CTLA4 and HIV infectious disease: By contrast, HIV infection of individuals with active TB disease was associated with a significant decrease in three subsets of Mtb-specific CD4 T cells, compared with HIV-uninfected individuals: BTLA+CTLA-4+PD-1+, BTLA+CTLA-4+PD-1−, and BTLA+CTLA-4−PD-1− cells (Figure 3F).