Role of In Vitro Stimulation with Lipopolysaccharide on T-Cell Activation in HIV-Infected Antiretroviral-Treated Patients

Figure 4

Ki67-expressing CD4+/CD8+ T-cells in HIV-negative and HIV-positive patients prior to and following LPS stimulation. Ki67 expression was measured on freshly ficoll-separated CD4+ and CD8+ T-cells at baseline (T0, top) and following 24- (T1, middle) and 48-hour (T2, bottom) LPS stimulation. PBMCs were cultured in medium alone (unstimulated, US) or in medium with 20 ng/mL LPS (stimulated, STIM). At T0, no differences between HIV-negative controls and HIV-positive subjects were measured in Ki67 expression on CD4+ (a) and CD8+ T-cells (c). T-cell proliferation levels did not vary according to the degree of immune-reconstitution in course of HAART ((b) and(d)). At T1, LPS stimulation did not account for significant increases in cell proliferation ((e)–(h)). At T2, a trend to increased Ki67 levels on CD4+ T-cells upon stimulation was detected in LR compared to HR and negative controls (j); no differences were detected in terms of Ki67+CD8+ T-cells proliferation among study groups following 48-hour stimulation with LPS ((k) and (l)).