Pathogenic conversion of regulatory B10 cells into osteoclast-priming cells in rheumatoid arthritis

Publication date: January 2017
Source:Journal of Autoimmunity, Volume 76
Author(s): Fanlei Hu, Hongjiang Liu, Xu Liu, Xia Zhang, Liling Xu, Huaqun Zhu, Yingni Li, Lianjie Shi, Limin Ren, Jian Zhang, Zhanguo Li, Yuan Jia
Regulatory B10 cells were functionally impaired in rheumatoid arthritis (RA), yet the mechanisms were unclear. B cells are recently recognized as important participants in osteoclastogenesis by producing RANKL. In this study, we investigated whether regulatory B10 cells could convert into RANKL-producing cells, thus impairing their immunosuppressive functions in RA and exacerbating the disease progression. Our results showed that human regulatory B10 cells could ectopically express RANKL. Under RA circumstance, RANKL-producing B10 cells expanded dramatically, partially induced by TNF-α. The frequencies of these cells were positively correlated with RA patient disease activities and tender joint counts, but negatively correlated with the frequencies of regulatory B10 cells. Strikingly, RANKL-producing B10 cells from RA patients, but not healthy individuals significantly promoted osteoclast differentiation and bone erosion in a paracrine and cell-cell contact-dependent manner. Moreover, these pathogenic RANKL-producing B10 cells declined while regulatory IL-10-producing B10 cells increased in RA patients with disease remission after therapy. Collectively, these results showed that in RA, regulatory B10 cells demonstrated the potential of converting into RANKL-producing cells, thus exacerbating osteoclast formation, bone destruction and disease progression. Modulating the status of B10 cells might provide novel therapeutic strategies for RA.



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