Expression And Related Function Of B7-H4on Salivary Gland In The Patients With Primary Sjogren’s Syndrome

Objective To investigate the expression and function of B7-H4on salivary gland inthe patients with primary sjogren’s syndrome (pSS).Methods Immunohistochemistry and flow cytometry were used to detect theexpression of B7-H4on salivary gland from40pSS patients and5controls withsalivary gland biopsies. ELISA was used to detect soluble B7-H4of serum in pSSpatients and20healthy donors. The induction of B7-H4by different cytokines onSEGC from pSS patients and the proliferation response of CD4+T cells against B7-H4associated cultured SEGC from non-pSS patients were investigated by flow cytometryResults Immunohistological staining revealed that B7-H4antigen is restricted totubular epithelium, The B7-H4positive expression of tubules on salivary gland biopsiesfrom pSS patients(18.20±13.93)%were lower than controls(85±23)%(P=0.012). flowcytometry revealed that The B7-H4expression of cell suspensions from salivary frompSS patients(42±21)%were lower than controls(47.74±21.99)%(P=0.001),.Excitingly, the level of soluble B7-H4detected in serum of pSSpatients(48.96±31.02ng/ml) were significantly deceased than healthydonors(70.57±27.34ng/ml)(P=0.018）and positive correlated with saliva flow rate andtear flow rate(r=0.629p<0.001;r=0.752p<0.001) respectively. In vitro, LPS and TGF-βderived the expression of B7-H4on single cell suspensions obtained from salivary gland derived from patients with pSS. Besides, the proliferation of CD4+T cells frompatients with non-SS was significantly suppressed by B7-H4-SEGC when compared toCD4+T cell cultured alone.Conclusion B7-H4costimulatory molecules were deceased on salivary glandepithelial cells and in serum in patients with pSS, and B7-H4related SEGC inhibitedthe proliferation of T cells, which reveal B7-H4molecules probably has effects duringthe progress of pSS, and a clear understanding of its functional roles may furtherelucidate the pathogenesis of this disease.