Expression of the mucosal lymphocyte integrin alphaEbeta7 and its ligand E-cadherin in salivary glands of patients with Sjögren's syndrome.

The expression of the mucosal lymphocyte integrin alphaEbeta7 and its ligand E-cadherin was analyzed in sialadenitic lesions of patients with Sjögren's syndrome in order to assess the potential interactions between the mucosal and the systemic immunological compartments. Immunohistochemical evaluation of the inflammatory infiltrates in the salivary gland tissues in Sjögren's syndrome patients revealed presence of alphaEbeta7-integrin-expressing lymphocytes, in 18 of 20 biopsies examined. The ligand for alphaEbeta7, E-cadherin was also found in 18 of 20 salivary gland biopsies analysed. These results suggest homing of lymphocytes derived from the gut epithelium through the blood stream to inflamed salivary gland tissue followed by in situ interaction with E-cadherin expressing cells, the ligand for alphaEbeta7 expressing T lymphocytes.