Accumulation of synovial fluid CD19+CD24hiCD27+ B cells was associated with bone destruction in rheumatoid arthritis
Xiaofeng Guo, Tingting Xu, Jing Zheng, Xiangjun Cui, Ming Li, Kai Wang, Min Su, Huifang Zhang, Ke Zheng, Sun Chongling, Shulin Song, Hongjiang Liu
Abstract
Abstract Regulatory CD19 + CD24 hi CD27 + B cells were proved to be numerically decreased and functionally impaired in the peripheral blood (PB) from rheumatoid arthritis (RA), with the potential of converting into osteoclast-priming cells. However, the distribution and function of CD19 + CD24 hi CD27 + B cells in RA synovial fluid (SF) were unclear. In this study, we investigated whether RA SF CD19 + CD24 hi CD27 + B cells were increased and associated with bone destruction. We found that the proportion of RA SF CD19 + CD24 hi CD27 + B cells was increased significantly, and was positively correlated with swollen joint counts, tender joint counts and disease activity. CXCL12, CXCL13, CCL19 contributed to the recruitment of CD19 + CD24 hi CD27 + B cells in RA SF. Notably, CD19 + CD24 hi CD27 + B cells in the SF from RA expressed significantly more RANKL compared to OA and that in the PB from RA. Critically, RA CD19 + CD24 hi CD27 + B cells promoted osteoclast (OC) differentiation in vitro, and the number of OCs was higher in cultures with RA SF CD19 + CD24 hi CD27 + B cells than in those derived from RA PB. Collectively, these findings revealed the accumulation of CD19 + CD24 hi CD27 + B cells in SF and their likely contribution to joint destruction in RA. Modulating the status of CD19 + CD24 hi CD27 + B cells might provide novel therapeutic strategies for RA.