Reduced binding of plasma-derived PMPs from HIV-infected adults to Tregs. Tregs isolated from 5 healthy donors were cultured for 16 hours with recombinant human IL-2 in the presence or absence of total microparticle (MP) fractions isolated by differential centrifugation from platelet-poor plasma of patients with ACS (n = 3), HIV-infected adults on stable combination antiretroviral therapy (n = 3), and healthy volunteers (HV; n = 3). Tregs were stained for surface CD4, CD25, CD41, P-selectin, and intracellular FOXP3 and analyzed by flow cytometry. (A) Dot plots show the percentage of CD41 and P-selectin double-positive CD4⁺CD25^highFOXP3⁺ Tregs. The dot plots were generated using merged data of 3 plasma microparticle donors. (B) The percentage of CD41 and P-selectin double-positive Tregs (n = 3 plasma microparticle donors). Representative results are shown. *P < .05.