CD226 + B Cells in Primary Sjögren's Syndrome:A Key Player in Clinical:Manifestations and Disease Pathogenesis

The costimulatory molecule CD226 has emerged as a key regulator of immune responses, yet its role in B cell-mediated pathogenesis of primary Sjögren's syndrome (pSS) remains poorly understood. The purpose of this study was to explore the relevance between CD226 + B cells and clinical features in pSS patients and to clarify the potential role of CD226-mediated B cell biological functions in contributing to the pathogenesis of pSS.Here, we identified a distinct CD226 + CD19 + B cell subset that exhibited pathogenic features in pSS. CD226 was significantly upregulated on B cells in the peripheral blood and salivary glands of pSS. patients.CD226 + CD19 + B cell showed a stronger correlation with clinical features, disease activity, and prognosis in pSS patients.The ROC curve demonstrated that CD226+CD19+ B cell exhibited significant diagnostic capability to distinguish pSS patients from healthy controls and to differentiate disease activity.This subset also exhibited heightened activation and pro-inflammatory phenotypes.Thereby,CD226+B cell may potentially be a promising therapeutic target and biomarker for the treatment of pSS. To investigate the functional role of CD226+CD19+ B cells in pSS, CD226+CD19+ and CD226−CD19+ B cell subsets were isolated from splenic mononuclear cells of NOD mice via FACS, followed by transcriptome-wide microarray profiling to delineate their differential molecular signatures