Overbaugh, Julie

Dr. Overbaugh's laboratory has a long-standing interest in understanding the mechanisms of HIV transmission and pathogenesis. A major hypothesis for the studies in her lab is that the variants of HIV-1 that are transmitted are a selected subset of all the viruses that evolve during the course of infection. Thus, a goal of Dr. Overbaugh's research is to determine whether some variants are more transmissible and others are more pathogenic in the host. Her lab has shown that the emergence and replication of particular variants of the virus is central to AIDS pathogenesis. Her research group has also shown that the late stage pathogenic variants have evolved to escape neutralizing antibodies, and they have found that these virus variants are protected by newly acquired sugars that limit access of antibodies. Ongoing studies include defining the patterns of genetic variation during retroviral infection and determining how particular changes in the virus influence replication, immunogenicity and disease outcome. One aspect of this research is defining the interactions of the viral envelope protein and proteins of the host cell, including the viral receptors and coreceptors. Other studies are focused on analyses of how genetic variation alters the efficacy of neutralizing antibodies in controlling virus replication.

Much of the HIV research in the lab is focused on populations in Africa because this is where the AIDS epidemic is most severe. The Overbaugh lab is analyzing HIV variants early in infection in Kenyan cohorts at high risk for HIV infection, including women and infants. These early HIV strains represent critical targets for vaccine design, and provide important insights into how HIV is transmitted. The laboratory is part of a larger team, comprising researchers in both Seattle and Kenya (The Nairobi HIV/STD Project), that is studying the molecular epidemiology of HIV transmission. The project is also examining the efficacy of various intervention strategies to limit the spread of HIV, particularly those that may be practical to implement in Africa and other parts of the developing world.