Multi-componet Vaccine for Staphylcoccus epidermidis

描述（由申请人提供）：凝固酶阴性葡萄球菌（con），特别是表皮葡萄球菌，是医院获得性感染的主要原因，由于生物膜形成和抗生素耐药性，治疗可能很困难。这种形成多层生物膜的能力部分依赖于被称为聚n -乙酰氨基葡萄糖（PNAG）的表面多糖的产生。先前的研究表明，PNAG是一种体内表达的抗原，是表皮葡萄球菌和金黄色葡萄球菌保护性免疫的靶点。然而，临床分离的con中PNAG的产量差异很大，这可能限制了这种表面聚合物作为抗葡萄球菌菌株疫苗的唯一成分的使用。因此，需要对其他潜在的候选疫苗进行研究。表皮葡萄球菌和其他相关的con精心制作，如细胞外聚合物，聚？- dl -谷氨酸（DL-PGA）促进人类宿主的生长和生存。这些聚合物也可由芽孢杆菌产生，包括地衣芽孢杆菌和炭疽芽孢杆菌，并且PGA抗体介导对炭疽的保护性免疫。初步研究表明，地衣芽孢杆菌dl - pga结合疫苗培养的小鼠抗体可以介导人多形核白细胞和补体对多种表皮芽孢杆菌菌株的杀伤。此外，调理吞噬细胞的杀伤与PNAG的产生无关，因为PNAG阳性和阴性的临床分离株都被类似地调理和杀伤。正在评估的主要假设是，针对表皮葡萄球菌的优化疫苗应该是多组分的，并包括PNAG和D-和/或l -谷氨酸的组合，以便最大限度地覆盖葡萄球菌临床分离株和/或从单个组分中获得协同效应。多种候选疫苗将被合成，包括高分子量的D-和L-PGA， 20聚体合成的D或L结构的PGA肽，以及与载体蛋白破伤风类毒素结合的dPNAG。体外调理噬细胞试验将作为潜在保护性抗体的第一个筛选。在小鼠导管感染模型中，将通过被动和主动免疫对多株con的攻击，进一步测试引发它们的高声音抗体和疫苗的免疫保护效果。从这些研究中获得的见解将有助于我们评估控制和预防con感染的免疫治疗策略。项目叙述：在过去的20年里，表皮葡萄球菌已经成为医院获得性感染中最常见的病原体之一。重要的是，许多表皮葡萄球菌菌株对常用的抗生素具有耐药性，这强调了寻找预防和治疗感染的新方法的必要性，例如为疫苗开发确定新的分子靶点。本申请旨在研究两种不同的表皮葡萄球菌表面聚合物，即聚dl -谷氨酸和去乙酰化聚n -乙酰氨基葡萄糖（dPNAG）单独或联合作为对抗该病原体的新疫苗成分的疫苗潜力。

DESCRIPTION (provided by applicant): Coagulase-negative staphylococci (CoNS), notably Staphylococcus epidermidis, are a predominant cause of hospital-acquired infections and treatment can be difficult owing to biofilm formation and antibiotic resistance. This ability to form a multi-layered biofilm depends, in part, on the production of the surface polysaccharide termed poly-N-acetyl-glucosamine (PNAG). Previous work has demonstrated that PNAG is an in vivo expressed antigen and the target for protective immunity for both S. epidermidis and Staphylococcus aureus. However, production of PNAG varies widely among clinical isolates of CoNS, potentially limiting the use for this surface polymer as the sole component of a vaccine against staphylococcal strains. Therefore, additional potential vaccine candidates need to be investigated. S. epidermidis and other related CoNS elaborate, as extracellular polymers, poly-?-DL-glutamic acid (DL-PGA) to facilitate growth and survival in the human host. These polymers are also produced by Bacillus spp., including B. licheniformis and more notably B. anthracis, and antibody to the PGA mediates protective immunity to anthrax. Preliminary work has shown that mouse antibodies raised to a B. licheniformis DL-PGA-conjugate vaccine can mediate killing of various S. epidermidis strains by human polymorphonuclear leukocytes and complement in an in vitro opsonophagocytic assay. Moreover, the opsonophagocytic killing was independent of PNAG production, as both PNAG positive and negative clinical isolates were similarly opsonized and killed. The major hypothesis being evaluated is that an optimized vaccine that would target S. epidermidis should be multi-component and include PNAG and D- and/or L-glutamic acid in combination in order to provide maximum coverage against staphylococcal clinical isolates and/or obtain a synergistic effect from the individual components. Multiple vaccines candidates will be synthesized including high molecular weight D- and L-PGA, 20-mer synthetic PGA peptides of either the D or L configuration and dPNAG conjugated to the carrier protein tetanus toxoid. The in vitro opsonophagocytic assay will be used as the first screen for potentially protective antibodies. Highly opsonic antibodies and vaccines that elicit them will be further tested for their immunoprotective efficacy by passive and active immunization against challenge with multiple strains of CoNS in a murine catheter-infection model. Insights gained by these studies will help us to evaluate immunotherapeutic strategies for control and prevention of infection by CoNS. Project Narrative: Over the past 2 decades, Staphylococcus epidermidis has become one of the most prevalent pathogens involved in hospital-acquired infections. Importantly many strains of S. epidermidis are resistant to commonly used antibiotics, underscoring the need to find new approaches to prevention and treatment of infection such as identifying novel molecular targets for vaccine development. This application proposes to investigate the vaccine potential of two different S. epidermidis surface polymers termed poly-DL-glutamic acid and deacetylated poly-N-acetyl-glucosamine (dPNAG) either alone or in combination as components of a novel vaccine against this pathogen.