Accelerated dissociation of IgE receptor complexes

项目摘要 Ige抗体和受体是过敏性级联反应的重要媒介，但也可能提供不同的 在抗肿瘤免疫治疗中的作用。Ige与其高亲和力的Ig E Fc受体(FceRI)结合于肥大细胞并 嗜碱性粒细胞和低亲和力受体(FceRII/CD23)表达于B细胞和上皮细胞。IGE绑定 TO FceRI使过敏效应细胞对变应原敏感，并且非常稳定，复合体持续时间为 即使在存在强大的抗IgE抗体的情况下，也会持续数月。我们已经开发出方法来快速 利用杂合双特异性Ig G/DARPin破坏IgE：FceRI复合体和脱敏变态反应细胞 识别IgE-Fc上两个不同表位的分子。在目标1中，我们将探索替代方案 新型双特异性抗IgE靶向和去除细胞表面IgE：FceRI复合体的研究 抗体。此外，我们将使用我们生产的两种抗IgE抗体来更深入地了解 完整的IgE的结构和动力学。IgE与CD23的相互作用也介导了重要的生物学作用 在B细胞中的作用，与CD21一起。在这里，在目标2中，我们将使用酵母展示来进化更高亲和力的变体 对其配体的CD23进行结构研究，并探索CD23依赖的 B细胞对免疫球蛋白E产生的调节。最后，在目标3中，我们试图分离和研究新的抗FceRIa 用酵母展示的抗体开发FceRI定向调节过敏效应器的新试剂 细胞活动。

Project Summary IgE antibodies and receptors are important mediators of the allergic cascade, but may also provide distinct functions in anti-tumor immunotherapy. IgE engages its high affinity IgE Fc receptor (FceRI) on mast cells and basophils as well as a low affinity receptor (FceRII/CD23) expressed on B cells and epithelial cells. IgE binding to FceRI sensitizes allergic effector cells to allergens and is very stable, with the complexes persisting for months even in the presence of potent anti-IgE antibodies. We have developed approaches to rapidly destabilizing IgE:FceRI complexes and desensitizing allergic effector cells using hybrid, bispecific IgG/DARPin molecules that recognize two distinct epitopes on the IgE-Fc. Here in Aim 1 we will explore alternative approaches to target and remove IgE:FceRI complexes from cell surfaces using novel bispecific anti-IgE antibodies. In addition, we will use two anti-IgE antibodies that we have produced to gain greater insights into the structure and dynamics of intact IgE. The IgE interaction with CD23 also mediates important biological effects in B cells, together with CD21. Here, in Aim 2, we will use yeast display to evolve higher affinity variants of CD23 for its ligands to enable structural studies of these complexes and to probe CD23-dependent regulation of IgE production by B cells. Finally, in Aim 3, we seek to isolate and study new anti-FceRIa antibodies using yeast display, to develop novel reagents for the FceRI-directed modulation of allergic effector cell activities.