Rajiv Kumar, PhD

Dr. Rajiv Kumar is an Assistant Professor at Institute of Medical Sciences, Banaras Hindu University, Varanasi-India. His research interests are to understand the immune mechanisms underlying the progression of diseases such as Malaria and Visceral Leishmaniasis, and to distinguish anti-parasitic host immune responses that control disease from the responses that cause disease. He has a broad background in cellular and molecular immunology of infectious diseases, as well as significant field and epidemiological work experience.  He received training at NIAID, NIH in Bethesda, USA and at QIMR Berghofer Medical Research Institute, Brisbane, Australia. He has published paper in prestigious international Journals like Naturte Immunology, Cell Reports, Nature Medicine, PLoS Pathogens, Journal of Immunology, Journal of Infectious Diseases etc and his lab is funded by many national and international grants.


ABSTRACT

Immunoregulatory Networks in Protozoan Infection

Rajiv Kumar-BHU, Varanasi, India

The development of vaccines to protect against parasites is difficult, in large part due to complex host-parasite interactions that have evolved over the course of time. Parasitic factors such as antigenic variation and host factors such as age, geneticinfluences andtransmission intensity are all thought to contribute to the limited efficacy of parasite vaccines. A developing theme in field studies investigating anti-parasitic immunity is the emergence, establishment, and maintenance of immunoregulatory networks that shape the immune responses to new infections, as well as vaccines, thereby influencing disease outcome. During intracellular protozoan parasite infections, the generation of IFNγ+ Tbet+ CD4+ T (Th1) cells following activation by peptide antigen presented by major histocompatibility complex II molecules on dendritic cells (DCs) help phagocytes kills captured or resident pathogens. However, inflammatory cytokines produced by Th1 cells can damage tissue, and as such, they need to be tightly controlled.The inflammatory cytokines produced by Th1 cells following infection can damage tissues, and as such, theseCD4+ T cell responses need to be tightly regulated. Thymus‐derived FoxP3+ regulatory T (Treg) as well as Th1 cells that initiate an IL‐10 production program (Tr1 cells) has now been recognized as major regulators of inflammation manyinfectious diseases.In addition, co‐inhibitory receptors such as CTLA‐4, LAG‐3, TIM‐3, and PD‐1 are often found on CD4+ T cell populations following chronic antigen exposure which have a profound influence on functional capacities of these cells.

In this lecture, we will see the role of immunoregulatory networks in influencing anti-parasitic immunity and vaccine efficacywith examples on leishmaniasis and malaria, the two most important parasitic diseases of humans.We will also focus on our current understanding about targeting the co-inhibitory receptors for host directed therapy.