Dr. Bruce Walker is the Director of the Ragon Institute of MGH, MIT and Harvard, a Professor of Medicine at Harvard Medical School, a Howard Hughes Medical Institute Investigator, and a board-certified Infectious Disease specialist. The overarching goal of his laboratory is to define the interplay of immunologic, virologic and host genetic factors that determine control of human viral infections, to guide vaccine development and immunotherapeutic interventions. His research focuses in particular on HIV and HIV-specific CD8+ T cell responses, and these studies are performed both at the Ragon Institute and at the Africa Health Research Institute, a state of the art Tb-HIV research facility he helped establish in Durban, South Africa and served as one of the founding co-directors. Important recent contributions include the demonstration of host dependency factors required for HIV replication (4), intrinsic resistance of HIV-infected macrophages to CTL mediated killing (5), application of network theory to define protective CTL epitopes in HIV infected persons (6), and longitudinal studies of persons with hyperacute HIV infection demonstrating interplay of host immune responses at the single cell level and the impact of immediate antiviral therapy on the functionality of virus-specific T cell responses. His studies are facilitated by extensive biobanks of samples from persons with acute and chronic HIV infection, as well as persons who are infected with HIV, but have never been treated and successfully control viremia by effective CD8 T cell responses. Dr. Walker is also an Adjunct Professor at the Nelson Mandela School of Medicine in Durban, South Africa, and a member of the American Academy of Arts and Sciences, American Society for Clinical Investigation (ASCI), the American Association of Physicians (AAP), and the National Academy of Medicine.