Work

CD5L associates with IgM via the J chain

Year: 2024

Type: article

Abstract: CD5 antigen-like (CD5L), also known as Spα or AIM (Apoptosis inhibitor of macrophage), emerges as an integral component of serum immunoglobulin M (IgM). However, the molecular mechanism underlying the interaction between IgM and CD5L has remained elusive. In this study, we present a cryo-electron microscopy structure of the human IgM pentamer core in complex with CD5L. Our findings reveal that CD5L binds to the joining chain (J chain) in a Ca2+-dependent manner and further links to IgM via a disulfide bond. We further show that CD5L reduces IgM binding to the mucosal transport receptor pIgR, but does not impact the binding of the IgM-specific receptor FcμR. Additionally, CD5L does not interfere with IgM-mediated complement activation. These results offer new insights into our understanding of IgM and shed new light on the function of the J chain in the immune system.

Source: Nature Communications

DOI: 10.1038/s41467-024-52175-y

Authors: Yuxin Wang, Chen Su, Chenggong Ji, Junyu Xiao

Institutions: Peking University, State Key Laboratory of Protein and Plant Gene Research, Center for Life Sciences, Changping Laboratory

Language: English

Topic: Monoclonal and Polyclonal Antibodies Research

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $6,790