SODIUM BENZYLIDENEASCORBATE INDUCES APOPTOSIS IN HIV-REPLICATING U1 CELLS

U1 cells, a subclone of U937 cells chronically infected with human imm unodeficiency virus type 1 (HIV-1), produced HIV-1 only in the presenc e of inducers such as 12-O-tetradecanoxylphorbol 13-acetate (TPA) or t umor necrosis factor (TNF)-alpha. The expression of HIV-antigen on U1 cells induced by TPA or TNF-alpha was found to be prevented by sodium 5,6-benzylidene-L-ascorbate (SBA) in a concentration-dependent manner. Treatment of U1 cells with SBA in the presence of inducers resulted i n cell death with cell shrinkage, chromatin condensation and DNA fragm entation into nucleosomal oligomers, characteristics of apoptosis. In contrast, SBA had scarcely any apoptotic effect on U1 cells in the abs ence of inducers. SBA did not also induce apoptosis in parental U937 c ells in the presence or absence of inducers. These results suggest tha t HIV-replicating U1 cells selectively undergo apoptosis on treatment with SBA.