美国基因泰克公司Marissa L. Matsumoto和Claudio Ciferri研究团队解析分泌型免疫球蛋白A（sIgA）核心结构。这一研究成果2020年2月6日在线发表在国际学术期刊《科学》上。

他们通过连接链（JC）与pIgR分泌成分复合物连接确定IgA-Fc二聚体、四聚体和五聚体的原子拆分结构。他们提出一种机制，其中JC模板进行IgA寡聚化并赋予pIgR结合和转胞吞作用不对称性。该框架将为未来基于IgA的疗法的设计提供依据。

据悉，分泌型免疫球蛋白A（sIgA）代表免疫系统抵御粘膜病原体的第一道防线。IgA作为二聚体和高级聚合物通过聚合免疫球蛋白受体（pIgR）跨上皮运输。到达管腔一侧后，sIgA介导宿主保护和病原体中和。近年来，作为新型治疗性抗体的IgA受到越来越多的关注。尽管进行了广泛的研究，但sIgA结构仍未知。

附：英文原文

Title: Structure of the secretory immunoglobulin A core

Author: Nikit Kumar, Christopher P. Arthur, Claudio Ciferri, Marissa L. Matsumoto

Issue&Volume: 2020/02/06

Abstract: AbstractSecretory immunoglobulin A (sIgA) represents the immune system’s first-line of defense against mucosal pathogens. IgAs are transported across the epithelium, as dimers and higher-order polymers, by the polymeric immunoglobulin receptor (pIgR). Upon reaching the luminal side, sIgAs mediate host protection and pathogen neutralization. In recent years, an increasing amount of attention has been given to IgA as a novel therapeutic antibody. Despite extensive studies sIgA structures have remained elusive. Here, we determine the atomic-resolution structures of dimeric, tetrameric, and pentameric IgA-Fc linked by the joining chain (JC) and in complex with the secretory component of the pIgR. We suggest a mechanism where the JC templates IgA oligomerization and imparts asymmetry for pIgR binding and transcytosis. This framework will inform the design of future IgA-based therapeutics.

DOI: 10.1126/science.aaz5807

Source: https://science.sciencemag.org/content/early/2020/02/06/science.aaz5807