T6SS secretes an LPS-binding effector to recruit OMVs for exploitative competition and horizontal gene transfer

作者：Changfu Li, Lingfang Zhu, Dandan Wang, Zhiyan Wei, Xinwei Hao, Zhuo Wang, Tengfei Li, Lei Zhang, Zhiqiang Lu, Mingxiu Long, Yao Wang, Gehong Wei, Xihui Shen · 发表于：The ISME Journal · 年份：2021 · DOI：10.1038/s41396-021-01093-8 · 被引用次数：96 · 研究领域：Bacterial Infections and Vaccines、Vibrio bacteria research studies、Legionella and Acanthamoeba research

Outer membrane vesicles (OMVs) can function as nanoscale vectors that mediate bacterial interactions in microbial communities. How bacteria recognize and recruit OMVs inter-specifically remains largely unknown, thus limiting our understanding of the complex physiological and ecological roles of OMVs. Here, we report a ligand-receptor interaction-based OMV recruitment mechanism, consisting of a type VI secretion system (T6SS)-secreted lipopolysaccharide (LPS)-binding effector TeoL and the outer membrane receptors CubA and CstR. We demonstrated that Cupriavidus necator T6SS1 secretes TeoL to preferentially associate with OMVs in the extracellular milieu through interactions with LPS, one of the most abundant components of OMVs. TeoL associated with OMVs can further bind outer membrane receptors CubA and CstR, which tethers OMVs to the recipient cells and allows cargo to be delivered. The LPS-mediated mechanism enables bacterial cells to recruit OMVs derived from different species, and confers advantages to bacterial cells in iron acquisition, interbacterial competition, and horizontal gene transfer (HGT). Moreover, our findings provide multiple new perspectives on T6SS functionality in the context of bacterial competition and HGT, through the recruitment of OMVs.