Poly-N-acetyl glucosamine as a vaccine for bacterial pathogens

描述(申请人提供)：这项研究计划的长期目标是了解细菌聚N-乙酰氨基葡萄糖(PNAG)的免疫化学性质，并利用这些信息生产一种有效的疫苗，用于治疗多种革兰氏阳性和革兰氏阴性细菌病原体，这些病原体将PNAG表达为表面多糖。PNAG由许多临床分离的表皮葡萄球菌和几乎所有的金黄色葡萄球菌产生，金黄色葡萄球菌是院内细菌感染的两个最常见的原因，以及致病性大肠杆菌耶尔森氏菌。包括鼠疫耶尔森氏菌、波尔德氏菌。和放线杆菌属。所有这些生物都是人类和动物疾病的重要原因。当正常的高度乙酰化的PNAG分子(天然的PNAG，&gt；70%N-乙酰化)被脱乙酰化(DPNAG)，使得-lt；20%的氨基被乙酰化时，产生最佳的光学杀灭和对葡萄球菌的保护性免疫。在这项建议中，将这些发现扩展到致病性大肠杆菌和耶尔森氏菌。将开展针对本地PNAG和dPNAG的主动和被动疫苗接种，以确定该抗原作为广泛基础抗菌疫苗的效力。抗体活性将通过结合试验(ELISA)、补体沉积ELISA法、光学杀灭试验和感染动物的体内保护试验进行评估。进一步的目的是使用合成的？-1-6连接的氨基葡萄糖低聚物来确定与最大保护性抗体结合的表位的化学结构，并评估寡糖-蛋白质结合疫苗所产生的抗体的结合、调理和保护效果。针对天然PNAG和dPNAG的全人单抗将被研究作为被动预防的可能性，这些单抗的活性将通过核糖体或噬菌体展示技术在体外亲和成熟抗体来增强。从公共卫生的角度来看，主动或被动接种是控制传染病的最有效的策略，而含有表面蛋白结合的多糖抗原的疫苗在降低几种细菌病原体的感染率方面已经非常有效。由于PNAG是由多种不同的细菌病原体产生的，有效的PNAG疫苗可以显著减轻由葡萄球菌、大肠杆菌、耶尔森氏菌引起的社区获得性疾病和医院内疾病的负担。包括鼠疫的原因，可能还有其他产生PNAG的生物体。

DESCRIPTION (provided by applicant): The long-term goal of this research program is to understand the immunochemical properties of bacterial poly-N-acetyl glucosamine (PNAG) and utilize this information to produce an effective vaccine for multiple Gram-positive and Gram-negative bacterial pathogens that express PNAG as a surface polysaccharide. PNAG is produced by many clinical isolates of S. epidermidis and almost all strains of S. aureus, the two most common causes of nosocomial bacterial infection, as well as by pathogenic E. coli, Yersinia spp. including Y. pestis, Bordetella spp. and Actinobacillus spp. All of these organisms are significant causes of human and animal disease. Optimal opsonic-killing and protective immunity to Staphylococci is engendered when the normally highly acetylated PNAG molecule (native PNAG, >70% N-acetylated) is deacetylated (dPNAG) such that <20% of the amino groups are acetylated. In this proposal, extension of these findings to pathogenic E. coli and Yersinia spp. will be undertaken, using active and passive vaccination against native PNAG and dPNAG to determine the efficacy of this antigen as a broad-based antibacterial vaccine. Antibody activity will be evaluated by binding assays (ELISA), complement deposition ELISA, opsonic-killing assays, and in vivo protection of infected animals. Further aims are to use synthetic ?-1-6 linked glucosamine oligomers to define the chemical structure of the epitopes that bind to maximally protective antibody and evaluate the binding, opsonic and protective efficacy of antibodies elicited by oligosaccharide-protein conjugate vaccines. Fully human monoclonal antibodies to native PNAG and dPNAG will be investigated for potential as passive prophylactic agents and the activity of these Mabs will be enhanced using ribosome or phage display technology to affinity mature the antibodies in vitro. From a public health viewpoint, active or passive vaccination is the most effective strategy to control infectious diseases, and vaccines containing surface protein-conjugated polysaccharide antigens have been highly effective at reducing infection rates by several bacterial pathogens. Since PNAG is produced by multiple and diverse bacterial pathogens, an effective PNAG vaccine could lead to a significant reduction in the burden of both community acquired and nosocomial disease caused by Staphylococci, E. coli, Yersinia spp. including the cause of plague, and possibly other PNAG-producing organisms.