Pathogen infections are recognized by the immune system, which consists of two types of responses: an innate immune response and an antigen-specific adaptive immune response. The innate response is characterized by being the first line of defense that occurs rapidly in which leukocytes such as neutrophils, monocytes, macrophages, eosinophils, mast cells, dendritic cells, etc., are involved. These cells recognize the pathogen-associated molecular patterns (PAMPs), which have been evolutionarily conserved by the diversity of microorganisms that infect humans. Recognition of these pathogen-associated molecular patterns occurs through pattern recognition receptors such as Toll-like receptors and some other intracellular receptors such as nucleotide oligomerization domain (NOD), with the aim of amplifying the inflammation and activating the adaptive cellular immune response, through the antigenic presentation. In the present chapter, we will review the importance of the main components involved in the innate immune response, such as different cell types, inflammatory response, soluble immune mediators and effector mechanisms exerted by the immune response against bacteria, viruses, fungi, and parasites; all with the purpose of eliminating them and eradicating the infection of the host.
Part of the book: Physiology and Pathology of Immunology
Currently, it is estimated that more than 11 million humans in the world are infected by helminth parasites of Trichinella species, mainly by Trichinella spiralis (T. spiralis), responsible for causing Trichinellosis disease in both animals and humans. Trichinellosis is a cosmopolitan parasitic zoonotic disease, which has direct relevance to human and animal health, because it presents a constant and important challenge to the host’s immune system, especially through the intestinal tract. Currently, there is an intense investigation of new strategies in pharmacotherapy and immunotherapy against infection by Trichinella spiralis. In this chapter, we will present the most current aspects of biology, epidemiology, immunology, clinicopathology, pharmacotherapy and immunotherapy in Trichinellosis.
Part of the book: Parasites and Parasitic Diseases
Pathogen infections are recognized by the immune system, which consists of two types of responses: an innate immune response that recognizes pathogen-associated molecular patterns (PAMPs) and an antigen-specific adaptive immune response. In both responses, there are several activated cells of the immune system, which play a key role in establishing the environment of cytokines, thus directing their differentiation either suppressing or promoting the immune response. This immune response is crucial against pathogen infections. In this chapter, we will describe the crucial role played by different families of cytokines during activation of the immune system to eliminate infectious pathogens.
Part of the book: Immune Response Activation and Immunomodulation
Dendritic cells (DC) represent an important link between innate and adaptive immunity, which play an important role during the immune response against pathogens. There are several populations and subpopulations of DC, but mainly two subpopulations are characterized: the classic DC specialized in the processing and presentation of the antigen; and the plasmacytoid DC that have a high phagocytic activity and capacity for the production of cytokines. This chapter aims to present the current aspects related to the most relevant characteristics and functions of DC, as well as their role in host defense against infections by viruses, parasites, bacteria, and fungi.
Part of the book: Cell Interaction