Generation of Islet Specific T Follicular Regulatory Like Cells for Autologous Cell Therapy of Type 1 Diabetes

项目概要/摘要 1型糖尿病（T1 D）是一种自身免疫性疾病，导致胰腺β细胞破坏和终身糖尿病。 依赖外源性胰岛素注射。旨在逆转β细胞的免疫调节剂 自身免疫已被证明可以延迟T1 D诊断，但不能阻止C肽水平的下降， 反映胰岛素的产生。自体干细胞疗法（ACT）是一种研究性疗法，旨在恢复 通过输注离体扩增的调节性T细胞（T细胞）使免疫设定点回到耐受性。treg是 负责下调免疫反应，而在糖尿病动物模型中它们的缺失导致 加速疾病进展。然而，ACT的早期临床试验表明，输注TlR持续时间为 年，但在预防C肽下降方面无效。 本项目拟通过基因工程技术从Tfos中诱导产生胰岛特异性T滤泡调节细胞（Tfr）， 编辑以提高其作为T1 D ACT的效用。Tfr细胞是Tfr的一个特化亚群，其作用于 淋巴结的生殖中心，其中成熟的B细胞被T滤泡辅助（Tfh）细胞激活。早B 细胞活化是T1 D预后的重要步骤，因为在T1 D患者中检测类别转换的胰岛自身抗体， 糖尿病前期预示着疾病的发作。因此，创造Tfr样细胞代表了一种潜在的 通过抑制Tfh介导的活化来预防T1 D的途径。 以下具体目的概述了利用基因组靶向产生Tfr样细胞的目的 作为T1 D的潜在细胞疗法。目的1：通过非病毒基因组产生胰岛反应性THBE 编辑以敲入TCR基因座中的胰岛反应性TCR。将在体外测试工程化THBE的胰岛抗原 反应性，并通过过继转移到NOD小鼠中进行体内测试，以确定其对糖尿病的影响 发病率。在目标2中，Tfr细胞特征性趋化因子受体CXCR 5将在Rosa 26基因座中被敲除 的胰岛反应性TdR，并测试对CXCL 13的反应性。工程化的CXCR 5阳性胰岛反应性T细胞 将其转移到NOD小鼠中以评估糖尿病发病率和Treg向胰腺的运输， 胰腺淋巴结 拟议的培训将在佛罗里达大学糖尿病研究所进行， 博士这是托德·哈勒科和迈克尔·哈勒医生培训计划将为申请人提供研究设计， 在自身免疫、细胞工程和糖尿病模型方面的技术技能以及教学方面的专业技能 和科学写作，以促进成长为一个独立的调查员。

Project Summary/Abstract Type 1 diabetes (T1D) is an autoimmune disease leading to pancreatic beta cell destruction and lifelong dependence on exogenous insulin injections. Immunomodulatory agents that aim to reverse beta cell autoimmunity have been shown to delay T1D diagnosis but cannot halt the decline of C-peptide levels that reflect insulin production. Autologous cell therapy (ACT) is an investigational therapy that aims to restore the immune set point back to tolerance by infusion of ex vivo expanded regulatory T cells (Tregs). Tregs are responsible for downregulating the immune response and their absence in animal models of diabetes leads to accelerated disease progression. Early clinical trials of ACT, however, show that transfused Tregs persist for years in patients but were ineffective in preventing C-peptide decline. This project proposes to generate islet specific T follicular regulatory (Tfr) cells from Tregs through gene editing to improve their utility as ACT for T1D. Tfr cells are a specialized subset of Tregs that act in the germinal centers of lymph nodes where mature B cells are activated by T follicular helper (Tfh) cells. Early B cell activation is an important step in T1D prognosis as the detection of class-switched islet autoantibodies in the pre-diabetic phase predicts onset of disease. Therefore, creating Tfr-like cells represents a potential avenue of T1D prevention through suppression of Tfh-mediated activation. The following Specific Aims outline the objectives for utilizing genome targeting to produce Tfr-like cells as potential cellular therapies of T1D. In Aim 1, islet reactive Tregs will be produced through non-viral genome editing to knock in islet reactive TCR in the TCR locus. Engineered Tregs will be tested in vitro for islet antigen reactivity and tested in vivo through adoptive transfer into NOD mice to determine its effects on diabetes incidence. In Aim 2, the Tfr cell characteristic chemokine receptor CXCR5 will be knocked in the Rosa26 locus of islet reactive Tregs and tested for responsivity to CXCL13. Engineered CXCR5-positive islet reactive Tregs will be transferred into NOD mice to assess diabetes incidence and Treg trafficking to the pancreas and pancreatic lymph nodes. The proposed training will take place at the University of Florida Diabetes Institute under the guidance of Dr. Todd Brusko and Dr. Michael Haller. The training plan will provide the applicant with research design and technical skills in autoimmunity, cell engineering, and diabetes models as well as professional skills in teaching and scientific writing to facilitate growth as an independent investigator.