Targeting surface-bound IgE as a novel allergy therapeutic

描述(由申请人提供)：这项SBIR申请的总体目标是开发下一代过敏生物疗法并将其商业化。这种新型的治疗性药物是一种抗IgE的单抗，针对过敏效应细胞上的表面结合的IgE，并在功能上阻断过敏反应。过敏性疾病已经增加到现在已经成为一个重大的全球公共卫生问题的地步，在美国等发达国家尤其如此。治疗过敏的新的有效治疗方案仍然是一个尚未得到满足的主要需求；目前还没有针对花生过敏等严重食物过敏的有效治疗方法，自2003年基于Xolair(R)的抗IgE疗法以来，也没有新的吸入性过敏平台获得许可。在这个应用中，我们提出了一种新的方法，其中基因工程抗？MAb半分子[AEHM]E-3.56用于阻断过敏反应。这种治疗方法的基本原理 方法是基于我们的初步发现，这种AEHM与变态反应效应细胞上Fc？RI结合的IgE不能介导交联性和触发细胞 其单价性质，同时，它的结合抑制随后的过敏原诱导的反应。因此，这项应用的主要目标是生产一种基因工程原型AEHM E-3.56，并实验证明E-3.56与过敏效应细胞表面结合的IgE具有抗过敏反应的新型治疗功能。在目标1中，我们将设计并表达一个原型的IgG1抗-epsilon(IgE)半抗体分子E-3.56，该分子由与人？1重链相连的小鼠VH和VL区和？轻链恒定区，C？1铰链区的两个关键半胱氨酸发生突变以阻止两个CH链的二聚化。通过瞬时转染法或通过已建立的稳定细胞系共表达嵌合的H链和L链，将产生与人IgE结合的单价E-3.56。在目标2中，我们将测试E-3.56在体外和VIV建立的过敏模型中抑制过敏反应的能力的安全性和治疗效果。我们将使用全身过敏反应模型、被动皮肤过敏反应模型和人嗜碱粒细胞刺激试验来测试E-3.56‘S的安全性和治疗效果。在目标3中，我们将定义E-3.56通过以下哪种机制抑制过敏反应：1)空间障碍阻止接触过敏原结合部位；2)触发效应肥大细胞和嗜碱性粒细胞中的负信号；3)促进细胞表面IgE-Fc？RI复合体的清除；4)触发IgE过敏原结合部位的构象变化，导致过敏原结合的丧失；和/或5)干扰过敏信号所需的IgE CRO连接。本申请旨在开发一种与公众健康相关的新型过敏疗法。 公共卫生相关性：靶向表面结合的IgE作为一种新的过敏治疗药物，涉及吸入剂和食物的过敏性疾病在过去几十年中在美国和其他发达国家的患病率和发病率都显着增加，现在已成为一个重大的全球公共卫生问题。此外，随着新的生物制剂的使用，IgE介导的药物反应性是一个日益严重的问题。该项目的目标是开发一种新的过敏生物疗法，并最终将其商业化，以有效预防/治疗严重过敏性哮喘和食物过敏等严重过敏反应。这种疗法还可以用来阻止过敏反应，并允许患者使用对其过敏的药物(抗生素等)。人们迫切需要这样一种治疗方法，这对公众健康将非常重要。

DESCRIPTION (provided by applicant): The overall goal of this SBIR application is to develop and commercialize a next generation allergy biologic therapy. This novel therapeutic, an anti-IgE monoclonal half antibody, targets the surface-bound IgE on allergic effector cells and functionally blocks allergic reactivity. Allergic disorders have increased to the point where they have now become a major worldwide public health issue and particularly so in developed countries such as the US. Novel effective treatment options for allergies remain a major unmet need; no effective therapy is available for severe food allergies such as peanut allergy and no new platforms for inhalant allergy have been licensed since Xolair(r)-based anti-IgE therapy in 2003. In this application we propose a new approach where a genetically engineered anti-? mAb half molecule [AEHM] E-3.56 is used to block allergic reactivity. The rationale of this therapeutic approach is based on our preliminary finding that binding of this AEHM to the Fc?RI bound IgE on allergic effector cells is incapable of mediating the cross-linking and triggering the cells due to its monovalent nature while at the same time, its binding inhibits subsequent allergen-induced reactivity. Thus the primary objective of this application is to produce a genetically engineered prototype AEHM E-3.56 and experimentally show that E-3.56 binding to surface-bound IgE on the allergic effector cells functions as a novel therapeutic against allergic reactivity. In Aim 1,we will engineer and express a prototypic IgG1 anti-epsilon (IgE) half antibody molecule E-3.56 composed of the mouse VH and VL regions linked to the human ?1 heavy chain and ? light chain constant regions respectively, with the two key cysteines in the C?1 hinge region mutated to preventing dimerization of the two CH chains. Co-expression of the chimeric H and L chains either by transient transfection or via established stable cell lines will result in the productionof E-3.56 that is monovalent for human IgE binding. In Aim 2, we will test the safety profile and therapeutic efficacy of E-3.56 for its ability to inhibit allergic responses in in vitro and in viv established allergy models. We will use a systemic allergic anaphylaxis model, passive cutaneous anaphylaxis model and human basophil stimulation to test an E-3.56's safety and therapeutic efficacy. In Aim 3 we will define by which of the following mechanisms E-3.56 suppresses allergic reactivity: 1) Steric hindrance preventing access to the allergen binding sites; 2) Triggering negative signaling in effector mast cells and basophils; 3) Promoting clearance of cell surface IgE- Fc?RI complexes; 4) Triggering conformational change of IgE's allergen-binding sites leading to loss of allergen binding; and/or 5) Interfering with the IgE cros-linking necessary for allergic signaling. This application is directed at the development of a nove allergy therapeutic that is relevant to the public health. PUBLIC HEALTH RELEVANCE: Targeting surface-bound IgE as a novel allergy therapeutic Allergic diseases involving both inhalants and foods have significantly increased in both prevalence and incidence over the past decades in the United States and other developed countries and now have become a major worldwide public health issue. Furthermore, IgE mediated reactivity to medications is an increasing problem with the use of newer biologic agents. The goal of this project is to develop and ultimately commercialize a novel allergy biologic therapeutic for the effective prevention/treatment of severe allergic reactivity such as occurs in severe allergic asthma and food allergy. This therapeutic would also be able to be used to block allergic reactivity and allow administration of agents (antibiotics etc) that patient are allergic to. A therapy such as is proposed is urgently needed and would be highly important for the public health.