CD161⁺⁺/MAIT cell analysis in the colon in HIV. Sections of colon from HIV-infected patients (n = 12) or controls (n = 12) were stained for CD3, CD8, and MDR-1. CD161⁺⁺/MAIT cells were defined as CD3⁺CD8⁺MDR1⁺⁺. (A) Representative images from control (left) and HIV-infected tissue (right) are shown. Arrows indicate CD3⁺CD8⁺MDR1⁺⁺ cells. Scale bars, 50 μm. (B) The proportion of CD3⁺CD8⁺ cells expressing high (++) levels of MDR1 was reduced in HIV infection. (C) The proportion of CD3⁺ cells expressing CD8 was increased in HIV infection. (D) No significant difference was seen in the number of CD3⁺CD8⁺MDR1⁺⁺ cells per mm². (E) The number of CD3⁺CD8⁺ cells per mm² was increased in HIV infection.