Evaluation of HIV-1 latency reversal and antibody-dependent viral clearance by quantification of singly spliced HIV-1 vpu / env mRNA

• Published in: Journal of virology 2021-05, Vol.95 (11)
• Main Authors: Gao, Hongbo, Ozantürk, Ayşe N, Wang, Qiankun, Harlan, Gray H, Schmitz, Aaron J, Presti, Rachel M, Deng, Kai, Shan, Liang
• Format: Article
• Language: English
• Subjects: Pathogenesis and Immunity
• ISSN: 0022-538X; 1098-5514
• DOI: 10.1128/JVI.02124-20

The latent reservoir of HIV-1 is a major barrier for viral eradication. Potent HIV-1 broadly neutralizing antibodies (bNabs) have been used to prevent and treat HIV-1 infections in animal models and clinical trials. Combination of bNabs and latency-reversing agents (LRAs) is considered a promising approach for HIV-1 eradication. PCR-based assays that can rapidly and specifically measure singly spliced HIV-1 / mRNA are needed to evaluate the induction of the viral envelope production at the transcription level and bNab-mediated reservoir clearance. Here we reported a PCR-based method to accurately quantify the production of intracellular HIV-1 / mRNA. With the vpu/env assay, we determined the LRA combinations that could effectively induce / mRNA production in CD4 T cells from ART-treated individuals. None of the tested LRAs were effective alone. A comparison between the quantitative viral outgrowth assay (Q-VOA) and the vpu/env assay showed that / mRNA production was closely associated with the reactivation of replication-competent HIV-1, suggesting that / mRNA was mainly produced by intact viruses. Finally, antibody-mediated killing in HIV-1-infected humanized mice demonstrated that the vpu/env assay could be used to measure the reduction of infected cells in tissues and was more accurate than the commonly used -based PCR assay which measured unspliced viral genomic RNA. In conclusion, the vpu/env assay allows convenient and accurate assessment of HIV-1 latency reversal and bNab-mediated therapeutic strategies. HIV-1 persists in individuals on antiretroviral therapy (ART) due to the long-lived cellular reservoirs that contain dormant viruses. Recent discoveries of HIV-1-specific broadly neutralizing antibodies (bNabs) targeting HIV-1 Env protein rekindled the interest in antibody-mediated elimination of latent HIV-1. Latency-reversing agents (LRAs) together with HIV-1 bNabs is a possible strategy to clear residual viral reservoirs, which makes the evaluation of HIV-1 Env expression upon LRA treatment critical. We developed a PCR-based assay to quantify the production of intracellular HIV-1 / mRNA. Using patient CD4 T cells, we found that induction of HIV-1 / mRNA required a combination of different LRAs. Using , and humanized mouse models, we showed that the vpu/env assay could be used to measure antibody efficacy in clearing HIV-1 infection. These results suggest that the vpu/env assay can accurately evaluate HIV-1 reactivation and bNab-based therapeutic