Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.
Department of Medicine, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia.
Trends Immunol. 2019 Mar;40(3):197-211. doi: 10.1016/j.it.2019.01.005. Epub 2019 Feb 10.
IgG3 comprises only a minor fraction of IgG and has remained relatively understudied until recent years. Key physiochemical characteristics of IgG3 include an elongated hinge region, greater molecular flexibility, extensive polymorphisms, and additional glycosylation sites not present on other IgG subclasses. These characteristics make IgG3 a uniquely potent immunoglobulin, with the potential for triggering effector functions including complement activation, antibody (Ab)-mediated phagocytosis, or Ab-mediated cellular cytotoxicity (ADCC). Recent studies underscore the importance of IgG3 effector functions against a range of pathogens and have provided approaches to overcome IgG3-associated limitations, such as allotype-dependent short Ab half-life, and excessive proinflammatory activation. Understanding the molecular and functional properties of IgG3 may facilitate the development of improved Ab-based immunotherapies and vaccines against infectious diseases.
IgG3 仅占 IgG 的一小部分，直到近年来才得到相对深入的研究。IgG3 的关键理化特性包括铰链区拉长、分子灵活性更大、广泛的多态性以及其他 IgG 亚类不存在的额外糖基化位点。这些特性使 IgG3 成为一种独特有效的免疫球蛋白，具有触发效应功能的潜力，包括补体激活、抗体（Ab）介导的吞噬作用或 Ab 介导的细胞毒性（ADCC）。最近的研究强调了 IgG3 效应功能对一系列病原体的重要性，并提供了克服 IgG3 相关限制的方法，例如同种型依赖性 Ab 半衰期短和过度促炎激活。了解 IgG3 的分子和功能特性可能有助于开发针对传染病的改进的 Ab 为基础的免疫疗法和疫苗。
