IgE-guided RNAi silencing of FceRIb expression as a novel allergy therapeutic

描述（由申请人提供）：本申请的总体目标是测试IgE引导的RNA干扰（RNAi）介导的靶向沉默IgE高亲和力受体（Fc <$RIb）的β链的可行性，该沉默通过小干扰RNA（siRNA）作为治疗过敏性疾病的新型治疗剂。在过去的几十年中，随着发病率的增加，过敏症现已成为全球主要的公共卫生问题。然而，过敏症的治疗选择仍然非常有限。所提出的新型治疗方法是基于IgE引导的RNAi策略的平台，靶向用于引发和/或调节过敏反应的关键基因FceRIb，以减弱嗜碱性粒细胞和肥大细胞中的过敏反应，从而最终抑制过敏性疾病。为此，靶向FceRIb表达沉默的带负电荷的siRNA分子与由偶联于带正电荷的阳离子聚合物聚乙烯亚胺（PEI）的抗IgE Fab片段组成的缀合物复合。因此，Fab-PEI：siRNA复合物可以高度有效地聚焦到IgE结合的嗜碱性粒细胞/肥大细胞的细胞表面上用于靶向递送。由于作为一个重要的角色， 作为过敏反应的有效放大器，预期过敏效应细胞中FceRIb的靶向沉默会减弱 信号级联，导致过敏反应的抑制。因此，我们假设过敏反应可以通过靶向沉默过敏效应细胞中的FceRIb表达来阻断。为了验证这一假设，在目标1中，我们将开发用于嗜碱性粒细胞/肥大细胞中靶向FceRIb沉默的最佳IgE引导的RNAi方法，作为在基于细胞培养的模型中体外抑制过敏反应的新策略。我们将完善和确定最大RNAi敲除对嗜碱性粒细胞/肥大细胞中FceRIb表达的影响的最佳条件，并确定FceRIb表达沉默对体外过敏反应抑制的结果。在目标2中，我们将在三种不同的动物模型中测试由IgE引导的RNAi介导的靶向FceRIb敲低以阻断过敏反应的治疗效果。这种应用可能会导致开发一种新的基于siRNA的方法来治疗和预防过敏性疾病。 公共卫生相关性：这种应用可能会导致开发一种新的基于siRNA的方法来治疗和预防过敏性疾病。

DESCRIPTION (provided by applicant): The overall goal of this application is to test the feasibility of an IgE-guided, RNA interference (RNAi)-mediated, targeted silencing of the beta chain of the high affinity receptor for IgE (Fc¿RIb) by small interfering RNA (siRNA) as a novel therapeutic to treat allergic diseases. With increasing prevalence in the past decades, allergies have now become a major public health problem worldwide. However, the treatment options for allergies remain very limited. The proposed novel therapeutic approach is a platform based on an IgE-guided RNAi strategy, targeting the critical gene for initiation and/or regulation of the allergic response, FceRIb, to attenuate the allergic response in basophils and mast cells for ultimate suppression of allergic diseases. To this end, the negatively charged siRNA molecules targeting for FceRIb expression silencing are complexed with the conjugates composed of the anti-IgE Fab fragment coupled to the positively charged cationic polymer polyethylenimine (PEI). Therefore, the Fab-PEI:siRNA complex can be highly effective for focusing onto the cell surfaces of the IgE-bound basophils/mast cells for targeted delivery. Due to the critical role as a potent amplifier for allergic response, targeted silencing of the FceRIb in allergic effector cellsis expected to attenuate the signaling cascade, resulting in the suppression of the allergic response. Thus we hypothesized that allergic responses can be blocked by targeted silencing of the FceRIb expression in the allergic effector cells. To test this hypothesis, in Aim 1 we will develop the optimal IgE-guided RNAi approach for targeted FceRIb silencing in basophils/mast cells as a novel strategy for suppression of allergic responses in vitro in cell culture based models. We will refine and determine the optimal conditions for maximal RNAi knockdown effects on FceRIb expression in basophil/mast cells and determine the outcome of FceRIb expression silencing on inhibition of allergic response in vitro. In Aim 2, we will test the therapeutic effects of the targeted FceRIb knockdown mediated by IgE-guided RNAi to block the allergic response in three different animal models. This application will likely lead to the development of a novel siRNA-based approach for the treatment and prevention of allergic diseases. PUBLIC HEALTH RELEVANCE: This application will likely lead to the development of a novel siRNA-based approach for the treatment and prevention of allergic diseases.