Annexin V, TRAIL, and DR5 expression in T cells. Percentages of annexin V⁺ cells from HIV-1–uninfected donors determined by flow cytometry in (A) unfractionated PBMCs cultured for 24 hours with microvesicles (control), infectious HIV-1_MN, or HIV-1_Ada; or (B) isolated CD4⁺ and CD8⁺ T cells cultured with microvesicles, or with infectious or AT-2 HIV-1_MN. (C) FACS analysis of TRAIL expression on CD4⁺ and CD8⁺ T cells cultured for 24 hours with infectious or noninfectious HIV-1_MN. (D) TRAIL mRNA expression after 24-hour culture of PBMCs, isolated CD4⁺ and CD8⁺ T cells with AT-2 HIV-1_MN, or microvesicles. (E) DR5 mRNA expression in CD4⁺ and CD8⁺ T cells cultured for 24 hours with AT-2 HIV-1_MN or microvesicles. (F) FACS analysis of DR5 expression on CD4⁺ and CD8⁺ T cells after 24 hours of culture with AT-2 HIV-1_MN (identical results obtained using infectious HIV-1_MN; data not shown). Eight percent to 13% of CD4⁺ T cells expressed DR5, whereas less than 1% of CD8⁺ T cells did. (A-B,D-E) Mean values with standard errors of 6 independent experiments for each condition tested. (C,F) Representative results of 4 independent experiments. (A-B,E) P values determined by 2-tailed Student t test.