IN-VITRO ADHERENCE OF RAT LYMPHOCYTES TO SALIVARY-GLAND EPITHELIA

Glandular mucosal tissues contain lymphocyte populations that contribu te to expression of IgA antibodies in external secretions. Interaction of circulating lymphocytes with glandular structures may regulate lym phocyte accumulation. An in vitro assay was used to investigate adhesi ve interactions between lymphocytes and salivary gland tissues. Thorac ic duct lymphocytes (TDL) bound to the serous acinar epithelia of paro tid salivary glands and to the mucous tubulo-acinar epithelium of subm andibular salivary glands. Lymph node cells and splenocytes adhered to these tissues in lesser numbers and thymocytes bound in negligible nu mbers. TDL adherence was an active process, being time- and cell dose- dependent and requiring intact membrane as well as cytoskeletal and me tabolic function. Calcium was required in each case and binding was me diated by a trypsin-sensitive lymphocyte surface determinant. These fi ndings suggest that the lymphocyte composition of salivary gland tissu es is regulated by active lymphocyte interaction with the glandular ep ithelium.