Novel Vaccines To Evoke Bladder Mucosal Immunity

描述(由申请人提供)：尿路感染(UTI)是第二种最常见的传染病，会导致严重的患者发病率和经济影响。大约一半的女性在一生中将遭受尿路感染，其中约25%的人将遭受复发性尿路感染(RUTI)，这表明不同患者的宿主易感性存在差异。近90%的社区获得性尿路感染是由致尿性大肠埃希菌(UPEC)引起的，但各种细菌如奇异变形杆菌、铜绿假单胞菌和肺炎克雷伯菌等常与复杂的尿路感染相关。由于UPEC和其他细菌现在已知在小鼠和人的膀胱尿路上皮细胞内建立稳定的细胞内储存库，一个新兴的范例是这种细胞内储存库是RUTI的基础。人们对膀胱的获得性免疫知之甚少，之前针对尿路感染疫苗的尝试也被证明是微乎其微的成功。我们最近建立了一种小鼠UTI再感染模型来表征对UPEC的免疫反应，该模型基于UPEC的原型分离株NU14的感染，该分离株通过导管被引入小鼠的膀胱腔。利用这个模型，我们证明了T细胞和抗体都介导了对NU14感染的保护性免疫。在平行研究中，我们还发现了Waal基因中的NU14突变，该突变对尿路感染具有高度减毒作用。初步研究表明，NU14突变体可显著保护膀胱和肾脏免受野生型NU14或系统发育不同的UPEC菌株的攻击，并表明其消除细胞内UPEC储存库的能力增强。因此，我们假设，病原菌的Waal突变代表了保护膀胱免受Ruti感染的新型疫苗，其机制是通过激发能够消除细胞内储藏的增强细胞中介反应。为了验证这一假设，我们将追求三个目标。在目标1中，我们将确定NU14-Waal诱导的保护性免疫的成分。在目标2中，我们将确认Waal疫苗对复杂的尿路感染病原体变形杆菌、克雷伯氏菌和假单胞菌的普适性。在目标3中，我们将量化在尿外部位接种Waal疫苗所引起的免疫反应。因此，我们的研究既对RFA高度敏感，又为新型疫苗预防UTI铺平了道路。在美国，数以百万计的患者患有尿路感染，导致严重的发病率和医疗系统的负担。尽管感染率很高，但人们对膀胱免疫反应知之甚少，也没有有效的疫苗来预防感染。该项目将表征对一类治疗尿路感染的新型疫苗的免疫反应。

DESCRIPTION (provided by applicant): Urinary tract infection (UTI) is the second most common infectious disease and causes significant patient morbidity and economic impact. Approximately half of all women will suffer a UTI during their lifetime, and about 25% of those will suffer recurrent UTIs (rUTI), suggesting differences in host susceptibility between patients. Uropathogenic E. coli (UPEC) cause approximately 90% of community-acquired UTIs, but diverse bacteria such as Proteus mirabilis, Pseudomonas aeruginosa, and Klebsiella pneumoniae are often associated with complicated UTIs. Since UPEC and other bacteria are now known to establish stable intracellular reservoirs within bladder uroepithelial cells in mice and men, an emerging paradigm is that such intracellular bacterial reservoirs underlie rUTI. Little is known of adaptive immunity in the bladder, and previous attempts at vaccines for UTI have proven marginally successful. We recently developed a murine re-infection model of UTI to characterize immune responses to UPEC, based on infection with the prototypical UPEC isolate NU14 that is introduced into the bladder lumen of mice via catheter. Using this model, we demonstrated that both T cells and antibodies mediate protective immunity against NU14 infection. In parallel studies, we also identified an NU14 mutant in the waaL gene that is highly attenuated for infection of the urinary tract. Preliminary studies demonstrate that this NU14 mutant confers significant protection of both the bladder and kidneys against subsequent challenge with either wild type NU14 or phylogenetically diverse UPEC strains and suggest an enhanced capacity to eradicate intracellular UPEC reservoirs. Therefore, we hypothesize that waaL mutations of pathogenic bacteria represent novel vaccines for protecting the bladder from rUTI by eliciting enhanced cell-mediated responses capable of eliminating intracellular reservoirs. To test this hypothesis, we will pursue three aims. In Aim 1, we will determine components of protective immunity induced by NU14-?waaL. In Aim 2, we will confirm the generalizability of waaL vaccines to the complicated UTI pathogens Proteus, Klebsiella, and Pseudomonas. In Aim 3, we will quantify immune responses induced by administration of waaL vaccines at extra-urinary sites. Thus, our study is both highly responsive to the RFA and paves the way for novel vaccines to protect against UTI. Millions of patients in the U.S. suffer urinary tract infection, causing significant morbidity and burden on the healthcare system. Despite the high prevalence of infection, little is known about the bladder immune response, and no effective vaccines exist to prevent infection. This project will characterize immune responses to a novel class of vaccines to treat urinary tract infection.