FIG 6.

Phenotype and functionality of SIV Gag-specific CD4⁺ and CD8⁺ T cells in foreskin. The CD4⁺ and CD8⁺ T cells in PBMC and foreskin expressing both IFN-γ and TNF-α after SIVmac239 Gag stimulation were identified via ICS using the Boolean function of FlowJo software. The proportions of naive (CD28+CD95-), central/transitional memory (CM/TM; CD28⁺ CD95⁺) and effector memory (EM; CD28⁻ CD95⁺) T cells among these SIV Gag-specific IFN-γ⁺ TNF-α⁺ T cells were subsequently identified in matched PBMC and foreskin of both infected animals (A) and vaccinated animals (B). Multifunctionality (IFN-γ and/or TNF-α secretion) of all SIV Gag-specific CD4⁺ and CD8⁺ T cells from PBMC and foreskin is presented in the pie charts for both infected animals (A) and vaccinated animals (B). *, P < 0.05 (two-tailed Student t test) for comparison of the proportion of CM/TM CD8⁺ T cells between PBMC and foreskin. Error bars represent the SEM.