CD161⁺TCRVα7.2⁺ MAIT cells are severely reduced in the blood of HIV-infected patients.

<p><b>A</b>) Gating Strategy for CD161 and TCRVα7.2 based MAIT cell characterization in the CD4^–CD3⁺T cell subset. All FACS analyses were performed on frozen PBMC samples. Depicted are representative plots from healthy control PBMCs (upper panel). Gating of the MAIT cell subsets comparing a healthy donor (HC) and an HIV patient (lower panel). <b>B</b>) Cumulative display of CD161⁺TCRVα7.2⁺ MAIT cell frequencies, CD161^–TCRVα7.2⁺ and total TCRVα7.2⁺ cells in % of CD3⁺ T cells comparing PBMC samples derived from healthy controls (HC n = 20), untreated patients with high viral loads (high VL n = 20), patients receiving antiretroviral treatment for a at least one year (ART n = 12), elite controller (EC n = 10) and patients with very low viremia and slow progression (<5000 copies/ml; LTNP n = 12). <b>C</b>) Absolute MAIT cell counts, CD161^–TCRVα7.2⁺ and total TCRVα7.2⁺ cells per µl peripheral blood, calculated based on absolute CD3⁺ T cell counts (available for 12 HC, 11 high VL, 6 ART, 8 EC and 6 LTNP). All groups were tested for normal distribution with the Kolmogorov-Smirnov test and were compared by the adequate test, ANOVA followed by Tukey's multiple comparisons test or Kruskal-Wallis followed by multiple comparison test, respectively. P-values smaller than 0.05 were considered significant, where *, ** and *** indicate p-values between 0.01 to 0.05, 0.001 to 0.01 and 0.0001 to 0.001, respectively. Bars and lines indicate median, 25% and 75% quartiles. <b>D</b>) Representative FACS plots and the percentages of cells that produce the cytokines IL-17 and INF-γ upon stimulation with PMA/ionomycin among MAIT cells and CD161^–TCRVα7.2⁺ cells are shown. PBMC samples derived from healthy donors (n = 22) and HIV-infected patients (ART treated and untreated with high viral loads, n = 10) were analyzed. Asterisks indicate the results of Wilcoxon matched-pairs signed-rank tests.