Download MendeleyCD72 negatively regulates B lymphocyte responses to the lupus-related endogenous toll-like receptor 7 ligand Sm/RNP
Akatsu, C., Shinagawa, K., Numoto, N., Liu, Z., Ucar, A.K., Aslam, M., Phoon, S., Adachi, T., Furukawa, K., Ito, N., Tsubata, T.(2016) J Exp Med 213: 2691-2706
- PubMed: 27810925
- DOI: https://doi.org/10.1084/jem.20160560
- Primary Citation of Related Structures:
5B1R - PubMed Abstract:
Toll-like receptor 7 (TLR7) plays an essential role in development of systemic lupus erythematosus by co-stimulating B cells reactive to the endogenous TLR7 ligand Sm/ribonucleoprotein (RNP), a crucial lupus self-antigen. However, how the TLR7-mediated autoimmune response is regulated is not yet known. In this study, we demonstrate that CD72, an inhibitory B cell co-receptor known to prevent development of lupus, recognizes Sm/RNP at the extracellular C-type lectin-like domain (CTLD) and specifically inhibits B cell response to Sm/RNP. Moreover, the CTLD of CD72 c , a lupus-susceptible allele, binds to Sm/RNP less strongly than that of lupus-resistant CD72 a Reduced binding of CD72 c is supported by x-ray crystallographic analysis that reveals a considerable alteration in charge at the putative ligand-binding site. Thus, CD72 appears to specifically inhibit B cell response to the endogenous TLR7 ligand Sm/RNP through CTLD-mediated recognition of Sm/RNP, thereby preventing production of anti-Sm/RNP antibody crucial for development of lupus.
Organizational Affiliation:
Department of Immunology, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo, Tokyo 113-8510, Japan.
