CD4^dimCD8^bright T cells have greater cytotoxic potential than CD4⁻CD8⁺ T cells. (A-B,D-E) Cumulative data (A,D) and representative dot plots (B,E) of CD107ab staining by CD4⁻CD8⁺ and CD4^dimCD8^bright T cells from HIV⁺ LTNP (A-B) and CMV⁺ (D-E) donors, cocultured with unloaded (left side) or loaded (right side) T1 target cells. (A,D) Data represent mean + SD percentage of 107ab expression from at least 3 donors. P values between groups are indicated within the figure and based on 2-tailed unpaired t test analysis. (C,F) Representative dot plots of CD4⁻CD8⁺ (left) and CD4^dimCD8^bright T cells (right) from an unstained HIV⁺ LTNP donor (C) and an isotype-stained CMV⁺ donor (F).