Inhibition of HIV-1 replication in chronically infected cell lines and peripheral blood mononuclear cells by retrovirus-mediated antitat gene transfer

Among potential genetic targets for intervention in the HIV-1 life cycle, t he fat gene product is a key target. We investigated the ability of an anti tat gene to inhibit HIV-1 activation and replication in chronically infecte d promonocyte (UI) and T cell (ACH-2) lines in vitro. U1 and ACH-2 cells we re transduced with an antitat gene expressing RNA with dual (polymeric Tat activation response element and antisensetat) function that interferes with HIV-1 replication. Tumor necrosis factor-alpha (TNF-alpha) plus phorbol 12 -myristate 13-acetate (PMA)-induced HIV-1 expression, as determined by reve rse transcribed PCR and reverse transcriptase (RT) assays, was significantl y inhibited in U1 and ACH-2 cells transduced with the antitat gene, compare d with the cells transduced with control vector and untransduced cells. Thi s resistance to TNF-alpha plus PMA-induced HIV-1 expression was demonstrate d in antitat gene-transduced UI and ACH-2 cells maintained in G418-free med ia for 5 months, suggesting that functional antitat gene may persist for ma ny months in transduced cells and their progeny. Most importantly, we demon strate that the antitat gene, when introduced into peripheral blood mononuc lear cells (PBMC) isolated from patients with HIV-1 infection, inhibited TN F-alpha plus PMA-induced viral replication as determined by RT-PCR and RT a ctivity. In addition, the antitat gene enhanced the survival of GD4(+) T ly mphocytes from such patients. These data suggest the feasibility of utilizi ng antitat gene therapy to block activation and replication of HIV-1 in lat ently infected monocytes and T- lymphocytes in vivo.