Fig. 4.

Increased platelet–T-cell conjugates after thrombin stimulation in CD8⁺ T-cell subsets.

PBMCs isolated from healthy controls (n = 8) or HIV-infected patients (n = 8) were stimulated at 37°C for 5 (circle symbols) or 15 min (square symbols) in the presence or absence of thrombin (50 U/ml). (a) PBMC gating strategy for platelet–T-cell conjugate formation. (b) Representative example of the effects of thrombin stimulation on PBMCs from an HIV-infected patient. The red rectangle represents the proportion of CD8⁺ T cells binding platelets after thrombin activation. (c) Proportion of CD8⁺ T-cell subsets binding platelets after thrombin stimulation in healthy controls (solid black symbols) and HIV-infected patients (solid red symbols). Nonparametric Wilcoxon paired test was used for comparisons between unstimulated and thrombin; P < 0.05 was considered significant.