Therapeutic antibodies have predominantly been IgG-based. However, the ongoing clinical trial of MOv18 IgE has highlighted the potential of using IgE antibodies in cancer therapy. While extensive studies targeting IgG glycosylation resulted in a rational basis for the development of enhanced biotherapeutics, IgE glycosylation remains an area with limited analyses. Previous studies on the role of IgE glycosylation present conflicting data with one study emphasizing the importance of N275 and T277 residues for FcεRI binding whereas another asserts the nonsignificance of IgE glycosylation in receptor interaction. While existing literature underscores the significance of glycans at the N275 position for binding to FcεR1 receptor and initiation of anaphylaxis, the role of other IgE glycosylation sites in folding or receptor binding remains elusive. This study systematically investigates the functional significance of N-linked glycosylation sites in the heavy chain of IgE which validates the pivotal role of N275 residue in IgE secretion and stability. Replacement of this asparagine to non-amine group moieties does not affect IgE function in vitro, yet substitution with aspartic acid compromises antibody yield. The deglycosylated IgE variant exhibits superior efficacy, challenging the conventional importance of glycosylation for effector function. In summary, our study unveils an intricate relationship between N-glycosylation sites and the structural–functional dynamics of IgE antibodies. Furthermore, it offers novel insights into the IgE scaffold, paving the way for the development of more effective and stable IgE-based therapeutics.

中文翻译：

---

系统突变分析揭示了 N275 在 IgE 稳定性中的重要作用


治疗性抗体主要基于 IgG。然而，正在进行的 MOv18 IgE 临床试验强调了在癌症治疗中使用 IgE 抗体的潜力。虽然针对 IgG 糖基化的广泛研究为开发增强型生物治疗药物奠定了合理的基础，但 IgE 糖基化仍然是一个分析有限的领域。以前关于 IgE 糖基化作用的研究提出了相互矛盾的数据，一项研究强调 N275 和 T277 残基对 FcεRI 结合的重要性，而另一项研究则断言 IgE 糖基化在受体相互作用中无意义。虽然现有文献强调了 N275 位点的聚糖对与 FcεR1 受体结合和引发过敏反应的重要性，但其他 IgE 糖基化位点在折叠或受体结合中的作用仍然难以捉摸。本研究系统研究了 IgE 重链中 N-连接糖基化位点的功能意义，验证了 N275 残基在 IgE 分泌和稳定性中的关键作用。将这种天冬酰胺取代为非胺基部分不会影响体外 IgE 功能，但用天冬氨酸取代会影响抗体产量。去糖基化的 IgE 变体表现出卓越的疗效，挑战了糖基化对效应器功能的传统重要性。总之，我们的研究揭示了 N-糖基化位点与 IgE 抗体的结构-功能动力学之间的复杂关系。此外，它为IgE支架提供了新的见解，为开发更有效、更稳定的基于IgE的疗法铺平了道路。