The natural history and pathogenesis of HIV-1 infection are linked closely to the replication of virus in the body. Studies obtained entirely from analyses of peripheral blood led to a shift in the understanding of HIV-1 pathogenesis. Recent studies have shown that lymphoid tissues are a major reservoir for HIV and the primary site of virus replication. The proposed studies will provide the first comprehensive assessment of HIV-1 expression and lymphocyte response in both blood and lymphocyte tissue compartments. The data obtained will provide new insight into HIV-1 pathogenesis and provide a more rational basis for treatment decisions concerning early therapy of HIV-1 infection.