Novel Anti-allergic Single-domain Antibody Against IgE

描述（由申请人提供）：阻断IgE激活的蛋白质疗法有望成为治疗哮喘的下一代药物。事实上，omalizumab是一种抑制IgE- fc与高亲和力IgE受体Fc5RI结合的人源化单克隆抗体，在治疗症状控制不充分的中重度过敏性哮喘患者中具有有益效果。尽管omalizumab有效，但它的治疗仅限于疾病非常严重的患者，可能是由于这种单克隆抗体药物的成本非常高。该项目旨在开发具有成本效益的ige - fc结合单域抗体（SDAs），用于治疗哮喘。具体来说，我们将使用一种称为mRNA-display的定向蛋白质进化方法来开发新一代基于新发现的单体人类VH结构域（hVH）的ige - fc结合sda。我们将首先从包含超过1013个独特序列的mrna显示的hVH结构域文库中，通过基于扩增的迭代体外选择，生成与人IgE-Fc上fc5ri结合区域紧密特异性结合的SDAs。选择的序列将通过特殊程序的组合进行优化，以获得高的目标结合亲和力和特异性。由此产生的SDAs将使用各种体外和体内方法详细表征其靶标结合特性。优化后的SDA将二聚体化，以增加其与IgE-Fc的结合强度。由此产生的基于hVH结构域的ige - fc结合SDAs具有许多优点，包括高靶向结合亲和力和特异性，低免疫原性，并且由于其在细菌中的高表达水平而显着降低了制造成本。这种sda在治疗哮喘方面可能有重要的应用。

DESCRIPTION (provided by applicant): Protein therapeutics that blocks the activation of IgE hold the promise of being used as the next generation of drugs in the treatment of asthma. Indeed, omalizumab, a humanized monoclonal antibody that inhibits the binding of IgE-Fc to the high-affinity IgE receptor Fc5RI, has beneficial effects in the treatment of moderate to severe allergic asthma in patients whose symptoms are inadequately controlled. Despite its effectiveness, omalizumab treatment is only limited in patients with very severe disease, presumably due to the very high cost of this monoclonal antibody drug. This project is directed at developing IgE-Fc-binding single domain antibodies (SDAs) for cost-effective treatment of asthma. Specifically, we will use a directed protein evolution method called mRNA-display to develop a new generation of IgE-Fc-binding SDAs that are based on a newly identified monomeric human VH domain (hVH). We will first generate SDAs that tightly and specifically bind to the Fc5RI-binding region on human IgE-Fc from an mRNA-displayed hVH domain library containing more than 1013 unique sequences through amplification-based, iterative rounds of in vitro selection. The selected sequences will be optimized to acquire high target-binding affinity and specificity through a combination of special procedures. The resulting SDAs will be characterized in detail for their target-binding properties using various in vitro and in vivo approaches. The optimized SDA will be dimerized to increase its binding strength with IgE-Fc. The resulting IgE-Fc-binding SDAs based on hVH domain would have a number of advantages, including high target-binding affinity and specificity, low immunogenicity, and significantly reduced manufacturing costs due to their high expression levels in bacteria. Such SDAs could have significant applications in the treatment of asthma. PUBLIC HEALTH RELEVANCE: Asthma is a major global health problem with an enormous increase in prevalence during the past few decades. In the United States alone, about 20 million people, including nearly 9 million children, have asthma. Despite the availability of effective and relatively cheap treatments that benefit the majority of asthma patients, approximately 5% of severe asthmatic patients remain poorly controlled. The proposed research aims at developing a novel class of anti-asthma human single domain antibodies that possess unique features, including high efficacy, low immunogenicity, and significantly reduced manufacturing cost. The availability of such biopharmaceuticals could greatly benefit many patients with severe-symptomatic asthma.