Comparison of NKT lymphocytes in AIDS-susceptible and AIDS-resistant nonhuman primate species.

A) Dot-plots of ex vivo peripheral blood NKT lymphocytes in one SIV-negative sooty mangabey (SM), rhesus macaque (RM) and cynomolgus macaque (CM). Gated CD3+ T lymphocytes co-staining for Vα24 and CD1d tetramers loaded with PBS-57 were used to identify NKT lymphocytes (top panel). Co-staining for Vα24 and unloaded CD1d tetramers served as a negative control (bottom panel). B) Frequency of peripheral blood NKT lymphocytes in SIV-negative SM (n = 50), RM (n = 48) and CM (n = 15). Dotted line at 0.002% denotes the cut-off for the lower limit of flow cytometric detection of NKT lymphocytes. C) Representative contour plots of CD4 and CD8 surface expression on NKT lymphocytes in SM, RM and CM. D) Frequencies of NKT subsets with CD4+CD8 (CD4 SP), CD8+CD4 (CD8 SP), CD4+CD8+ (CD4/8 DP), and CD4CD8 (CD4/8 DN) phenotype in SIV-negative SM (n = 12), RM (n = 15), and CM (n = 15). * P<0.05, ** P<0.01, *** P<0.001, Mann-Whitney U test. Horizontal bars denote mean values.