Probiotic Lactobacilli and Vaginal Epithelium

描述(由申请人提供)：尿路感染(UTI)是最常见的由大肠杆菌引起的，在所有年龄段的女性中都很常见。最近尿路病原菌耐药性的增加激发了人们对替代抗生素预防和治疗尿路感染的非抗菌方法的兴趣。在尿路感染之前，阴道菌群会发生特殊的变化。通常以乳杆菌为主，在UTI发生之前，阴道微核菌就会被大肠杆菌定植。阴道乳酸菌的枯竭与大肠杆菌和其他病原体在阴道的定植有关，增加了尿路感染和某些性传播疾病的风险。一项正在进行的临床研究正在调查一种名为L的乳杆菌阴道栓剂预防尿路感染复发的疗效。然而，乳酸菌在阴道中的益生菌菌株介导保护的机制尚未被系统地研究。这一提议的中心假设是，阴道乳杆菌，如这种益生菌L，利用特殊的机制来保护阴道上皮免受致尿性大肠杆菌等病原体的侵袭。我们将使用皱纹乳杆菌CTV-05、我们收集的其他分离物和原代培养的阴道上皮细胞来研究以下具体假设：(1)乳杆菌使用特定的黏附分子附着在阴道上皮细胞上，并通过竞争抑制(包括通过与阴道上皮细胞(VECs)上常见的球形系列GSL受体结合)来防止致尿性大肠杆菌的黏附。黏附也可能通过S层介导；(2)乳杆菌在体外通过产生HZO_2和细菌素样物质在体外杀死致尿系大肠杆菌，并通过共聚集抑制致尿系大肠杆菌的生长；以及(3)乳杆菌在与阴道上皮黏附时诱导修复和屏障功能基因，而不是像大肠杆菌这样的病原体诱导促炎基因。这些研究将对了解正常菌群和益生菌在阴道微粒子以及其他上皮表面(如胃肠道和上呼吸道)的保护机制具有重要意义，并将建议合理设计和/或增强益生菌。

DESCRIPTION (provided by applicant): Urinary tract infections (UTIs) are most frequently caused by Escherichia coli and are common among women of all ages. Recent increases in antimicrobial resistance among uropathogens have stimulated interest in alternative, non-antimicrobial methods of preventing and treating UTI in lieu of antibiotics. UTI is preceded by specific alterations in the vaginal flora. Normally dominated by Lactobacillus species, the vaginal microniche becomes colonized with E. coli prior to the development of UTI. Depletion of vaginal lactobacilli is associated with vaginal colonization with E. coli and other pathogens, increasing the risk of UTI and certain sexually transmitted diseases. An ongoing clinical study is investigating the efficacy of a vaginal Lactobacillus suppository, L crispatus CTV-05, in preventing recurrent UTI (DK53369). However, the mechanisms that mediate protection by probiotic strains of Lactobacillus in the vagina have not been systematically investigated. The central hypothesis of this proposal is that vaginal lactobacilli such as this probiotic isolate L crispatus CTV-05 utilize specific mechanisms in protecting the vaginal epithelium against pathogens such as uropathogenic E. coli. We will investigate the following specific hypotheses, using L. crispatus CTV-05, additional isolates from our collections, and primary cultured vaginal epithelial cells: (1) Lactobacilli adhere to the vaginal epithelium using specific adherence molecules and protect against adherence of uropathogenic E. coli via competitive inhibition, including by binding to common globoseries GSL receptors on vaginal epithelial cells (VECs). Adherence may also be mediated via S-layers; (2) Lactobacilli kill uropathogenic E. coli in vitro via production of HZO2 and bacteriocin-like substances and inhibits growth of uropathogenic E. coli via co-aggregation; and (3) Lactobacilli induce repair and barrier function genes upon adherence to vaginal epithelium, in contrast with pathogens such as E. coli, which induce proinflammatory genes. These studies will have important implications for understanding mechanisms of protection by normal flora and probiotics in the vaginal microniche and at other epithelial surfaces such as the gastrointestinal and upper respiratory tracts and will suggest rational design and/or enhancement of probiotics.