Antigen specific therapy for bullous pemphigoid

描述(申请人提供)：大疱性类天疱疮(BP)是一种自身免疫性水疱性皮肤病。这种情况的特点是对一种表皮细胞表面蛋白BP180(也称为XVII胶原蛋白)的潜在威胁生命的体液免疫反应。全球免疫抑制治疗通常被用来控制这种抗体介导的疾病；然而，严重的副作用强调了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治疗方法，以抗原特异性的方式耗尽自身反应性B细胞。我们对这一探索性/发展性研究拨款(R21)应用的假设是，BP180特异性抗原毒素能够通过与BP180特异性B细胞结合并选择性地杀死BP180特异性B细胞，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，这是一种血浆核糖核酸酶，在被输送到靶细胞的细胞质中之前是无毒的。第一个目标将集中在产生和表征血管生成素-抗原融合和控制蛋白，这是检验我们的假设所必需的。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部分的抗原性没有改变。第二个目标是测试抗原毒素在体外和体内的效果。我们的体外方法包括监测BP180特异性B细胞杂交瘤(人和小鼠)以及BP患者外周血细胞的细胞死亡。非特异性免疫细胞将作为阴性对照。这种抗原毒素的有效性和安全性的体内测试将使用在BP中复制抗BP180免疫反应的小鼠模型进行。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。先天免疫系统和获得性免疫系统的其他细胞的命运也将随之而来。这项研究是第一次在体内系统中测试血管生成素-抗原。这项研究与公共卫生的相关性：如果我们的假设得到证实，该项目的发现很可能导致为BP和其他B细胞驱动的自身免疫性疾病患者开发特定的治疗方法。预期的结果是与这些临床情况相关的发病率和死亡率显著降低。我们设想，抗原特异性免疫调节也可以用来改善某些类型的基因替代治疗的结果，其中对转基因产品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.