Abstract：
BACKGROUND: Existing therapeutic strategies are challenged by long times to achieve effect and often require frequent administration. Peanut-allergic individuals would benefit from a therapeutic that provides rapid protection against accidental exposure within days of administration while carrying little risk of adverse reactions.
OBJECTIVE: Guided by the repertoire of human IgE mAbs from allergic individuals, we sought to develop a treatment approach leveraging the known protective effects of allergen-specific IgG4 antibodies.
METHODS: We applied our single-cell RNA-sequencing SEQ SIFTER platform (IgGenix, Inc, South San Francisco, Calif) to whole blood samples from peanut-allergic individuals to discover IgE mAbs. These were then class-switched by replacing the IgE constant region with IgG4 while retaining the allergen-specific variable regions. In vitro mast cell activation tests, basophil activation tests, ELISAs, and an in vivo peanut allergy mouse model were used to evaluate the specificity, affinity, and activity of these recombinant IgG4 mAbs.
RESULTS: We determined that human peanut-specific IgE mAbs predominantly target immunodominant epitopes on Ara h 2 and Ara h 6 and that recombinant IgG4 mAbs effectively block these epitopes. IGNX001, a mixture of 2 such high-affinity IgG4 mAbs, provided robust protection against peanut-mediated mast cell activation in vitro as well as against anaphylaxis upon intragastric peanut challenge in a peanut allergy mouse model.
CONCLUSIONS: We developed a peanut-specific IgG4 antibody therapeutic with convincing preclinical efficacy starting from a large repertoire of human IgE mAbs from demographically and geographically diverse individuals. These results warrant further clinical investigation of IGNX001 and underscore the opportunity for the application of this therapeutic development strategy in other food and environmental allergies.
OBJECTIVE: Guided by the repertoire of human IgE mAbs from allergic individuals, we sought to develop a treatment approach leveraging the known protective effects of allergen-specific IgG4 antibodies.
METHODS: We applied our single-cell RNA-sequencing SEQ SIFTER platform (IgGenix, Inc, South San Francisco, Calif) to whole blood samples from peanut-allergic individuals to discover IgE mAbs. These were then class-switched by replacing the IgE constant region with IgG4 while retaining the allergen-specific variable regions. In vitro mast cell activation tests, basophil activation tests, ELISAs, and an in vivo peanut allergy mouse model were used to evaluate the specificity, affinity, and activity of these recombinant IgG4 mAbs.
RESULTS: We determined that human peanut-specific IgE mAbs predominantly target immunodominant epitopes on Ara h 2 and Ara h 6 and that recombinant IgG4 mAbs effectively block these epitopes. IGNX001, a mixture of 2 such high-affinity IgG4 mAbs, provided robust protection against peanut-mediated mast cell activation in vitro as well as against anaphylaxis upon intragastric peanut challenge in a peanut allergy mouse model.
CONCLUSIONS: We developed a peanut-specific IgG4 antibody therapeutic with convincing preclinical efficacy starting from a large repertoire of human IgE mAbs from demographically and geographically diverse individuals. These results warrant further clinical investigation of IGNX001 and underscore the opportunity for the application of this therapeutic development strategy in other food and environmental allergies.
摘要：
背景：现有的治疗策略受到长时间的挑战以达到效果，并且通常需要频繁的给药。花生过敏个体将受益于在给药的几天内提供针对意外暴露的快速保护的治疗剂,同时携带很少的不良反应风险。
目的：以来自过敏个体的人IgE单克隆抗体（mAb）为指导，我们试图开发一种利用已知的过敏原特异性IgG4抗体保护作用的治疗方法.
方法：我们将我们的单细胞RNA测序SEQSIFTER™平台应用于来自花生过敏个体的全血样品，以发现IgEmAb。然后通过用IgG4替换IgE恒定区同时保留变应原特异性可变区来对这些进行类别转换。体外肥大细胞活化试验（MATs），嗜碱性粒细胞活化试验（BAT），酶联免疫吸附测定(ELISA)，并使用体内花生过敏小鼠模型来评估其特异性，亲和力,和这些重组IgG4mAb的活性。
结果：我们确定人花生特异性IgEmAb主要靶向Arah2和Arah6上的免疫显性表位，重组IgG4mAb有效阻断了这些表位。IGNX001，两种高亲和力IgG4mAb的混合物，在花生过敏小鼠模型中，针对花生介导的肥大细胞活化以及在胃内花生攻击后的过敏反应提供了强大的保护。
结论：我们开发了一种花生特异性IgG4抗体治疗药物，具有令人信服的临床前疗效，从人口统计学和地理上不同个体的大量人单克隆IgE抗体开始。这些结果值得对IGNX001进行进一步的临床研究，并强调了将这种治疗开发策略应用于其他食物和环境过敏的机会。
目的：以来自过敏个体的人IgE单克隆抗体（mAb）为指导，我们试图开发一种利用已知的过敏原特异性IgG4抗体保护作用的治疗方法.
方法：我们将我们的单细胞RNA测序SEQSIFTER™平台应用于来自花生过敏个体的全血样品，以发现IgEmAb。然后通过用IgG4替换IgE恒定区同时保留变应原特异性可变区来对这些进行类别转换。体外肥大细胞活化试验（MATs），嗜碱性粒细胞活化试验（BAT），酶联免疫吸附测定(ELISA)，并使用体内花生过敏小鼠模型来评估其特异性，亲和力,和这些重组IgG4mAb的活性。
结果：我们确定人花生特异性IgEmAb主要靶向Arah2和Arah6上的免疫显性表位，重组IgG4mAb有效阻断了这些表位。IGNX001，两种高亲和力IgG4mAb的混合物，在花生过敏小鼠模型中，针对花生介导的肥大细胞活化以及在胃内花生攻击后的过敏反应提供了强大的保护。
结论：我们开发了一种花生特异性IgG4抗体治疗药物，具有令人信服的临床前疗效，从人口统计学和地理上不同个体的大量人单克隆IgE抗体开始。这些结果值得对IGNX001进行进一步的临床研究，并强调了将这种治疗开发策略应用于其他食物和环境过敏的机会。
