B7-H4 deficiency in salivary gland of patients with primary Sjögren's syndrome impairs the regulatory effect on T cells.

Aim Our previous study confirmed the defect of B7-H4 expression in peripheral blood and salivary glands of patients with primary Sjögren's syndrome ( pSS). The aim of this study was to analyze the effect of the deficit expression of B7-H4 on CD4⁺ T cells. Methods CD4⁺ T cells were purified by magnetic-activated cell sorting MACS. The proliferation and cytokine production of CD4⁺ T cells co-cultured with purified salivary gland epithelial cells ( SGECs) from pSS or non- SS sicca syndrome were detected. Results By co-culturing the gland cells with CD4⁺ T cells, we found the proliferation of CD4⁺ T cells was significantly suppressed. The effect was weaker when SGECs from pSS patients were used compared to that from non- pSS sicca syndrome controls. Simultaneously, the productions of cytokines interleukin ( IL)-5, IL-13, IL-17A, IL-6 in supernatant were reduced and also SGECs from pSS patients decreased them less than that from non- SS controls. Conclusions The decrease of B7-H4 expression in salivary glands of SS patients contributes to the defect of negatively regulating the inflammation caused by CD4⁺ T cells, thereby providing new insights into the role of B7-H4 in the inflammatory process of salivary glands in SS. [ABSTRACT FROM AUTHOR]