In vivo HIV gag DNA in MTB-specific CD4 T cells. (A) Gating/sorting strategy used to sort different memory CD4 T cell populations delineated by IFN-γ, IL-2, and MIP-1β production. MIP-1β⁻ memory CD4 T cells were further delineated into IFNγ⁺IL-2⁺TNF⁺, IFNγ⁺IL-2⁻TNF⁺, and cytokine-negative memory CD4 T cells. The HIV gag DNA/10,000 cells determined within these populations is indicated. (B) The ratio of HIV gag copies/10,000 cells detected within cytokine-positive to cytokine-negative memory T cells from 16 cytokine-positive CD4 T cell populations sorted from 10 HIV⁺ subjects (different symbols) with active TB. (C) The mean number of gag copies/10,000 cells detected in MTB-specific CD4 T cells or total memory CD4 T cells is shown for each subject. Memory CD4 T cells were defined by expression of CD45RO and CD27. The PBMCs were stimulated overnight with a mix of PPD and RD1 peptide pools and further analyzed as described in the Materials and methods section. Gag DNA within different CD4 T cell populations of the same subject was quantified during the same RT-PCR run. The statistical analysis in C was performed using the Wilcoxon-rank-matched pairs test.