Repertoire selection of AQP4-specific T cells that cause CNS autoimmunedisease

引起中枢神经系统自身免疫性疾病的 AQP4 特异性 T 细胞的库选择

• 批准号: 10303022
• 负责人: SCOTT S ZAMVIL
• 金额: $ 44.26万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-24 至 2023-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10303022
• 关键词: Adoptive Transfer; Advanced Development; Affinity; Alleles; Amino Acid Sequence; Animals; Antibodies; Autoantigens; Autoimmunity; B-Lymphocytes; Binding; CNS autoimmune disease; CNS autoimmunity; Cells; Cerebrospinal Fluid; Clinical; Clone Cells; Data; Defect; Development; Epitopes; Exhibits; Experimental Models; Foundations; Genes; Goals; HLA-DRB1; Histologic; IgG1; Immune response; Immunization; Immunotherapy; Inflammation; Interleukin-17; Lesion; Mediating; Modeling; Multiple Sclerosis; Mus; Myelin; Neuromyelitis Optica; Optical Coherence Tomography; Organ Model; Paralysed; Pathogenesis; Pathogenicity; Pathology; Patients; Peptides; Peripheral; Phenotype; Rattus; Regulation; Role; T cell regulation; T cell response; T-Cell Proliferation; T-Cell Receptor; T-Lymphocyte; T-Lymphocyte Epitopes; T-cell receptor repertoire; Testing; Thymic epithelial cell; Thymus Gland; Tissues; Transgenic Mice; Transgenic Organisms; Visual system structure; Wild Type Mouse; aquaporin 4; base; cytokine; in vivo; insight; novel; peptide P; programs; response; success; targeted treatment

PROJECT SUMMARY / ABSTRACT Based upon the observation that aquaporin-4 (AQP4)-specific antibodies are IgG1, a T cell-dependent isotype, it was hypothesized that aquaporin-4 (AQP4)-specific T cells have a key role in neuromyelitis optica (NMO) pathogenesis. AQP4-specific T cells have been identified in NMO patients and, in comparison to healthy controls (HC), AQP4-reactive T cells are expanded and exhibit Th17 polarization, findings that further support the role of Th17 cells in NMO. Unfortunately, it is not feasible to evaluate how AQP4-reactive T cells participate directly in CNS inflammation in NMO patients. Thus, it is important to develop models to evaluate the potential role of AQP4-specific T cells in NMO. Initial attempts in generating an in vivo AQP4-based NMO model in wild-type (WT) mice and rats have not met with success. Recently, it was observed that pathogenic AQP4-specific T cells exist in AQP4-deficient (AQP4-/-) mice. Those T cells recognize two novel determinants. In comparison to other AQP4 determinants identified in WT mice, the novel determinants induce robust proliferation in AQP4-/- mice, but only a weak response in WT mice. Hyper-reactivity is AQP4-specific, but not epitope-specific as we discovered a second AQP4 epitope induced vigorous proliferation in AQP4- /-, but not WT, mice. The T cell receptor (TCR) repertoires used for recognition of these determinants in AQP4-/- and WT mice are distinct. T cells reactive to these determinants isolated from AQP4-/- donor mice induced clinical and histologic CNS autoimmune disease in 100% of recipient WT mice tested. Collectively, these findings represent the first successful induction of clinical AQP4-targeted CNS autoimmunity. Our findings suggest responses to those epitopes in AQP4-/- mice reflect a loss of central T cell tolerance. Findings from studying mice deficient in T cells only or B cells only indicate that peripheral T cell regulation also alters expression of pathogenic AQP4-specific T cells. We propose to test our hypothesis that there is a defect in thymic negative selection of AQP4-specific T cells in mice, a possibility that may be relevant to NMO pathogenesis. We will examine how peripheral T cell regulation may influence pathogenic AQP4-specific immune responses. In Specific Aim 1, by using unique approaches and novel mice, we will characterize the phenotype of pathogenic AQP4-specific T cells and generate AQP4-specific TCR transgenic mice. In Specific Aim 2, we will characterize the repertoire of AQP4-specific T cells in AQP4-/- and WT mice that express HLA- DR17 (DRB1*0301), the MHC II allele most highly associated with NMO. Separately, we will examine AQP4-specific T cell responses in NMO patients to determine if DR17-restricted AQP4-specific T cell epitopes identified those mice correspond to AQP4 T cell epitopes in NMO patients. In preliminary data, using these mice we discovered a novel HLA- DR17-restricted AQP4 determinant, and observed that it is recognized by T cells from HLA-DR17+ NMO patients, findings that support feasibility of this aim. Findings obtained in this program should elucidate mechanisms controlling development of pathogenic AQP4-specific T cells in NMO, provide a foundation advancing development of in vivo NMO models, and may provide insight for development of selective NMO immunotherapy.

项目总结/摘要 基于水通道蛋白-4（AQP 4）特异性抗体是IgG 1（一种T细胞依赖性同种型）的观察， 假设水通道蛋白-4（AQP 4）特异性T细胞在视神经肌萎缩症（NMO）发病机制中具有关键作用。 已经在NMO患者中鉴定了AQP 4特异性T细胞，并且与健康对照（HC）相比， T细胞扩增并表现出Th 17极化，这一发现进一步支持了Th 17细胞在NMO中的作用。 不幸的是，在NMO中评估AQP 4反应性T细胞如何直接参与CNS炎症是不可行的。 患者因此，重要的是开发模型来评估AQP 4特异性T细胞在NMO中的潜在作用。 在野生型（WT）小鼠和大鼠中产生体内基于AQP 4的NMO模型的初始尝试尚未满足要求。 成功最近，观察到致病性AQP 4特异性T细胞存在于AQP 4缺陷（AQP 4-/-）小鼠中。那些T 细胞识别两个新的决定因素。与WT小鼠中鉴定的其他AQP 4决定簇相比， 决定簇在AQP 4-/-小鼠中诱导稳健的增殖，但在WT小鼠中仅诱导弱反应。高反应性是 AQP 4特异性，但不是表位特异性的，因为我们发现第二个AQP 4表位诱导AQP 4- /-，但不是WT小鼠。用于识别AQP 4-/-和WT中这些决定簇的T细胞受体（TCR）库 老鼠是不同的。从AQP 4-/-供体小鼠中分离的对这些决定簇反应的T细胞诱导了临床和组织学 在100%的受试WT小鼠中发生CNS自身免疫性疾病。总的来说，这些发现代表了第一个成功的 诱导临床AQP 4靶向CNS自身免疫。我们的研究结果提示AQP 4-/-小鼠对这些表位的反应 反映了中央T细胞耐受性的丧失。研究仅缺乏T细胞或仅缺乏B细胞的小鼠的结果表明， 外周T细胞调节也改变致病性AQP 4特异性T细胞的表达。 我们建议验证我们的假设，即小鼠中AQP 4特异性T细胞的胸腺阴性选择存在缺陷， 这可能与NMO的发病机制有关。我们将研究外周T细胞调节如何影响 致病性AQP 4特异性免疫应答。在具体目标1中，通过使用独特的方法和新型小鼠，我们将 表征致病性AQP 4特异性T细胞的表型并产生AQP 4特异性TCR转基因小鼠。在 具体目标2，我们将表征AQP 4-/-和WT小鼠中表达HLA-1的AQP 4特异性T细胞的库。 DR 17（DRB 1 *0301），与NMO最高度相关的MHC II等位基因。另外，我们将研究AQP 4特异性T 细胞反应，以确定DR 17限制性AQP 4特异性T细胞表位是否识别了这些小鼠 对应于NMO患者中的AQP 4 T细胞表位。在初步数据中，使用这些小鼠，我们发现了一种新的HLA- DR 17限制性AQP 4决定簇，并观察到它被来自HLA-DR 17 + NMO患者的T细胞识别， 这些发现支持这一目标的可行性。在这个项目中获得的发现应该阐明控制 NMO中致病性AQP 4特异性T细胞的发展，为推进体内NMO的发展提供了基础 模型，并可能为选择性NMO免疫疗法的开发提供见解。