R&D Laboratory, Division of Immunology and Allergy, University State Hospital (CHUV), Epalinges, Switzerland.
Bracco Suisse SA, Plan-Les-Ouates, Switzerland.
Allergy. 2016 Jul;71(7):957-66. doi: 10.1111/all.12859. Epub 2016 Mar 2.
Venom immunotherapy is efficient to desensitize people suffering from insect sting allergies. However, the numerous injections required over several years and important risks of severe side reactions complicate the widespread use of immunotherapy. In the search for novel approaches to blunt the overwhelming pro-allergic Th2 response, we evaluated the therapeutic efficacy of a treatment based on a denatured form of the major allergen, phospholipase A2, associated with microbubbles (PLA2denat -MB) in a mouse model of honeybee venom allergy.
Antibodies measured by ELISA, T-cell responses assessed by CFSE-based proliferation assays and ELISA, and basophil degranulation were examined after PLA2denat -MB-based therapeutic treatment of sensitized mice. Mice were challenged with a lethal dose of PLA2 to evaluate protection against anaphylaxis.
Therapeutic subcutaneous administration of two different PLA2denat -MB formulations, in contrast to PLA2denat alone, reduced allergic symptoms and protected all mice from anaphylaxis-mediated death after allergen challenge. At the functional level, the use of PLA2denat decreased IgE-mediated basophil degranulation as compared to the native form of the allergen. In comparison with PLA2denat alone, both PLA2denat -MB formulations decreased allergen-specific Th2 CD4 T-cell reactivity. At the mechanistic level, PLA2denat -MB containing 20% palmitic acid and PEG induced PLA2-specific IgA and increased Foxp3(+) Treg frequencies and TGF-β production, whereas the formulation bearing 80% palmitic acid triggered the production of IFN-γ, IgG2a, and IgG3.
In contrast to conventional PLA2 subcutaneous immunotherapy, the therapeutic administration of PLA2-MB treatment to mice that already had established allergy to PLA2 protects all subsequently challenged animals.
毒液免疫疗法对于缓解昆虫叮咬过敏的人群非常有效。然而，多年来需要进行多次注射，并且存在严重的副作用风险，这使得免疫疗法的广泛应用变得复杂。为了寻找新的方法来减轻压倒性的 Th2 过敏反应，我们评估了一种基于主要过敏原（磷脂酶 A2）的变性形式与微泡（PLA2denat-MB）结合的治疗方法在蜜蜂毒液过敏小鼠模型中的治疗效果。
通过 ELISA 测量抗体，通过 CFSE 增殖测定和 ELISA 评估 T 细胞反应，以及检测肥大细胞脱颗粒，在致敏小鼠接受 PLA2denat-MB 治疗后进行检测。使用 PLA2 进行致命剂量的挑战，以评估对过敏反应的保护作用。
与 PLA2denat 单独治疗相比，两种不同的 PLA2denat-MB 制剂的皮下治疗减少了过敏症状，并在过敏原挑战后保护所有小鼠免受过敏反应介导的死亡。在功能水平上，与天然形式的过敏原相比，PLA2denat 的使用减少了 IgE 介导的肥大细胞脱颗粒。与 PLA2denat 单独治疗相比，两种 PLA2denat-MB 制剂均降低了过敏原特异性 Th2 CD4 T 细胞反应。在机制水平上，含有 20%棕榈酸和 PEG 的 PLA2denat-MB 诱导 PLA2 特异性 IgA，并增加了 Foxp3+Treg 频率和 TGF-β 产生，而含有 80%棕榈酸的制剂则触发了 IFN-γ、IgG2a 和 IgG3 的产生。
与传统的 PLA2 皮下免疫疗法相比，已经对 PLA2 建立过敏反应的小鼠接受 PLA2-MB 治疗的治疗性给药可保护所有随后接受挑战的动物。
