Study On Noval Compounds To Reactivate The Latent HIV Reservoir In Primary CD4+ T Cells

Human acquired immune deficiency syndrome (AIDS) is still a serious challenge for global public health, although it has been discovered in 1981 for more than three decades. The development of highly active antiretroviral therapy (HAART) to treat HIV-1 infected patient results in an effective control of HIV-1 replication, which makes HIV from a fatal disease to a controllable and chronic disease. However, HIV viral load will rebound quickly within several days once HARRT is interrupted. The major barrier to curing HIV-1 infection is the latent virus reservoirs in the resting memory CD4+T cells.To date, one of promising strategies for eliminating the latent provirus is to pharmacologically purging HIV-1 gene expression in latently infected cells, rendering these cells susceptible to cytolytic T lymphocytes or viral cytopathic effects. Recently,varities of latency-reversing agents (LRA) are being developed to activate HIV provirus. IL-2, anti-CD3 monoantibody effectively reactivated the latent HIV-1, but the associated systemic toxicity made it impossible for clinical use. Some compounds are tested to specially reactive latent HIV in vitro, including histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid and valproic acid (VPA), but it didn't perturb the reservoir of infected individuals with HARRT treatment,which made it ultimately unsuitable for clinical use. Therefore, it is urgent to develop new agents kicking the latent HIV without extensive T cell activation.Previous studies demonstrated that pyranoindole skeleton is a pharmacology-privileged structure core in drug discovery, and kinds of pyranoindole derivatives have shown activities for anti-inflammation, anti-cancer and anti-bacterial infection. Recently, our collaborators developed an efficient method for the organocatalytic enantioselective synthesis of dihydropyranoindole derivatives, and then we synthesized a series of novel compounds bearing trifluoromethylated all-carbon-substituted stereocentersin high yields (up to 99%) with excellent enantioselectivity (up to 98% ee). In this study, we tested those compounds in a high-throughput screening model-Jurkat-Lat cell line that mimics the latent state of HIV-1 in primary CD4+ T cells. Based on structure modification and screening, we finally identified that one compound, named as ethyl-2-amino-3-cyano-9-methyl-4-(trifluoromethyl)-4,9-dihydropyrano[2,3-b]indole-4-carboxylate(GIBH-LRA002),possess the most optimized reactivation efficacy and the less cytotoxicity.Subsequently, we tested its activation activity in primary CD4+T cells from SIV-infected macaques and HIV-infected patients. For this aim, we developed a nested quantitative PCR method to detect the transcriptional level of cell-associated RNA, which is a biomarker of the HIV reactivation. Our data demonstrated that GIBH-LRA002 potently reverse the SIV/HIV provirus in primary CD4+ T cells. Our futher study showed that no significant elevation of CD25, CD69 and CCR5 expression was found in the GIBH-LRA002-treated CD3+ T and CD4+ T cells.In conclusion, GIBH-LRA002 effectively reactivated the latent proviruses but without involving in systemic activation in our study, which is consistent with the requirements of an ideal LRA. GIBH-LRA002 is a promising candidate compound for HIV functional cure, and this study provides implications for the design of optimal LRA compounds to purge HIV-1 latent reservoir.