Rapid, safe suppression of IgE-mediated disease with monovalent anti-ceRIa mAb

使用单价抗 ceRIa mAb 快速、安全地抑制 IgE 介导的疾病

• 批准号: 10213608
• 负责人: FRED Douglass FINKELMAN
• 金额: $ 56.61万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-05 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10213608
• 关键词: Adverse effects; Affect; Affinity; Allergens; Allergic; Allergic Disease; Anaphylaxis; Animal Model; Animals; Antibodies; Antigens; Basophils; Binding; Blood Cells; Cells; Clinical; Clinical Trials; Complement; Complement Receptor; Disease; Dose; Endocytosis; Excision; Exposure to; Flow Cytometry; Food Hypersensitivity; Granulocyte-Macrophage Colony-Stimulating Factor; Hour; Human; Hypersensitivity; IgE; IgE Receptors; IgG1; Immunodeficient Mouse; Immunoglobulin Class Switching; Immunoglobulin Constant Region; Immunoglobulin G; In Vitro; Injections; Interleukin 4 Receptor; Life; Macaca mulatta; Mediating; Modeling; Monoclonal Antibodies; Morbidity - disease rate; Mus; Preparation; Prevalence; Procedures; Process; Protein Tyrosine Kinase; Protocols documentation; Reagent; Safety; Serum; Signal Transduction; Stem Cell Factor; Structure; Surface; Testing; Transgenic Mice; Transgenic Organisms; Umbilical Cord Blood; Variant; Work; anergy; crosslink; cytokine; desensitization; humanized mouse; improved; in vivo; mast cell; mouse model; mutant; passive sensitization; prevent; receptor; reconstitution

This proposal tests the hypothesis that sustained, limited in vivo crosslinking of the high affinity IgE receptor, FcεRI, on mast cells (MCs) and basophils (BAs) rapidly desensitizes these cells and safely and effectively prevents IgE-mediated diseases, such as food allergy and anaphylaxis. Rapid desensitization (RD) is traditionally a procedure in which MCs and BAs from people who have IgE-mediated allergy to a specific allergen are made temporarily unresponsive to that allergen by exposure to increasing allergen concentrations over several hours. We modified RD by inoculating mice with increasing concentrations of an anti FcεRI α chain mAb. These studies showed that: (1) RD with anti-FcεRIα mAb is effective, safer and longer lasting than RD with allergen; (2) RD with anti-FcεRIα mAb is antigen-nonspecific; (3) MC unresponsiveness can be safely sustained by maintaining serum levels of this mAb; (4) this process works with anti-human (hu) FcεRIα mAbs in mice that express hu, rather than mouse FcεRIα (huFcεRIα mice); and (5) RD depends both on induction of MC anergy and removal of MC FcεRI and IgE. Recently, we have found that IgE-mediated anaphylaxis can be fully suppressed in huFcεRIα mice, without adverse effect, by repeatedly injecting <1 µg of IE7, a mouse mAb that binds to huFcεRIα regardless of FcεRI association with IgE. These mice can also be safely and dose- dependently desensitized by a single injection of a monovalent (mv) form of IE7 that has human IgG1-derived constant regions (mv huIgG1 IE7). mv huIgG1 IE7 also depletes blood BAs, and removes ~90% of MC IgE, but little FcεRIα. The loss of MC IgE and particularly, its disproportionate loss compared to FcεRI, was unexpected, because IE7 does not cause MCs to lose IgE in vitro and this mv Ab should only crosslink FcεRI if the Ab becomes multivalent by aggregating or by binding to cellular Fcγ or complement receptors. This proposal builds on these observations. Aim 1 uses flow cytometry, structural studies, anti-FcγR mAb, and hu IgG isotype switch variants of mv IE7 to determine whether mv huIgG1 IE7 crosslinks FcεRI in vivo and, if so, through what mechanism(s). Aim 1 also evaluates whether mv huIgG1 IE7 aggregation or internalization of IgE-loaded FcεRI is required for the disproportionate in vivo loss of MC IgE. Aim 2 applies Aim 1 results to use mv IE7 to safely desensitize actively sensitized, hyperallergic huFcεRIα mice that express a mutant IL-4 receptor as well as passively sensitized hu cord blood-reconstituted, hu cytokine-secreting, immunodeficient mice that develop large numbers of activated hu MCs and BAs; both models have been difficult to desensitize with increasing doses of divalent IE7. Aim 3 applies aim 2 results to desensitize rhesus monkeys, which express FcεRIα that reacts with IE7. Together, these aims should optimize the use of mv anti- FcεRIα mAb for RD and suggest whether and how it could be used to suppress hu IgE-mediated disease.

该提案测试了高亲和力 IgE 持续、有限的体内交联这一假设 肥大细胞 (MC) 和嗜碱性粒细胞 (BA) 上的受体 FcεRI 可以快速使这些细胞脱敏，并安全且安全地 有效预防IgE介导的疾病，如食物过敏和过敏反应。快速脱敏（RD） 传统上是一种程序，其中来自对特定特定物质有 IgE 介导过敏的人的 MC 和 BA 通过暴露于不断增加的过敏原浓度，过敏原暂时对该过敏原无反应 几个小时内。我们通过给小鼠接种浓度不断增加的抗 FcεRI α 来修改 RD 链单克隆抗体。这些研究表明：（1）抗 FcεRIα mAb 的 RD 比 RD 更有效、更安全、更持久。 含有过敏原的RD； (2) 使用抗 FcεRIα mAb 进行的 RD 是抗原非特异性的； (3) MC无反应可以安全处理 通过维持该单克隆抗体的血清水平来维持； (4) 此过程适用于抗人 (hu) FcεRIα mAb 在表达 hu 而不是小鼠 FcεRIα 的小鼠中（huFcεRIα 小鼠）； (5) RD 取决于感应 MC 无反应性并去除 MC FcεRI 和 IgE。最近，我们发现IgE介导的过敏反应可以 通过重复注射 <1 µg IE7（一种小鼠​​单克隆抗体），在 huFcεRIα 小鼠中完全受到抑制，且没有副作用 无论 FcεRI 与 IgE 的关联如何，它都会与 huFcεRIα 结合。这些小鼠也可以安全且剂量- 通过单次注射单价 (mv) 形式的 IE7（具有人 IgG1 衍生的）实现依赖性脱敏 恒定区（mv huIgG1 IE7）。 mv huIgG1 IE7 也会消耗血液 BA，并去除约 90% 的 MC IgE，但是 FcεRIα 很少。 MC IgE 的损失，特别是与 FcεRI 相比，其损失不成比例， 出乎意料，因为 IE7 不会导致 MC 在体外失去 IgE，并且该 mv Ab 应该仅在以下情况下交联 FcεRI： Ab 通过聚集或与细胞 Fcγ 或补体受体结合而变得多价。 该提案建立在这些观察的基础上。目标 1 使用流式细胞术、结构研究、抗 FcγR mAb、 和 hu IgG 同种型转换 mv IE7 的变体，以确定 mv huIgG1 IE7 是否在体内交联 FcεRI 如果是，通过什么机制？目标 1 还评估 mv huIgG1 IE7 聚集或 MC IgE 体内不成比例的损失需要负载 IgE 的 FcεRI 内化。目标 2 适用 目标 1 结果是使用 mv IE7 使表达主动致敏、超过敏的 huFcεRIα 小鼠安全脱敏 突变型 IL-4 受体以及被动致敏的 hu 脐带血重构、hu 细胞因子分泌， 免疫缺陷小鼠产生大量激活的 hu MC 和 BA；两种型号均已 随着二价 IE7 剂量的增加很难脱敏。目标 3 应用目标 2 结果使恒河猴脱敏 猴子，表达与 IE7 反应的 FcεRIα。总之，这些目标应优化 mv 抗的使用 用于 RD 的 FcεRIα mAb 并表明它是否以及如何用于抑制 hu IgE 介导的疾病。