MONOCLONAL-ANTIBODY TO LIVER METALLOTHIONEIN - A NOVEL MARKER FOR MYOEPITHELIAL CELLS

Myoepithelial cells (MEC) are situated between acinar or ductal lumina l cells and the basal lamina in various secretory glands, including sa livary gland. The in-situ demonstration of MEC in benign and malignant conditions has long been hampered by the lack of suitable markers, mo st of which do not label MEC exclusively. We report here the reactivit y of L2E3, a monoclonal antibody directed against liver metallothionei n (MT). In the major and minor salivary glands, L2E3 stained two types of cells: a slender, elongated cell that surrounded acini; and a smal l, basal, cuboidal cell observed in the excretory (interlobular) ducts . Our results indicate that L2E3 represents a novel, useful marker for the immunohistochemical identification of MEC, and a highly sensitive marker for ductal basal or ''reserve'' cells in salivary glands.