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，以预防A组链球菌 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 组织交叉反应表位和保护性表位。可以分离出血清型特异性保护性表位 通过使用M蛋白的有限N端肽来防止潜在有害的自身免疫表位。保护性的M 然后，可以将代表A组链球菌的多种血清型的蛋白质片段结合起来形成多价 疫苗。这项提议的具体目的是：1)确定M蛋白或其他表面的一级结构 含有A组链球菌血清型的调理(保护性)表位的蛋白质 重要的，因此，必要的疫苗组件，2)构建重组多价疫苗，唤起 实验动物对26种不同血清型A组链球菌的最佳调理抗体反应，3) 抗猪瘟临床分离株多价疫苗免疫兔血清的实验研究 从美国10个地理地点的咽炎儿童中收集的A组链球菌，4)制定策略 鼻腔注射多价M蛋白疫苗，导致分泌性和系统性免疫反应， 5)直接比较以M蛋白为基础的多价疫苗对小鼠的保护性免疫原性 无论是肌肉内途径还是鼻腔途径。在我们的初步研究中，我们在流行病学上确定了六种 A组链球菌的重要血清型，不被N-末端M蛋白多肽的抗血清调理。 我们提出了一系列实验来确定M蛋白、类M蛋白或其他蛋白的共价结构 含有操纵子表位的表面蛋白，以使这些M血清型可包括在多价疫苗中。我们 将构建一种由4种不同的重组、杂交蛋白组成的26价疫苗。个体杂合蛋白 将在肌肉注射兔子后进行保护性和组织交叉反应免疫原性测试。因为 与非肠道注射相比，粘膜注射链球菌疫苗在免疫学和实用性上都有优势 在给药时，我们将评估不同的鼻腔给药策略，然后直接比较静脉注射的保护效果。 VS I.M.在老鼠身上接种疫苗。研究应提供所需的详细信息以开发安全有效的 可以预防北美和西欧大多数链球菌感染的多价疫苗。

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.