Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris, France.
Institut Pasteur, Université Paris Cité, CNRS UMR6047, Unit Evolutionary Biology of the Microbial Cell, Paris, France.
Nat Commun. 2024 Sep 4;15(1):7702. doi: 10.1038/s41467-024-51946-x.
The human gut virome, which is mainly composed of bacteriophages, also includes viruses infecting archaea, yet their role remains poorly understood due to lack of isolates. Here, we characterize a temperate archaeal virus (MSTV1) infecting Methanobrevibacter smithii, the dominant methanogenic archaeon of the human gut. The MSTV1 genome is integrated in the host chromosome as a provirus which is sporadically induced, resulting in virion release. Using cryo-electron tomography, we capture several intracellular virion assembly intermediates and confirm that only a small fraction of the host population actively produces virions in vitro. Similar low frequency of induction is observed in a mouse colonization model, using mice harboring a stable consortium of 12 bacterial species (OMM). Transcriptomic analysis suggests a regulatory lysogeny-lysis switch involving an interplay between viral proteins to maintain virus-host equilibrium, ensuring host survival and viral persistence. Thus, our study sheds light on archaeal virus-host interactions and highlights similarities with bacteriophages in establishing stable coexistence with their hosts in the gut.
人类肠道病毒组主要由噬菌体组成，还包括感染古菌的病毒，但由于缺乏分离物，其作用仍不清楚。在这里，我们描述了一种感染产甲烷菌（Methanobrevibacter smithii）的温和型古菌病毒（MSTV1），产甲烷菌是人类肠道中占主导地位的产甲烷古菌。MSTV1 基因组作为前病毒整合在宿主染色体中，前病毒随机诱导，导致病毒粒子释放。通过冷冻电镜断层扫描，我们捕获了几个细胞内病毒粒子组装的中间产物，并证实只有一小部分宿主群体在体外积极产生病毒粒子。在使用携带稳定的 12 种细菌群落（OMM）的小鼠进行的小鼠定植模型中，也观察到类似的低诱导频率。转录组分析表明，存在一种涉及病毒蛋白相互作用的溶原-裂解调控开关，以维持病毒-宿主平衡，确保宿主存活和病毒持续存在。因此，我们的研究揭示了古菌病毒-宿主相互作用，并强调了与噬菌体在肠道中与宿主建立稳定共存方面的相似性。
