Lymphocyte adhesive interactions with cultured parotid salivary gland epithelial cells from rats

Cellular interactions control lymphocyte localization within salivary gland tissues and contribute to the immune defense of oral surfaces. We examined lymphocyte adherence to cultured parotid cells using an in vitro assay and found good correlation with previously reported binding to parotid gland frozen sections. Thoracic duct lymphocytes (TDL) bound to parotid cells in greater numbers than thymocytes (74 vs 11 cells/mm2). B cells showed preferential adherence compared to T cells (75% vs 28%). TDL binding was inhibited by sodium azide or cytochalasin B (60% and 80%, respectively). EDTA inhibition (63%) was restored by replacing calcium (9%) but not magnesium (65%). Binding was inhibited by fucoidin or phosphomannan (approximately 70%). Fibronectin peptides had no effect. Culture supernatants were inhibitory for TDL adherence (60%), suggesting that molecules involved in lymphocyte localization may be shed and that parotid cell cultures will be useful for ligand isolation and characterization.