FIMH ADHESIN VACCINES TO PREVENT URINARY TRACT INFECTION

细菌附着在宿主上皮上是一个重要的早期事件 大肠杆菌尿路感染的发病机制。这个附件 由与杂聚体相关的粘附素蛋白介导 细菌表面的纤维状结构，称为菌毛。的 菌毛远端尖端粘附素的鉴定提供了 作为疫苗开发的重要新目标，作为早期尝试使用 整个pili并没有成功地抵御广泛的 致病细菌分离株。 泌尿道致病性大肠杆菌能够产生多种粘附素，例如 以及菌毛类型，它们赋予宿主细胞受体特异性 病原体。这些结构决定了组织向性、位点 泌尿生殖道内的定植，以及由此产生的疾病 由感染引起。与类型相关的 FimH 粘附素 l -菌毛与 α-D-甘露糖苷糖缀合物结合，该糖缀合物在 膀胱上皮。流行病学和实验证据支持 L型毛状大肠杆菌在膀胱炎发展中的作用。我们有 最近发现专门针对两种形式的抗体 纯化的 FimH 粘附素可防止 L 型毛状大肠杆菌与 a- 结合 D-甘露糖苷受体，通过抑制凝集来测量 豚鼠红细胞和 L 型毛毛附着阻断 大肠杆菌在体外对人膀胱细胞的作用。此外，FimH 衍生的 疫苗导致尿路致病菌在膀胱的定植减少 小鼠膀胱炎模型体内 L 型毛状大肠杆菌的分离株。这些 数据表明，针对粘附素的抗菌疫苗可能会阻断 体内附着，可能是预防复发和急性发作的一种手段 尿路感染。我们这项研究的目标是：1.) 评估第三种基于 FimH 的候选疫苗，即 l 型尖端纤维，该疫苗 应诱导针对结合域的最大保护性免疫 该凝集素基于该复合物中 FimH 的构象，2.) 至 通过多项试验测定了三种疫苗中最好的候选 FimH 疫苗 佐剂包括明矾、MF-59 和 rBCG，以确定哪种佐剂 刺激最佳的功能性免疫反应（体外测量） 和体内，以及 3.) 测试针对最佳候选者的抗血清 FimH 疫苗可针对多种疾病进行体外功能活性 原发性尿路致病性大肠杆菌临床分离株。 拟议的商业应用：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，这是最有效的疫苗之一 需要就医的常见疾病。粘膜佐剂是 测试可能会刺激粘膜和体液免疫反应 泌尿道致病细菌。

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.