In vitro adherence of rat lymphocytes to salivary gland epithelia.

Glandular mucosal tissues contain lymphocyte populations that contribute to expression of IgA antibodies in external secretions. Interaction of circulating lymphocytes with glandular structures may regulate lymphocyte accumulation. An in vitro assay was used to investigate adhesive interactions between lymphocytes and salivary gland tissues. Thoracic duct lymphocytes (TDL) bound to the serous acinar epithelia of parotid salivary glands and to the mucous tubulo-acinar epithelium of submandibular salivary glands. Lymph node cells and splenocytes adhered to these tissues in lesser numbers and thymocytes bound in negligible numbers. TDL adherence was an active process, being time- and cell dose-dependent and requiring intact membrane as well as cytoskeletal and metabolic function. Calcium was required in each case and binding was mediated by a trypsin-sensitive lymphocyte surface determinant. These findings suggest that the lymphocyte composition of salivary gland tissues is regulated by active lymphocyte interaction with the glandular epithelium.