Lacrimal gland is destroyee by CD8⁺CD103⁺ t lymphocytes in patients with sjogren's syndrome

Purpose. The lymphocytes infiltrating into the exocrine glands in Sjögren's syndrome (SjS) may participate in the altered function or even destruction of the glands. However, the mechanisms by which the infiltrating lymphocytes affect the secretory function of the exocrine glands have not been fully clarified. In this study we focus on the lymphocytes wh.ch adhered to the glandular and ductal epithelial cells, and characterize the cell to cell interaction. Methods. Lacrimal gland biopsies were performed from dry eye patients with SjS and non-SjS. Expression of CD4, CDS, CD103(aEβ), LFA-1, ICAM-1, HLA-DR or Ecadherin in the lacrimal glands from Iry eye patients were determined by immunofluoresence analysis. Furtherr tore, apoptic cells were detected by TUNNEL method. Results. In the lacrimal gland tissue, the infiltrating lymphocytes were located in the two majcr sites, the interstitial, and the glandular lobular area. Interestingly, CD4" lymphocytes aggregated in the interstitial area between the glandular lobules, whereas CDS⁺ and CD103⁺ cells localized around acinar and ductal epithelial cells in the glandular lobular area. The glandular epithelial cells expressed E-cadherin, which is the Iigand for CD101 The apoptic signals were observed in the acinar and ductal cells adjacent to CDS' lymphocytes by TUNNEL method. Conclusion- aEpl integrin (CD103) mediates the idhesion of infiltrated lymphocytes to the acinar and ductal epithelial cells, which nay induce apoptosis in the lacrimal glands from SjS patients. These bservation suggests that CD8⁺CD103⁺ T lymphocytes may play an important role >r the altered function of the glands, at le ist in part through inducing apoptosis in ie glandular cells in SjS.