NKp80⁺ effector CD8 T cells possess an inflammatory NK-like phenotype. (A) NKp80⁺ and NKp80⁻ cells within the effector memory CD8 subset (CCR7⁻ CD8⁺ αβ TCR⁺) in freshly isolated PBMCs (pooled from 6 donors and depleted of CD4⁺ and CD14⁺ cells) were sorted by FACS for transcriptional profiling by microarray analysis. (B) Signal intensities of mRNA microarrays for FACS-sorted NKp80⁺ versus NKp80⁻ cells. One dot represents expression of one gene. Differentially expressed genes are listed in Table 1. (C-F) Flow cytometric analysis of effector memory CD8 T cells (CCR7⁻ CD8⁺ αβ TCR⁺) for coexpression of NKp80 and various cell surface receptors selected on the basis of differential mRNA expression in NKp80⁺ versus NKp80⁻ subsets of CCR7⁻ CD8⁺ T cells (see Table 1). (C) Results for a representative donor. For analysis of most surface molecules, respective histograms for NKp80⁺ (dark gray) and NKp80⁻ cells (light gray) are overlaid. Coexpression of 4-1BBL and CD161, respectively, with NKp80 is shown in dot plots. (D,E) Data compiled from 3 donors and depicted either as fold change in MFI in NKp80⁺ versus NKp80⁻ cells (D) or percentage of marker-positive cells (E) among NKp80⁺ cells (■) and NKp80⁻ cells (). Mean values of data are shown with error bars indicating standard deviation. For analysis of NKR-P1A/CD161 in (D), only MFI of the CD161⁺ subpopulation were considered. (F) Coexpression of PD-1 and KLRG1, respectively, with NKp80 on effector memory CD8 T cells (CCR7⁻ CD8⁺ αβ TCR⁺) of 2 representative donors.