Peripheral blood mononuclear cell proliferation assessed by %Ki67 expression is shown in CD3+CD4+ (A) and CD3+CD8+ (B) cells. Both CD4+ and CD8+ T-cell proliferation increased following SIVMAC251 infection between 14 and 42 days of infection, but CD4+ T-cells in Experimental group (EG) maintained higher proliferation rates compared to Control group (CG). In contrast, proliferation in CD8+ T-cells both EGs and CGs returned to baseline thereafter. Cells were gated through CD3+ “bright” T lymphocytes and at least 20,000 events were collected by gating on lymphocytes. Asterisk (*) indicates significant differences between EG (n = 5) and CG (n = 4) for the specified cell subsets using the Student’s t-test, with a significance level of p < 0.05.