R Ahmed

Biography

Dr Ahmed has made seminal contributions in understanding the roles of both the T and B cells in the immune system and how they respond to pathogens in eliciting long-lasting immunity (immunological memory) in the host. Another major area of his interest is the molecular understanding of how chronic infection leads to the functional exhaustion of T cells. The major highlights of the accomplishments includes: a) T cell Memory: Dr Ahmed studied critical role of CD8 T cells in the control/elimination of pathogens and the molecular understanding of immunological memory, a cardinal feature of effective. He also did a pioneering study on the robust induction of anti-viral CD8 T cell immune responses and maintenance of CD8 T memory cells. Gene profiling of CD8 T cells responding to infection and the molecular dissection of the differentiation program of the anti-viral CD8 T cell immune response has provided a new paradigm for understanding the differentiation pathways by which immunological memory is generated in the host. These molecular insights have implications in the design and development of a new generation of vaccines against a multitude of pathogens in humans. b) Mechanisms of T cell exhaustion in chronic infection: He provided a critical insight for the mechanism by which chronic viral infection could disable the anti-viral CD8 T cell immune and defined the critical role that CD4 T cells play in eliciting effective anti-viral CD8 T cell responses. Identification of the PD-1 pathway playing a critical role in inducing CD8 T cell exhaustion. These studies have had global implications in understanding the mechanisms of chronic infections (HIV, HCV, HBV, malaria, and TB) and neoplastic transformation (cancer) in humans. In addition, importantly, these critical insights in T cell exhaustion have led to the development of novel immuno-therapies that are being currently tested in human clinical trials. c) B cell memory: Dr Ahmed’s research efforts in generation and maintenance of long-lived plasma cells during infection and in identification of molecular mechanism by which longevity of antibody response is maintained in the host are remarkable. He also studied long-lasting antibody responses against smallpox in humans and helped in development of novel cloning strategies for the generation of high affinity human monoclonal antibodies (mAbs) and this technology has been applied to identify high affinity mAbs against H1N1 swine flu.

Research Interest

Molecular Understanding of Immunological Memory in Infection and Vaccination