The Distribution And Function Of Peripheral And Minor Salivary Gland NKT Cells In Primary Sjogren’s Syndrome

Objectives:To investigate the peripheral and minor salivary gland distribution of iNKT cells, NKT-like cells and their related chemokines in pSS patients. To explore the possible function mechanism of NKT-like cells in primary Sjogren’s syndrome. Methods:6B11 antibody was used to detect iNKT cells, while NKT-like cells was identified by CD3CD56 double positive. The proportion of peripheral iNKT cells, NKT-like cells and their subsets were evaluated by flow cytometry, along with the expression of related chemokines and activation markers on the surface of NKT-like cells. ELISA was designed to measure the concentrations of chemokines in sera. The distribution of 6B11+iNKT cells in minor salivary gland was detected by IHC; That of NKT-like cells and CXCR5-CXCL13, CX3CR1-CX3CL chemokines was by IF. Correlation analysis was then conducted between data from periphery, sera, minor salivary gland and clinical manifestations. Results:The proportion of peripheral iNKT, NKT-like cells of pSS patients were decreased significantly than health controls, while that were increased in minor salivary gland; The changes were closely related to the disease severity. The expression of CXCR5-CXCL13 in peripheral NKT-like cells and minor salivary gland were elevated, positively related to the proportion of NKT-like cells in tissue. The expression of CX3CR1 was found to decrease in periphery, sera, but increase in minor salivary gland, which was well paralleled with the trend of NKT-like cells. Conclusions: The reduced peripheral iNKT cells, NKT-like cells of pSS patients were increased in minor salivary gland, suggesting they were probably recruited and function to the target tissue. Of which, NKT-like cells may be recruited by CXCR5-CXCL13 and incline to serve as Th1 cells, regulating the immune response through proinflammatory ways.