Identification of a novel Vpr-binding compound that inhibits HIV-1 multiplication in macrophages by chemical array.

Although HIV-1 replication can be controlled by highly active anti-retroviral therapy (HAART) using protease and reverse transcriptase inhibitors, the development of multidrug-resistant viruses compromises the efficacy of HAART. Thus, it is necessary to develop new drugs with novel targets. To identify new anti-HIV-1 compounds, recombinant Vpr was purified from transfected COS-7 cells and used to screen compounds by chemical array to identify those that bound Vpr. From this screen, 108 compounds were selected as positive for Vpr binding. Among these, one structurally similar group of four compounds showed anti-HIV activity in macrophages. In particular, compound SIP-1 had high inhibition activity and reduced the levels of p24 by more than 98% in macrophages after 8 or 12 days of infection. SIP-1 had no cytotoxic effects and did not disrupt cell cycle progression or induce apoptosis of Molt-4 and HeLa cell lines as measured by MTT assay, flow-cytometry analysis, and a caspase-3 assay. In addition, SIP-1 specifically bound to Vpr as assessed by photo-cross-linked small-molecule affinity beads. These results suggest that Vpr is a good target for the development of compounds that could potentially inhibit HIV-1 replication. Collectively, our results strongly suggest that chemical array is a useful method for screening anti-viral compounds.