Ma Mingtong, Duan Yongjia, Peng Cheng, Wu You, Zhang Xinning, Chang Boran, Wang Fei, Yang Hua, Zheng Ruijuan, Cheng Hongyu, Cheng Yuanna, He Yifan, Huang Jingping, Lei Jinming, Ma Hanyu, Li Liru, Wang Jie, Huang Xiaochen, Tang Fen, Liu Jun, Li Jinsong, Ying Ruoyan, Wang Peng, Sha Wei, Gao Yawei, Wang Lin, Ge Baoxue
Shanghai Key Laboratory of Tuberculosis, Shanghai Pulmonary Hospital, Key Laboratory of Pathogen-Host Interaction, Ministry of Education, Tongji University School of Medicine, Shanghai, China.
Department of Microbiology and Immunology, Tongji University School of Medicine, Shanghai, China.
Cell Discov. 2024 Mar 29;10(1):36. doi: 10.1038/s41421-024-00653-4.
Internal N-methyladenosine (mA) modifications are among the most abundant modifications of messenger RNA, playing a critical role in diverse biological and pathological processes. However, the functional role and regulatory mechanism of mA modifications in the immune response to Mycobacterium tuberculosis infection remains unknown. Here, we report that methyltransferase-like 14 (METTL14)-dependent mA methylation of NAPDH oxidase 2 (Nox2) mRNA was crucial for the host immune defense against M. tuberculosis infection and that M. tuberculosis-secreted antigen EsxB (Rv3874) inhibited METTL14-dependent mA methylation of Nox2 mRNA. Mechanistically, EsxB interacted with p38 MAP kinase and disrupted the association of TAB1 with p38, thus inhibiting the TAB1-mediated autophosphorylation of p38. Interaction of EsxB with p38 also impeded the binding of p38 with METTL14, thereby inhibiting the p38-mediated phosphorylation of METTL14 at Thr72. Inhibition of p38 by EsxB restrained liquid-liquid phase separation (LLPS) of METTL14 and its subsequent interaction with METTL3, preventing the mA modification of Nox2 mRNA and its association with the mA-binding protein IGF2BP1 to destabilize Nox2 mRNA, reduce ROS levels, and increase intracellular survival of M. tuberculosis. Moreover, deletion or mutation of the phosphorylation site on METTL14 impaired the inhibition of ROS level by EsxB and increased bacterial burden or histological damage in the lungs during infection in mice. These findings identify a previously unknown mechanism that M. tuberculosis employs to suppress host immunity, providing insights that may empower the development of effective immunomodulators that target M. tuberculosis.
内部N - 甲基腺苷（mA）修饰是信使RNA中最丰富的修饰之一，在多种生物和病理过程中起关键作用。然而，mA修饰在结核分枝杆菌感染免疫反应中的功能作用和调控机制仍不清楚。在此，我们报告，烟酰胺腺嘌呤二核苷酸磷酸氧化酶2（Nox2）mRNA的甲基转移酶样14（METTL14）依赖性mA甲基化对于宿主抵抗结核分枝杆菌感染的免疫防御至关重要，并且结核分枝杆菌分泌的抗原EsxB（Rv3874）抑制Nox2 mRNA的METTL14依赖性mA甲基化。机制上，EsxB与p38丝裂原活化蛋白激酶相互作用，破坏TAB1与p38的结合，从而抑制TAB1介导的p38自身磷酸化。EsxB与p38的相互作用还阻碍了p38与METTL14的结合，从而抑制p38介导的METTL14苏氨酸72位点的磷酸化。EsxB对p38的抑制作用抑制了METTL14的液 - 液相分离（LLPS）及其随后与METTL3的相互作用，阻止了Nox2 mRNA的mA修饰及其与mA结合蛋白IGF2BP1的结合，从而使Nox2 mRNA不稳定，降低活性氧水平，并增加结核分枝杆菌的细胞内存活率。此外，METTL14磷酸化位点的缺失或突变削弱了EsxB对活性氧水平的抑制作用，并增加了小鼠感染期间肺部的细菌负荷或组织学损伤。这些发现确定了结核分枝杆菌用于抑制宿主免疫的一种先前未知的机制，为开发靶向结核分枝杆菌的有效免疫调节剂提供了思路。
