{"title":"<b>Functional characteristics of membrane vesicles produced by</b> <i><b>Streptococcus mitis</b></i>.","authors":"Airi Matsumoto, Yuichi Oogai, Haruka Kurashige, Tomoko Sumitomo, Atsushi Tabata, Masanobu Nakata","doi":"10.1080/20002297.2025.2557962","DOIUrl":null,"url":null,"abstract":"<p><strong>Objective: </strong>Mitis group streptococci (MGS) are the predominant oral bacteria that cause bacteremia and infective endocarditis. Although membrane vesicle (MV) secretion has been reported in <i>Streptococcus pneumoniae</i> among MGSs, comprehensive studies using various streptococcal species are limited. We aimed to determine whether MGS species produce MVs and to examine their biological functions.</p><p><strong>Materials and methods: </strong>MVs were isolated from MGS cultures using density gradient ultracentrifugation. The particle sizes of MVs were measured, and proteins in MVs were identified by liquid-chromatography tandem mass spectrometry analysis. Effects of MVs on host cells and oral pathogenic bacteria were investigated.</p><p><strong>Results: </strong>MV production was confirmed in <i>Streptococcus mitis</i> strains NCTC12261, Nm-65, and Nm-76, with particle diameters ranging from 100 to 120 nm. The MVs contained numerous cytoplasmic proteins. The MVs showed internalization into alveolar epithelial cells and induced the production of multiple cytokines, including TNF-<i>α</i>, IL-8, IL-6, IL-1β, and IL-10, in macrophages while suppressing phagocytic activity. In neutrophil-differentiated cells, MVs induced IL-8 but not TNF-<i>α</i> production. MVs from <i>S. pneumoniae</i> TIGR4 and <i>S. mitis</i> Nm-65 inhibited biofilm formation of <i>Aggregatibacter actinomycetemcomitans</i>.</p><p><strong>Conclusions: </strong>MVs play crucial roles in MGS survival strategies through immune modulation and interspecies competition, contributing to their pathogenicity and host-pathogen interactions.</p>","PeriodicalId":16598,"journal":{"name":"Journal of Oral Microbiology","volume":"17 1","pages":"2557962"},"PeriodicalIF":5.5000,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12459155/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Oral Microbiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1080/20002297.2025.2557962","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Objective: Mitis group streptococci (MGS) are the predominant oral bacteria that cause bacteremia and infective endocarditis. Although membrane vesicle (MV) secretion has been reported in Streptococcus pneumoniae among MGSs, comprehensive studies using various streptococcal species are limited. We aimed to determine whether MGS species produce MVs and to examine their biological functions.
Materials and methods: MVs were isolated from MGS cultures using density gradient ultracentrifugation. The particle sizes of MVs were measured, and proteins in MVs were identified by liquid-chromatography tandem mass spectrometry analysis. Effects of MVs on host cells and oral pathogenic bacteria were investigated.
Results: MV production was confirmed in Streptococcus mitis strains NCTC12261, Nm-65, and Nm-76, with particle diameters ranging from 100 to 120 nm. The MVs contained numerous cytoplasmic proteins. The MVs showed internalization into alveolar epithelial cells and induced the production of multiple cytokines, including TNF-α, IL-8, IL-6, IL-1β, and IL-10, in macrophages while suppressing phagocytic activity. In neutrophil-differentiated cells, MVs induced IL-8 but not TNF-α production. MVs from S. pneumoniae TIGR4 and S. mitis Nm-65 inhibited biofilm formation of Aggregatibacter actinomycetemcomitans.
Conclusions: MVs play crucial roles in MGS survival strategies through immune modulation and interspecies competition, contributing to their pathogenicity and host-pathogen interactions.
期刊介绍:
As the first Open Access journal in its field, the Journal of Oral Microbiology aims to be an influential source of knowledge on the aetiological agents behind oral infectious diseases. The journal is an international forum for original research on all aspects of ''oral health''. Articles which seek to understand ''oral health'' through exploration of the pathogenesis, virulence, host-parasite interactions, and immunology of oral infections are of particular interest. However, the journal also welcomes work that addresses the global agenda of oral infectious diseases and articles that present new strategies for treatment and prevention or improvements to existing strategies.
Topics: ''oral health'', microbiome, genomics, host-pathogen interactions, oral infections, aetiologic agents, pathogenesis, molecular microbiology systemic diseases, ecology/environmental microbiology, treatment, diagnostics, epidemiology, basic oral microbiology, and taxonomy/systematics.
Article types: original articles, notes, review articles, mini-reviews and commentaries