IFIH1 (MDA5) is required for innate immune detection of intron- containing RNA expressed from the HIV-1 provirus

• 成果类型: Article
• 署名作者: Guney, Mehmet Hakan; Nagalekshmi, Karthika; McCauley, Sean Matthew; Carbone, Claudia; Aydemir, Ozkan; Luban, Jeremy
• 署名单位: University of Massachusetts System; University of Massachusetts Worcester; UMass Chan Medical School; University of Massachusetts System; University of Massachusetts Worcester; UMass Chan Medical School; Harvard University; Massachusetts Institute of Technology (MIT); Broad Institute; Harvard University; Massachusetts Institute of Technology (MIT); Ragon Institute
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10233
• DOI: 10.1073/pnas.2404349121
• 发表日期: 2024-07-16
• 关键词: plasmacytoid dendritic cells; double-stranded-rna; nf-kappa-b; virus type-1 infection; sensors rig-i; 5'-triphosphate rna; latent reservoir; adapter protein; lymphoid-cells; nuclear export

摘要

Intron-- containing RNA expressed from the HIV- 1 provirus activates type 1 interferon in primary human blood cells, including CD4+T + T cells, macrophages, and dendritic cells. To identify the innate immune receptor required for detection of intron-- containing RNA expressed from the HIV- 1 provirus, a loss- of-- function screen was performed with short hairpin RNA-- expressing lentivectors targeting twenty- one candidate genes in human monocyte-- derived dendritic cells. Among the candidate genes tested, only knockdown of XPO1 (CRM1), IFIH1 (MDA5), or MAVS prevented activation of the interferon-- stimulated gene ISG15. The importance of IFIH1 protein was demonstrated by rescue of the knockdown with nontargetable IFIH1 coding sequence. Inhibition of HIV- 1-- induced ISG15 by the IFIH1-specific- specific Nipah virus V protein, and by IFIH1-- transdominant 2- CARD domain-- deletion or phosphomimetic point mutations, indicates that IFIH1 (MDA5) filament formation, dephosphorylation, and association with MAVS are all required for innate immune activation in response to HIV- 1 transduction. Since both IFIH1 (MDA5) and DDX58 (RIG- I) signal via MAVS, the specificity of HIV- 1 RNA detection by IFIH1 was demonstrated by the fact that DDX58 knockdown had no effect on activation. RNA-Seq- Seq showed that IFIH1 knockdown in dendritic cells globally disrupted the induction of IFN-- stimulated genes by HIV- 1. Finally, specific enrichment of unspliced HIV- 1 RNA by IFIH1 (MDA5), over two orders of magnitude, was revealed by formaldehyde cross-- linking immunoprecipitation (f-- CLIP). These results demonstrate that IFIH1 is the innate immune receptor for intron-- containing RNA from the HIV- 1 provirus and that IFIH1 potentially contributes to chronic inflammation in people living with HIV- 1, even in the presence of effective antiretroviral therapy.