Analysis of peripheral tolerance in vivo

体内外周耐受性分析

基本信息

批准号：
8308579
负责人：
Marc Kevin Jenkins
金额：
$ 33.06万
依托单位：
UNIVERSITY OF MINNESOTA
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-08-01 至 2013-05-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8308579
关键词：
Accounting Adoptive Transfer Affinity Antigen-Presenting Cells Antigens Autoantigens Autoimmune Diseases Autoimmunity CD4 Positive T Lymphocytes Cell Death Cells Complex Development Ectopic Expression Epithelial Cells Event Female Gene Targeting Goals Individual Inflammation Lead Ligands Light Lymphoid Lymphokines Magnetism Major Histocompatibility Complex Mature T-Lymphocyte Mediating Methods Modeling Mus Organ Peptides Peripheral Phenotype Physiological Play Pregnancy Principal Investigator Process Production Proliferating Proteins Regulatory T-Lymphocyte Role Series Survivors T cell anergy T-Cell Receptor T-Lymphocyte Testing Thymus Gland Tissues Transgenic Mice base functional status immunogenic in vivo member peripheral tolerance pregnant programs receptor research study sperm cell success theories thymocyte tool transcription factor

项目摘要

The long-term goal of this project is an understanding of the mechanisms that account for CD4+ T cell tolerance to antigens that are presented in the secondary lymphoid organs but not the thymus. Previously, we showed that naive CD4+ T cells that are exposed to model antigens in the secondary lymphoid organs in the absence of inflammation proliferate poorly, then most of the progeny die, and the survivors enter an anergic state characterized by poor lymphokine production. The goal of this application is to establish whether or not a similar series of events accounts for peripheral tolerance to certain natural self-proteins. This has become a pressing issue since the discovery that the AIRE transcription factor drives ectopic expression of extrathymic gene products in the thymus. Thus, it remains possible that the physiological role that peripheral tolerance was thought to play is really played by AIRE-mediated intrathymic tolerance. Here, we will test the hypothesis that peripheral tolerance is physiologically-relevant by using new tools to identify the tolerance mechanisms that apply to two pregnancy-specific proteins, one that appears to be regulated by AIRE and another that does not, and one sperm-specific protein. We will determine whether or not these proteins are immunogenic in mice that have never expressed them in the relevant tissue (e.g., non-pregnant female mice), and become non-immunogenic in mice after expression (e.g., pregnant female mice). The relevant antigenic peptides will be identified and used to produce peptide-MHC II multimers. The multimers will then be used with a sensitive new enrichment method capable of detecting fewer than 100 cells per mouse to enumerate peptide MHC II- specific CD4+ T cells before, during, and after expression of the relevant protein within the polyclonal repertoires of normal mice. This approach should reveal whether or not the relevant CD4+ T cells are deleted, turn into regulatory cells, or become anergic during or after the period when these developmental^ regulated self-proteins are expressed. This approach will then be used in gene-targeted mice to determine whether or not molecules such as Fas and Cbl-b, and others identified by other members of the P01, are involved in the identified tolerance mechanism. Success would provide the first definitive identification of the peripheral tolerance mechanism that applies to a natural self-antigen. This information should help focus future research on the relevant mechanism and shed light on the potential ways that it could fail and lead to autoimmunity.

该项目的长期目标是了解 CD4+ T 细胞的机制对次级淋巴器官而非胸腺中存在的抗原具有耐受性。此前，我们研究表明，暴露于次级淋巴器官中模型抗原的初始 CD4+ T 细胞没有炎症，增殖不良，然后大多数后代死亡，幸存者进入无反应状态淋巴因子产生不良的状态。该应用程序的目标是确定是否一系列类似的事件解释了外周对某些天然自身蛋白的耐受性。这已经成为一个自从发现 AIRE 转录因子驱动胸腺外异位表达以来，这是一个紧迫的问题胸腺中的基因产物。因此，外周耐受性的生理作用仍然是可能的。被认为发挥的作用实际上是由AIRE介导的胸腺内耐受发挥的。在这里，我们将检验假设通过使用新工具来识别耐受机制，外周耐受具有生理相关性适用于两种妊娠特异性蛋白质，一种似乎受 AIRE 调节，另一种则受 AIRE 调节不，还有一种精子特异性蛋白质。我们将确定这些蛋白质是否具有免疫原性在从未在相关组织中表达过它们的小鼠（例如，未怀孕的雌性小鼠）中，并成为表达后对小鼠（例如怀孕的雌性小鼠）无免疫原性。相关的抗原肽将被鉴定并用于生产肽-MHC II 多聚体。然后多聚体将与敏感的新的富集方法能够检测每只小鼠少于 100 个细胞来计数肽 MHC II- 多克隆内相关蛋白表达之前、期间和之后的特异性 CD4+ T 细胞正常小鼠的曲目。这种方法应该揭示相关的 CD4+ T 细胞是否被删除，转变为调节细胞，或者在这些发育^调节期间或之后变得无能自身蛋白被表达。然后，该方法将用于基因靶向小鼠，以确定是否或并非 Fas 和 Cbl-b 等分子以及 P01 其他成员识别的其他分子参与确定的耐受机制。成功将提供外设的第一个明确识别适用于天然自身抗原的耐受机制。这些信息应该有助于集中未来的研究相关机制并阐明其可能失败并导致自身免疫的潜在方式。