Novel Vaccines To Evoke Bladder Mucosal Immunity

描述（由申请人提供）：尿路感染（UTI）是第二大最常见的传染病，造成重大的患者发病率和经济影响。大约一半的女性在其一生中会遭受尿路感染，其中约25%的人会遭受复发性尿路感染（rUTI），这表明患者之间的宿主易感性存在差异。尿路致病性大肠杆菌（UPEC）引起大约90%的社区获得性尿路感染，但多种细菌如变形杆菌、铜绿假单胞菌和肺炎克雷伯菌通常与复杂的尿路感染有关。由于现在已知UPEC和其他细菌可以在小鼠和男性的膀胱尿上皮细胞内建立稳定的细胞内储存库，一种新兴的范式是这种细胞内细菌储存库是rUTI的基础。人们对膀胱中的适应性免疫知之甚少，以前对尿路感染疫苗的尝试被证明是略微成功的。我们最近开发了一种小鼠尿路感染再感染模型，以表征对UPEC的免疫反应，该模型基于UPEC分离物原型NU14的感染，该模型通过导管引入小鼠膀胱腔。通过这个模型，我们证明了T细胞和抗体都介导了针对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突变体，该突变体对尿路感染具有高度减毒作用。初步研究表明，该NU14突变体对膀胱和肾脏具有显著的保护作用，可抵抗野生型NU14或系统发育不同的UPEC菌株的后续攻击，并表明其根除细胞内UPEC储存库的能力增强。因此，我们假设致病细菌的waaL突变代表了一种新型疫苗，可以通过激发增强的细胞介导反应来消除细胞内储存库，从而保护膀胱免受rUTI的侵害。为了验证这一假设，我们将追求三个目标。在Aim 1中，我们将确定NU14-?waaL诱导的保护性免疫成分。在Aim 2中，我们将证实waaL疫苗对复杂的UTI病原体变形杆菌、克雷伯氏菌和假单胞菌的推广作用。在Aim 3中，我们将量化在尿外部位接种waaL疫苗诱导的免疫反应。因此，我们的研究不仅对RFA有高度反应，而且为开发新型疫苗来预防UTI铺平了道路。在美国，数以百万计的患者患有尿路感染，造成了严重的发病率和医疗保健系统的负担。尽管感染的患病率很高，但对膀胱免疫反应知之甚少，也没有有效的疫苗来预防感染。这个项目将描述免疫反应对一类新型疫苗治疗尿路感染。

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.