FIMH ADHESIN VACCINES TO PREVENT URINARY TRACT INFECTION

细菌附着在宿主上皮细胞是一种重要的早期事件 大肠埃希菌尿路感染的发病机制。此附件 是由与杂多聚体相关的粘附素蛋白介导的 细菌表面的纤维状结构，称为菌毛。这个 毛端末端粘附素的鉴定提供了一种 疫苗开发的重要新靶点作为早期尝试使用 整个菌毛都不能成功地抵御广泛的 致病细菌分离株。 致泌尿系统的大肠杆菌能够产生多种粘附素，如 以及菌毛类型，它们将宿主细胞受体特异性地授予 病原体。这些结构决定了组织的趋向性，部位 在泌尿生殖道内的定植，以及由此导致的疾病 因感染而产生。与该类型关联的FimH粘附素 L-菌毛与α-D-甘露糖苷糖偶联物结合 膀胱上皮细胞。流行病学和实验证据支持 L纤毛大肠杆菌在膀胱炎发生发展中的作用我们有 最近发现，针对两种形式的 纯化的FimH粘附素阻止L毛状埃希氏菌与α-DNA结合 D-甘露糖苷受体，通过抑制凝集测定 L纤毛型豚鼠红细胞及其粘附性的阻断 大肠埃希菌对人膀胱细胞的体外杀伤作用。此外，FimH派生的两个 疫苗导致泌尿系病原体对膀胱的定植减少 L纤毛大肠杆菌在小鼠膀胱炎模型中的体内分离这些 数据显示，针对粘附素的抗菌疫苗可能会阻止 体内依附，可能是预防复发和急性 尿路感染。我们研究的目标是：1.)至 评估第三种基于FIMH的候选疫苗，L尖端纤毛，它 应诱导针对结合区域的最大保护性免疫 根据FimH在该复合体中的构象，确定了该凝集素的结构。)至 对三种疫苗中最好的候选FimH疫苗进行测试 佐剂包括明矾、MF-59和rBCG，以确定哪种佐剂 刺激最好的功能性免疫反应，在体外测量 和活体内，以及3)测试针对最好的候选人而产生的抗血清 FIMH疫苗对多种流行性感冒的体外功能活性 原发泌尿系致病大肠杆菌临床分离株。 建议的商业应用：这些研究可能会导致开发 一种针对细菌性尿路感染的疫苗，这是世界上最 促使医生注意的常见疾病。粘膜佐剂是 试验可刺激粘膜和体液免疫反应，以对抗 尿失禁细菌。

Bacterial attachment to host epithelium is an important early event in the pathogenesis of Escherichia coli urinary tract infections. This attachment is mediated by adhesin proteins that are associated with heteropolymeric fiber-like structures on the bacterial surface, called pili. The identification of tip adhesins at the distal end of pili provides an important novel target for vaccine development as early attempts to use whole pili were not successful in protecting against a broad range of pathogenic bacterial isolates. Uropathogenic E.coli are capable of producing a variety of adhesins as well as pilus types, which confer host cell receptor specifically to the pathogens. These structures dictate the tissue tropism, sites of colonization within the urogenital tract, and the resultant diseases that ensue from infection. The FimH adhesin which is associated with the type l -pilus binds to alpha-D-mannoside glycoconjugates which are abundant on bladder epithelium. Epidemiological and experimental evidence supports a role for type l -piliated E.coli in the development of cystitis. We have recently found that antibody raised specifically against two forms of the purified FimH adhesin prevents type l -piliated E.coli from binding to a- D-mannoside receptors, as measured by inhibition of agglutination of guinea pig erythrocytes and blocking of attachment by type l -piliated E.coli to human bladder cells in vitro. Furthermore, both the FimH-derived vaccines resulted in reduced colonization of the bladder by uropathogenic isolates of type l-piliated E.coli in vivo in murine cystitis model. These data suggest that anti-bacterial vaccines targeting adhesins may block attachment in vivo, and may be a means of preventing recurrent and acute urinary tract infections. Our objectives in this study are: 1.) to evaluate a third FimH-based vaccine candidate, type l tip fibrillae, which should induce maximal protective immunity, targeted to the binding domain of this lectin based on the conformation of FimH in this complex, 2.) to assay the best candidate FimH vaccine among the three with a number of adjuvants including alum, MF-59 and rBCG to determine which adjuvant stimulates the best functional immune response as measured both in vitro and in vivo, and 3.) to test antisera raised against the best candidate FimH vaccine for in vitro functional activity against a wide range of primary uropathogenic E.coli clinical isolates. PROPOSED COMMERCIAL APPLICATION: These studies may lead to the development of a vaccine against bacterial urinary tract infections, one of the most common disorders prompting medical attention. The mucosal adjuvants being tested may stimulate mucosal as well as humoral immune responses against uropatheogenic bacteria.