CD8+ T cell supernatants of HIV type 1-infected individuals have opposite effects on long terminal repeat-mediated transcription in T cells and monocytes.

CD8+ T lymphocytes of HIV-1-infected individuals can efficiently suppress HIV-1 replication in CD4+ T lymphocytes via soluble factors. We compared the effect of CD8+ T cell-derived supernatants on HIV-1 LTR-driven gene expression in T cells and monocytic cell lines. Our results demonstrate that CD8+ T cell supernatants that suppressed HIV-1 LTR-driven gene expression in Jurkat T cells significantly enhanced expression in Tat-activated U38 monocytic cells in the presence and absence of mitogenic stimulation. Examination of a panel of CD8+ T cell-derived supernatants form HIV-infected individuals demonstrated that the extent of enhancement of transcription in U38 cells was mirrored in most cases by a similar level of suppression of transcription in Jurkat T cells. In latently infected U1 cells treated with TNF-alpha, culture with CD8+ T cell supernatants markedly enhanced virus production. In addition, the percentage increase in the enhancement of HIV-1 LTR-driven CAT expression by CD8+ T cell supernatants correlated strongly (r = 0.911) with the level of p24 detected. The level of LTR-mediated gene expression in U38 cells was not influenced by rhMIP-1 alpha rhMIP-1 beta, or rhRANTES over a wide range of chemokine concentration. Treatment of CD8+ T cell supernatant with a combination of antibodies to these chemokines resulted in a further augmentation of LTR-mediated CAT expression in U38 cells. Taken together, these results demonstrate that CD8+ T cell suppressive factors may have opposite effects on HIV-1 LTR-driven gene expression and replication dependent on target cell type and further suggest that the beta-chemokines do not influence HIV-1 LTR-mediated gene expression in monocytic cells.