Figure 1. The traditional direct antiviral mechanismes of selected milk proteins. Several proteins are characterized to interact directly with cell surface heparan sulphate, like lactoferrin (1) and lactoperoxidase. Casein species like -casein (3) and s2-casein (4) are despite high cationic character on their surface not described to interact with heparan sulphate, and the latter in stead been demonstated to interact with the virus pareticle. Anionic milk proteins like -lactalbumine (5) and -lactoglobuline (6) are also illustrated to interact directly with the virus particle, thus preventing host receptor interaction.

Milk Derived Peptides with Immune Stimulating Antiviral Properties

Haiyan Sun1 and Håvard Jenssen2

1. Introduction

Milk is thought to be the main source of biologically active compounds for infants, providing antibacterial and antiviral activities, facilitating nutrient absorption, promoting bone growth, enhancing immunological protection and supporting the development of host immune competence. In milk, the main categories of compounds related to antiviral activity through immune stimulation and suppression of host immune inflammation are the casein proteins, whey proteins and their derived peptides [1-3].

Casein proteins, as well as casein fragments, function as antiviral and immune regulatory factors by regulating the innate immune response both through up-regulation to enhance killing of viruses, and down-regulation to reduce detrimental conditions such as sepsis [1, 3-7]. Additionaly, caseins link the innate immune system to the adaptive immune system by activating and/or enhancing B- and T-cell mediated functions. The whey protein lactoferrin, and pepsin derived peptide fragments of this protein (e.g. lactoferricin) have been studied extensively for its antiviral properties [8-10] i.e. its direct interaction with the virus particle, interaction with cellular receptors on the target cells, and lately more complex antiviral mechanisms involving stimulation and regulation of the immune system have been discovered [2, 11-16]. Similarly, peptides tailored on specific protein fragments of casein and α-lactalbumin have also been investigated for their antiviral and immunomodulatory properties. Many of these studies have identified biologically active peptides that can prevent a viral infection, as well as regulate the immune status of the host [1, 2, 17-21]. Currently, some of these peptides are being investigated in clinical trials, like human lactoferrin fragment 1-11 (AM Pharma, Bunnvik, The Netherlands) [22] and LTX-302 (Lytix Biopharma, Tromsø, Norway) [20]. Moreover, another promising class of synthetic peptides with therapeutic potential is a group of innate defence regulator peptides, which exhibit immune protection by enhancing or suppressing the host immune response [23-26]. It is tremendously encouraging that many of these proteins and peptides have pharmaceutical potential within antiviral and anticancer therapy, as vaccine adjuvants, as immunosuppressants for the treatment of autoimmune diseases and in conjunction with organ transplantation, etc. [20, 23-25, 27-29].

Studies have demonstrated that active milk protein and peptide compounds can be extracted from a variety of species including humans, bovine, porcine, mice and camel. The main focus in this paper is the antiviral and immune regulating properties (Table 1) of milk proteins (Table 2) and their peptide derived fragments (Table 3). The vast majority of the discussed studies deal with proteins and peptides of bovine origin, and these will be referenced with their protein names, while proteins and peptides from other origins will be explicitly specified with the species name.

VirusProtein or peptideModel of antiviral functionReference
Enveloped Virus
Herpes simplex virus 1human and bovine lactoferrin and lactoferricin, lactoperoxidaseBinding to both virus particle and cellular receptors (heparan sulphate) to prevent viral adsorption and entry;
Interference with intracellular replication events or synthesis of progeny viral components
[9, 35, 55, 77-79, 81-83]
chemically modified milk proteins e.g. serum albumin, α-lactalbumin,
[89, 93, 99, 100]
Herpes simplex virus 2human and bovine lactoferrinBinding to virus receptor of non-GAG nature[10]
-lactoglobulineBinding to virus particle [93]
Hepatitis C viruslactoferrinBinding to viral envelope protein E1 and E2[52, 63, 71, 220]
Hepatitis B virusiron- or zinc-saturated lactoferrinBinding to cellular molecules interfering with viral attachment/entry[47, 59]
Hepatitis G viruslactoferrinUnknown[63]
Respiratory syncytial viruslactoferrin, lactoperoxidaseBinding to F1 subunit of RSV F protein to inhibit viral absorption[35, 44-46]
Human immunodeficiency virushuman and bovine lactoferrin, lactoperoxidaseBinding to cellular receptor to inhibit viral absorption and replication[8, 18, 19, 34, 48, 49, 62, 68, 70]
chemically modified milk proteins like serum albumin, α-lactalbumin,
[9, 89-92]
Influenza virus (H3N2, H1N1 and H5N1) lactoferrin, κ-casein, glycomacropeptide, lactoperoxidaseBinding to hemagglutinin of virus[36, 53, 135]
modified human serum albumin and
α-lactalbumin, lactoferrin
[94, 101-103]
Human cytomegaloviruslactoferrin and lactoferricinInterfere with virus target cells; up-regulation of killer cells; synergistic antiviral effect with cidofovir[12-16]
chemically modified milk proteins like serum albumin, α-lactalbumin,
Binding to virus particle[12, 93, 96, 221]
Feline herpes virus 1human and bovine lactoferrinBinding to cellular molecules[54]
Canine herpes virushuman and bovine lactoferrin (apo- and holo-)Binding to virus particle and cellular receptor on target cell[74]
HantaviruslactoferrinBinding to cellular molecules; synergistic effect with Ribavirin on inhibiting viral replication[72, 122]
Vesicular stomatitis viruslactoferrinInduction interferon-α/β expression to inhibit viral replication[11]
Friend virus complexhuman lactoferrinRegulation on the myelopoiesis; synergistic effect with interferon-γ[11, 56, 57, 64]
Human papillomavirushuman and bovine lactoferrin,
human and bovine lactoferricin
Binding to heparan sulphate cell receptor [65, 121]
Alphavirus heparan sulphate- adapted sindbis virus and semliki forest virushuman lactoferrin, charge-modified human serum albuminBinding to heparan sulphate cell receptor [73]
Severe acute respiratory syndrome coronaviruslactoferrinBinding to heparan sulphate cell receptor[120]
Non-enveloped virus
Rotavirushuman lactoferrin (apo-/holo-), α-lactalbumin,
Binding to viral particles to prevent both rotavirus haemagglutination and viral binding to receptors on susceptible cells[30, 40]
human lactadherinBinding to structural protein of rotavirus and inhibits virus replication[37, 38]
high molecular glycoprotein (e.g. mucin)Inhibitor for viral-cell binding to prevent productive virus infection[107, 108]
immune globulinIn vivo effect on inhibition of viral replication[107]
Polioviruslactoferrin, modified bovine β-lactoglobulinBinding to viral receptor on target cell[50, 58, 104]
Coxsackie virusmodified bovine
Binding to viral receptor on target cell[104]
AdenoviruslactoferrinBinding to viral protein III and IIIa; competition with virus for common membrane receptors[60, 61, 69]
Enterovirus (71, echovirus 6)lactoferrinBinding to both cellular receptors and the viral surface protein VP1[51, 66, 67]
Felin caliciviruslactoferrinBinding to cell receptor [50]
Echoviruslactoferrin, lactoperoxidaseBinding to cell receptor and viral structural proteins[35, 75, 95]

Table 1.

Models of antiviral proteins & peptides from milk proteins.

2. Protein composition of milk and their antiviral activity

There are in general two groups of proteins found in milk, casein and whey. The casein family accounts for approximately 80% of the protein mass and includes several types of casein, e.g. αs1, αs2, β and κ, which form micelle complexes in the water phase of milk. The whey proteins account for the remaining 20%, and include β-lactoglobulin (not present in human milk), α-lactalbumin, serum albumin, immunoglobulins, lactoferrin, transferring, and many minor proteins. Most of the whey proteins have been demonstrated to effectively prevent viral infection. For example, milk derived proteins including α-lactalbumin, β-lactoglobulin, apo-lactoferrin (iron free), and homo-lactoferrin (Fe3+ carrying), were able to inhibit rotavirus attachment to cellular receptors by binding to the viral particle [30]. Among these proteins, apo-lactoferrin was proven to be the most active. Studies also showed that immunoglobulins of raw milk from non-immunized cows and camels, as well as from a commercially available bovine macromolecular whey protein fraction, have specific antibodies against human rotavirus, which are capable of inhibiting replication of rotaviruses in tissue culture and protect mice from infection in a murine model of rotavirus infection [31-33]. Lactoperoxidase, a haem-containing glycoprotein of the mammalian peroxidase family, is an important enzyme in the whey fraction of milk. In combination with its physiological substrates hydrogen peroxide and thiocyanate, lactoperoxidase manifests a wide spectrum of virucidal activities against human immunodeficiency virus, herpes simplex virus 1, respiratory syncytial virus and echovirus [34, 35]. Oral administration of lactoperoxidase also attenuate pneumonia in influenza virus infected mice through suppression of infiltration of the inflammatory cells in the lungs [36]. Furthermore, the 46kD glycoprotein termed lactadherin, also known as milk fat globule-EGF factor 8 protein, inhibited rotavirus binding to cellular receptors (acetylneuraminic acid and/or integrin) on target and/or specifically interacting with viral structural glycoprotein VP4 of rotavirus, blocking host-pathogen interaction [37-40].

Lactoferrin, first isolated in 1960 from both human [41, 42] and bovine milk [43], has been demonstrated to exhibit antiviral activity against many viruses [8, 10-16, 18, 19, 40, 44-74] (Table 2). Most studies indicate that lactoferrin and its derived peptides are likely to interfere in the virus host cell interaction (Figure 1). For example it has been demonstrated that lactoferrin is able to bind both viral receptor and the viral surface protein VP1 on enterovirus (enterovirus 71 and echovirus 6), thus interfering with viral entry [51, 66, 67, 75, 76]. Similarly, both apo- and holo-lactoferrin has been demonstrated to interact both with canine herpes virus and surface receptors on the Madin-Darby canine kidney cells, thus inhibiting canine herpes virus infection [74]. With regard to the anti-herpes simplex virus 1 ability of lactoferrin, both bovine and human lactoferrin and lactoferricin have demonstrated the ability to block viral entry and also inhibit viral cell-to-cell spread in a dose dependent manner [55, 77-79], through interaction with negatively charged glycosaminoglycans like heparan sulphate on the cell surface [55, 80-83] and elements of the viral particle [55]. Differently from herpes simplex virus 1, Marchetti et. al. found that lactoferrin inhibited herpes simplex virus 2 plaque forming activity also in cells without glycosaminoglycans suggesting that lactoferrin might block one of the specific herpes simplex virus 2 entry receptors [10].

Many of the traditional entry blocking effects observed by lactoferrin involve electrostatic interaction with anionic heparan sulphate molecules on the host cell surface [82]. The ability to interact with anionic heparan sulphate is maybe not that surprising, when evaluating the three dimensional structural composition of lactoferrin, demonstrating a rather striking cationic patch on the N-terminal lobe of the molecule [84] (Figure 1). Similarly, other highly cationic peptides have also been demonstrated to effectively interfere with herpes simplex virus attachment and entry [80, 85].

Conversely, several other milk proteins i.e. β-lactoglobulin [86], α-lactalbumin [87] are described with anionic patches on their surfaces, while the casein homologues like αs2-casein [88] have both specific anionic and cationic patches on the surface (Figure 1). Thus, charge modification of milk proteins may increase their ability to interfere with virus host cell interactions. 3-hydroxyphthalic anhydride modification of human and bovine serum albumin, and bovine β-lactoglobulin, increased the proteins negative charges in addition to their ability to prevent interaction between human immunodeficiency virus 1 envelope glycoprotein gp120 and the CD4 host cell receptor, by direct interaction and blocking of the CD4 receptor [89, 90]. Similar effects have also been observed for 3-hydroxyphthalic anhydride modified α-lactalbumin and αs2-casein, as well as for maleylated- and succinylated-human serum albumin, indicating that human immunodeficiency virus inhibition was a general property of negatively charged polypeptides [9, 91, 92]. Among the inhibitory proteins, 3-hydroxyphthalic anhydride β-lactoglobulin also demonstrated a broad spectrum activity affecting herpes simplex virus 1 and 2 in addition to human cytomegalovirus by binding to the virus particles, inhibiting particularly the binding of monoclonal antibodies towards glycoprotein E and glycoprotein C [93]. Comparative results have been shown for anionic-modified human serum albumin and β-lactoglobulin which prevents influenza virus membrane fusion with the host cell membrane, a process mediated by the viral glycoprotein hemagglutinin [94]. Interestingly, this anti-influenza effect has not been observed for other milk proteins carrying negative charges, like succinylated bovine serum albumin, lactalbumin, lactoferrin, lysozyme and transferrin [94]. It is said that inhibition of viral fusion demonstrates a certain degree of specificity for negative charged proteins. However, addition of net negative charges to lactoferrin by acylation with either succinic- or acetic anhydride abolished its anti-poliovirus and anti-feline calicivirus activity, which may be attributed to the obliterate binding of acylated lactoferrin to the surfaces of susceptible cells [95]. Also, when negatively charged groups were added to lactoferrin by succinylation, the antiviral effect on human immunodeficiency virus 1 was increased, but the antiviral potency against human cytomegalovirus was mostly decreased [96], illustrating the proteins different modes of action. Similar results were also obtained by Florisa et. al. which demonstrated a stronger antiviral effect against human immunodeficiency virus by developing poly-anionic milk proteins, while stronger effects could be obtained against human cytomegalovirus by creating poly-cationic milk proteins [12].


Figure 1.

The traditional direct antiviral mechanismes of selected milk proteins. Several proteins are characterized to interact directly with cell surface heparan sulphate, like lactoferrin (1) and lactoperoxidase. Casein species like -casein (3) and s2-casein (4) are despite high cationic character on their surface not described to interact with heparan sulphate, and the latter in stead been demonstated to interact with the virus pareticle. Anionic milk proteins like -lactalbumine (5) and -lactoglobuline (6) are also illustrated to interact directly with the virus particle, thus preventing host receptor interaction.

SourceProtein% of whey protein% of caseinMolecular size (kDa)NaturePDB code
Whey β-lactoglobulin50-55NA~18.4Apolipoprotein1DV9
Serum albumin5-10NA~66Albumin
Casein αs1-caseinNA40-50~23Phosphoprotein

Table 2.

Bioactive proteins from bovine milk.

The strong antiviral activity of poly-cationic compounds is generally explained by the compounds ability to interact with anionic heparan sulphate on the host cell surface, which works as a broad spectrum attachment receptor for several viruses [97, 98]. Thus, it is not surprising that methylated or ethylated α-lactalbumin and β-lactoglobulin demonstrate antiviral activity against the bacteriophage M13 through the inhibition of the phage DNA replication, as well as against herpes simplex virus 1 replication, with increasing activity proportional to the extent of esterification or increased basicity of the modified proteins [99, 100]. The net positive charge-modified human serum albumin had a similar antiviral effect as lactoferrin, against heparan sulphate adapted sindbis virus and semliki forest virus, by blocking the virus receptor on the cell surface, indicating that the antiviral activity of lactoferrin mainly is related to its net positive charge [73]. Methylated α-lactalbumin, β-lactoglobulin and lactoferrin also demonstrate enhanced antiviral activity against human influenza virus A subtype H3N2 and subtype H1N1 [101, 102], and lethal avian influenza A (H5N1) [103]. This effect is most likely linked to the disruption of the electrostatic interactions within hemagglutinin, by the esterified whey proteins, thus affecting the proteins stability and capacity to trigger envelope fusion with the host cell. Furthermore, methylation of β-lactoglobulin does also enhance the proteins antiviral activity against coxsackie virus and poliovirus type 1 in a dose dependent manner [104]. This illustrates that chemically modified whey proteins with added negative or positive charges can exert increased antiviral effect against a diverse group of viruses, through different antiviral mechanisms. The virucidal activity of the modified milk proteins, with additional negative charges, may attribute to a stronger interaction of these proteins with the viral envelope proteins. Esterification of whey proteins with methanol or ethanol would increase their cationic charge, thus increasing their affinity for negatively charged macromolecules such as host cell receptors and viral DNA or RNA, thus inhibiting viral attachment to cellular membranes or inhibiting viral replication and transcription, respectively. The structural differences between enveloped and non-enveloped viruses in addition to the unique protein composition in milk from different species preclude a generalized conclusion of the milk proteins potential. Thus, further studies should be carried out to identify the underlying molecular interactions involved, and the true therapeutic potential of these milk derived molecules.

3. Traditional antiviral mechanisms of milk-derived proteins

The life cycle of a virus comprises several phases such as binding to the host cell surface, entry or fusion, replication of the viral genome, viral protein synthesis, virus progeny assembly and release. All these steps may be targeted by antiviral agents or milk derived proteins.

Binding to structural virus proteins prevent virus host cell interaction. For the non-enveloped viruses, structural proteins on the surface of the virion protruding as spikes, such as glycoprotein VP4 of rotavirus [105] or fibers associated with each penton base of the capsid on for example adenovirus [106]. These proteins recognize host cell surface receptors, and are involved in facilitating the initial virus to host cell attachment. Enveloped viruses, meaning the viral capsid is coated with a lipid membrane known as the viral envelop, infect host cells via the interaction between envelop proteins and cellular receptors. The envelop proteins include E1 and E2 of hepatitis C virus, F protein of respiratory syncytial virus, hemagglutinin of influenza viruses, etc.

Many of the antiviral milk proteins can bind to structural proteins of the virion in order to prevent binding of the virus to the target cell and subsequently inhibit entry of the viral genome into the host cell. Human lactoferrin (apo- or Fe3+), α-lactalbumin, β-lactoglobulin, human lactadherin, mucin, and immunoglobulin from milk could prevent rotavirus infection through the binding to structural viral protein VP4 [30, 37, 38, 40, 107, 108]. Also, the antiviral activity of lactoferrin against adenovirus has been attributed to the interaction of the milk protein with viral capsid proteins [60, 61, 69].

Furthermore, Ikeda et. al. has also demonstrated that lactoferrin effectively protect against hepatitis C virus infection in hepatocytes and lymphocytes by neutralizing the virus, while a basic N-terminal loop of lactoferrin named lactoferricin exhibited no antiviral properties in the same experiments [63]. Lactoferrin has also been demonstrated to inhibit the absorption and growth of respiratory syncytial virus in cell culture through direct interaction with the F(1) subunit of the viral F protein, which is the most important surface glycoprotein participating in viral penetration [44, 45]. Blocking of viral entry like this, leads to down-regulation of respiratory syncytial virus induced interleulin-8 secretion from the HEp-2 cells, which consequently leads to a dampening of the immune response as the low levels of interleukine-8 is inadequate to recruit neutrophils to phagocytose the viral antigen [46].

Hemagglutinin is an antigenic glycoprotein found on the surface of influenza viruses. The glycoprotein has two main functions; recognition of target cells through the binding of sialic acid-containing receptors and facilitating entry of the viral genome into the target cells by initiating fusion of host endosomal membrane with the viral membrane. Thus, targeting the hemagglutination activity of hemaglutinin could be a robust mechanism in fighting influenza virus infections. Influenza hemaglutinin has also successfully been targeted by both human and bovine lactoferrin (apo- and holo-), as well as κ-casein glycomacropeptide, reduce viral hemagglutination [30, 53]. Moreover, the addition of methylated β-lactoglobulin in the medium of Madin-Darby canine kidney cell lines infected with influenza virus H1N1 reduced hemagglutination in a concentration-dependent manner [101].

Interference with viral entry, through virus and/or cell surface interaction. Viruses recognize and conjugate to specific host cell receptors. These receptor molecules are mainly of protein nature, including glycoprotein, lipoprotein and glycolipid-protein. Hence, host cell specificity or preference is guided by the level of expression of these individual receptor molecules on the different cells. For example, the main goal of human immunodeficiency virus is to infect CD4+ T-lymphocytes and initiate replication of a large number of progeny virions. However, the initial infection with this virus is usually of epithelial dendritic cells, which then are used for transport to the lymph nodes. Human immunodeficiency virus attachment to for example emigrating dendritic cells, is mediated by the successive interactions of the viral envelop glycoprotein gp120 with CD4 (a glycoprotein known as cluster of differentiation 4) and a co-receptor, CXCR4 (C-X-C chemokine receptor type 4, also known as fusin or CD184) or CCR5 (C-C chemokine receptor type 5, also known as CD195) [109-111]. However, in cells like macrophages and skin dendritic cells that are lacking or weakly expressing CD4, many other cell surface molecules such as heparan sulphate proteoglycans [112, 113], mannose receptor [48, 114], or dendritic cells-specific intracellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) [62, 109] can play a key role in the initial multistep interaction between the virus and host cell surface. Consequently, one might hypothesis that human immunodeficiency virus entry into the host cell might be efficiently inhibited via the interaction between antiviral milk proteins from bovine or human sources and some of the receptors described above. This has also been demonstrated to be true, for lactoferrin which effectively can bind heparan sulphate as well as mannose receptor like nucleolin, both which will inhibit virus attachment [18, 48]. Other studies have also indicated that a peptide fragment (hLF1-33) of human lactoferrin (residue 1-33) constituting the glycosaminoglycan recognizing site of the human lactoferrin, exhibit inhibitory effect on human immunodeficiency virus 1 attachment to epithelial cells, though its activity was lower as compared to the native protein [19]. Interestingly however, hLF1-33 had no inhibitory effect on transferring human immunodeficiency virus 1 from immature dendritic cells to CD4 T-lymphocytes, but enhancing virus transmission in contrast to human lactoferrin. This may suggest that the hLF1-33 exposed domain is not involved in human lactoferrin associated inhibition of human immunodeficiency virus 1 transfer to CD4 T-cells [19]. Moreover, bovine lactoferrin could bind strongly to DC-SIGN to prevent human immunodeficiency virus 1 capture and subsequent transmission on dendritic cells, and bovine lactoferrin was a much more efficient inhibitor than human lactoferrin on blocking not only dendritic cell mediated human immunodeficiency virus 1 transmission to - but also replication in CD4 T-cells [49].

Although it has been identified that a metallopeptidase, angiotensin-converting enzyme 2, is a functional receptor for severe acute respiratory syndrome coronavirus infection [115], other reports have demonstrated that DC-SIGN, L-SIGN (also called CD209L, specific for liver/lymph node) [116-119], and heparan sulphate [120] also are involved in the virus pathogenesis. Thus, there are reasons to believe that lactoferrin could prevent severe acute respiratory syndrome coronavirus spread in the host through the same mechanism as described for human immunodeficiency virus, by interacting with DC-SIGN or heparan sulphate receptors. Recently, Lang et. al. also described that lactoferrin curtailed the entry of severe acute respiratory syndrome coronavirus into HEK293E/ angiotensin-converting enzyme 2-Myc cells by binding to heparan sulphate [120].

Human papillomavirus can also use heparan sulphate on the target cell surface as a receptor. Thus, by incubating HaCaT cells and papillomavirus 16 virus like particles with human and bovine lactoferrin Drobni et. al. have confirmed that human papillomavirus entry can be inhibited by lactoferrin in a dose-dependent fashion [65]. Subsequently, they also demonstrated that bovine lactoferrin peptide (bLF17-33) region 17-33 was a more potent inhibitor of both human papillomavirus 5 and 16 pseudovirus infection than the native protein, while human lactoferricin (hLF1-49) region 1-49 from human lactoferrin, showed modest antiviral activity against the same viruses and bLF17-42 prevented only papillomavirus 5 pseudovirus infection. With regard to the viral attachment, only hLF1-49 and bLF17-42 exhibited antiviral effect [121].

In a classical pre-incubation study on Vero E6 cells, it was demonstrated that lactoferrin had enhanced antiviral activity against hantavirus infection when added prior to infection. However, this boost in activity could be removed if the cells were subsequently washed with phosphate buffered saline prior to infection [72, 122]. These results might be explained by the weak interaction between lactoferrin and other cellular molecules rather than heparan sulphate, as the interaction between lactoferrin and heparan sulphate should withstand phosphate buffered saline washing [80]. Further research should be developed to identify whether β3 integrin and/or β1 integrin molecules are binding to lactoferrin [123-125].

Similarly, using indirect immunofluorescence, McCann et. al. found that bovine lactoferrin could bind to Crandell-Reese feline kidney cells used for propagation of feline calicivirus, as well as Monkey Embryo kidney cells used with poliovirus, indicating that the interference of viral infection might be attributed to lactoferrin binding to the cellular receptor on the respective cells, though the related cell receptors for feline calicivirus and poliovirus have not yet been identified [50]. Contradicting this, it was demonstrated that lactoferricin decreased feline calicivirus but not poliovirus infection. Moreover, feline herpes virus-1 replication could be prevented by exposing cultured Crandell-Reese feline kidney cells to lactoferrin prior to or during viral adsorption, but not following viral adsorption, suggesting that the inhibitory effect on feline herpes virus 1 adsorption to the cell surface and/or viral penetration into the cell might be related to the interaction between lactoferrin and cellular receptor on the Crandell-Reese feline kidney cells [54].

Interference with certain viral enzymes required for virus replication. The process of viral replication will involve a myriad of enzymes, such as DNA- or RNA-polymerases, reverse transcriptase, integrase, etc. The necessity of viral enzymes for viral replication means that interference with any of them potentially could result in a selective antiviral mode of action. Ng et. al. has assayed the inhibitory effect of proteins from bovine milk on the crucial enzymes for the human immunodeficiency virus type 1 life cycle [126]. They demonstrated that lactoferrin strongly inhibited reverse transcriptase but only slightly inhibited the viral protease and integrase. In parallel, α-lactalbumin, β-lactoglobulin and casein were demonstrated to affect human immunodeficiency virus protease and integrase, while not affecting the reverse transcriptase [126].

4. Modulation of innate immune responses - A novel antiviral strategy

The immune system consists of the innate and the adaptive branch, which exerts its functions through recognition of foreign pathogen resulting in a series of responses to eliminate the infectious material. Both innate leukocytes (including macrophages, dendritic cells, and natural killer cells) and adaptive immune cells (B-cells and T-cells) are involved in host immune protection and bridging these two pathways is a variety of traditional signal molecules (cytokines and chemokines). Recently it has also been documented that natural occurring host defence peptides (and proteins) are involved in the orchestration of a well balanced and effective immune response [127-129]. Lactoferrin is one such host defence protein, and it has been demonstrated that lactoferrin can increase the cytotoxic functions of natural killer cells and lymphokine-actived killer cells especially in infants, which normally have low activity in these cell populations [130]. Lactoferrin can also enhance the mobility of polymorphonuclear leucocytes and increase the production of superoxide [131], activate macrophages and stimulate the release of both pro- and anti-inflammatory cytokines, i.e. interleukin-1,-6,-8,-18, interferon-γ and tumor necrosis factor-α [132]. The antiviral effect of lactoferrin on cytomegalovirus in a murine infection model has been demonstrated to be a result of augmentation of natural killer cell activity rather than of the cytolytic T-lymphocytes [14]. Similarly, human lactoferrin has also been proven to have an effect on natural killer cell cytotoxicity against haematopoietic and epithelial tumor cells [133].

Furthermore, the antiviral activity of lactoferrin against vesicular stomatitis virus has been related to its capacity of up-regulating the accumulation of interferon-β in peritoneal macrophages from mice [11]. Another experiment with interperitoneal administration of lactoferrin to CBA mice demonstrated enhanced production of tumor necrosis factor-α and interleukin-12. Similar results were also reported after in vitro stimulation of J774A.1 murine macrophages by lactoferrin [134]. Increased expression of interleukin-12, in addition to interferon-β and NOD2, were also observed in mice that were administered lactoferrin orally after being infected with influenza virus, thus suggesting that lactoferrin potentially can promote systemic host immunity [135]. As an important inductor of interferon-γ production in T-cells and natural killer cells, interleukin-12 exhibited a marked synergism with interferon-γ in activating monocytes and macrophages, promoting the differentiation of B-cells and T-cells, and increasing the induction of major histocompatibility complex I and II molecules by up-regulating expression of the interleukin-18 receptor on cells producing interferon-γ [136-138].

With regard to modulation of the adaptive immune system, lactoferrin could exert higher growth stimulatory activity on lymphocytes than transferrin [139], induce phenotypic changes of immature B- and T-cells from newborn or chromosome X-linked immunodeficient mice, as well as enable B-cells to present antigen to an antigen-specific T-helper type 2 cell line [140, 141]. Immature B-cells cultured with lactoferrin will also increase their ability to promote antigen-specific T-cell proliferation, indirectly indicating enhanced B-cell antigen presentation [140].

In summary, the effects of lactoferrin on the activation, maturation, migration and antigen presentation of the innate and adaptive immune cells, suggest that lactoferrin have the potential to associate the cellular functions and responses of the innate and adaptive immune cells, respectively. The modulating effects of lactoferrin on cytokine levels, especially of interleukin-12 and interleukin-18 illuminates the milk proteins role in connecting the innate and adaptive immune response.

5. Milk derived peptides as immune modulators

There is a great quantity of milk proteins and peptides other than lactoferrin that can lead to immune regulation, involving in both up- and down-regulation of the immune system. Peptides from casein [4, 6, 142], β-lactoglobulin [143, 144], and α-lactalbumin [7] also enhance and/or suppress immune cell function (Table 3).

Precursor proteinFragmentPeptide sequenceNameFunctionReference
αs1-casein23-27FFVAPα-casokinin-5ACE-inhibition[222, 223]
23-34FFVAP FPEVFGKACE-inhibition[224]
158-162YVPFPαs1-casomorphinOpioid agonist, immunomodulation[159, 226]
194-199TTMPLWα-casokinin-6ACE-inhibition, immunostimulatory activity[5, 228]
casein phosphopeptideImmunostimulatory activity[3]
54-59VEPIPYImmunostimulatory activity[6, 149]
ACE-inhibition, immunomodulation activity[1, 230, 231]
63-68PGPIPNImmunomodulation[6, 232]
Immunostimulatory activity, opioid and ACE-inhibitory activities[233]
114-118YPVEPβ-casochemotide-1Promote innate host immune response[142]
169-175KVLPVPQACE-inhibition[225, 229]
191-193LLYImmunomodulation activity[6, 234]
193-202YQQPVLGPVRβ-casokinin-10ACE-inhibition, immunostimulatory activity[1]
106-116MAIPPKKNQDKcasoplatelinAntithrombotic activity[236]
YIPIQYVLSRCasoxin C Opioid agonist[237]
YPSYCasoxin 4Opioid agonist[238]
50-53YGLFα-lactorphinACE-inhibition[143, 144]
102-105YLLFβ-lactorphinACE-inhibition[143, 144]
Bovine serum albumin399-404YGFQNAserorphinOpioid[241]
208-216ALKAWSVARalbutensin AACE-inhibition[242]
Bovine lactoferrin17-41FKCRRWQWRMKKLGAPSITCVRRAFlactoferricinAnti-herpes simplex virus activity, ACE-inhibition, immunomodulation activity[2, 80]
17-26FKCRRWQWRWimmunomodulation activity[21]
lactoferricinAnti-herpes simplex virus activity[80]
LF-33 (human)Anti-human immunodeficiency virus activity[18, 19]
222-230; 264-268ADRDQYELL;
Inhibit herpes simplex virus 1 infection[243]
268-284KWNLLRQAQEKFGKDKSLactoferrampin Immunomodulation activity[148]
318-323YLGSGYLactoferroxin AOpioid agonist[244]
536-540RYYGYLactoferroxin BOpioid agonist[244]
673-679KYLGPQYLactoferroxin COpioid agonist[244]

Table 3.

Milk proteins-derived peptides with antiviral and immunemodulatory activity

Up-regulation of immune system. Bovine and human lactoferricin, from N-terminal end of bovine and human lactoferrin, respectively, are known for their ability to improve and modulate the function of host immune system [145-147]. Additional, deletion fragments of lactoferrin like the peptide sequence FKCRRWQWRW, corresponding to N-terminal fragment 17-26 of bovine lactoferrin, has demonstrated potent activation of polymorphonuclear leukocytes [21]. Another lactoferrin derived peptide termed lactoferrampin, containing residues 268-284 from the N-terminal domain of lactoferrin, is located in close proximity to the cationic lactoferricin sequence, in the three dimensional structure. Lactoferrampin has been shown to exhibit antimicrobial activity and can improving immune function and gut health in the present of lactoferricin. Dietary supplementation of piglets with an expressed fusion peptide composed of bovine lactoferricin linked to lactoferrampin demonstrated the ability to increased serum levels of IgA, IgG, and IgM, while decreasing the incidence of diarrhea in the piglets [148].

Immunomodulating casein peptides have been found to stimulate the proliferation of human lymphocytes and the phagocytic activities of macrophages [4]. Casein phosphopeptides from fermented milk products, such as plain yogurts and cheeses, has shown beneficial effects on the immune system including the mitogenic effect and IgA enhancing effect in mouse spleen cell cultures [3]. According to the results of other studies, human β-casein fraction 54-59 has demonstrated to enhance the phagocytic activity of macrophages both in mice and humans and increase resistance against certain bacteria in mice [6, 149].

Chemotactic factors in the tissue do also play an essential role in host defence against microbial infection by inducing leukocyte infiltration. A pentapeptide (β-casochemotide-1) with amino acid sequence (YPVEP) matching an actinase E digest peptide from bovine β-casein (corresponding to fraction 114-118), has been tested and demonstrated to both chemoattract and activate, human and mouse monocytes and macrophages by using a unique G-protein coupled receptors [142].

In addition, Colostrinin, also known as PRP, is a naturally occurring mixture of proline-rich polypeptides derived from colostrums and it can stimulate the immune response in animal and in vitro studies by causing differentiation of murine thymocytes into functionally active T-cells [150], as well as inhibit autoimmune disorders. Subsequent studies have shown that Colostrinin largely consists of the peptides derived from proteolytic processing of the milk proteins β-casein and β-casein homolog’s [151]. Among the Colostrinin digestion peptides are an active nona-peptide fragment VESYVPLFP demonstrating a full spectrum of biological activities [150]. Furthermore, fermentation of milk by Lactobacillus helveticus has also proven to generate novel peptide fragments, i.e. three derived from β-casein and one peptide from α-lactalbumin, and the peptides have demonstrated the ability to stimulate the production of tumor necrosis factor-α and modulate macrophage activity [7].

Down-regulation of immune responses. It has been demonstrated that a modified whey protein concentrate, developed as a by-product from commercial manufacturing of cheese, not only suppress B- and T-lymphocyte proliferating responses to mitogens in a dose-dependent fashion, but also suppress alloantigen-induced lymphocyte proliferation during a mixed leukocyte reaction. Moreover, the modified whey protein concentrate could also have been demonstrated to suppress other indices of lymphocyte activation, e.g. cytokine secretion and the formation of activated (CD25+) T-cell blasts, showing that the mechanism of suppression may be related to an inhibition of the lymphocyte activation process. However, the interleukin-2 cytokine-mediated response was not affected by the presence of the modified whey protein concentrate in culture [152]. Similarly, intact -casein and -caseinoglycopeptide (fragment 106-169), which have been prepared from -casein digested with rennin, in addition to a commercial whey protein concentrate, all significantly inhibit the mitogen-induced proliferative response of mouse spleen lymphocytes and Peyer’s patch cells [153-155]. As a result of this it has been proposed that -caseinoglycopeptide fragment 106-169 can inhibit the phytohaemagglutinin induced proliferation of mouse splenocytes via at least two different models; production of an inhibitory component that reacts with the anti-interleukin-1 antibody or through suppression of interleukin-2 receptor expression on CD4+ T-cells [156].

The opioid system plays a major role in immune modulation, both through classical opioid receptor, but also through other mechanisems. For example, opioid peptides have been demonstrated to inhibit phagocytosis [157], decrease natural killer cell number and activity and decrease cell-mediated hypersensitivity [158]. Also, αs1-casomorphin, an opioid agonist, can modulate antibody and cytokine secretion by multiple myeloma cells in a cell line-dependent and opioid receptor-independent manner, but it was shown to decrease the antibody secretion by normal B-lymphocytes and the proliferation rate of multiple myeloma cells through opioid receptor activation [159]. In other words, there might be two different opioid mechanisms, mediated by parallel signalling pathways, i.e. one early non-opioid receptor related effect modulating the constitutive secretion of immunoglobulin and cytokine, as well as a second long lasting receptor-mediated action of cell growth. Thus, opioids might be employed in controlling the humoral immunity.

Furthermore, the rennin-angiotensin-aldosterone system is not only a major regulator of blood pressure; it also plays a key role in autoimmunity. The angiotensin peptide (AII), is one component of the rennin-angiotensin-aldosterone system, and has direct activity on T-cell function, including activation, expression level of tissue-homing markers and production of tumor necrosis factor-α [160]. Inhibitors of angiotensin-converting enzyme will dampen the proteolytic process of the larger angiotensin peptides (AI) to the active AII. Thus, inhibition of T-cell angiotensin-converting enzyme blocks production of tumor necrosis factor-α, which modulates the proliferation of human immunodeficiency virus [161] and regulates the helper activity in B-cell activation [162]. This will also suppress the auto-reactive T-helper 1 and T-helper 17 cells and promotes antigen-specific CD4+FoxP3+ regulatory T-cells through inhibition of the canonical NF-κB1 transcription factor complex and activation of the alternative NF-κB2 pathway [163]. Moreover, angiotensin-converting enzyme inhibitors play a pivotal role in immune defence by decreasing the degradation of bradykinin and enkephalin [4, 164].

A variety of angiotensin-converting enzyme inhibitory peptides have been found in the hydrolysates of milk using different enzymes; the bovine αs1-casein (fragment) f24-47, f104-109, f169-193, f194-199 and f201-212, αs2- casein f94-103 and f163-176, β-casein f60-66, f60-70, f169-175, f177-183 and f193-202, α-lactalbumin f18-20 and f50-53; β-lactoglobulin f102-105 and f142-148, bovine serum albumin f208-216, lactoferrin f17-41 (Table 3). Among all these angiotensin-converting enzyme inhibitors, it should be emphasised that peptides αs1-casein f194-199, β-casein f60-66 and f193-202 have shown to have both angiotensin-converting enzyme inhibitory activities and immune stimulatory effect.

Moreover, recombinant human αs1-casein expressed in Escherichia coli has been purified and digested with trypsin in an attempt to find peptides with angiotensin-I-converting enzyme inhibitory activity. Three novel angiotensin-converting enzyme inhibitory peptides, A-II, B-II and C, have been isolated and their amino acid sequences identified as YPER (residues 8-11), YYPQIMQY (residues 136-143) and NNVMLQW (residues 164-170), respectively [165]. Two other sequences QKALNEINQF and TKKTKLTEEEKNRL from bovine milk αs2-casein have even stronger inhibitory effects on the angiotensin-converting enzyme [166]. Regardless, no structure-function relationship study for milk-derived peptides in respect to their angiotensin-converting enzyme inhibitory effect has yet been described. However, it has been suggested that peptides with angiotensin-converting enzyme inhibitory function show some common features. First, the interaction between different inhibitory peptides and the angiotensin-converting enzyme is strongly influenced by the C-terminal tripeptide residues of the substrate, which interacts with the active sites of the enzyme [167]. The inhibitory potency of the peptides is further attributed by the hydrophobic (e.g. proline) as well as the positive charged (e.g. arginine and lysine) amino acids in the C-terminal end [168]. Additionally, the model of angiotensin-converting enzyme inhibition involves interaction, not only to the active site but also to the anionic inhibitor binding sites, which are different from the catalytic sites of the enzyme.

6. Synergy between milk proteins and conventional antiviral drugs

A combination of human lactoferrin with recombinant murine interferon-γ resulted in synergistic suppressive effects on disease progression in friend virus complex infected mice [56]. The experiment concluded that natural killer cell activity decreased by friend virus complex, and that the cellular activity returned to normal levels and survival rates increased upon treatment with lactoferrin and interferon-γ. Another study also supporting immune cell regulation by lactoferrin was performed by Spadaro et. al. In this study the anticancer activity of a recombinant form of human lactoferrin, talactoferrin-alfa (Agennix, Houston, TX) was evaluated. Talactoferrin-alfa was administered orally to BALB/c mice and the results showed an increase in the intestinal mucosal interferon-γ production, CD8+ T-cell cytotoxicity and the Peyer’s patch cellularity which included expansion of CD8+ T lymphocytes and nature killer T-cells, whereas no such phenomena were showed in interferon-γ knockout mice [169]. Thus, the inhibition of friend virus complex infection and tumor growth by lactoferrin/talactoferrin-alfa seems to be mediated by an interferon-γ-dependent enhancement of CD8+ T-cells and natural killer T-cell activity, leading to diversified functions like antiviral defence, immune activation and cell growth regulation [170-173].

Also, combined pre-infection administration of lactoferrin with post-infection administration of Ribavirin on Vero E6 cells could completely inhibit focus formation during hantavirus infection (similar to the traditional plaque formation). This combination therapy also demonstrated significantly increased survival rates in an in vivo mice model, not particularly surprising as lactoferrin inhibits viral adsorption to cells and Ribavirin interferes with viral RNA synthesis [122]. Moreover, the antiviral synergy of lactoferrin/lactoferricin with Cidofovir, Ribavirin, Zidovudine, and Acyclovir as all been well documented against human cytomegalovirus, hepatitis C virus, human immunodeficiency virus 1 and herpes simplex virus, respectively [13, 174-176].

Although it is known that lactoferrin has been used to inhibit initial viral infection by interfering with viral attachment and/or entry, the mode of antiviral activity against lots of viruses needs to be clarified in the future, e.g. the infection with hepatitis G virus in human MT-2C T-cells was prevented by bovine lactoferrin with no clear mechanism [63]. With regard to friend virus complex infection, most researchers have confirmed that human lactoferrin has anti-friend virus complex activity in a mouse leukemia model [57, 64], but have no direct effect on friend virus complex infection in vitro, indicating a mechanism involving immune regulationg rather than direct viral affects. They discovered that human lactoferrin prolonged survival rates and decreased viral titres in the spleen of infected mice by administering human lactoferrin intraperitoneally in the early phase of friend virus complex infection. Probably, the anti-friend virus complex mechanism of human lactoferrin related to the regulation on the myelopoiesis [64], which should be verified thoroughly.

7. Commercial potential of milk derived proteins and peptides.

Immune regulation. There is emerging evidence that the utility of many immune mediators originating from milk represents novel therapeutic approaches depending on their activity of immune stimulation, immune suppression and induction of immunological tolerance. Hence, milk-derived proteins and peptides with immune modulating activity are claimed to be a health enhancing nutritional dietary supplement in functional food and pharmaceutical preparations. For instance, Colostrinin from bovine colostrum have demonstrated possible efficacy against various illnesses including viral infections, and ailments characterized by an overactive immune system, such as allergies, autoimmune diseases, neurodegenerative diseases like Alzheimer’s disease, etc. Capsules or chewable tablets containing Colostrinin are sold as an over the counter dietary supplement and are available in many countries in the world under names like Colostrinin, MemoryAid, Cognisure, Cognase, Cognate and Dyna (ReGen Therapetutics Limited, London, England) [151]. Moreover, whey proteins are used as common ingredients in various products including infant formulas, specialized enteral and clinical protein supplements, sports nutrition products, and specific weight management- and mood control products.

Additionally, synthetic peptides derivatives tailored on natural milk proteins or fragments there of, may be another powerful way for design of immune regulating pharmaceutical candidates. For example, synthetic peptides tailored from milk proteins have been shown to enhance proliferation of human peripheral blood lymphocytes. In particular, two fragments (YG and YGG), of bovine α-lactalbumin (fraction 18-19 and 18-20) can significantly stimulate the lymphocyte proliferation, while β-casomorphin-7 and β-casokinin-10, corresponding to fragments 60-66 and 193-202 of bovine β-casein, respectively, suppresses lymphocyte proliferation at low concentrations while enhanced proliferation at high concentrations [1] (Table 3).

Recent studies have shown that synthetic innate defence regulator peptides offer protection by enhancing innate immune defenses of the host while suppressing potentially harmful excessive inflammatory response triggered by the invading pathogen. For example, innate defence regulator peptide 1 was chemotactic for T-helper cells type 1 [23], monocytes [27] and neutrophil response [28], acting in a mitogen-activated protein kinase-dependent manner, while reducing pro-inflammatory cytokine responses. Another peptide, innate defence regulator 1002, induces chemokines in human peripheral blood mononuclear cells [24] which prevents the production of interleukin-1β-induced matrix metalloproteinase 3 and monocyte chemotactic protein-1 and selectively suppresses the inflammatory response [25].

With the aid of computational molecular modeling technologies, theoretical prediction of immune regulatory peptides has become available and practical. For example, RDP58, a novel d-amino acid decapeptide (r-(nle)3-r-(nle)3-gy-CONH2), which was developed by computer-aided rational based design on human leukocyte antigen-derived peptides [177], has been discovered to suppress the T-helper 1 cytokine profile, decrease production of inflammatory cytokines including tumor necrosis factor-α, interferon-γ, interleukin-2 and interleukin-12 in both cell lines and animal models [26, 178, 179]. Several clinical trials on human including phase I safety in normal volunteers, phase II mild-moderate active ulcerative colitis, phase II moderate active ulcerative colitis and phase IICrohn’s disease had been completed (Genzyme Corporation; Sanofi, Bridgewater, NJ). Moreover, quantitative structure-activity relationship analysis has been done for peptide design and optimization in developing novel antimicrobial drugs [180-183], and the numerical improvements of quantitative structure-activity relationship studies has been exemplified recently [184], though there are limitations to the predictive ability of the models [185, 186] this technology clearly accelerates lead peptide discovery.

Suppression of immunological functions by milk derived proteins is thought to be important in the ontogeny of the neonatal gastrointestinal immune system, specifically by ensuring a state of tolerance with respect to food proteins. Kulkarni and Karlsson has demonstrated the essential role of milk-derived immunosuppressive factors (i.e. growth factor-β) during early development, and that neonatal mice deficient in transforming growth factor-β remain viable only as long as they receive maternal milk containing this same growth factor [187].

Also, it is envisaged that most of the potential immunosuppressive activity of milk-derived peptides would be effective on chronic inflammatory diseases and organ transplant patients by decreasing allergy, autoimmunity, and organ rejection. For example, lactoferrin could enhance the production of anti-inflammatory factors, like interleukin-11, not only in a hepatitis mouse model, but also in human intestinal myofibroblasts [188]. Additionally, hydrolysis of caseins with L. casei GG-derived enzymes has generated molecules with suppressive effects on lymphocyte proliferation and benefited the intestinal bacteria in the down-regulation of hypersensitivity reactions to ingested proteins in patients with food allergy [189]. Furthermore, two synthesized analogs of the hexapeptide of human β-casein (fraction 54-59) with modification at the N-terminal region not only showed inhibition in alloantigen inducing lymphocyte proliferation and production of interferon-γ in a SRBC mice model, but also demonstrated increased production of interleukin-4 and improved the skin graft survival. Thus, these peptides might serve as good templates for development of safe and effective immunosuppressant drugs [17]. Similarly, two other synthetic β-casein peptides HLPLP and WSVPQPK, have demonstrated potent antioxidant activity and inhibitory activity of angiotensin-converting enzyme [190]. Accordingly, proteins and peptides from milk could potentially be used in production of immune stimulating- and immunosuppressant agents for both prophylaxis and treatment of infectious diseases and immune related illnesses.

Antiviral therapy. Lactoferrin might be a useful addition to conventional antiretroviral therapy, as traditional therapy supplemented with lactoferrin has demonstrated a more effective increase in CD4+ cell count than either treatments alone [191]. A potential oral vaccine resulting in expression of enterovirus 71 VP1 capsid protein in a transgenic animal system, under the control of an α-lactalbumin promoter and an α-casein leader sequence has demonstrated protection against enterovirus 71 [192]. Also, the combined treatment with human lactoferrin and recombinant murine interferon-γ on feline calicivirus infection might be of significance as a potential therapy for patients with leukemia and those infected with retroviruses [56].

Most of the proteins and peptides with antiviral potential has also demonstrated synergy with conventional antiviral drugs, reducing the dose of the antiviral drugs, and limiting the development of drug-resistant viruses on account of the selective targeting of the host rather than infectious pathogens. At the present time, many peptides with immune regulating effects have been approved for clinical use against virus infection, such as Zadaxin, IM862, SCV-07 and so on [193]. Similarly, two peptide inhibitors of interleukin-10 may be applied to increase anti-hepatitis C virus immune response by restoring the immune stimulatory capabilities of dendritic cells, which have been suppressed by high levels of interleukin-10 [194]. Moreover, candidacidal activities of a synthetic peptide from human lactoferrin fraction 1-11 and 21-31 have been investigated for killing of multidrug-resistant pathogens [195-199]. Present research results, such as phase I safety and tolerability trials of human lactoferrin by AM Pharma [22], indicate that human lactoferrin 1-11 acts by selectively stimulating the innate immune system [200]. Thus, human lactoferrin 1-11 is more likely to be an interesting candidate for further exploration in various clinical tests, such as coating for dental or bone implants, in biosensing applications or in radiopharmaceutical therapy [199].

Vaccine adjuvant. Vaccine adjuvants, such as an immune potentiator or immunomodulator, have been used for decades to improve the immune response to vaccine antigens. This involves presentation of the antigen to the immune system, regulation of both quantitative and qualitative aspects of the immune responses, targeting of specific cells, etc. Many adjuvants had been developed in the past, but were never accepted for routine vaccination because of safety concerns, such as acute toxicity and the possibility of delayed side effects. Thus, novel vaccine adjuvants without side effects should be proposed. Despite numerous publications on milk proteins and milk derived peptides with immune regulating activity, there are scarse reports of their adjuvant potential to vaccine. Lactoferrin could function as an effective adjuvant as it has been documented to enhance efficacy of the Bacillus Calmette-Guerin, the current vaccine for tuberculosis disease by promoting host protection and decreasing disease manifestation [201, 202]. Additionally, recombinant porcine lactoferrin significantly increased serum IgA, IgG and infectious bursal disease virus-specific antibody, as well as enhanced interferon-γ and interleukin-12 expressed in chicken T-lymphocytes, suggesting that porcine lactoferrin could enhance cell-mediated immunity and strengthen the ability of vaccinating against infectious bursal disease infection [203, 204].

An innate defence regulator peptide, HH2, has shown synergy with oligonucleotides containing CpG motifs, when used as an immunoadjuvant to enhance the immune response through stimulation of T-helper 1 and T-helper 2 responses in newborn piglets which were vaccinated with a pseudorabies attenuated virus vaccine [29]. Recently, Brown et. al. found that the combination of oligonucleotides contain CpG motifs and HH2 displayed robust adjuvant effects on induction of T-helper 1 cellular immune response in mice by formulating with a booster recombinant Chlamydia antigen subunit vaccine [205]. Another synthetic peptide, WKYMVm, originally identified as a peptide that stimulated the activity of monocytes, neutrophils and dendritic cells [206-210], has demonstrated to selectively enhance the vaccine-induced CD8+ T-cell responses in a dose-dependent manner, in terms of interferon-γ secretion and cytolytic activity when it was co-delivered with human immunodeficiency virus, hepatitis B virus and influenza virus vaccines [211]. It is indicated that WKYMVm may function as a novel adjuvant for DNA vaccine.

Cancer inhibition. More recently, a widely-read article focused on the amazing cases in which milk proteins and derived peptides were used in the treatment of different kinds of cancers. Whey protein is superior to other dietary proteins for suppression of tumour development in animal models usually for colon and mammary tumorigenesis [212]. Furthermore, lactoferrin and its peptides, for example, lactoferricin [212-214], both possess anticancer activity by inducing apoptosis; inhibit angiogenesis, modulating the carcinogen metabolizing enzymes, and so on. Casein and casein derived peptides have antimutagenic properties, and other whey protein components, such as β-lactoglobulin, α-lactalbumin and serum albumin, have also demonstrated anticancer potential [212, 215-217]. Moreover, a recombinant adenovirus containing the human lactoferrin cDNA has been constructed and its effects against tumor growth have been investigated in mice bearing EMT6 breast cancer. The results showed that recombinant delivery of human lactoferrin cDNA could induce apoptosis of the tumor cells by triggering the mitochondrial-dependent pathway and activation of caspase 3, suggesting that this recombinant cDNA delivery might be a promising drug strategy for breast cancer gene therapy [218].

In addition, the synthetic peptide, P60 (RDFQSFRKMWPFFAM) [219], has demonstrated potential of inhibiting the immunosuppressive activity of murine and human derived regulatory T-cells and enhances the effector T-cell stimulation in vitro by binding to regulatory T-cells specific forkhead or winged helix transcription factor 3. Thus, P60 can improve the immunogenicity of cancer and viral vaccines against CT26 tumor challenge and hepatitis C virus infection. Also, the in vivo antitumoral effects of LTX-302, a 9-mer peptide derived from bovine lactoferricin, have been examined by intratumoral injection. The results showed that LTX-302 induced tumor necrosis and infiltration of inflammatory cells followed by complete regression of the tumors, as it results in long term and specific cellular immunity against the A20 B-cell lymphoma that is CD4+ and CD8+ T-cells dependent [20].

8. Conclusion

Most of the milk proteins and peptides that have been identified with antiviral properties are broad spectrum components targeting general features and mechanismes involved in a viral infection cycle. Hence, many of these milk proteins do also demonstrate synergy with conventional antiviral drugs. Recently, the diverse immunomodulatory activities of milk proteins/peptides have illustrated these molecules interesting potential as antiviral therapeutics, though the precise mechansiems of immune regulation needs to be thoroughly described. Although the synthetic peptides usually are shorter than natural proteins, the antiviral immune regulating properties of many of these synthetic derivatives appear to be similar as for the entire proteins. Thus we would argue that milk proteins and peptides, have great potential to serve as templates for design of more potent antiviral drugs. With proper scientific effort these molecules may have great therapeutic potential as supplements for current antiviral and anticancer therapy, as novel vaccine adjuvants for both human and far animals, and as immunosuppressants for autoimmune diseases and allergy treatment.


1 - H. Kayser, H. Meisel, 1996Stimulation of human peripheral blood lymphocytes by bioactive peptides derived from bovine milk proteins,FEBS Lett 3831820
2 - W. Bellamy, M. Takase, K. Yamauchi, H. Wakabayashi, K. Kawase, M. Tomita, 1992Identification of the bactericidal domain of lactoferrin, Biochim Biophys Acta 1121130136
3 - T. Kawahara, K. Aruga, H. Otani, 2005Characterization of casein phosphopeptides from fermented milk products,J Nutr Sci Vitaminol (Tokyo) 51377381
4 - H. Meisel, 1997Biochemical properties of regulatory peptides derived from milk proteins,Biopolymers43119128
5 - A. M. Fiat, S. Levy-Toledano, J. P. Caen, P. Jolles, 1989Biologically active peptides of casein and lactotransferrin implicated in platelet function,J Dairy Res 56351355
6 - D. Migliore-Samour, F. Floc’h, P. Jolles, 1989Biologically active casein peptides implicated in immunomodulation,J Dairy Res 56357362
7 - A. Tellez, M. Corredig, L. Y. Brovko, M. W. Griffiths, 2010Characterization of immune-active peptides obtained from milk fermented by Lactobacillus helveticusJ Dairy Res 77129136
8 - B. Berkhout, J. L. van Wamel, L. Beljaars, D. K. Meijer, S. Visser, R. Floris, 2002Characterization of the anti-HIV effects of native lactoferrin and other milk proteins and protein-derived peptides,Antiviral Res 55341355
9 - B. Berkhout, G. C. Derksen, N. K. Back, B. Klaver, C. G. de Kruif, S. Visser, 1997Structural and functional analysis of negatively charged milk proteins with anti-HIV activityAIDS Res Hum Retroviruses 1311011107
10 - M. Marchetti, M. G. Ammendolia, F. Superti, 2009Glycosaminoglycans are not indispensable for the anti-herpes simplex virus type 2 activity of lactoferrinBiochimie91155159
11 - P. Puddu, M. G. Carollo, F. Belardelli, P. Valenti, S. Gessani, 2007Role of endogenous interferon and LPS in the immunomodulatory effects of bovine lactoferrin in murine peritoneal macrophagesJ Leukoc Biol 82347353
12 - R. Florisa, I. Recio, B. Berkhout, S. Visser, 2003Antibacterial and antiviral effects of milk proteins and derivatives thereof,Curr Pharm Des 912571275
13 - B. W. van der Strate, F. M. De Boer, H. I. Bakker, D. K. Meijer, G. Molema, M. C. Harmsen, 2003Synergy of bovine lactoferrin with the anti-cytomegalovirus drug cidofovir in vitro, Antiviral Res 58159165
14 - K. Shimizu, H. Matsuzawa, K. Okada, S. Tazume, S. Dosako, Y. Kawasaki, K. Hashimoto, Y. Koga, 1996Lactoferrin-mediated protection of the host from murine cytomegalovirus infection by a T-cell-dependent augmentation of natural killer cell activity,Arch Virol 14118751889
15 - L. Beljaars, B. W. van der Strate, H. I. Bakker, C. Reker-Smit, A. M. van Loenen-Weemaes, F. C. Wiegmans, M. C. Harmsen, G. Molema, D. K. Meijer, 2004Inhibition of cytomegalovirus infection by lactoferrin in vitro and in vivo, Antiviral Res 63197208
16 - J. H. Andersen, S. A. Osbakk, L. H. Vorland, T. Traavik, T. J. Gutteberg, 2001Lactoferrin and cyclic lactoferricin inhibit the entry of human cytomegalovirus into human fibroblasts,Antiviral Res 51141149
17 - A. Puri, M. Bhattacharya, L. M. Tripathi, W. Haq, 2009Derivatives of human beta-casein fragments (54-59) exhibit highly potent immunosuppressant activity,Int Immunopharmacol 910921096
18 - H. Saidi, J. Eslahpazir, C. Carbonneil, L. Carthagena, M. Requena, N. Nassreddine, L. Belec, 2006Differential modulation of human lactoferrin activity against both R5 and X4-HIV-1 adsorption on epithelial cells and dendritic cells by natural antibodies,J Immunol 17755405549
19 - L. Carthagena, P. Becquart, H. Hocini, M. D. Kazatchkine, H. Bouhlal, L. Belec, 2011Modulation of HIV Binding to Epithelial Cells and HIV Transfer from Immature Dendritic Cells to CD4 T Lymphocytes by Human Lactoferrin and its Major Exposed LF-33 Peptide,Open Virol J 52734
20 - G. Berge, L. T. Eliassen, K. A. Camilio, K. Bartnes, B. Sveinbjornsson, O. Rekdal, 2010Therapeutic vaccination against a murine lymphoma by intratumoral injection of a cationic anticancer peptideCancer Immunol Immunother 5912851294
21 - E. Ueta, T. Tanida, T. Osaki, 2001A novel bovine lactoferrin peptide, FKCRRWQWRM, suppresses Candida cell growth and activates neutrophilsJ Pept Res 57240249
22 - W. J. Velden, T. M. van Iersel, N. M. Blijlevens, J. P. Donnelly, 2009Safety and tolerability of the antimicrobial peptide human lactoferrin 1-11 (hLF1-11),BMC Med 7, 44 EOF
23 - D. M. Bowdish, D. J. Davidson, M. G. Scott, R. E. Hancock, 2005Immunomodulatory activities of small host defense peptides, Antimicrob Agents Chemother 4917271732
24 - A. Nijnik, L. Madera, Ma S. , M. Waldbrook, M. R. Elliott, D. M. Easton, M. L. Mayer, S. C. Mullaly, J. Kindrachuk, H. Jenssen, R. E. Hancock, 2010Synthetic cationic peptide IDR-1002 provides protection against bacterial infections through chemokine induction and enhanced leukocyte recruitment, J Immunol 18425392550
25 - E. Turner-Brannen, K. Y. Choi, D. N. Lippert, J. P. Cortens, R. E. Hancock, H. El -Gabalawy, N. Mookherjee, 2011Modulation of interleukin-1beta-induced inflammatory responses by a synthetic cationic innate defence regulator peptide, IDR-1002, in synovial fibroblasts, Arthritis Res Ther 13, R129.
26 - S. Iyer, R. Lahana, R. Buelow, 2002Rational design and development of RDP58,Curr Pharm Des 822172229
27 - M. G. Scott, E. Dullaghan, N. Mookherjee, N. Glavas, M. Waldbrook, A. Thompson, A. Wang, K. Lee, S. Doria, P. Hamill, J. J. Yu, Y. Li, O. Donini, M. M. Guarna, B. B. Finlay, J. R. North, R. E. Hancock, 2007An anti-infective peptide that selectively modulates the innate immune response, Nat Biotechnol 25465472
28 - H. Y. Lee, Y. S. Bae, 2008The anti-infective peptide, innate defense-regulator peptide, stimulates neutrophil chemotaxis via a formyl peptide receptor, Biochem Biophys Res Commun 369573578
29 - D. Cao, H. Li, Z. Jiang, Q. Cheng, Z. Yang, C. Xu, G. Cao, L. Zhang, 2011CpG oligodeoxynucleotide synergizes innate defense regulator peptide for enhancing the systemic and mucosal immune responses to pseudorabies attenuated virus vaccine in piglets in vivoInt Immunopharmacol 11748754
30 - F. Superti, M. G. Ammendolia, P. Valenti, L. Seganti, 1997Antirotaviral activity of milk proteins: lactoferrin prevents rotavirus infection in the enterocyte-like cell line HT-29,Med Microbiol Immunol 1868391
31 - R. H. Yolken, G. A. Losonsky, S. Vonderfecht, F. Leister, S. B. Wee, 1985Antibody to human rotavirus in cow’s milk, N Engl J Med 312605610
32 - E. I. el Agamy, R. Ruppanner, A. Ismail, C. P. Champagne, R. Assaf, 1992Antibacterial and antiviral activity of camel milk protective proteins,J Dairy Res 59169175
33 - A. Bojsen, J. Buesa, R. Montava, A. S. Kvistgaard, M. B. Kongsbak, T. E. Petersen, C. W. Heegaard, J. T. Rasmussen, 2007Inhibitory activities of bovine macromolecular whey proteins on rotavirus infections in vitro and in vivo, J Dairy Sci 906674
34 - M. Pourtois, C. Binet, N. Van Tieghem, P. Courtois, A. Vandenabbeele, L. Thiry, 1990Inhibition of HIV infectivity by lactoperoxidase-produced hypothiocyanite, J Biol Buccale 18251253
35 - H. Mikola, M. Waris, J. Tenovuo, 1995Inhibition of herpes simplex virus type 1, respiratory syncytial virus and echovirus type 11 by peroxidase-generated hypothiocyanite,Antiviral Res 26161171
36 - K. Shin, H. Wakabayashi, K. Yamauchi, S. Teraguchi, Y. Tamura, M. Kurokawa, K. Shiraki, 2005Effects of orally administered bovine lactoferrin and lactoperoxidase on influenza virus infection in mice,J Med Microbiol 54717723
37 - D. S. Newburg, J. A. Peterson, G. M. Ruiz-Palacios, D. O. Matson, A. L. Morrow, J. Shults, M. L. Guerrero, P. Chaturvedi, S. O. Newburg, C. D. Scallan, M. R. Taylor, R. L. Ceriani, L. K. Pickering, 1998Role of human-milk lactadherin in protection against symptomatic rotavirus infection, Lancet 35111601164
38 - D. S. Newburg, 1999Human milk glycoconjugates that inhibit pathogens,Curr Med Chem 6117127
39 - M. J. Hewish, Y. Takada, B. S. Coulson, 2000Integrins alpha2beta1 and alpha4beta1 can mediate SA11 rotavirus attachment and entry into cells,J Virol 74228236
40 - A. S. Kvistgaard, L. T. Pallesen, C. F. Arias, S. Lopez, T. E. Petersen, C. W. Heegaard, J. T. Rasmussen, 2004Inhibitory effects of human and bovine milk constituents on rotavirus infections, J Dairy Sci 8740884096
41 - B. Johansson, 1960Isolation of an iron-containing red protein from human milk, Acta Chem Scand 14510512
42 - J. Montreuil, J. Tonnelat, S. Mullet, 1960Preparation and properties of lactosiderophilin (lactotransferrin) of human milk, Biochim Biophys Acta 45413421
43 - M. L. Groves, 1960The isolation of a red protein from milk, J. Am. Chem. Sco. 8233453350
44 - M. Grover, O. Giouzeppos, R. D. Schnagl, J. T. May, 1997Effect of human milk prostaglandins and lactoferrin on respiratory syncytial virus and rotavirus,Acta Paediatr 86315316
45 - J. Portelli, A. Gordon, J. T. May, 1998Effect of compounds with antibacterial activities in human milk on respiratory syncytial virus and cytomegalovirus in vitro,J Med Microbiol 4710151018
46 - H. Sano, K. Nagai, H. Tsutsumi, Y. Kuroki, 2003Lactoferrin and surfactant protein A exhibit distinct binding specificity to F protein and differently modulate respiratory syncytial virus infection,Eur J Immunol 3328942902
47 - S. Li, H. Zhou, G. Huang, N. Liu, 2009Inhibition of HBV infection by bovine lactoferrin and iron-, zinc-saturated lactoferrinMed Microbiol Immunol 1981925
48 - D. Legrand, K. Vigie, E. A. Said, E. Elass, M. Masson, M. C. Slomianny, M. Carpentier, J. P. Briand, J. Mazurier, A. G. Hovanessian, 2004Surface nucleolin participates in both the binding and endocytosis of lactoferrin in target cells, Eur J Biochem 271303317
49 - F. Groot, T. B. Geijtenbeek, R. W. Sanders, C. E. Baldwin, M. Sanchez-Hernandez, R. Floris, Y. van Kooyk, E. C. de Jong, B. Berkhout, 2005Lactoferrin prevents dendritic cell-mediated human immunodeficiency virus type 1 transmission by blocking the DC-SIGN--gp120 interaction, J Virol 7930093015
50 - K. B. Mc Cann, A. Lee, J. Wan, H. Roginski, M. J. Coventry, 2003The effect of bovine lactoferrin and lactoferricin B on the ability of feline calicivirus (a norovirus surrogate) and poliovirus to infect cell culturesJ Appl Microbiol 9510261033
51 - T. Y. Lin, C. Chu, C. H. Chiu, 2002Lactoferrin inhibits enterovirus 71 infection of human embryonal rhabdomyosarcoma cells in vitro,J Infect Dis 18611611164
52 - M. Ikeda, K. Sugiyama, T. Tanaka, K. Tanaka, H. Sekihara, K. Shimotohno, N. Kato, 1998Lactoferrin markedly inhibits hepatitis C virus infection in cultured human hepatocytes,Biochem Biophys Res Commun 245549553
53 - Y. Kawasaki, H. Isoda, H. Shinmoto, M. Tanimoto, S. Dosako, T. Idota, I. Nakajima, 1993Inhibition by kappa-casein glycomacropeptide and lactoferrin of influenza virus hemagglutination,Biosci Biotechnol Biochem 5712141215
54 - S. L. Beaumont, D. J. Maggs, H. E. Clarke, 2003Effects of bovine lactoferrin on in vitro replication of feline herpesvirusVet Ophthalmol 6245250
55 - H. Valimaa, J. Tenovuo, M. Waris, V. Hukkanen, 2009Human lactoferrin but not lysozyme neutralizes HSV-1 and inhibits HSV-1 replication and cell-to-cell spreadVirol J 6, 53.
56 - L. Lu, R. N. Shen, S. Z. Zhou, C. Srivastava, M. Harrington, K. Miyazawa, B. Wu, Z. H. Lin, S. Ruscetti, H. E. Broxmeyer, 1991Synergistic effect of human lactoferrin and recombinant murine interferon-gamma on disease progression in mice infected with the polycythemia-inducing strain of the Friend virus complex,Int J Hematol 54117124
57 - L. T. Chen, L. Lu, H. E. Broxmeyer, 1987Effects of purified iron-saturated human lactoferrin on spleen morphology in mice infected with Friend virus complex,Am J Pathol 126285292
58 - M. Marchetti, F. Superti, M. G. Ammendolia, P. Rossi, P. Valenti, L. Seganti, 1999Inhibition of poliovirus type 1 infection by iron-, manganese- and zinc-saturated lactoferrinMed Microbiol Immunol 187199204
59 - K. Hara, M. Ikeda, S. Saito, S. Matsumoto, K. Numata, N. Kato, K. Tanaka, H. Sekihara, 2002Lactoferrin inhibits hepatitis B virus infection in cultured human hepatocytes, Hepatol Res 24, 228.
60 - A. M. Di Biase, A. Pietrantoni, A. Tinari, R. Siciliano, P. Valenti, G. Antonini, L. Seganti, F. Superti, 2003Heparin-interacting sites of bovine lactoferrin are involved in anti-adenovirus activity, J Med Virol 69495502
61 - A. Pietrantoni, A. M. Di Biase, A. Tinari, M. Marchetti, P. Valenti, L. Seganti, F. Superti, 2003Bovine lactoferrin inhibits adenovirus infection by interacting with viral structural polypeptides, Antimicrob Agents Chemother 4726882691
62 - B. Berkhout, R. Floris, I. Recio, S. Visser, 2004The antiviral activity of the milk protein lactoferrin against the human immunodeficiency virus type 1Biometals17291294
63 - M. Ikeda, A. Nozaki, K. Sugiyama, T. Tanaka, A. Naganuma, K. Tanaka, H. Sekihara, K. Shimotohno, M. Saito, N. Kato, 2000Characterization of antiviral activity of lactoferrin against hepatitis C virus infection in human cultured cells, Virus Res 665163
64 - L. Lu, G. Hangoc, A. Oliff, L. T. Chen, R. N. Shen, H. E. Broxmeyer, 1987Protective influence of lactoferrin on mice infected with the polycythemia-inducing strain of Friend virus complex,Cancer Res 4741844188
65 - P. Drobni, J. Naslund, M. Evander, 2004Lactoferrin inhibits human papillomavirus binding and uptake in vitro,Antiviral Res 646368
66 - A. Tinari, A. Pietrantoni, M. G. Ammendolia, P. Valenti, F. Superti, 2005Inhibitory activity of bovine lactoferrin against echovirus induced programmed cell death in vitroInt J Antimicrob Agents 25433438
67 - T. Y. Weng, L. C. Chen, H. W. Shyu, S. H. Chen, J. R. Wang, C. K. Yu, H. Y. Lei, T. M. Yeh, 2005Lactoferrin inhibits enterovirus 71 infection by binding to VP1 protein and host cells, Antiviral Res 673137
68 - P. J. Swart, M. E. Kuipers, C. Smit, R. Pauwels, M. P. de Bethune, E. de Clercq, D. K. Meijer, J. G. Huisman, 1996Antiviral effects of milk proteins: acylation results in polyanionic compounds with potent activity against human immunodeficiency virus types 1 and 2 in vitroAIDS Res Hum Retroviruses 12769775
69 - D. Arnold, A. M. Di Biase, M. Marchetti, A. Pietrantoni, P. Valenti, L. Seganti, F. Superti, 2002Antiadenovirus activity of milk proteins: lactoferrin prevents viral infection, Antiviral Res 53153158
70 - P. Puddu, P. Borghi, S. Gessani, P. Valenti, F. Belardelli, L. Seganti, 1998Antiviral effect of bovine lactoferrin saturated with metal ions on early steps of human immunodeficiency virus type 1 infectionInt J Biochem Cell Biol 3010551062
71 - M. Yi, S. Kaneko, D. Y. Yu, S. Murakami, 1997Hepatitis C virus envelope proteins bind lactoferrin,J Virol 7159976002
72 - M. E. Murphy, H. Kariwa, T. Mizutani, K. Yoshimatsu, J. Arikawa, I. Takashima, 2000In vitro antiviral activity of lactoferrin and ribavirin upon hantavirus,Arch Virol 14515711582
73 - B. L. Waarts, O. J. Aneke, J. M. Smit, K. Kimata, R. Bittman, D. K. Meijer, J. Wilschut, 2005Antiviral activity of human lactoferrin: inhibition of alphavirus interaction with heparan sulfate, Virology 333284292
74 - T. Tanaka, S. Nakatani, X. Xuan, H. Kumura, I. Igarashi, K. Shimazaki, 2003Antiviral activity of lactoferrin against canine herpesvirus, Antiviral Res 60193199
75 - A. Pietrantoni, M. G. Ammendolia, A. Tinari, R. Siciliano, P. Valenti, F. Superti, 2006Bovine lactoferrin peptidic fragments involved in inhibition of Echovirus 6 in vitro infectionAntiviral Res 6998106
76 - M. G. Ammendolia, A. Pietrantoni, A. Tinari, P. Valenti, F. Superti, 2007Bovine lactoferrin inhibits echovirus endocytic pathway by interacting with viral structural polypeptidesAntiviral Res 73151160
77 - M. G. Ammendolia, M. Marchetti, F. Superti, 2007Bovine lactoferrin prevents the entry and intercellular spread of herpes simplex virus type 1 in Green Monkey Kidney cellsAntiviral Res 76252262
78 - H. Jenssen, K. Sandvik, J. H. Andersen, R. E. Hancock, T. J. Gutteberg, 2008Inhibition of HSV cell-to-cell spread by lactoferrin and lactoferricin, Antiviral Res 79192198
79 - A. K. Marr, H. Jenssen, M. R. Moniri, R. E. Hancock, N. Pante, 2009Bovine lactoferrin and lactoferricin interfere with intracellular trafficking of Herpes simplex virus-1Biochimie91160164
80 - H. Jenssen, J. H. Andersen, L. Uhlin-Hansen, T. J. Gutteberg, O. Rekdal, 2004Anti-HSV activity of lactoferricin analogues is only partly related to their affinity for heparan sulfate,Antiviral Res 61101109
81 - M. Marchetti, C. Longhi, M. P. Conte, S. Pisani, P. Valenti, L. Seganti, 1996Lactoferrin inhibits herpes simplex virus type 1 adsorption to Vero cells,Antiviral Res 29221231
82 - J. H. Andersen, H. Jenssen, K. Sandvik, T. J. Gutteberg, 2004Anti-HSV activity of lactoferrin and lactoferricin is dependent on the presence of heparan sulphate at the cell surface,J Med Virol 74262271
83 - M. Marchetti, E. Trybala, F. Superti, M. Johansson, T. Bergstrom, 2004Inhibition of herpes simplex virus infection by lactoferrin is dependent on interference with the virus binding to glycosaminoglycansVirology 318405413
84 - S. A. Moore, B. F. Anderson, C. R. Groom, M. Haridas, E. N. Baker, 1997Three-dimensional structure of diferric bovine lactoferrin at 2.8 A resolutionJ Mol Biol 274222236
85 - H. Jenssen, J. H. Andersen, D. Mantzilas, T. J. Gutteberg, 2004A wide range of medium-sized, highly cationic, alpha-helical peptides show antiviral activity against herpes simplex virus,Antiviral Res 64119126
86 - S. Uhrinova, M. H. Smith, G. B. Jameson, D. Uhrin, L. Sawyer, P. N. Barlow, 2000Structural changes accompanying pH-induced dissociation of the beta-lactoglobulin dimer, Biochemistry 3935653574
87 - N. Chandra, K. Brew, K. R. Acharya, 1998Structural evidence for the presence of a secondary calcium binding site in human alpha-lactalbumin,Biochemistry3747674772
88 - E. Pechkova, G. Zanotti, C. Nicolini, 2003Three-dimensional atomic structure of a catalytic subunit mutant of human protein kinase CK2Acta Crystallogr D Biol Crystallogr 5921332139
89 - A. R. Neurath, A. K. Debnath, N. Strick, Y. Y. Li, K. Lin, S. Jiang, 1995Blocking of CD4 cell receptors for the human immunodeficiency virus type 1 (HIV-1) by chemically modified bovine milk proteins: potential for AIDS prophylaxis,J Mol Recognit 8304316
90 - A. R. Neurath, S. Jiang, N. Strick, K. Lin, Y. Y. Li, A. K. Debnath, 1996Bovine beta-lactoglobulin modified by 3-hydroxyphthalic anhydride blocks the CD4 cell receptor for HIV,Nat Med 2230234
91 - R. W. Jansen, G. Molema, R. Pauwels, D. Schols, E. De Clercq, D. K. Meijer, 1991Potent in vitro anti-human immunodeficiency virus-1 activity of modified human serum albumins,Mol Pharmacol 39818823
92 - M. Takami, T. Sone, K. Mizumoto, K. Kino, H. Tsunoo, 1992Maleylated human serum albumin inhibits HIV-1 infection in vitro,Biochim Biophys Acta 1180180186
93 - A. R. Neurath, N. Strick, Y. Y. Li, 1998Hydroxyphthaloyl beta-lactoglobulin. III. Antiviral activity against herpesviruses, Antivir Chem Chemother 9177184
94 - P. Schoen, J. Corver, D. K. Meijer, J. Wilschut, P. J. Swart, 1997Inhibition of influenza virus fusion by polyanionic proteins, Biochem Pharmacol 539951003
95 - Y. Pan, J. Wan, H. Roginski, A. Lee, B. Shiell, W. P. Michalski, M. J. Coventry, 2007Comparison of the effects of acylation and amidation on the antimicrobial and antiviral properties of lactoferrinLett Appl Microbiol 44229234
96 - M. C. Harmsen, P. J. Swart, M. P. de Bethune, R. Pauwels, E. De Clercq, T. H. The, D. K. Meijer, 1995Antiviral effects of plasma and milk proteins: lactoferrin shows potent activity against both human immunodeficiency virus and human cytomegalovirus replication in vitro,J Infect Dis 172380388
97 - T. C. Mettenleiter, 2002Brief overview on cellular virus receptors,Virus Res 8238
98 - D. Spillmann, 2001Heparan sulfate: anchor for viral intruders?Biochimie83811817
99 - M. Sitohy, J. M. Chobert, U. Karwowska, A. Gozdzicka-Jozefiak, T. Haertle, 2006Inhibition of bacteriophage m13 replication with esterified milk proteins,J Agric Food Chem 5438003806
100 - M. Sitohy, S. Billaudel, T. Haertle, J. M. Chobert, 2007Antiviral activity of esterified alpha-lactalbumin and beta-lactoglobulin against herpes simplex virus type 1. Comparison with the effect of acyclovir and L-polylysines,J Agric Food Chem 551021410220
101 - M. Sitohy, B. Besse, S. Billaudel, T. Haertle, J. M. Chobert, 2010Antiviral action of methylated beta-lactoglobuline on the human influenza virus A subtype H3N2., Probiotics Antimicrobial Prot. 2104111
102 - M. Sitohy, M. Scanu, B. Besse, C. Mollat, S. Billaudel, T. Haertle, J. M. Chobert, 2010Influenza virus A subtype H1N1 is inhibited by methylated beta-lactoglobulin, J Dairy Res 77411418
103 - S. H. Taha, M. A. Mehrez, M. Z. Sitohy, Dawood. A. G. Abou, Hamid. M. M. Abd El, W. H. Kilany, 2010Effectiveness of esterified whey proteins fractions against Egyptian Lethal Avian Influenza A (H5N1), Virol J 7, 330.
104 - M. Sitohy, M. Dalgalarrondo, M. Nowoczin, B. Besse, S. Billaudel, T. Haertle, J. M. Chobert, 2008The effect of bovine whey proteins on the ability of poliovirus and Coxsackie virus to infect Vero cell culturesInt Dairy J 18658668
105 - C. F. Arias, P. Isa, C. A. Guerrero, E. Mendez, S. Zarate, T. Lopez, R. Espinosa, P. Romero, S. Lopez, 2002Molecular biology of rotavirus cell entry, Arch Med Res 33356361
106 - R. Bilbao, S. Srinivasan, D. Reay, L. Goldberg, T. Hughes, P. W. Roelvink, D. A. Einfeld, T. J. Wickham, P. R. Clemens, 2003Binding of adenoviral fiber knob to the coxsackievirus-adenovirus receptor is crucial for transduction of fetal muscle, Hum Gene Ther 14645649
107 - R. Yolken, J. Kinney, J. Wilde, R. Willoughby, J. Eiden, 1990Immunoglobulins and other modalities for the prevention and treatment of enteric viral infections,J Clin Immunol 10, 80S EOF86S%3B EOFS; discussion 86S-87S.
108 - R. H. Yolken, J. A. Peterson, S. L. Vonderfecht, E. T. Fouts, K. Midthun, D. S. Newburg, 1992Human milk mucin inhibits rotavirus replication and prevents experimental gastroenteritis, J Clin Invest 9019841991
109 - S. G. Turville, P. U. Cameron, A. Handley, G. Lin, S. Pohlmann, R. W. Doms, A. L. Cunningham, 2002Diversity of receptors binding HIV on dendritic cell subsets, Nat Immunol 3975983
110 - S. G. Turville, K. Vermeire, J. Balzarini, D. Schols, 2005Sugar-binding proteins potently inhibit dendritic cell human immunodeficiency virus type 1 (HIV-1) infection and dendritic-cell-directed HIV-1 transferJ Virol 791351913527
111 - S. Turville, J. Wilkinson, P. Cameron, J. Dable, A. L. Cunningham, 2003The role of dendritic cell C-type lectin receptors in HIV pathogenesis,J Leukoc Biol 74710718
112 - A. C. Saphire, M. D. Bobardt, Z. Zhang, G. David, P. A. Gallay, 2001Syndecans serve as attachment receptors for human immunodeficiency virus type 1 on macrophages,J Virol 7591879200
113 - R. R. Vives, A. Imberty, Q. J. Sattentau, H. Lortat-Jacob, 2005Heparan sulfate targets the HIV-1 envelope glycoprotein gp120 coreceptor binding site,J Biol Chem 2802135321357
114 - D. G. Nguyen, J. E. Hildreth, 2003Involvement of macrophage mannose receptor in the binding and transmission of HIV by macrophages,Eur J Immunol 33483493
115 - W. Li, M. J. Moore, N. Vasilieva, J. Sui, S. K. Wong, M. A. Berne, M. Somasundaran, J. L. Sullivan, K. Luzuriaga, T. C. Greenough, H. Choe, M. Farzan, 2003Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus, Nature 426450454
116 - J. Chen, K. Subbarao, 2007The Immunobiology of SARS*,Annu Rev Immunol 25443472
117 - D. P. Han, M. Lohani, M. W. Cho, 2007Specific asparagine-linked glycosylation sites are critical for DC-SIGN- and L-SIGN-mediated severe acute respiratory syndrome coronavirus entry,J Virol 811202912039
118 - S. A. Jeffers, S. M. Tusell, L. Gillim-Ross, E. M. Hemmila, J. E. Achenbach, G. J. Babcock, W. D. Thomas, Jr , L. B. Thackray, M. D. Young, R. J. Mason, D. M. Ambrosino, D. E. Wentworth, J. C. Demartini, K. V. Holmes, 2004CD209L (L-SIGN) is a receptor for severe acute respiratory syndrome coronavirus, Proc Natl Acad Sci U S A 1011574815753
119 - Z. Y. Yang, Y. Huang, L. Ganesh, K. Leung, W. P. Kong, O. Schwartz, K. Subbarao, G. J. Nabel, 2004pH-dependent entry of severe acute respiratory syndrome coronavirus is mediated by the spike glycoprotein and enhanced by dendritic cell transfer through DC-SIGN,J Virol 7856425650
120 - J. Lang, N. Yang, J. Deng, K. Liu, P. Yang, G. Zhang, C. Jiang, 2011Inhibition of SARS pseudovirus cell entry by lactoferrin binding to heparan sulfate proteoglycansPLoS One 6, e23710.
121 - N. Mistry, P. Drobni, J. Naslund, V. G. Sunkari, H. Jenssen, M. Evander, 2007The anti-papillomavirus activity of human and bovine lactoferricin, Antiviral Res 75258265
122 - M. E. Murphy, H. Kariwa, T. Mizutani, H. Tanabe, K. Yoshimatsu, J. Arikawa, I. Takashima, 2001Characterization of in vitro and in vivo antiviral activity of lactoferrin and ribavirin upon hantavirus,J Vet Med Sci 63637645
123 - M. Jin, J. Park, S. Lee, B. Park, J. Shin, K. J. Song, T. I. Ahn, S. Y. Hwang, B. Y. Ahn, K. Ahn, 2002Hantaan virus enters cells by clathrin-dependent receptor-mediated endocytosis, Virology 2946069
124 - J. W. Song, K. J. Song, L. J. Baek, B. Frost, M. Poncz, K. Park, 2005In vivo characterization of the integrin beta3 as a receptor for Hantaan virus cellular entry,Exp Mol Med 37121127
125 - P. R. Hall, A. Leitao, C. Ye, K. Kilpatrick, B. Hjelle, T. I. Oprea, R. S. Larson, 2010Small molecule inhibitors of hantavirus infection, Bioorg Med Chem Lett 2070857091
126 - T. B. Ng, T. L. Lam, T. K. Au, X. Y. Ye, C. C. Wan, 2001Inhibition of human immunodeficiency virus type 1 reverse transcriptase, protease and integrase by bovine milk proteins,Life Sci 6922172223
127 - R. E. Hancock, H. G. Sahl, 2006Antimicrobial and host-defense peptides as new anti-infective therapeutic strategies,Nat Biotechnol 2415511557
128 - J. J. Oppenheim, P. Tewary, G. de la Rosa, D. Yang, 2007Alarmins initiate host defense, Adv Exp Med Biol 601185194
129 - J. J. Oppenheim, D. Yang, 2005Alarmins: chemotactic activators of immune responses,Curr Opin Immunol 17359365
130 - H. Shau, A. Kim, S. H. Golub, 1992Modulation of natural killer and lymphokine-activated killer cell cytotoxicity by lactoferrin,J Leukoc Biol 51343349
131 - M. Gahr, C. P. Speer, B. Damerau, G. Sawatzki, 1991Influence of lactoferrin on the function of human polymorphonuclear leukocytes and monocytes,J Leukoc Biol 49427433
132 - J. Artym, 2006Antitumor and chemopreventive activity of lactoferrin, Postepy Hig Med Dosw 60352369
133 - E. Damiens, J. Mazurier, I. el Yazidi, M. Masson, I. Duthille, G. Spik, Y. Boilly-Marer, 1998Effects of human lactoferrin on NK cell cytotoxicity against haematopoietic and epithelial tumour cells,Biochim Biophys Acta 1402277287
134 - J. K. Actor, S. A. Hwang, M. Olsen, M. Zimecki, R. L. Hunter, Jr , M. L. Kruzel, 2002Lactoferrin immunomodulation of DTH response in mice, Int Immunopharmacol 2475486
135 - K. Yamauchi, H. Wakabayashi, K. Shin, M. Takase, 2006Bovine lactoferrin: benefits and mechanism of action against infections,Biochem Cell Biol 84291296
136 - M. A. Farrar, R. D. Schreiber, 1993The molecular cell biology of interferon-gamma and its receptor,Annu Rev Immunol 11571611
137 - H. A. Young, K. J. Hardy, 1995Role of interferon-gamma in immune cell regulation,J Leukoc Biol 58373381
138 - H. Okamura, S. Kashiwamura, H. Tsutsui, T. Yoshimoto, K. Nakanishi, 1998Regulation of interferon-gamma production by IL-12 and IL-18,Curr Opin Immunol 10259264
139 - S. Hashizume, K. Kuroda, H. Murakami, 1983Identification of lactoferrin as an essential growth factor for human lymphocytic cell lines in serum-free medium,Biochim Biophys Acta 763377382
140 - M. Zimecki, J. Mazurier, G. Spik, J. A. Kapp, 1995Human lactoferrin induces phenotypic and functional changes in murine splenic B cells,Immunology 86122127
141 - B. Adamik, A. Wlaszczyk, 1996Lactoferrin- its role in defense against infection and immunotropic properties, Postepy Hig Med Dosw 503341
142 - H. Kitazawa, K. Yonezawa, M. Tohno, T. Shimosato, Y. Kawai, T. Saito, J. M. Wang, 2007Enzymatic digestion of the milk protein beta-casein releases potent chemotactic peptide(s) for monocytes and macrophages, Int Immunopharmacol 711501159
143 - P. Antila, I. Paakkari, A. Järvinen, M. J. Mattila, M. Laukkanen, A. Pihlanto-Leppälä, P. Mäntsälä, P. Hellman, 1991Opioid peptides derived from in vitro proteolysis of bovine whey proteins, Int Dairy J 1251229
144 - M. M. Mullally, H. Meisel, Gerald. R. J. Fitz, 1996Synthetic peptides corresponding to alpha-lactalbumin and beta-lactoglobulin sequences with angiotensin-I-converting enzyme inhibitory activity,Biol Chem Hoppe Seyler 377259260
145 - H. Wakabayashi, M. Takase, M. Tomita, 2003Lactoferricin derived from milk protein lactoferrin,Curr Pharm Des 912771287
146 - J. L. Gifford, H. N. Hunter, H. J. Vogel, 2005Lactoferricin: a lactoferrin-derived peptide with antimicrobial, antiviral, antitumor and immunological properties,Cell Mol Life Sci 6225882598
147 - M. Tomita, H. Wakabayashi, K. Yamauchi, S. Teraguchi, H. Hayasawa, 2002Bovine lactoferrin and lactoferricin derived from milk: production and applications,Biochem Cell Biol 80109112
148 - Z. Tang, Y. Yin, Y. Zhang, R. Huang, Z. Sun, T. Li, W. Chu, X. Kong, L. Li, M. Geng, Q. Tu, 2009Effects of dietary supplementation with an expressed fusion peptide bovine lactoferricin-lactoferrampin on performance, immune function and intestinal mucosal morphology in piglets weaned at age 21 dBr J Nutr 1019981005
149 - F. Parker, D. Migliore-Samour, F. Floc’h, A. Zerial, G. H. Werner, J. Jolles, M. Casaretto, H. Zahn, P. Jolles, 1984Immunostimulating hexapeptide from human casein: amino acid sequence, synthesis and biological properties, Eur J Biochem 145677682
150 - M. Janusz, J. Lisowski, 1993Proline-rich polypeptide (PRP)--an immunomodulatory peptide from ovine colostrum, Arch Immunol Ther Exp (Warsz) 41275279
151 - M. Rattray, 2005Technology evaluation: colostrinin, ReGen,Curr Opin Mol Ther 77884
152 - M. L. Cross, H. S. Gill, 1999Modulation of immune function by a modified bovine whey protein concentrate,Immunol Cell Biol 77345350
153 - H. Otani, M. Monnai, Y. Kawasaki, H. Kawakami, M. Tanimoto, 1995Inhibition of mitogen-induced proliferative responses of lymphocytes by bovine kappa-caseinoglycopeptides having different carbohydrate chains,J Dairy Res 62349357
154 - H. Otani, M. Monnai, 1995Induction of an interleukin-1 receptor antagonist-like component produced from mouse spleen cells by bovine kappa-caseinoglycopeptide,Biosci Biotechnol Biochem 5911661168
155 - H. Otani, I. Hata, 1995Inhibition of proliferative responses of mouse spleen lymphocytes and rabbit Peyer’s patch cells by bovine milk caseins and their digestsJ Dairy Res 62339348
156 - H. Otani, Y. Horimoto, M. Monnai, 1996Suppression of interleukin-2 receptor expression on mouse CD4+ T cells by bovine kappa-caseinoglycopeptide,Biosci Biotechnol Biochem 6010171019
157 - A. M. Casellas, H. Guardiola, F. L. Renaud, 1991Inhibition by opioids of phagocytosis in peritoneal macrophages,Neuropeptides183540
158 - I. Castilla-Cortazar, A. Castilla, M. Gurpegui, 1998Opioid peptides and immunodysfunction in patients with major depression and anxiety disorders,J Physiol Biochem 54203215
159 - D. Vassou, E. Bakogeorgou, M. Kampa, H. Dimitriou, A. Hatzoglou, E. Castanas, 2008Opioids modulate constitutive B-lymphocyte secretion, Int Immunopharmacol 8634644
160 - N. E. Hoch, T. J. Guzik, W. Chen, T. Deans, S. A. Maalouf, P. Gratze, C. Weyand, D. G. Harrison, 2009Regulation of T-cell function by endogenously produced angiotensin II, Am J Physiol Regul Integr Comp Physiol 296, R208216
161 - M. A. Munoz-Fernandez, J. Navarro, A. Garcia, C. Punzon, E. Fernandez-Cruz, M. Fresno, 1997Replication of human immunodeficiency virus-1 in primary human T cells is dependent on the autocrine secretion of tumor necrosis factor through the control of nuclear factor-kappa B activation,J Allergy Clin Immunol 100838845
162 - M. Higuchi, K. Nagasawa, T. Horiuchi, M. Oike, Y. Ito, M. Yasukawa, Y. Niho, 1997Membrane tumor necrosis factor-alpha (TNF-alpha) expressed on HTLV-I-infected T cells mediates a costimulatory signal for B cell activation--characterization of membrane TNF-alpha,Clin Immunol Immunopathol 82133140
163 - M. Platten, S. Youssef, E. M. Hur, P. P. Ho, M. H. Han, T. V. Lanz, L. K. Phillips, M. J. Goldstein, R. Bhat, C. S. Raine, R. A. Sobel, L. Steinman, 2009Blocking angiotensin-converting enzyme induces potent regulatory T cells and modulates TH1- and TH17-mediated autoimmunity, Proc Natl Acad Sci U S A 1061494814953
164 - E. Schlimme, H. Meisel, 1995Bioactive peptides derived from milk proteins. Structural, physiological and analytical aspects,Nahrung 39120
165 - Y. K. Kim, S. Yoon, D. Y. Yu, B. Lonnerdal, B. H. Chung, 1999Novel angiotensin-I-converting enzyme inhibitory peptides derived from recombinant human alpha s1-casein expressed in Escherichia coli,J Dairy Res 66431439
166 - S. Srinivas, V. Prakash, 2010Bioactive peptides from bovine milk alpha-casein: Isolation, characterization and multifunctional properties., Int. J. Pept. Res. Ther. 16715
167 - M. A. Ondetti, D. W. Cushman, 1982Enzymes of the renin-angiotensin system and their inhibitors,Annu Rev Biochem 51283308
168 - M. A. Ondetti, B. Rubin, D. W. Cushman, 1977Design of specific inhibitors of angiotensin-converting enzyme: new class of orally active antihypertensive agents,Science 196441444
169 - M. Spadaro, C. Curcio, A. Varadhachary, F. Cavallo, J. Engelmayer, P. Blezinger, F. Pericle, G. Forni, 2007Requirement for IFN-gamma, CD8+ T lymphocytes, and NKT cells in talactoferrin-induced inhibition of neu+ tumors,Cancer Res 6764256432
170 - U. Muller, U. Steinhoff, L. F. Reis, S. Hemmi, J. Pavlovic, R. M. Zinkernagel, M. Aguet, 1994Functional role of type I and type II interferons in antiviral defense, Science 26419181921
171 - X. Chen, Q. Xue, R. Zhu, X. Fu, L. Yang, L. Sun, W. Liu, 2009Comparison of antiviral activities of porcine interferon type I and type II, Sheng Wu Gong Cheng Xue Bao 25806812
172 - M. A. Modestou, L. J. Manzel, S. El -Mahdy, D. C. Look, 2010Inhibition of IFN-gamma-dependent antiviral airway epithelial defense by cigarette smoke,Respir Res 11, 64 EOF
173 - K. Schroder, P. J. Hertzog, T. Ravasi, D. A. Hume, 2004Interferon-gamma: an overview of signals, mechanisms and functions,J Leukoc Biol 75163189
174 - Y. Ishibashi, K. Takeda, N. Tsukidate, H. Miyazaki, K. Ohira, H. Dosaka-Akita, M. Nishimura, 2005Randomized placebo-controlled trial of interferon alpha-2b plus ribavirin with and without lactoferrin for chronic hepatitis C,Hepatol Res 32218223
175 - R. M. Viani, T. J. Gutteberg, J. L. Lathey, S. A. Spector, 1999Lactoferrin inhibits HIV-1 replication in vitro and exhibits synergy when combined with zidovudine,AIDS 1312731274
176 - J. H. Andersen, H. Jenssen, T. J. Gutteberg, 2003Lactoferrin and lactoferricin inhibit Herpes simplex 1 and 2 infection and exhibit synergy when combined with acyclovir,Antiviral Res 58209215
177 - G. Grassy, B. Calas, A. Yasri, R. Lahana, J. Woo, S. Iyer, M. Kaczorek, R. Floc’h, R. Buelow, 1998Computer-assisted rational design of immunosuppressive compounds, Nat Biotechnol 16748752
178 - S. Travis, L. M. Yap, C. Hawkey, B. Warren, M. Lazarov, T. Fong, R. J. Tesi, 2005RDP58 is a novel and potentially effective oral therapy for ulcerative colitis,Inflamm Bowel Dis 11713719
179 - W. Liu, B. R. Deyoung, X. Chen, D. P. Evanoff, Y. Luo, 2008RDP58 inhibits T cell-mediated bladder inflammation in an autoimmune cystitis modelJ Autoimmun 30257265
180 - K. Hilpert, M. R. Elliott, R. Volkmer-Engert, P. Henklein, O. Donini, Q. Zhou, D. F. Winkler, R. E. Hancock, 2006Sequence requirements and an optimization strategy for short antimicrobial peptides, Chem Biol 1311011107
181 - H. Jenssen, C. D. Fjell, A. Cherkasov, R. E. Hancock, 2008QSAR modeling and computer-aided design of antimicrobial peptidesJ Pept Sci 14110114
182 - C. D. Fjell, H. Jenssen, K. Hilpert, W. A. Cheung, N. Pante, R. E. Hancock, A. Cherkasov, 2009Identification of novel antibacterial peptides by chemoinformatics and machine learning, J Med Chem 5220062015
183 - F. J. Prado-Prado, F. Borges, E. Uriarte, L. G. Perez-Montoto, H. Gonzalez-Diaz, 2009Multi-target spectral moment: QSAR for antiviral drugs vs. different viral speciesAnal Chim Acta 651159164
184 - A. Linusson, M. Elofsson, I. E. Andersson, M. K. Dahlgren, 2010Statistical molecular design of balanced compound libraries for QSAR modelingCurr Med Chem 1720012016
185 - C. D. Fjell, R. E. Hancock, H. Jenssen, 2010Computer-aided design of antimicrobial peptidesCurr Pharmacutical Anal 66675
186 - C. D. Fjell, H. Jenssen, W. A. Cheung, R. E. Hancock, A. Cherkasov, 2011Optimization of antibacterial peptides by genetic algorithms and cheminformaticsChem Biol Drug Des 774856
187 - A. B. Kulkarni, S. Karlsson, 1993Transforming growth factor-beta 1 knockout mice. A mutation in one cytokine gene causes a dramatic inflammatory disease, Am J Pathol 14339
188 - T. Kuhara, K. Yamauchi, K. Iwatsuki, 2012Bovine lactoferrin induces interleukin-11 production in a hepatitis mouse model and human intestinal myofibroblastsEur J Nutr 51343351
189 - Y. Sutas, E. Soppi, H. Korhonen, E. L. Syvaoja, M. Saxelin, T. Rokka, E. Isolauri, 1996Suppression of lymphocyte proliferation in vitro by bovine caseins hydrolyzed with Lactobacillus casei GG-derived enzymes,J Allergy Clin Immunol 98216224
190 - B. Hernández-Ledesma, A. Quirós, L. Amigo, I. Recio, 2007Identification of bioactive peptides after digestion of human milk and infant formula with peptis and pancreatin., Int Dairy J 174249
191 - G. V. Zuccotti, F. Salvini, E. Riva, C. Agostoni, 2006Oral lactoferrin in HIV-1 vertically infected children: an observational follow-up of plasma viral load and immune parameters,J Int Med Res 348894
192 - H. L. Chen, J. Y. Huang, T. W. Chu, T. C. Tsai, C. M. Hung, C. C. Lin, F. C. Liu, L. C. Wang, Y. J. Chen, M. F. Lin, C. M. Chen, 2008Expression of VP1 protein in the milk of transgenic mice: a potential oral vaccine protects against enterovirus 71 infection, Vaccine 2628822889
193 - P. Hamill, K. Brown, H. Jenssen, R. E. Hancock, 2008Novel anti-infectives: is host defence the answer?Curr Opin Biotechnol 19628636
194 - N. Diaz-Valdes, L. Manterola, V. Belsue, J. I. Riezu-Boj, E. Larrea, I. Echeverria, D. Llopiz, J. Lopez-Sagaseta, H. Lerat, J. M. Pawlotsky, J. Prieto, J. J. Lasarte, F. Borras-Cuesta, P. Sarobe, 2011Improved dendritic cell-based immunization against hepatitis C virus using peptide inhibitors of interleukin 10, Hepatology 532331
195 - A. Lupetti, A. Paulusma-Annema, M. M. Welling, S. Senesi, J. T. van Dissel, P. H. Nibbering, 2000Candidacidal activities of human lactoferrin peptides derived from the N terminus, Antimicrob Agents Chemother 4432573263
196 - P. H. Nibbering, E. Ravensbergen, M. M. Welling, L. A. van Berkel, P. H. van Berkel, E. K. Pauwels, J. H. Nuijens, 2001Human lactoferrin and peptides derived from its N terminus are highly effective against infections with antibiotic-resistant bacteria, Infect Immun 6914691476
197 - A. Lupetti, A. Paulusma-Annema, M. M. Welling, H. Dogterom-Ballering, C. P. Brouwer, S. Senesi, J. T. Van Dissel, P. H. Nibbering, 2003Synergistic activity of the N-terminal peptide of human lactoferrin and fluconazole against Candida species, Antimicrob Agents Chemother 47262267
198 - A. Lupetti, J. T. van Dissel, C. P. Brouwer, P. H. Nibbering, 2008Human antimicrobial peptides’ antifungal activity against Aspergillus fumigatusEur J Clin Microbiol Infect Dis 2711251129
199 - C. P. Brouwer, M. Rahman, M. M. Welling, 2011Discovery and development of a synthetic peptide derived from lactoferrin for clinical usePeptides3219531963
200 - T. Kruse, H. H. Kristensen, 2008Using antimicrobial host defense peptides as anti-infective and immunomodulatory agentsExpert Rev Anti Infect Ther 6887895
201 - S. A. Hwang, K. J. Welsh, S. Boyd, M. L. Kruzel, J. K. Actor, 2011Comparing efficacy of BCG/lactoferrin primary vaccination versus booster regimenTuberculosisEdinb) 91 Suppl 1, S9095
202 - S. A. Hwang, R. Arora, M. L. Kruzel, J. K. Actor, 2009Lactoferrin enhances efficacy of the BCG vaccine: comparison between two inbred mice strains (C57BL/6 and BALB/c)TuberculosisEdinb) 89 Suppl 1, S4954
203 - C. M. Hung, S. C. Wu, C. C. Yen, M. F. Lin, Y. W. Lai, Y. T. Tung, H. L. Chen, C. M. Chen, 2010Porcine lactoferrin as feedstuff additive elevates avian immunity and potentiates vaccination, Biometals 23579587
204 - C. M. Hung, C. C. Yeh, H. L. Chen, C. W. Lai, M. F. Kuo, M. H. Yeh, W. Lin, M. Y. Tu, H. C. Cheng, C. M. Chen, 2010Porcine lactoferrin administration enhances peripheral lymphocyte proliferation and assists infectious bursal disease vaccination in native chickens, Vaccine 2828952902
205 - T. H. Brown, J. David, E. Acosta-Ramirez, J. M. Moore, S. Lee, G. Zhong, R. E. Hancock, Z. Xing, S. A. Halperin, J. Wang, 2012Comparison of immune responses and protective efficacy of intranasal prime-boost immunization regimens using adenovirus-based and CpG/HH2 adjuvanted-subunit vaccines against genital Chlamydia muridarum infectionVaccine30350360
206 - Y. S. Bae, S. A. Ju, J. Y. Kim, J. K. Seo, S. H. Baek, J. Y. Kwak, B. S. Kim, P. G. Suh, S. H. Ryu, 1999Trp-Lys-Tyr-Met-Val-D-Met stimulates superoxide generation and killing of Staphylococcus aureus via phospholipase D activation in human monocytes, J Leukoc Biol 65241248
207 - Y. S. Bae, Y. Kim, J. H. Kim, T. G. Lee, P. G. Suh, S. H. Ryu, 2000Independent functioning of cytosolic phospholipase A2 and phospholipase D1 in Trp-Lys-Tyr-Met-Val-D-Met-induced superoxide generation in human monocytes,J Immunol 16440894096
208 - Y. S. Bae, Y. Kim, J. H. Kim, P. G. Suh, S. H. Ryu, 1999Trp-Lys-Tyr-Met-Val-D-Met is a chemoattractant for human phagocytic cells, J Leukoc Biol 66915922
209 - S. H. Baek, J. K. Seo, C. B. Chae, P. G. Suh, S. H. Ryu, 1996Identification of the peptides that stimulate the phosphoinositide hydrolysis in lymphocyte cell lines from peptide libraries,J Biol Chem 27181708175
210 - J. K. Seo, S. Y. Choi, Y. Kim, S. H. Baek, K. T. Kim, C. B. Chae, J. D. Lambeth, P. G. Suh, S. H. Ryu, 1997A peptide with unique receptor specificity: stimulation of phosphoinositide hydrolysis and induction of superoxide generation in human neutrophils, J Immunol 15818951901
211 - C. G. Lee, S. Y. Choi, S. H. Park, K. S. Park, S. H. Ryu, Y. C. Sung, 2005The synthetic peptide Trp-Lys-Tyr-Met-Val-D-Met as a novel adjuvant for DNA vaccine, Vaccine 2347034710
212 - P. W. Parodi, 2007A role for milk proteins and their peptides in cancer prevention,Curr Pharm Des 13813828
213 - J. S. Mader, J. Salsman, D. M. Conrad, D. W. Hoskin, 2005Bovine lactoferricin selectively induces apoptosis in human leukemia and carcinoma cell lines,Mol Cancer Ther 4612624
214 - A. Richardson, R. de Antueno, R. Duncan, D. W. Hoskin, 2009Intracellular delivery of bovine lactoferricin’s antimicrobial core (RRWQWR) kills T-leukemia cellsBiochem Biophys Res Commun 388736741
215 - J. Pettersson, A. K. Mossberg, C. Svanborg, 2006alpha-Lactalbumin species variation, HAMLET formation, and tumor cell death,Biochem Biophys Res Commun 345260270
216 - S. Perego, S. Cosentino, A. Fiorilli, G. Tettamanti, A. Ferraretto, 2011Casein phosphopeptides modulate proliferation and apoptosis in HT-29 cell line through their interaction with voltage-operated L-type calcium channelsJ Nutr Biochem.
217 - R. B. Raja, K. D. Arunachalam, 2011Anti-genotoxic potential of casein phosphopeptides (CPPs): a class of fermented milk peptides against low background radiation and prevention of cancer in radiation workersToxicol Ind Health 27867872
218 - J. Wang, Q. Li, Y. Ou, Z. Han, K. Li, P. Wang, S. Zhou, 2011Inhibition of tumor growth by recombinant adenovirus containing human lactoferrin through inducing tumor cell apoptosis in mice bearing EMT6 breast cancerArch Pharm Res 34987995
219 - N. Casares, F. Rudilla, L. Arribillaga, D. Llopiz, J. I. Riezu-Boj, T. Lozano, J. Lopez-Sagaseta, L. Guembe, P. Sarobe, J. Prieto, F. Borras-Cuesta, J. J. Lasarte, 2010A peptide inhibitor of FOXP3 impairs regulatory T cell activity and improves vaccine efficacy in mice, J Immunol 18551505159
220 - R. M. Redwan el, A. Tabll, 2007Camel lactoferrin markedly inhibits hepatitis C virus genotype 4 infection of human peripheral blood leukocytes,J Immunoassay Immunochem 28267277
221 - J. M. Chobert, M. Sitohy, S. Billaudel, M. Dalgalarrondo, T. Haertle, 2007Anticytomegaloviral activity of esterified milk proteins and L-polylysines, J Mol Microbiol Biotechnol 13255258
222 - S. Maruyama, H. Mitachi, H. Tanaka, N. Tomizuka, H. Suzuki, (1987) Studies of the active site and antihypertensive activity of angiotensin I-converting enzyme inhibitors derived from casein., Agric. Biol. Chem 5115811586 .
223 - S. Maruyama, K. Nakagomi, N. Tomizuka, H. Suzuki, 1985Angiotensin I-converting enzyme inhibitor derived from and enzymatic hydrolysate of casein. II. Isolation and bradykinin-potentiating activity on the uterus of the ileum of rats., Agric. Biol. Chem 4914051409
224 - S. Maruyama, H. Suzuki, 1982A peptide inhibitor of angiotensin I-converting enzyme in the tryptic hydrolysate of casein.Agric. Biol. Chem 4613931394
225 - M. Maeno, N. Yamamoto, T. Takano, 1996Identification of an antihypertensive peptide from casein hydrolysate produced by a proteinase from Lactobacillus helveticus CP790,J Dairy Sci 7913161321
226 - M. Kampa, S. Loukas, A. Hatzoglou, P. Martin, P. M. Martin, E. Castanas, 1996Identification of a novel opioid peptide (Tyr-Val-Pro-Phe-Pro) derived from human alpha S1 casein (alpha S1 -casomorphin, and alpha S1-casomorphin amide),Biochem J 319 ( Pt 3), 903-908.
227 - F. Minervini, F. Algaron, C. G. Rizzello, P. F. Fox, V. Monnet, M. Gobbetti, 2003Angiotensin I-converting-enzyme-inhibitory and antibacterial peptides from Lactobacillus helveticus PR4 proteinase-hydrolyzed caseins of milk from six species,Appl Environ Microbiol 6952975305
228 - S. Maruyama, H. Mitachi, J. Awaya, M. Kurono, N. Tomizuka, H. Suzuki, 1987Angiotnsin I-converting enzyme inhibitor activity of the C-terminal hexapeptide of αs1-casein., Agric. Biol. Chem 5125572561
229 - M. Hayes, C. Stanton, H. Slattery, O. O’Sullivan, C. Hill, G. F. Fitzgerald, R. P. Ross, 2007Casein fermentate of Lactobacillus animalis DPC6134 contains a range of novel propeptide angiotensin-converting enzyme inhibitors,Appl Environ Microbiol 7346584667
230 - V. Brantl, H. Teschemacher, A. Henschen, F. Lottspeich, (1979) Novel opioid peptides derived from casein (beta-casomorphins). I. Isolation from bovine casein peptone, Hoppe Seylers Z Physiol Chem 36012111216 .
231 - V. Brantl, H. Teschemacher, J. Blasig, A. Henschen, F. Lottspeich, 1981Opioid activities of beta-casomorphins, Life Sci 2819031909
232 - D. Migliore-Samour, P. Jolles, 1988Casein, a prohormone with an immunomodulating role for the newborn?, Experientia 44188193
233 - H. Meisel, H. Frister, 1989Chemical characterization of bioactive peptides from in vivo digests of casein,J Dairy Res 56343349
234 - J. Berthou, D. Migliore-Samour, A. Lifchitz, J. Delettre, F. Floc’h, P. Jolles, 1987Immunostimulating properties and three-dimensional structure of two tripeptides from human and cow caseins,FEBS Lett 2185558
235 - Y. Nakamura, N. Yamamoto, K. Sakai, A. Okubo, S. Yamazaki, T. Takano, 1995Purification and characterization of angiotensin I-converting enzyme inhibitors from sour milk,J Dairy Sci 78777783
236 - P. Jollés, J. P. Caen, 1991Parallels between milk clotting and blood clotting: opportunities for milk-derived productsTrends Food Sci Technol.
237 - M. Takahashi, S. Moriguchi, H. Suganuma, A. Shiota, F. Tani, H. Usui, K. Kurahashi, R. Sasaki, M. Yoshikawa, 1997Identification of casoxin C, an ileum-contracting peptide derived from bovine kappa-casein, as an agonist for C3a receptors,Peptides18329336
238 - G. S. Patten, R. J. Head, M. Y. Abeywardena, 2011Effects of casoxin 4 on morphine inhibition of small animal intestinal contractility and gut transit in the mouseClin Exp Gastroenterol 42331
239 - A. Pihlanto-Leppala, P. Koskinen, K. Piilola, T. Tupasela, H. Korhonen, 2000Angiotensin I-converting enzyme inhibitory properties of whey protein digests: concentration and characterization of active peptides,J Dairy Res 675364
240 - M. M. Mullally, H. Meisel, Gerald. R. J. Fitz, 1997Identification of a novel angiotensin-I-converting enzyme inhibitory peptide corresponding to a tryptic fragment of bovine beta-lactoglobulin,FEBS Lett 40299101
241 - F. Tani, A. Shiota, H. Chiba, M. Yoshikawa, 1994Serorphin, an opiod peptide derived from bovine serum albumin, in β-casomorphins and related peptides, In Recent developments, (Brantl, V., and Teschemacher, H., Eds.), 4953VCH-Verlag, Weinheim.
242 - K. Yamauchi, 1992Biologically functional proteins of milk and peptides derived from milk proteins., Bulletin of the IDF 2725158
243 - R. Siciliano, B. Rega, M. Marchetti, L. Seganti, G. Antonini, P. Valenti, 1999Bovine lactoferrin peptidic fragments involved in inhibition of herpes simplex virus type 1 infection,Biochem Biophys Res Commun 2641923
244 - F. Tani, K. Iio, H. Chiba, M. Yoshikawa, 1990Isolation and characterization of opioid antagonist peptides derived from human lactoferrin,Agric Biol Chem 5418031810