Engineering of pH-dependent antigen binding properties for toxin-targeting IgG1 antibodies using light-chain shuffling

IF 4.4 2区生物学 Q2 BIOCHEMISTRY & MOLECULAR BIOLOGY

Structure Pub Date : 2024-08-14 DOI:10.1016/j.str.2024.07.014

引用次数: 0

Abstract

Immunoglobulin G (IgG) antibodies that bind their cognate antigen in a pH-dependent manner (acid-switched antibodies) can release their bound antigen for degradation in the acidic environment of endosomes, while the IgGs are rescued by the neonatal Fc receptor (FcRn). Thus, such IgGs can neutralize multiple antigens over time and therefore be used at lower doses than their non-pH-responsive counterparts. Here, we show that light-chain shuffling combined with phage display technology can be used to discover IgG1 antibodies with increased pH-dependent antigen binding properties, using the snake venom toxins, myotoxin II and α-cobratoxin, as examples. We reveal differences in how the selected IgG1s engage their antigens and human FcRn and show how these differences translate into distinct cellular handling properties related to their pH-dependent antigen binding phenotypes and Fc-engineering for improved FcRn binding. Our study showcases the complexity of engineering pH-dependent antigen binding IgG1s and demonstrates the effects on cellular antibody-antigen recycling.

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利用轻链洗牌技术为毒素靶向 IgG1 抗体设计 pH 依赖性抗原结合特性

以 pH 依赖性方式结合其同源抗原的免疫球蛋白 G（IgG）抗体（酸开关抗体）可释放其结合的抗原，以便在内质体的酸性环境中降解，而这种 IgG 可被新生 Fc 受体（FcRn）所拯救。因此，这种 IgG 可以长期中和多种抗原，因此使用剂量比非 H 反应性抗体低。在这里，我们以蛇毒毒素肌毒素 II 和α-桔梗毒素为例，展示了轻链洗牌与噬菌体展示技术相结合可用于发现具有更强 pH 依赖性抗原结合特性的 IgG1 抗体。我们揭示了所选 IgG1 与其抗原和人类 FcRn 结合方式的差异，并展示了这些差异如何转化为与其 pH 依赖性抗原结合表型相关的不同细胞处理特性，以及如何通过 Fc 工程改善 FcRn 结合。我们的研究展示了依赖 pH 值的抗原结合 IgG1s 工程的复杂性，并证明了其对细胞抗体-抗原循环的影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Structure 生物-生化与分子生物学

CiteScore

8.90

自引率

1.80%

发文量

155

审稿时长

3-8 weeks

期刊介绍： Structure aims to publish papers of exceptional interest in the field of structural biology. The journal strives to be essential reading for structural biologists, as well as biologists and biochemists that are interested in macromolecular structure and function. Structure strongly encourages the submission of manuscripts that present structural and molecular insights into biological function and mechanism. Other reports that address fundamental questions in structural biology, such as structure-based examinations of protein evolution, folding, and/or design, will also be considered. We will consider the application of any method, experimental or computational, at high or low resolution, to conduct structural investigations, as long as the method is appropriate for the biological, functional, and mechanistic question(s) being addressed. Likewise, reports describing single-molecule analysis of biological mechanisms are welcome. In general, the editors encourage submission of experimental structural studies that are enriched by an analysis of structure-activity relationships and will not consider studies that solely report structural information unless the structure or analysis is of exceptional and broad interest. Studies reporting only homology models, de novo models, or molecular dynamics simulations are also discouraged unless the models are informed by or validated by novel experimental data; rationalization of a large body of existing experimental evidence and making testable predictions based on a model or simulation is often not considered sufficient.