Fig. 2.

HIV-specific cTfh express multiple IRs despite viral suppression. cTfh specific for HIV, CMV and HBV were analyzed by flow cytometry for expression of the co-inhibitory receptors TIGIT, PD-1 and CD200. (a) Example plots showing expression of TIGIT, PD-1 or CD200 on unstimulated (black) or HIV-specific cTfh (red) from one representative donor. FMO controls are shown as dotted lines. (b) Frequency of TIGIT-, PD-1- or CD200-expressing Ag-specific cTfh. (c) Analysis of co-expression of TIGIT, PD-1 and CD200 on Ag-specific cTfh. (d) Comparison of frequency of TIGIT⁺CD200⁺PD-1⁺ Ag-specific cTfh. n = 27 (HIV), n = 23 (CMV) or n = 6 (HBV) for (b-d). Significant p-values are shown in figure and were calculated by Kruskal–Wallis test with Dunn's post test (b,d) or permutation test (c). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)