Distribution of immunoreactive transforming growth factor-alpha in non-neoplastic human salivary glands

Abstract

The distribution of immunoreactive transforming growth factor-alpha (TGF-a) was studied in non-neoplastic human major and minor salivary glands using an immunoperoxidase assay in conjuction with an antiserum to human TGF-a. The ductal cell components of all major and minor salivary glands were found to contain significant amounts of TGF-a immunoreactivity. In contrast, acinar and myoepithelial cells consistently lacked immune reaction product in both types of glands. Occasionally, an asynchronous pattern of TGF-a ductal cell immunoreactivity was observed in specific ducts within a section. Also, intraductal secretions, when present, were found to contain TGF-a immunoreactive material. Ductal cells and connective tissue from salivary glands samples showing significant lymphocytic infiltration and loss of acinar cells exhibited higher levels of TGF-a immunoreactivity than normal salivary gland samples. These observations demonstrate, for the first time, the presence of TGF-a immunoreactivity in specific structural components of non-neoplastic human major and minor salivary glands. It will be important in future studies to determine whether alterations in TGF-a expression are detectable in diverse types of salivary gland tumors.