Higher levels of immune exhaustion markers in smokers compared to non-smokers.

<p>T-cell exhaustion markers (PD1, Tim3, and CTLA4) were evaluated by flow cytometry in CD4+ and CD8+ T-cells of HIV⁺S (n = 25), HIV⁺NS (n = 25), HIV^negS (n = 15) and HIV^negNS (n = 15). (A, B, C) frequency of exhausted CD4+ T-cells: CD4+PD1+ (A), CD4+Tim3+ (B), CD4+CTLA4+ (C) and (D, E, F) frequency of exhausted CD8+ T-cells: CD8+PD1+ (D), CD8+Tim3+ (E) and CD8+CTLA4+ (F). (G–L) Pie chart shows the comparison of frequencies of dual positive markers in CD4+ and CD8+ T-cells of HIV⁺S, HIV⁺NS, HIV^negS and HIV^negNS: CD4+PD1+Tim3+ (G); CD4+PD1+CTLA4+ (H); CD4+Tim3+CTLA4+ (I); CD8+PD1+Tim3+ (J); CD8+PD1+CTLA4+ (K) and CD8+Tim3+CTLA4+ (L). Box plots represent median with 25th and 75th percentile borders, error bars represent 10th and 90th percentile. The mean ± SEM for each group are given below the bar for that particular group.