Expression of TLR10 in B cells Correlates With Primary Sjögren’s Syndrome Progression

Abstract Primary Sjögren’s Syndrome (pSS) is considered a B cell-mediated disease, yet the precise role of B cells in the pathogenesis is not fully understood. Toll-like receptor 10 (TLR10) is highly expressed in human B cells, indicating that TLR10 probably plays a vital role in regulating B cell function as well as B cell-related diseases. However, the biology of TLR10 in pSS was rarely researched. Here, we examined the TLR10 expression in peripheral B cell subsets isolated from both pSS patients and healthy controls (HCs) and further analyzed the correlations between TLR10 expression and disease activity. We observed that TLR10 expression in peripheral total CD19+ B cells, naïve B cells (CD19+CD27-IgD+) and switched memory B cells (CD19+CD27+IgD-) was significantly increased in low-activity pSS patients as compared with HCs and high-activity pSS patients. TLR10 expression in total and switched memory B cells in pSS patients was significantly negatively correlated with serum levels of anti-SSA antibody and B cell activating factor of TNF family (BAFF). As compared with the TLR10 low-, the TLR10 high-expressed pSS patients presented with reduced switched memory B cells. Moreover, a much lower proportion of high-activity pSS patients was observed in TLR10 high- as compared to low-expressed patients. Our study concluded that TLR10 expression in peripheral total and switched memory B is negatively correlated with pSS disease activity, suggesting that TLR10 might suppress pSS progression via inhibiting the B cell class switch recombination. These results should contribute to the diagnosis and treatment of pSS.