Host immunity and cellular responses to bacterial outer membrane vesicles

• Published in: Trends in immunology Vol. 42; no. 11; pp. 1024 - 1036
• Main Authors: Tiku, Varnesh, Tan, Man-Wah
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2021; Elsevier Limited
• Subjects: adaptive immunity; Animals; Apoptosis; Bacteria; Bacterial infections; Bacterial Outer Membrane; Bacterial physiology; Bacterial vesicles; Biosynthesis; Colonization; Cytokines; E coli; Gram-negative bacteria; Gram-Negative Bacteria - metabolism; Humans; immune evasion; Immune response; immune responses; Infections; innate immunity; Lipopolysaccharides; Mammals; Membrane vesicles; Membranes; outer membrane vesicles; Pathogenesis; Pathogens; Phospholipids; Proteins; Vertebrates; Vesicles; Virulence; Virulence factors; Virulence Factors - metabolism; Gram-negative bacteria; outer membrane vesicles; innate immunity; immune evasion; adaptive immunity; immune responses
• ISSN: 1471-4906; 1471-4981
• DOI: 10.1016/j.it.2021.09.006

All Gram-negative bacteria produce outer membrane vesicles (OMVs) which are minute spherical structures emanating from the bacterial outer membrane. OMVs are primarily enriched in lipopolysaccharide (LPS) and phospholipids, as well as outer membrane and periplasmic proteins. Recent research has provided convincing evidence for their role in multiple aspects of bacterial physiology and their interaction with vertebrate host cells. OMVs play vital roles in bacterial colonization, delivery of virulence factors, and disease pathogenesis. Here, we discuss the interactions of OMVs with mammalian host cells with a focus on how bacteria use OMVs to modulate host immune responses that eventually enable bacteria to evade host immunity. All Gram-negative bacteria secrete outer membrane vesicles (OMVs) that contain components of the bacterial outer membrane, including lipopolysaccharide and outer membrane proteins.Bacteria use OMVs to deliver toxins into host cells that can modulate host cell homeostasis and induce cytopathic effects.Epithelial cells and myeloid cells recognize pathogen-associated molecular patterns (PAMPs) present in OMVs and trigger innate immune signaling leading to the secretion of proinflammatory cytokines.OMVs can also trigger adaptive immune responses by activating T and B cells.