Probiotic Lactobacilli and Vaginal Epithelium

描述（由申请人提供）：尿路感染（uti）最常由大肠杆菌引起，在所有年龄段的女性中都很常见。最近尿路病原体中抗菌素耐药性的增加刺激了人们对替代抗生素预防和治疗尿路感染的非抗菌素方法的兴趣。尿路感染发生之前，阴道菌群发生了特定的改变。通常由乳杆菌种主导，阴道微微菌在尿路感染发展之前就被大肠杆菌定植。阴道乳酸菌的消耗与大肠杆菌和其他病原体在阴道定植有关，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阴道乳杆菌栓剂L crispatus CTV-05在预防尿路感染复发方面的功效（DK53369）。然而，介导阴道乳酸杆菌益生菌菌株保护的机制尚未系统研究。该建议的中心假设是阴道乳酸菌，如这种益生菌分离物crispatus CTV-05，利用特定机制保护阴道上皮免受尿路致病性大肠杆菌等病原体的侵害。我们将使用crispatus cv -05、我们收集的其他分离株和原代培养的阴道上皮细胞来研究以下特定假设：(1)乳酸菌使用特异性粘附分子粘附阴道上皮，并通过竞争性抑制保护尿路致病性大肠杆菌的粘附，包括与阴道上皮细胞（VECs）上常见的globoseries GSL受体结合。粘附也可以通过s层介导；(2)乳酸菌在体外通过产生HZO2和细菌素样物质杀死尿路致病性大肠杆菌，并通过共聚集抑制尿路致病性大肠杆菌的生长；(3)乳酸菌附着于阴道上皮后诱导修复和屏障功能基因，而大肠杆菌等病原体则诱导促炎基因。这些研究将对理解正常菌群和益生菌在阴道微微孔和其他上皮表面（如胃肠道和上呼吸道）的保护机制具有重要意义，并将为合理设计和/或增强益生菌提供建议。

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.