Production of Autoreactive Heavy Chain-Only Antibodies in Systemic Lupus Erythematosus

Frontiers in Immunology

Hongyan Liao¹  Song Li²  Yangsheng Yu³  Yinshi Yue³  Kaihong Su⁴  Zhixin Zhang⁵  Yue Zhuo⁵  Shu Xu⁶  Hong Yang⁶ 

[1] Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China;Department of Medical Oncology, Cancer Center, Qilu Hospital of Shandong University, Jinan, China;Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States;Education-Microbiology/Immunology, Department of Medical Education, California University of Science and Medicine, San Bernardino, CA, United States;Health Management Center, Institute of Health Management, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China;State Key Laboratory of Biotherapy, Sichuan University, Chengdu, China;

关键词: B cell;    plasmablast;    heavy chain antibody;    polyreactive antibody;    autoreactive antibody;    somatic hypermutation;   

DOI  :  10.3389/fimmu.2020.00632

来源: DOAJ

【 摘 要 】

Systemic lupus erythematosus (SLE) is characterized by the overproduction of high-affinity autoreactive antibodies. Here, we show that more than 65.8% of 222 recombinant antibodies derived from 8 SLE patients can be secreted as heavy chain-only antibodies (HCAbs) when expressed in HEK-293T cells. The secretion of HCAbs follows the conventional endoplasmic reticulum-Golgi apparatus pathway, despite triggering a weaker unfolded protein response (UPR). Many of the purified SLE HCAbs remain autoreactive and have an even higher affinity for dsDNA, Sm, nucleosome, and cardiolipin than HCAbs from healthy individuals. Extended analyses of the CDR3 region and the heavy chain variable (VH) region of HCAb F3 show that the VH region is responsible for IgH secretion, while the CDR3 region determines its reactivity. Such a high frequency of HCAb secretion cannot fully concur with our current understanding of antibody assembly and secretion. The presence of a large proportion of autoreactive HCAbs in SLE reveals a novel mechanism for the generation of autoreactive antibodies in lupus.

【 授权许可】

Unknown