Fig. 2.

Activated antigen-specific CD4⁺ T cells inhibit X4 and R5 HIV-1 isolates, and this activity is mediated by the CC chemokines. (A) Individual supernatants harvested on days 4 and 7 from SEB-, TSST-1-, or allogeneic MDDC-activated cells were tested for inhibition of X4 (HIV-1_IIIB) and R5 (HIV-1_BaL) viruses in the viral inhibition assay as described in Materials and Methods. The data are shown as the average percentage of inhibition by the individual supernatants. Anti-HIV-1 chemokine concentrations (□, CCL1; •, CCL3; ⋄, CCL4; ▪, CCL5, and ○, CCL22), determined by ELISA in the supernatants, are shown for naïve CD4⁺ T cells cultured with autologous MDDC in the presence of TSST-1 (B) and for naïve CD4⁺ T cells cultured with MDDC alone (C) (see Materials and Methods for details). Data are representative of 10 experiments. (D) Temporal correlation between CCL22 concentration (⋄) and HIV-1_IIIB inhibition (□) for eight different individuals in supernatants from naïve CD4⁺ T cells cultured with autologous MDDC and superantigens (SEB or TSST-1) or with allogeneic MDDC. (E) CCL22-neutralizing antibodies reverse the antiviral activity of activated CD4⁺ T cell supernatants against HIV-1_IIIB. The reversal of HIV-1_IIIB suppressor activity by CCL22-neutralizing antibodies is shown as the average percentage of reversal in three independent experiments (using independent donors) in which naïve CD4⁺ T cells were cultured with autologous MDDC and SEB. Error bars represent the SEM.