Pathways Towards Immune Tolerance To Coagulation Factors

该申请为旨在剖析获得性免疫下调的研究寻求资金。 针对蛋白质或基因替代疗法引入的凝血因子的反应 变成X连锁出血性疾病血友病的个体。这些潜在的有害反应不是 只会导致形成抑制因子VIII(缺乏血友病A)或因子IX的抗体 (F.IX，缺乏血友病B)，它们还包括产生细胞毒性T淋巴细胞，这可以 消除在基因转移时被修改的细胞。虽然这两组反应都依赖于抗原 特异性辅助性CD4+T细胞和对F.IX的获得性免疫反应被NAIVE或抗原特异性抑制 调节性T细胞(Treg、TR1、NKT)。尽管如此，我们才刚刚开始了解免疫调节在血友病治疗中的意义，因为我们需要剖析这些调节过程的遗传和机制基础。 在这一竞争性的更新申请中提出的实验旨在测试一般假设，即几个调节性T细胞亚群合作防止初级反应或减轻对通过基于AAV的基因转移或作为蛋白质引入的F.IX的现有反应。建议的实验分为以下具体目标：i)优化F.IX特异性Treg的体外生成。Ii)验证体内针对F.IX的抗体和CD8+T细胞反应可被Treg诱导抑制的假设。Iii)验证传统的Treg、产生IL-10的Treg和NKT细胞调节针对AAV-hF.IX的免疫反应的假设。 总之，这些实验应该阐明控制抑制物和T细胞对凝血因子和治疗性蛋白质的反应的基本机制。研究结果可直接用于血友病治疗策略的设计。

This application seeks funding for studies aimed at dissecting the down-regulation of adaptive immune responses directed against coagulation factors that are introduced by protein or gene replacement therapy into individuals with the X-linked bleeding disorder hemophilia. These potentially detrimental responses not only result in the formation of inhibitory antibodies against factor VIII (deficient in hemophilia A) or factor IX (F.IX, deficient in hemophilia B), they also include the generation of cytotoxic T lymphocytes, which can eliminate cells that are modified upon gene transfer. Whilst both sets of responses are dependent on antigen specific helper CD4+ T cells, adaptive immune responses to F.IX are suppressed by naive or antigen specific regulatory T cells (Treg, Tr1, NKT). Nonetheless, we are only beginning to understand the implications of immune regulation in the treatment of hemophilia, as we need to dissect the genetic and mechanistic underpinnings of these regulatory processes. The experiments proposed in this Competing Renewal application are designed to test the general hypothesis that several regulatory T cell subsets cooperate in the prevention of a primary response or mitigate an existing response to F.IX introduced via AAV-based gene transfer or as a protein. The proposed experiments are grouped into the following Specific Aims: i) To optimize the in vitro generation of F.IX specific Treg. ii) To test the hypothesis that in vivo antibody and CD8+ T cell responses directed against F.IX can be suppressed by induction by Treg. iii) To test the hypothesis that conventional Treg, IL-10 producing Treg and NKT cells regulate immune responses directed against AAV-hF.IX. Together these experiments should clarify the basic mechanisms, which govern inhibitor and T cell responses to coagulation factors and therapeutic proteins. The results could directly be used for the design of therapeutic strategies that can be applied treatment of hemophilia.