Figure 1:

Summary HIV and SIV infection in chronic progressors and elite controllers. A. Summary of CD4+ and CD8+ T cell response in HIV and SIV chronic progressors. 1. Acute HIV infection induces activation and expansion of all CD8+ T cells, including virus-specific CD8+ T-cells. 2. After an initial lag period, 3. expanded CD8+ T cells control peak viremia and chronic infection follows. 4. HIV specific CD8+ T-cells become exhausted and contribute to disease progression during chronic infection. 5. Emergence of CD8 escape mutants indicating selective pressure by CD8+ T-cells. 6. Despite ART, CD8+ T-cell function is not fully restored. (B) Summary of CD4+ and CD8+ T cell response in elite controller. Elite controllers have similar expansion of CD8+ T cells which leads to control of peak viremia and subsequent viral control and restoration of CD4+ T cells. 1. Specific MHC class I alleles are associated with viral control, indicating CD8 selective pressure. 2. HIV specific CD8+ T cells maintain high levels of polyfunctionality, proliferative capacity and maintenance of cytolytic potential throughout infection. Abbreviations: SIV, simian immunodeficiency virus; HIV, human immunodeficiency virus; ART, antiretroviral therapy; MHC, major histocompatibility class.