Caruana Julie C, Walper Scott A
American Society for Engineering Education, Washington, DC, United States.
US Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC, United States.
Front Microbiol. 2020 Mar 24;11:432. doi: 10.3389/fmicb.2020.00432. eCollection 2020.
Bacterial membrane vesicles are proteoliposomal nanoparticles produced by both Gram-negative and Gram-positive bacteria. As they originate from the outer surface of the bacteria, their composition and content is generally similar to the parent bacterium's membrane and cytoplasm. However, there is ample evidence that preferential packaging of proteins, metabolites, and toxins into vesicles does occur. Incorporation into vesicles imparts a number of benefits to the cargo, including protection from degradation by other bacteria, the host organism, or environmental factors, maintenance of a favorable microenvironment for enzymatic activity, and increased potential for long-distance movement. This enables vesicles to serve specialized functions tailored to changing or challenging environments, particularly in regard to microbial community interactions including quorum sensing, biofilm formation, antibiotic resistance, antimicrobial peptide expression and deployment, and nutrient acquisition. Additionally, based on their contents, vesicles play crucial roles in host-microbe interactions as carriers of virulence factors and other modulators of host cell function. Here, we discuss recent advances in our understanding of how vesicles function as signals both within microbial communities and between pathogenic or commensal microbes and their mammalian hosts. We also highlight a few areas that are currently ripe for additional research, including the mechanisms of selective cargo packaging into membrane vesicles and of cargo processing once it enters mammalian host cells, the function of vesicles in transfer of nucleic acids among bacteria, and the possibility of engineering commensal bacteria to deliver cargo of interest to mammalian hosts in a controlled manner.
细菌膜泡是革兰氏阴性菌和革兰氏阳性菌产生的蛋白脂质体纳米颗粒。由于它们起源于细菌的外表面，其组成和内容物通常与亲代细菌的膜和细胞质相似。然而，有充分的证据表明，蛋白质、代谢物和毒素确实会优先被包装到膜泡中。被纳入膜泡为所载物质带来了许多好处，包括免受其他细菌、宿主生物体或环境因素的降解，维持有利于酶活性的微环境，以及增加长距离移动的可能性。这使得膜泡能够发挥专门的功能，以适应不断变化或具有挑战性的环境，特别是在微生物群落相互作用方面，包括群体感应、生物膜形成、抗生素抗性、抗菌肽表达和释放以及营养获取。此外，基于其内容物，膜泡作为毒力因子和宿主细胞功能的其他调节剂的载体，在宿主 - 微生物相互作用中发挥关键作用。在这里，我们讨论了我们对膜泡如何在微生物群落内部以及在致病或共生微生物与其哺乳动物宿主之间作为信号发挥作用的理解的最新进展。我们还强调了目前几个有待进一步研究的领域，包括选择性地将所载物质包装到膜泡中的机制以及所载物质进入哺乳动物宿主细胞后的处理机制、膜泡在细菌间核酸转移中的功能，以及改造共生细菌以可控方式将感兴趣的物质递送至哺乳动物宿主的可能性。
