Core Insights - The research conducted by the Shanghai Institute of Nutrition and Health reveals the molecular mechanism of APOL9 protein's specific binding to gut microbiota, which plays a crucial role in maintaining intestinal immune homeostasis [1][2] - APOL9 protein acts as a "bacterial diplomat," inducing specific bacteria to release outer membrane vesicles (OMVs) that enhance the host's immune response [1][2] Group 1: Research Findings - The study published in the journal "Nature" highlights that APOL9 does not kill target bacteria but instead promotes the release of OMVs, which are rich in bacterial molecules that can be captured by the host immune system [1] - OMVs activate the interferon-γ signaling pathway and increase the expression of MHC-II molecules on intestinal cells, leading to the training of a specific type of T cells that maintain intestinal immune stability [1][2] Group 2: Experimental Validation - To validate the physiological function of APOL9, the research team created APOL9 gene knockout mice, which showed uncontrolled bacterial spread and increased mortality when infected with Salmonella [2] - Supplementing these knockout mice with OMVs significantly improved infection symptoms and enhanced immune responses, demonstrating the active role of host proteins in shaping beneficial immune reactions [2]

撰文丨王聪 编辑丨王多鱼 排版丨水成文 哺乳动物 （包括人类） 的肠道内寄居着数以万亿计的共生菌，它们通过各种生物活性分子与宿主相互作 用。然而，宿主为从这些共生关系中获益而进化出的互利策略，在很大程度上尚未得到探索。 2025年5月14日，中国科学院上海营养与健康研究所 钱友存 团队联合 中国科学院分子细胞科学卓越创新 中心 宋昕阳 团队 （ 杨涛 、 胡孝虎 、 曹飞 为论文共同第一作者 ） ，在国际顶尖学术期刊 Nature 上 发 表了题为： Targeting symbionts by apolipoprotein L proteins modulates gut immunity 的研究论文。 该研究首次揭示了小鼠 肠道上皮细胞 （IEC） 分泌的载脂蛋白 APOL9a/b 及其人源同源蛋白 APOL2 可 特异性识别 拟杆菌目 （Bacteroidales） 细菌，诱导其释放 外膜囊泡 （OMV） ，进而激活宿主免疫因子 IFN-γ-MHC-II 信号通路，提升肠道黏膜屏障的抗感染能力。 这项研究不仅扩展了我们对宿主-共生菌在共同进化过程中互作机制的理解，也为开发新型微生态干预策略 提供了理论支 ...