Designing IgG Constructs for Tolerance to Diabetogenic *

我们的实验室专注于控制免疫应答，以防止不良或无效的免疫应答，主要是在自身免疫中。我们的方法是利用通过逆转录病毒载体传递的免疫球蛋白融合蛋白来耐受。这项技术是基于免疫球蛋白载体的耐受性，我们在免疫球蛋白载体上设计了多个含有表位的多肽，并以这种免疫球蛋白支架为框架。两个实验性自身免疫模型(葡萄膜炎和EAE)的数据很有希望，因为已经取得了显著的临床疗效。也就是说，当通过逆转录病毒感染在骨髓来源的细胞或脂多糖母细胞中表达时，多肽-IgG在模型系统中诱导对T细胞和B细胞表位的显著低反应性，并可以预防和逆转葡萄膜炎和耳部的自身免疫反应。在NOD小鼠作为糖尿病模型的初步结果令人鼓舞，因为无论是胰岛素B链-IgG还是GAD-IgG构建物都可以用于转染B细胞母细胞，并在NOD小鼠中提供临床保护，即使在胰岛素炎发作之后！然而，目前还不清楚这一平台技术中用于糖尿病长期耐受的最佳靶向抗原/表位是什么，也不清楚用于耐受基因治疗的最佳递送细胞和载体是什么。在这项建议中，我们希望将GAD和胰岛素B链的多个表位设计成逆转录病毒融合蛋白结构，以有效地诱导免疫耐受，如通过测量岛炎，以及免疫参数，如细胞因子反应性。为了探索机制，我们将检查不同靶细胞对基因治疗的效果和胰岛素特异性T细胞的命运。最后，我们将把这些结果应用于基于FIV的非灵长类慢病毒载体，以诱导耐受，作为未来糖尿病临床试验的重要一步。

Our laboratory is focused on the manipulation of immune responsiveness for the prevention of undesirable or ineffective immune responsiveness, primarily in autoimmunity. Our approach has been to utilize immunoglobulin fusion proteins delivered via retroviral vectors for tolerance. This technology is based on the tolerogenicity of immunoglobulin carriers, onto which we engineer multiple epitope- containing polypeptides in frame with this IgG scaffold. Data in two experimental autoimmune models (uveitis and EAE) are promising in that significant clinical efficacy has been achieved. That is, when expressed in bone marrow-derived cells or LPS blasts via retroviral infection, the polypeptide-IgG induces significant hyporesponsiveness to both T-cell and B-cell epitopes in model systems, and can both prevent and reverse autoimmune responsiveness in uveitis and EAR Preliminary results in NOD mice as a model for diabetes are encouraging in that either an insulin B chain-IgG or a GAD-IgG construct can be used to transfect B cell blasts and provide clinical protection in NOD mice even after the onset of insulitis! However, it is not clear what the best target antigens/epitopes in this platform technology are for long-term tolerance in diabetes, nor the best delivery cells and vectors our gene therapy for tolerance. In this proposal, we wish to engineer multiple epitopes of GAD and insulin B chains into retroviral fusion protein constructs for effective tolerance induction, as measured by insulitis, as well as immune parameters, such as cytokine responsiveness. To explore mechanisms, we will examine the efficacy of different target cells for gene therapy and the fate of insulin-specific T cells. Finally, we will apply these results to an FIV based non-primate lentivirus vectors for tolerance induction as an important step toward future clinical trials for diabetes.