Antiretroviral drugs effectively halt HIV-1 replication and disease progression, however, due to the presence of a stable viral latent reservoir, the infection cannot be cured by antiretroviral drugs alone. Elucidating the molecular mechanisms underlying HIV-1 latent infection remains a critical hurdle that precludes the development of novel therapeutic strategies aiming for a potential functional cure. Cellular metabolism has been reported to affect HIV-1 replication in CD4⁺ T cells, but it remains largely unclear whether it is involved in the regulation of HIV-1 latency. Here, we performed a sub-pooled CRISPR library knockout screen targeting 1773 metabolic-related genes in a cell model of HIV-1 latent infection and found that Methionine Adenosyltransferase 2A (MAT2A) contributes to HIV-1 latency. MAT2A knockout enhanced the reactivation of latent HIV-1 while MAT2A overexpression did the opposite. Mechanistically, MAT2A modulates HIV-1 latency through S-Adenosylmethionine (SAM)-mediated one-carbon flux. MAT2A knockout resulted in a significant downregulation of DNA and histone methylation at the HIV-1 5’-LTR. Importantly, we found that the plasma level of SAM is positively correlated with HIV-1 DNA in PBMCs from ART-treated infected individuals, suggesting SAM could serve as a potential biomarker for the latent viral reservoir. Overall, this study reveals an important role of MAT2A-mediated one-carbon metabolism in regulating HIV-1 latency and provides a promising target for the development of new strategies for a functional cure of HIV-1.

抗逆转录病毒药物有效地阻止了 HIV-1 的复制和疾病进展，但是，由于存在稳定的病毒潜伏库，仅靠抗逆转录病毒药物无法治愈感染。阐明 HIV-1 潜伏感染的分子机制仍然是阻碍开发旨在实现潜在功能性治愈的新治疗策略的关键障碍。据报道，细胞代谢会影响 CD4 ^{+ 中的}HIV-1 复制T 细胞，但目前尚不清楚它是否参与调节 HIV-1 潜伏期。在这里，我们在 HIV-1 潜伏感染的细胞模型中进行了针对 1773 个代谢相关基因的子池 CRISPR 文库敲除筛选，发现蛋氨酸腺苷转移酶 2A (MAT2A) 有助于 HIV-1 潜伏期。MAT2A 敲除增强了潜伏 HIV-1 的再激活，而 MAT2A 过表达则相反。从机制上讲，MAT2A 通过 S-腺苷甲硫氨酸 (SAM) 介导的一碳通量调节 HIV-1 潜伏期。MAT2A 敲除导致 HIV-1 5'-LTR 的 DNA 和组蛋白甲基化显着下调。重要的是，我们发现 SAM 的血浆水平与来自 ART 治疗的感染个体的 PBMC 中的 HIV-1 DNA 呈正相关，表明SAM可以作为潜在病毒库的潜在生物标志物。总体而言，这项研究揭示了 MAT2A 介导的单碳代谢在调节 HIV-1 潜伏期中的重要作用，并为开发功能性治愈 HIV-1 的新策略提供了一个有希望的目标。