Department of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, 252-0880, Japan; Department of Bacteriology, National Institute of Infectious Diseases, Tokyo, 162-8640, Japan.
Department of Bacteriology, National Institute of Infectious Diseases, Tokyo, 162-8640, Japan.
Microb Pathog. 2020 Dec;149:104260. doi: 10.1016/j.micpath.2020.104260. Epub 2020 Jun 15.
Glucosyltransferase (Gtf) B and GtfC from Streptococcus mutans are key enzymes for the development of biofilm-associated diseases such as dental caries. Gtfs are involved in membrane vesicles (MVs) and function in the formation of biofilms by initial colonizers such as Streptococcus mitis and Streptococcus oralis on the tooth surface. Therefore, MVs may be important virulence factors and targets for the prevention of biofilm-associated disease. To clarify how GtfB encoded by gtfB and GtfC encoded by gtfC associate with MVs and whether MVs are effective as a mucosal immunogen to induce the production of antibodies against Gtfs, MVs from S. mutans UA159 wild-type (WT), gtfB, gtfC and gtfBC were extracted from culture supernatants by ultracentrifugation and observed by scanning electron microscopy. Compared with GtfB, GtfC was mainly contained in MVs and regulated the size and aggregation of MVs, and the biofilm formation of S. mutans. The intranasal immunization of BALB/c mice with MVs plus a TLR3 agonist, poly(I-C), was performed 2 or 3 times for 5 weeks, with an interval of 2 or 3 weeks. MVs from all strains caused anti-MV IgA and IgG antibody production. In quality analysis of these antibodies, the IgA and IgG antibodies produced by immunization with MVs from WT and gtfB strains reacted with Gtfs in the saliva, nasal wash and serum but those produced by immunization with MVs from gtfC and gtfBC strains did not. S. mutans MVs mainly formed by GtfC are an intriguing immunogen for the production of anti-Gtf antibodies in mucosal immunogenicity.
葡糖基转移酶（Gtf）B 和 GtfC 来自变形链球菌是生物膜相关疾病如龋齿发展的关键酶。Gtfs 参与膜泡（MVs）的形成，并通过在牙齿表面的初始定植者如变形链球菌和口腔链球菌的作用，在生物膜的形成中发挥作用。因此，MVs 可能是重要的毒力因子和生物膜相关疾病预防的靶标。为了阐明由 gtfB 编码的 GtfB 和由 gtfC 编码的 GtfC 如何与 MVs 相关联，以及 MVs 是否作为粘膜免疫原有效地诱导针对 Gtfs 的抗体产生，通过超速离心从培养上清液中提取 S. mutans UA159 野生型（WT）、gtfB、gtfC 和 gtfBC 的 MVs，并通过扫描电子显微镜观察。与 GtfB 相比，GtfC 主要包含在 MVs 中，调节 MVs 的大小和聚集，并调节变形链球菌的生物膜形成。通过鼻腔内免疫接种 BALB/c 小鼠 2 或 3 次 5 周，间隔 2 或 3 周，用 MVs 加 TLR3 激动剂 poly（I-C）进行。所有菌株的 MVs 均可引起抗-MV IgA 和 IgG 抗体的产生。在这些抗体的质量分析中，用 WT 和 gtfB 株 MVs 免疫产生的 IgA 和 IgG 抗体与唾液、鼻腔冲洗液和血清中的 Gtfs 反应，但用 gtfC 和 gtfBC 株 MVs 免疫产生的抗体则不反应。主要由 GtfC 形成的 S. mutans MVs 是粘膜免疫原性中产生抗 Gtf 抗体的一种有趣的免疫原。
