Figure 1.

Immunoediting during natural infection. During the acute phase of infection, HIV rapidly expands infecting new target CD4⁺ T cells. Approximately 2 weeks post-infection, HIV-specific CD8⁺ T cell responses develop and eliminate many infected CD4⁺ T cells decreasing viral burden by ~1 × 10²⁻³ RNA copies/ml of plasma. A viral set point is reached when virus replication and CD8⁺ T cell elimination of infected cells reaches an equilibrium. During the equilibrium phase, ongoing rounds of viral replication and CD8⁺ T cell elimination provides evolutionary pressure to select for viral variants that are not recognized by CD8⁺ T cell responses. A combination of viral escape variants and CD8⁺ T cell exhaustion eventually leads to viral escape and progression to AIDS.