Designing IgG Constructs for Tolerance to Diabetogenic *

我们的实验室专注于免疫反应的操纵，以预防不良或无效的免疫反应，主要是在自身免疫中。我们的方法是利用免疫球蛋白融合蛋白通过逆转录病毒载体提供的耐受性。该技术基于免疫球蛋白载体的致耐受性，我们在其上工程化与该IgG支架框内的多个含表位的多肽。两种实验性自身免疫模型（葡萄膜炎和EAE）的数据是有希望的，因为已经实现了显着的临床疗效。也就是说，当通过逆转录病毒感染在骨髓来源的细胞或LPS母细胞中表达时，多肽-IgG在模型系统中诱导对T细胞和B细胞表位的显著低应答性，并且可以预防和逆转葡萄膜炎和葡萄膜炎中的自身免疫应答。NOD小鼠作为糖尿病模型的初步结果是令人鼓舞的，因为胰岛素B链-IgG或GAD-IgG构建体可用于抑制B细胞母细胞，并在NOD小鼠中提供临床保护，即使在胰岛炎发作后也是如此！ 然而，目前尚不清楚该平台技术中用于糖尿病长期耐受的最佳靶抗原/表位是什么，也不清楚我们用于耐受的基因疗法的最佳递送细胞和载体。在这个提议中，我们希望将GAD和胰岛素B链的多个表位工程化到逆转录病毒融合蛋白构建体中，用于有效的耐受诱导，如通过胰岛炎以及免疫参数（如细胞因子反应性）测量的。为了探索机制，我们将研究不同靶细胞的基因治疗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到基于FIV的非灵长类慢病毒载体中，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.