Expression of T-cell activation markers after PBMC exposure to HIV and βCD-treated HIV. (A) Flow cytometric contour plots showing detection of T cells (CD3⁺; left panel) and distinction of T-cell subsets based on CD4 and CCR5 expression (right panel). (B) Flow cytometric histograms of CD38 (top panels) and CD69 (bottom panels) expression on the gated T-cell subpopulations in the different culture conditions (vertical dotted lines indicate thresholds of positive staining based on isotype controls; 1 example of 15 experiments is shown). (C) CD38 (top panel) and CD69 (bottom panel) expression measured as frequency of expressing T cells in the different culture conditions for each T-cell subset (n = 15). Horizontal bars represent median values; vertical lines extend to 75th and 25th percentiles. P values show comparisons with control. *P values that remained significant after Hochberg correction for multiple comparisons.