Chemistry and Immunology of Streptococcal M Proteins

该项目的总体目标是开发一种安全和广泛有效的疫苗， 感染.先前的研究表明，作为主要保护性抗原的表面M蛋白含有 组织交叉反应性表位以及保护性表位。表型特异性保护性表位可以分离， 从潜在有害的自身免疫表位通过使用有限的N-末端肽的M蛋白。保护M 然后可以将代表A组链球菌的多种血清型的蛋白片段组合以形成多价的 疫苗本研究的具体目标是：1）鉴定M蛋白或其他表面蛋白的一级结构 含有来自A组链球菌血清型的调理（保护）表位的蛋白质， 2）为了构建重组多价疫苗， 实验室动物对26种不同血清型A组链球菌的最佳调理素抗体应答，3） 测试由多价疫苗诱发的免疫兔血清针对临床分离株的调理素和杀菌抗体， 从美国10个地理位置的咽炎儿童中收集的A组链球菌，4)制定战略 鼻内递送多价M蛋白基疫苗导致分泌和全身免疫应答， 和5）为了直接比较通过免疫调节剂递送至小鼠的基于多价M蛋白的疫苗的保护性免疫原性， 肌肉内或鼻内途径。在我们的初步研究中，我们已经确定了六个流行病学 不被抗N-末端M蛋白肽的抗血清调理的A组链球菌的重要血清型。 我们提出了一系列的实验，以确定M蛋白，M样蛋白，或其他的共价结构， 含有调理素表位的表面蛋白，使得这些M血清型可以包括在多价疫苗中。我们 将构建由4种不同的重组杂交蛋白组成的26价疫苗。单个杂交蛋白 将在兔肌内注射后测试保护性和组织交叉反应免疫原性。因为 链球菌疫苗的粘膜递送可能比胃肠外递送具有免疫学和实际优点 递送，我们将评估鼻内递送的不同策略，然后直接比较i.n. 与肌内注射相比小鼠的疫苗这些研究应提供开发安全有效的 这种多价疫苗可以预防北美和西欧的大多数链球菌感染。

The overall goal of this project is to develop a safe and broadly effective vaccine that will prevent group A streptococcal infections. Previous studies have shown that the surface M proteins, which are the major protective antigens, contain tissue-crossreactive epitopes as well as protective epitopes. The serotype-specific protective epitopes may be separated from potentially harmful autoimmune epitopes by using limited N-terminal peptides of M proteins. The protective M protein fragments representing multiple serotypes of group A streptococci may then be combined to form a multivalent vaccine. The specific aims of this proposal are: 1) To identify the primary structures of M proteins or other surface proteins that contain opsonic (protective) epitopes from serotypes of group A streptococci that areepidemiologically important and, therefore, necessary vaccine components, 2) To construct recombinant, multivalent vaccines that evoke optimal opsonic antibody responses in laboratory animals against 26 different serotypes of group A streptococci, 3) To test immune rabbit sera evoked by multivalent vaccines for opsonic and bactericidal antibodies against clinical isolates of group A streptococci collected from children with pharyngitis in 10 geographic sites in the U.S., 4) To develop strategies of intranasal delivery of multivalentM protein-based vaccines that result in secretory and systemic immune responses, and 5) To directly compare the protective immunogenicity of multivalent M protein-based vaccines delivered to mice via either the intramuscular or intranasal routes. In our preliminary studies, we have identified six epidemiologically important serotypes of group A streptococci that are not opsonized by antisera against the N-terminalM protein peptides. We propose a series of experiments to determine the covalent structures of the M proteins, M-like proteins, or other surface proteins that contain opsonic epitopes so that these M serotypes may be included in multivalent vaccines. We will construct a 26-valent vaccine composed of 4 different recombinant, hybrid proteins. The individual hybrid proteins will be tested for protective and tissue-crossreactive immunogenicity after intramuscular injection of rabbits. Because mucosal delivery of streptococcal vaccines may have both immunological and practical advantages over parenteral delivery, we will assess different strategies of intranasal delivery and then directly compare the protective efficacy of i.n. vs i.m. vaccines in mice. The studies should provide the detailed information needed to develop a safe and effective multivalent vaccine that could prevent the majority of streptococcal infections in North America and Western Europe.