Screening Of HIV-1Replication Inhibitors And Study Of Their Mechanisms

HIV-1reverse transcriptase is one of important functional enzymes in the process of viral replication. It is responsible for catalyzing single-stranded positive-sense RNA of HIV-1genome into double-stranded DNA. HIV-1undergoning replication process after infecting cells must rely on reverse transcriptase. Therefore, HIV-1reverse transcriptase is an important target of anti AIDS drugs research and development. HIV-1reverse transcriptase is a heterodimer composed of p66subunit and p51subunit. The p66subunit is a functional subunit, which has three kinds of enzyme activities:RNA-dependent DNA polymerase activity, DNA-dependent DNA polymerase activity and RNase H activity. At present, all reverse transcriptase inhibitors in clinical are DNA polymerase activity inhibitors. HIV-1virus highly prones to drug resistance. Therefore, discovering and researching new HIV reverse transcriptase inhibitors has significant value for development of a new anti-AIDS drug.We screened98thiazole derivatives, which were designed for RT inhibitors, by using VSVG/HIV recombinant viral system. We found22active compounds with IC50at0.01-20μmol·L-1. Four compounds (GCB123, GCB130, GCB133and GCB162) were selected for studying mechanisms. It showed that they inhibited both RNA-dependent DNA polymerase activity and RNase H activity. Furthermore, these compound exhibited inhibitory activities on NNRTIs-resistant HIV strains (HIVRT-k103N and HIVRT-Y18ic).We also found that two natural products by screening over one thousand compounds, RM-1and KHY-033, showed inhibitory-effects on HIV-1replication with IC50at0.420μmol·L-1and1.87μmol·L-1, respectively. Quantitative PCR results proved that RM-1and KHY-033inhibited reverse transcription process. The mechanism study indicted that RM-1inhibited HIV-1replication through inhibiting both RNA-dependent DNA polymerase activity and RNase H activity; and compound KHY-033was an RNase H inhibitor. Both RM-1and KHY-033had inhibitory effects on NNRTIs-resistant HIV strains. VSVG/MLV-GFP model was used for testing RM-1and KHY-033anti-viral spetrum. It is showed that KHY-033inhibited MLV replication, and RM-1did not.