Chronic SIV infection alters functional profiles of gut NK cells. (A) Colorectal mononuclear cells were stimulated with phorbol 12-myristate 13-acetate/ionomycin for 12 hours and then IL-17, IFN-γ, and TNF-α production and CD107a expression were measured on NKG2A⁺ and NKp44⁺ NK cells in naive and SIV-infected macaques. The monofunctional profiles of each subpopulation were determined by expressing each response as a proportion of the total cell population. The means ± SEM for 12 animals per group are shown. (B) Multiparametric analyses on the data shown in Figure 6A were performed with SPICE 5.0 software. Pies indicate means of 12 animals per group. Tables show results of 1-sided permutation tests comparing each of the pies as calculated by SPICE; P < .05 are considered significant and are highlighted in yellow. (C) Intracellular perforin expression was determined in NK cells ex vivo; bars represent means ± SEM for 13-16 animals per group. (D) Expression of CCL4 (MIP-1β) was determined by ICS. (E) Quantitative RT-PCR analysis of constitutively expressed CCL3 (MIP-1α) and CCL5 (RANTES) in NKG2A⁺ and NKp44⁺ NK cells sorted from rectal biopsies of normal macaques. Mann-Whitney U tests were used for naïve versus SIV comparisons, and Wilcoxon matched pairs tests were used to compare NKG2A⁺ and NKp44⁺ NK cells (*P < .05, **P < .01, ***P < .001. MFI indicates median fluorescence intensity.