Antigen specific therapy for bullous pemphigoid

描述（由申请人提供）：大疱性类天疱疮（BP）是一种自身免疫性起泡性皮肤病。这种疾病的特点是对表皮细胞表面蛋白BP180（也称为胶原XVII）的潜在威胁生命的体液免疫反应。总体免疫抑制治疗通常用于控制这种抗体介导的疾病；然而，严重的副作用强调了对特定靶向治疗的迫切需要。这项R21应用的目标是探索和开发一种以抗原特异性方式消耗自身反应性b细胞的疗法。我们对这一探索性/发展性研究申请（R21）的假设是，bp180特异性抗原毒素能够通过结合并选择性杀死bp180特异性b细胞，从而大大减少抗bp180抗体的产生。这种融合蛋白的细胞毒性部分是人血管生成素，这是一种血浆rna酶，在进入靶细胞的细胞质之前是无毒的。第一个目标将集中在生成和表征血管生成素-抗原融合和控制蛋白，以检验我们的假设。将进行生化和免疫学分析，以确保血管生成素的酶活性和BP180片段的抗原特性没有改变。第二个目的是在体内和体外测试抗原毒素的功效。我们的体外方法包括监测bp180特异性b细胞杂交瘤（人类和小鼠）的细胞死亡，以及BP患者的外周血细胞。非特异性免疫细胞作为阴性对照。这种抗原毒素的有效性和安全性的体内测试将使用小鼠模型进行，该模型在BP中复制抗bp180免疫反应。治疗的效果将通过跟踪抗bp180抗体滴度和监测小鼠中bp180特异性b细胞群来量化。先天免疫系统和适应性免疫系统的其他细胞的命运也将随之发生。这项研究代表了血管生成素抗原在体内系统中的首次测试。该研究与公众健康的相关性：如果我们的假设得到证实，该项目的发现很可能导致针对BP和其他b细胞驱动的自身免疫性疾病患者的特异性治疗的发展。预期的结果是显著降低与这些临床状况相关的发病率和死亡率。我们设想抗原特异性免疫调节也可以用于改善某些类型的基因替代疗法的结果，其中对转基因产物的体液免疫反应是一个严重的陷阱。

DESCRIPTION (provided by applicant): Bullous Pemphigoid (BP) is an autoimmune blistering skin disease. This condition is characterized by potentially life-threatening humoral immune reactions to an epidermal cell surface protein, BP180 (also known as collagen XVII). Global immunosuppressive treatments are generally used to control such antibody-mediated disorders; however, serious side effects underscore the critical need for specific targeted therapy. The goal of this R21 application is to explore and develop a therapy that would deplete autoreactive B-cells in an antigen-specific manner. Our hypothesis for this exploratory/developmental research grant (R21) application is that a BP180-specific antigen-toxin is capable of greatly reducing the production of anti-BP180 antibodies by binding to, and selectively killing, BP180-specific B-cells. The cytotoxic moiety of this fusion protein is human angiogenin, a plasma RNase that is non-toxic until it is delivered into the cytoplasm of the target cell. The first aim will focus on generating and characterizing the angiogenin-antigen fusion and control proteins necessary to test our hypothesis. Biochemical and immunological analyses will be carried out to ensure that the enzymatic activity of angiogenin and the antigenic properties of the BP180 moiety have not been altered. The second aim is directed toward testing the efficacy of the antigen-toxin in vitro and in vivo. Our in vitro approaches involve monitoring cell death in BP180-specific B-cell hybridomas (both human and murine), as well as on BP patients' peripheral blood cells. Non-specific immune cells will be used as negative control. In vivo testing of the efficacy and safety of this antigen-toxin will be carried out using a murine model that reproduces the anti-BP180 immune response in BP. The effects of the treatments will be quantified by following anti-BP180 antibody titers and monitoring BP180-specific B-cell populations in the mice. The fate of other cells of the innate and adaptive immune systems will be followed. This study represents the first test of an angiogenin-antigen in an in vivo system. RELEVANCE of this research to public health: If our hypothesis is confirmed, the findings from this project could well lead to the development of specific therapies for patients with BP and other B-cell driven autoimmune disorders. The expected outcome is a significant reduction in the morbidity and mortality associated with these clinical conditions. We envision that antigen-specific immuno-modulation could also be employed to improve the outcomes of certain types of gene replacement therapy, in which a humoral immune response to the transgene product is a serious pitfall.