Identification of T-Cell Immunogens in Anaplasma

描述（由申请方提供）：由CD4+ T淋巴细胞介导的MHC II类限制性反应是无形体科蜱传病原体免疫控制的核心。CD4+ T淋巴细胞的引发和扩增是开发针对细菌表面的高亲和力中和IgG抗体和有效激活吞噬细胞以杀死细菌所必需的。该研究的目标是确定诱导免疫所需的T细胞反应的病原体蛋白质。到目前为止，只有四个T细胞免疫刺激分子已被确定在边缘无形体，模式物种，没有在相关的人类病原体内的无形体科。我们将使用一种全面的策略来解决这一知识差距，以确定外膜蛋白，该外膜蛋白引发幼稚CD4+ T淋巴细胞并诱导免疫和保护动物的回忆记忆T细胞应答。在该项目的第1部分中，我们建议使用结合基因组分析的外膜生化分离的组合来识别T细胞应答的靶点。在第一部分的结论，我们希望已经确定了新的外膜蛋白携带的CD4+ T细胞表位保守的A。边缘菌株在无形体科物种之间存在分子和免疫学直向同源物，表明研究结果应具有广泛的适用性，并加强对人类疾病的理解和控制。 在项目的第2部分，我们将研究在产生免疫力的共价结合的外膜蛋白的连接识别的要求。A.边缘外膜蛋白通过广泛的二硫键共价连接。这种共价键如何影响免疫力的产生尚不清楚。主要表面蛋白（MSP）1a特异性CD4+ T细胞为B淋巴细胞分泌共价结合的MSPlb抗体提供帮助的观察结果表明，外膜蛋白的天然结合在诱导保护性反应中可能是至关重要的。我们假设，这种“连接识别”的CD4+ T细胞和B细胞表位从不同的外膜蛋白可以模拟使用嵌合多表位构建体。在第2部分的结论中，我们期望已经确定，如果共价结合的外膜蛋白之间的连接识别，使用MSPla和MSPlb作为模型复合免疫原，可以由嵌合表位构建体表示。

DESCRIPTION (provided by applicant): MHC class II-restricted responses mediated by CD4+ T lymphocytes are central to immune control of the tick-borne pathogens of the Family Anaplasmataceae. Priming and expansion of CD4+ T lymphocytes is required for development of high affinity neutralizing IgG antibodies directed against the bacterial surface and for efficient phagocyte activation leading to bacterial killing. The goal of the research is to identify the pathogen proteins that induce the T cell responses required for immunity. To date, only four T cell immunostimulatory molecules have been identified in Anaplasma marginale, the type species, and none in the related human pathogens within the Anaplasmataceae. We will address this knowledge gap using a comprehensive strategy to identify outer membrane proteins that prime naive CD4+ T lymphocytes and induce recall memory T cell responses of immunized and protected animals. In part 1 of the project, we propose to use a combination of biochemical fractionation of outer membranes combined with genomic analysis to identify the targets of the T cell response. At the conclusion of part 1, we expect to have identified novel outer membrane proteins bearing CD4+ T cell epitopes conserved among A. marginale strains. The presence of molecular and immunological orthologs among species in the Family Anaplasmataceae indicates that the research results should be broadly applicable and enhance understanding and control of human diseases. In part 2 of the project, we will examine the requirement for linked recognition of covalently associated outer membrane proteins in generating immunity. A. marginale outer membrane proteins are covalently linked by extensive disulfide bonding. How this covalent bonding affects generation of immunity is unknown. The observation that Major Surface Protein (MSP) 1a-specific CD4+ T cells provide help for B-lymphocytes to secrete antibody to the covalently bound MSPlb suggests that the native association of outer membrane proteins can be critical in inducing protective responses. We hypothesize that this "linked recognition" of CD4+ T cell and B cell epitopes from different outer membrane proteins can be mimicked using chimeric multiple epitope constructs. At the conclusion of part 2, we expect to have determined if linked recognition between covalently bound outer membrane proteins, using MSPla and MSPlb as a model complex immunogen, can be represented by a chimeric epitope construct.