FIG. 2.
HIV-1 virions require conformational integrity to deplete CD4+ T lymphocytes. (A) PBMC were mock treated or treated with CEMX174/(T1) microvesicles (10 μg/ml), infectious, AT-2-inactivated or heat-denatured HIV-1NL4-3/CEMX174/(T1) (10 ng of p24CA equivalent per ml) or recombinant gp120 at 0.001, 0.01, 0.1, 1.0, 10, 100, 1,000, or 10,000 ng/ml. PBMC were analyzed for the total number of CD4+ T lymphocytes on day 10. Statistical differences between mock-and virion-treated groups were evaluated using Student's t-test for comparisons between mean values of triplicate measurements. ∗∗∗, P < 0.001; ∗∗, P < 0.01. (B) gp120 and p24 levels on infectious and AT-2-inactivated HIV-1NL4-3 derived from CEMX174/(T2), CEMX174/(T1), and H9 cells. gp120/p24 ratios: HIV-1NL4-3(+)/T2, 0.23 ± 0.09; HIV-1NL4-3-AT2/T2, 0.22 ± 0.02; HIV- 1NL4-3(+)/T1, 0.89 ± 0.22; HIV-1NL4-3-AT2/T1, 0.75 ± 0.10; and HIV-1NL4-3(+)/H9, 0.65 ± 0.18. The gp120 content of 3,000 or 6,000 ng of HIV-1 virions (p24CA equivalent) was estimated by Western blot analysis with an anti-gp120 MAb (3F5-D5-F8). Recombinant gp120 concentrations are in nanograms. The 6,000 ng of p24 equivalents of HIV-1NL4-3/T1 has between 1 and 10 ng of gp120, approximately. The 10 ng/ml of p24 HIV-1NL4-3/T1 equivalents (estimated gp120 content = 0.0083 ng) readily induced apoptosis compared to rgp120 at 1,000 to 10,000 ng/ml but 600,000-fold more rgp120 is required to induce apoptosis compared to the levels of gp120 on 10 ng/ml (p24) of HIV-1.