HIV-specific CD8 T-cell parameters in primary HIV infection that correlate with viral control in chronic infection. (A) Comparable frequencies of tetramer⁺ cells from the primary to chronic phase of infection in the same donors. Differential expression of Ki67 (B), PD-1 (C), and CD127 (D) by HIV-specific CD8 T cells between the acute/early and chronic time points. Longitudinal analysis of the Stat5 phosphorylation (E) and the secretion of IFN-γ (F) by HIV-specific CD8 T cells. (G) Inverse correlation between the viral load set-point and the expression of CD127 on HIV-specific CD8 T cells in primary infection. (H) Inverse correlation between the percentage of HIV-specific CD8 T cells in primary infection expressing IL-2 in response to antigen and the viral load set-point. *P < .05. **P < .005. ***P < .0005. ns indicates not significant.