Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.
Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
Front Immunol. 2024 May 3;15:1343024. doi: 10.3389/fimmu.2024.1343024. eCollection 2024.
Around 20% of the population in Northern and Central Europe is affected by birch pollen allergy, with the major birch pollen allergen Bet v 1 as the main elicitor of allergic reactions. Together with its cross-reactive allergens from related trees and foods, Bet v 1 causes an impaired quality of life. Hence, new treatment strategies were elaborated, demonstrating the effectiveness of blocking IgG antibodies on Bet v 1-induced IgE-mediated reactions. A recent study provided evidence for the first time that Bet v 1-specific nanobodies reduce patients´ IgE binding to Bet v 1. In order to increase the potential to outcompete IgE recognition of Bet v 1 and to foster cross-reactivity and cross-protection, we developed Bet v 1-specific nanobody trimers and evaluated their capacity to suppress polyclonal IgE binding to corresponding allergens and allergen-induced basophil degranulation.
Nanobody trimers were engineered by adding isoleucine zippers, thus enabling trimeric formation. Trimers were analyzed for their cross-reactivity, binding kinetics to Bet v 1, and related allergens, and patients' IgE inhibition potential. Finally, their efficacy to prevent basophil degranulation was investigated.
Trimers showed enhanced recognition of cross-reactive allergens and increased efficiency to reduce IgE-allergen binding compared to nanobody monomers. Furthermore, trimers displayed slow dissociation rates from allergens and suppressed allergen-induced mediator release.
We generated high-affine nanobody trimers that target Bet v 1 and related allergens. Trimers blocked IgE-allergen interaction by competing with IgE for allergen binding. They inhibited IgE-mediated release of biological mediators, demonstrating a promising potential to prevent allergic reactions caused by Bet v 1 and relatives.
北欧和中欧约有 20%的人口受桦树花粉过敏影响，主要的桦树花粉过敏原 Bet v 1 是引发过敏反应的主要诱因。与相关树木和食物中的交叉反应性过敏原一起，Bet v 1 降低了生活质量。因此，制定了新的治疗策略，证明了阻断 Bet v 1 诱导的 IgE 介导反应中的 IgG 抗体的有效性。最近的一项研究首次提供了证据，表明 Bet v 1 特异性纳米抗体可减少患者的 IgE 与 Bet v 1 的结合。为了增加与 IgE 识别竞争的潜力，促进交叉反应和交叉保护，我们开发了 Bet v 1 特异性纳米抗体三聚体，并评估了它们抑制相应过敏原和过敏原诱导的嗜碱性粒细胞脱颗粒的多克隆 IgE 结合的能力。
通过添加异亮氨酸拉链来设计纳米抗体三聚体，从而实现三聚体的形成。分析三聚体的交叉反应性、与 Bet v 1 和相关过敏原的结合动力学以及患者 IgE 抑制潜力。最后，研究了它们预防嗜碱性粒细胞脱颗粒的功效。
三聚体显示出对交叉反应性过敏原的增强识别能力，并提高了降低 IgE-过敏原结合的效率。此外，三聚体与过敏原的解离速率较慢，并抑制过敏原诱导的介质释放。
我们生成了针对 Bet v 1 和相关过敏原的高亲和力纳米抗体三聚体。三聚体通过与 IgE 竞争过敏原结合来阻断 IgE-过敏原相互作用。它们抑制 IgE 介导的生物介质释放，显示出预防由 Bet v 1 和相关物引起的过敏反应的有前途的潜力。
