Resting Regulatory CD4 T Cells: A Site of HIV Persistence in Patients on Long-Term Effective Antiretroviral Therapy
Figure 4
Quiescent Tregs are sensitive to specific CD8+ T cell cytotoxicity.
Fig. 4A: CD25+ cell-depleted PBMCs were activated with PMA-inonomycin then extensively washed. Untreated HLADR−CD25+CD4+ T cells were then added at a physiological ratio. Cells were assayed by ELISPOT for granzyme B. Results correspond to the mean±SEM of results obtained in 2 patients. In Fig. 4B, HIV-specific CTL were co-cultured with CD25+HLADR−CD4+ and CD25−HLADR−CD4+ T cells loaded with HIV peptides. Controls were co-cultures of CD4+ T-cell subsets without peptides. Apoptosis was analyzed following annexin V staining on CD25hiHLADR−CD4+ and CD25−HLADR−CD4+ T cells. Results are expressed as the difference in the percentage of annexin V-positive cells in the presence and absence of HIV peptides. Results correspond to the mean±SEM of results obtained for 7 patients. Statistical comparison involved the Wilcoxon Signed Rank Test.