8 mai 2013: Prof. Rafi Ahmed

Wednesday, MAY 8th 2013, 12h30

Prof. Rafi AHMED, Ph.D.
Director Emory Vaccine Center and Department of Microbiology and Immunology,
Emory University School of Medicine, Atlanta - USA

«Rafi Ahmed is a key opinion leader in the field of immunological memory and antiviral immune responses.
He has made fundamental contributions to current concepts how immunological memory is maintained,
and has performed pioneering work on immune dysfunction during persistent viral infection.»

(Daniel PINSCHEWER, Host, Department of Pathology and Immunology, Faculty of medicine - UNIGE)


"T Cell Memory and Exhaustion"
Acute viral infections result in the generation of a long-lived and self-renewing pool of highly functional memory CD8 T cells. These memory CD8T cells play an important role in faster control of infection upon re-exposure to the same pathogen. In contrast, chronic antigen stimulation during persistent viral infections or during cancer can lead to functional exhaustion of CD8 T cells. A characteristic feature of these exhausted CD8 T cells is sustained expression of inhibitory receptors such as PD-1. It is now well established that PD-1 plays a major role in T cell exhaustion and that blockade of the PD-1 inhibitory pathway can restore function in exhausted T cells. The role of PD-1 in T cell exhaustion was first described in mice during chronic LCMV infection and these observations have been extended to other chronic infections in mice, non-human primates and humans. Most recently, PD-1 directed immunotherapy has shown promising results in a phase l clinical trial in cancer patients. In this talk I will describe a new role for PD-1 in regulating T cell differentiation and also discuss strategies for enhancing PD-1 directed immunotherapy text

Dr. Rafi Ahmed is the Georgia Research Alliance Professor of Microbiology and Immunology, and Director of the Emory Vaccine Center at Emory University School of Medicine in Atlanta, GA. He earned his undergraduate degree from Osmania University, India and his Ph.D. from Harvard University in Cambridge, Massachusetts. After completing his postdoctoral training in the Department of Immunology at Scripps Clinic and Research Foundation in La Jolla, CA, he joined the Department of Microbiology and Immunology at the UCLA School of Medicine. He was at UCLA from 1984-1995 and moved to Emory University in 1995. His research efforts are directed towards: 1. Understanding the mechanisms of immunological memory and using this knowledge to develop new and more effective vaccines. 2. Defining the mechanisms of T cell exhaustion during chronic viral infections and cancer and developing strategies for restoring function in exhausted T cells. Dr. Ahmed is a member of the U.S. National Academy of Sciences.