Outer membrane vesicles (OMVs) (∼50–250 nm in diameter) are produced by both pathogenic and nonpathogenic bacteria as a canonical end product of secretion. In this review, we focus on the OMVs produced by gram-negative bacteria. We provide an overview of the OMV structure, various factors regulating their production, and their role in modulating host immune response using a few representative examples. In light of the importance of the diverse cargoes carried by OMVs, we discuss the different modes of their entry into the host cell and advances in the high-throughput detection of these OMVs. A conspicuous application of OMVs lies in the field of vaccination; we discuss its success in immunization against human diseases such as pertussis, meningitis, shigellosis and aqua-farming endangering diseases like edwardsiellosis.

病原菌和非病原菌均会分泌外膜囊泡（直径约50-250 nm），作为分泌的典型终产物。在这篇综述中，我们专注于革兰氏阴性细菌产生的OMV。我们使用几个代表性的例子概述了OMV结构，调节其产生的各种因素以及它们在调节宿主免疫反应中的作用。鉴于OMV携带的各种货物的重要性，我们讨论了它们进入宿主细胞的不同模式，以及这些OMV的高通量检测方面的进展。OMV的显着应用在于疫苗接种领域。我们讨论了其在针对人类疾病（如百日咳，脑膜炎，志贺氏菌病和危害水产养殖的疾病，如埃德氏菌病）的免疫接种中的成功经验。