Peptide antigens in CD45RBhigh CD4+T cell colitis model

描述(由申请人提供)： 慢性炎症性肠病，如克罗恩、S病和 溃疡性结肠炎，在这一事件中困扰着大约200万人 孤身一人的国家。这些疾病的主要特征是存在 肠粘膜小室内T淋巴细胞的活化形式。穿过 对IBD小鼠模型的一些研究以及对人体的研究， 越来越多的人认识到IBD与鲁米纳或 环境刺激对遗传易感宿主的影响。其中一个 最具特征的IBD小鼠模型是CD45RBHigh CD4+T细胞 转移模型。通过将这一特定的T细胞亚群转移到 严重联合免疫缺陷(SCID)同基因受者，缺乏 功能正常的B或T细胞，导致结肠炎。然而，领养转让 CD45RBlow CD25+CD4+T细胞抑制结肠炎。最近的证据表明 这两个T细胞亚群都依赖于MHC II类并被激活 通过一组有限的T细胞受体，这表明扩张到 有限的一组抗原。该模型还依赖于环境抗原。 暴露在无菌条件下饲养的SCID小鼠不会发生 细胞转移后的结肠炎。总而言之，这意味着效应器 而调节性CD4+T细胞在结肠炎的这种转移模型中最多 可能被MHC中呈现的有限数量的多肽抗原激活 第二类依赖于时尚，可能源于流明环境。 因此，这个项目的主要目标是阐明多肽。 抗原(S)参与CD45RBhCD_4~+T细胞群效应 应答或CD45RBlow CD25+CD4+抑制应答。具体来说， 我们计划使用一种涉及cDNA表达文库的方法学方法来 识别这些T细胞亚群的未知多肽抗原。初步 用小鼠DO11.10 CD4+T细胞杂交瘤细胞识别 鸡卵清蛋白17个氨基酸多肽表位的MHC分析 第II类)指出了这一方法的初始参数。初级阶段 目的是从重组融合蛋白中鉴定表达的多肽(S) 由组织和盲肠细菌提取物制成的cdna文库创建。这个 将根据增殖和细胞因子筛选文库中的反应性表位 制作。接下来，这些重要的T细胞将接受T细胞受体 评估。通过这种方法，潜在地，导致CD45RBH高的抗原 结肠炎的CD4+T细胞过继转移模型可阐明，这可能 有助于更好地了解人类炎症性肠病。

DESCRIPTION (provided by applicant): Chronic human inflammatory bowel diseases (IBD), such as Crohn?s Disease and Ulcerative Colitis, afflicts approximately two million individuals in this country alone. These disorders are primarily characterized by the presence of activated forms of T lymphocytes in the intestinal mucosal compartment. Through a number of investigations in murine models of IBD, as well as human studies, it is becoming increasingly recognized that IBD is associated with luminal or environmental stimuli in a genetically susceptible host. One of the best-characterized murine models of IBD is the CD45RBhigh CD4+ T cell transfer model. Adoptive transfer of this particular subset of T cells into a severe combined immunodeficient (SCID) congeneic recipient, who lacks functional B or T cells, results in colitis. However, adoptive transfer of the CD45RBlow CD25+ CD4+ T cells inhibits colitis. Recent evidence indicates that both T cell subsets are dependent on MHC class II and are activated through a restricted set of T cell receptors, which indicates expansion to a limited set of antigens. The model is also dependent on environmental antigen exposure, as SCID mice raised under germ-free conditions, do not develop colitis following cell transfer. Taken together, this implies that the effector and regulatory CD4plus T cells in this transfer model of colitis are most likely activated by a limited number of peptide antigens presented in a MHC class II dependent fashion, and possibly derived from the luminal environment. Therefore, the primary goal of this project is to elucidate the peptide antigen(s) involved in the CD45RBhigh CD4+ T cell population effector response or the CD45RBlow CD25+ CD4+ inhibitory response. Specifically, we plan to use a methodological approach involving cDNA expression libraries to identify unknown peptide antigens for these subsets of T cells. Preliminary experiments with murine DO11.10 CD4+ T cell hybridoma cells, which recognize a 17 amino-acid peptide epitope of chicken ovalbumin in the context of MHC class II, has indicated the initial parameters of this methodology. The primary goal is to identify expressed peptide(s) from recombinant fusion proteins created from cDNA libraries made from tissue and cecal bacteria extracts. The libraries will be screened for reactive epitopes by proliferation and cytokine production. Next, these important T cells will undergo T cell receptor evaluation. Potentially, by this approach, antigens responsible for CD45RBhigh CD4plus T cell adoptive transfer model of colitis can be elucidated, this may lead to a better understanding of human inflammatory bowel disease.