Phenotype of mononuclear leucocytes resident in rat major salivary and lacrimal glands.

The phenotypic distribution of lymphocytes and mononuclear phagocytes resident in rat secretory glands was examined. Isolated exocrine gland mononuclear leucocyte populations contained 50-61% W3/13+ T cells and greater proportions of W3/25+ T helper cells relative to OX8+ T suppressor cells. Surface Ig+ cells (sIg) constituted from 32% to 34% of the cells and their distribution was sIgM greater than sIgA greater than sIgG. The macrophage populations comprised from 0.02% to 0.1% of the unfractionated gland cells. Fractionated secretory gland-adherent cells consisted primarily of non-specific esterase+, phagocytic and Fc receptor-bearing cells. From 35% to 79% of the macrophages in exocrine glands expressed I-A molecules. The results suggest that exocrine glands have the ability to respond locally to an antigenic challenge independently of a central mucosal immune response.