Figure 4.

Comparison of activation and PD-1 expression in T cells. A, Frequency of total CD4⁺ T cells coexpressing HLA-DR and CD38, total CD4⁺ T cells expressing PD-1, and memory CD4⁺ T cells expressing PD-1 (B) are higher in men than in women. C, Total CD8⁺ T cells also showed a higher frequency of HLA-DR and CD38 coexpression and PD-1 expression. D, A greater frequency of memory CD8⁺ T cells coexpressed HLA-DR and CD38 or individually expressed PD-1 or CCR5 in men compared with women. For all values, median and interquartile ranges and comparisons with Mann–Whitney statistics are shown.