NKp80 expression on CD8 T cells is largely restricted to subsets of effector memory cells. Freshly isolated PBMCs from healthy donors were analyzed for NKp80 surface expression (anti-NKp80 mAb 5D12) by various subsets of αβ T cells. (A) Frequencies of NKp80⁺ cells among CD8 αβ T cells or CD4 αβ T cells. Stained PBMCs of 30 donors were gated for CD3 and αβ TCR and analyzed for frequencies of NKp80⁺ cells among CD4- or CD8-expressing cells. (B) Frequencies of NKp80⁺ cells among CD56⁺ and CD56⁻ CD8 T cells (left), and of CD56⁺ cells among CD8 T cells (right). Stained PBMCs of 11 donors were analyzed for NKp80⁺ cells after gating on CD3 and CD8. (C,D) Analysis of NKp80 expression by naive (T_N), central memory (T_CM), effector memory (T_EM), and effector (T_EMRA) CD8 αβ T cells. PBMCs gated for CD8 and αβ TCR-gated cells were further subgated according to CD45RA and CCR7 expression (C, right), and subgated cells analyzed for frequencies of NKp80⁺ cells. (C) Representative example and (D) data compiled from 8 donors are shown. (E,F) Prevalence of NKp80⁺ cells among subsets of T_EM and T_EMRA CD8 αβ T cells. PBMCs were gated as in (C) and T_EM and T_EMRA cells further subdivided according to their CD27/CD28 expression (E, right). (E) Representative analysis of T_EM and T_EMRA CD8 T cells for distribution of NKp80⁺ (black dots) and NKp80⁻ (gray dots) cells in the respective subsets. (F) Distribution of NKp80⁺ T_EM CD8 αβ T cells among subsets EM1, EM2, EM3, and EM4 (left) and NKp80⁺ T_EMRA CD8 αβ T cells among pE1, pE2, and E subsets (right) is depicted for 8 donors. In panels A, B, D, and F, means are indicated by horizontal bars.