MAIT cells are depleted in the peripheral blood of chronically HIV-infected patients. (A) Identification of peripheral blood MAIT cells in uninfected and HIV-infected individuals. The frequency of total MAIT cells (B), and DN, CD4, and CD8 subsets (C) was determined in 34 HIV-1–uninfected individuals and 33 patients with chronic untreated HIV-infection. (D) The relationship between MAIT-cell frequency and time since HIV diagnosis was assessed using Spearman rank correlation. The numbers (E) and frequency (F) of MAIT cells, and CD4 T-cell counts (G) were compared in 22 HIV-infected patients before and after commencing cART. Box and whisker plots show median, IQR and the 10th to 90th percentile. Tx indicates therapy.