Effector functions of differentially glycosylated anti-Bet v 1 human IgG subclasses

桦树花粉过敏的特征是产生针对主要过敏原Bet v1的IgE和Ig G抗体。成功的过敏原特异性免疫治疗(SIT；减敏)通常与Bet v 1反应性血清Ig G抗体的大量增加有关，主要是Ig G1和Ig G4。关于这些抗Bet v1抗体的功能，人们普遍认为它们捕获过敏原，并抑制其与肥大细胞结合的促炎IgE。然而，最近的研究表明，免疫球蛋白抗体的Fc N-糖基化模式决定了它们的促炎或抗炎效应：非半乳糖化和非唾液酸化的免疫球蛋白抗体是促炎的，半乳糖化和唾液酸化的免疫球蛋白抗体是抗炎的。在这种情况下，我们已经证明唾液酸化的免疫球蛋白抗体是在用蛋白质抗原成功诱导耐受后在小鼠和人类中诱导的，提示唾液酸化的过敏原特异性的免疫球蛋白抗体参与了这种SIT依赖的耐受诱导。进一步的结果表明，唾液酸化，而不是G0，抗卵清蛋白(OVA)小鼠单抗IgG1Abs，可以减少OVA依赖小鼠模型的过敏性呼吸道炎症。此外，这些研究表明，含有抗原特异性唾液酸化Ig G抗体的免疫复合物能够抑制树突状细胞的成熟，从而抑制促炎T细胞的启动。在本研究中，我们希望克隆和制备差异糖基化的人源化和真人化的人源性和真人化抗Bet v 1 IgG1和IgG4抗体，以研究它们在人免疫细胞培养试验中的抑制潜力，并与差异糖基化的小鼠抗Bet v 1 IgG1抗体并行，在BET v 1依赖的小鼠过敏模型中。在这个小鼠模型中，我们还想要表征不同糖基化的免疫球蛋白抗体的受体复合体。此外，我们还想分析皮下注射前、中和后人抗Bet v1血清免疫球蛋白抗体的Fc糖基化模式。总之，我们想要确定抑制过敏反应的最佳Fc糖基化的人免疫球蛋白G亚类，并表征其功能作用。这将对成功的SIT的验证、用于被动免疫的抗体的可能开发以及个性化SIT方案的优化具有重要意义。

Allergy to birch pollen is characterized by the development of IgE and IgG antibodies (Abs) against the major allergen Bet v 1. Successful allergen-specific immunotherapy (SIT; hyposensibilization) to combat birch pollen allergy is often associated with a large increase in Bet v 1-reactive serum IgG Abs, mainly IgG1 and IgG4. The common idea about the function of these anti-Bet v 1 IgG Abs is that they capture the allergen and inhibit its binding to the pro-inflammatory IgE bound to mast cells. However, it has recently been shown that the Fc N-glycosylation pattern of IgG Abs determines their pro- or anti-inflammatory effector functions: agalactosylated (non-galactosylated and non-sialylated; G0) IgG Abs are pro-inflammatory and galactosylated plus sialylated IgG Abs are anti-inflammatory.In this context, we have shown that sialylated IgG Abs are induced after successful tolerance induction with protein antigens in mice and after SIT in humans, suggesting that sialylated allergen-specific IgG Abs are involved in this SIT-dependent tolerance induction. Further results indicated that sialylated, but not G0, anti-ovalbumin (OVA) murine monoclonal IgG1 Abs, can reduce allergic airway inflammation in an OVA-dependent mouse model. Furthermore, these studies indicated that immune complexes containing antigen-specific sialylated IgG Abs are able to inhibit dendritic cell maturation and therefore priming of pro-inflammatory T cells.In this study, we want to clone and produce differentially glycosylated monoclonal humanized and real human anti-Bet v 1 IgG1 and IgG4 Abs to investigate their inhibitory potential in human immune cell culture assays and, in parallel with differentially glycosylated murine anti-Bet v 1 IgG1 Abs, in a Bet v 1-dependent mouse allergy model. In this mouse model, we also want to characterize the receptor complexes of the differentially glycosylated IgG Abs.Additionally, we want to analyze the Fc glycosylation patterns of human anti-Bet v 1 serum IgG Abs before, during and after subcutaneous SIT.Overall, we want to identify the optimal Fc glycosylated allergen-specific human IgG subclass to inhibit allergic reactions and characterize its functional role. This will be important for the validation of successful SIT, the possible development of Abs for passive immunization and the optimization of individualized SIT protocols.