Rajeev K. Tyagi
Dr. Rajeev K. Tyagi earned Ph.D. degree at Biomedical Parasitology Unit, Institute Pasteur, Paris, France in June 2011 on a very challenging and interesting topic of malaria immunology/parasitology. He developed a long lasting, stable and straightforward laboratory animal model (humanized mouse model: a versatile mouse model). The developed humanized mouse model was deployed to study asexual blood stage infection of P. falciparum and understand biology, physiology and immunology of this human parasite during his doctoral thesis at Pasteur (Tyagi et al, Malaria J 2010, PloS One 2011). As P. falciparum has the potential to evolve extreme artemisinin resistance and more complex patterns of multidrug resistance than anticipated, therefore Dr. Tyagi explored the developed mouse to study the artemisinin resistance (Tyagi et al, BMC Medicine 2018). Dr. Tyagi worked as postdoc fellow in the laboratory of Dr. John Adams, University of South Florida, USA and received training to explore the potential of the developed “humanized mouse” to characterize attenuated asexual blood stage falciparum parasite to understand the innate immune response of the attenuated parasite (growth mutant). Additionally, he developed small laboratory human liver chimeric mice by transplanting the human hepatocytes in transgenic/immunodeficient mice (TK/NOG) at USF, USA to study the least known liver stage infection of P. falciparum (Tyagi et al, 2018 Frontiers in Immunology). Further, discovery of novel dendritic like cell population called “pathogen differentiated dendritic cells (PDDCs)” when incubated with P. gingivalis and tracking of monocyte derived dendritic cells (MoDcs) in a reconstituted immunodeficient NOD.PrkdcscidIl2rg-/- (NSG) mice gave Dr. Tyagi a platform to make the excellent use of his post-Ph.D. training at Augusta University, USA to gain expertise in advanced translational biomedical research aimed at understanding the host-pathogen interaction (Tyagi et al, 2017 Scientific Reports). Dr. Tyagi at the Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition Vanderbilt University Medical Centre (VUMC), USA deployed his efforts to understand the role of IL-23R in the modulation of functioning of regulatory T cells and its role in the pathogenesis of colitis in an experimental humanized mouse (reconstituted with stem cells) as well as IL-23R deficient and sufficient mice (Tyagi et al, 2020, Biochem. Pharmacology). Also, he looked at the role of low-dose IL-2 in expanding Foxp3 regulatory T cells in CD34+ cells reconstituted NSG (NOD-scid IL2Rgammanull) mice and its therapeutic role on the treatment of experimental colitis in these mice. Dr. Tyagi has been leading group at CSIR-Institute of Microbial Technology, Chandigarh and his lab is focused to: 1) develop human-liver chimeric mice for huHep transplantation. The huHep reconstituted TK/NOG transgenic mice by non-invasive Ultra Sound Guided Injection technique through intrasplenic route showing development of human liver “chimeric mouse” to study liver stage infection of P. falciparum and transition to asexual blood stage infection to test antimalarial drugs and vaccine candidates in one host. 2) select highly Artemisinin-resistant asexual blood stage Plasmodium falciparum (ART-R) with Quinine co-resistance under in vitro artesunate pressure. The experimentally selected resistant P. falciparum parasites are being used to find-out the underlying molecular mechanisms that parasite may have been employing to escape and/or cope-up the drug pressure. The engraftment of select ART-R parasites will be grafted in a blood stage humanized mice to complement the in vitro results. 3) Dendritic cells as "therapeutic vaccines" playing a crucial role in translational biomedical research. 4) formulation and characterization of nanoscale drug carriers to deliver methotrexate (MTX) and aceclofenac to address Rheumatoid Arthritis, cancer and other inflammatory diseases (Tygai et al, Nanomedicine, 2016, Int. J. Pharmaceutics, 2016, Acta Biomaterialia, 2015) as well as candidate vaccines (Tyagi et al, vaccine 2015, Human Vacc. Immunothear, 2016). His group is looking at anti-inflammatory effect of methotrexate in breast cancer therapeutics. Dr. Tyagi’s group is funded by DST-SERB, DBT and ICMR, New Delhi. There are grants applications under review with DBT, Wellcome-DBT India Alliance, DST-SERB and BIRAC, New Delhi.