Preparation of a monoclonal antibody recognizing the Golgi apparatus of serous exocrine cells.

Abstract

To analyze in detail the dynamics of Golgi apparatus in exocrine cells, a monoclonal antibody against resident protein of the Golgi apparatus was prepared. A BALB/C mouse was immunized with fractions enriched in Golgi apparatus of guinea pig pancreas. The derived monoclonal antibody, GF-1, showed intense immunofluorescent staining of the Golgi area of rat pancreatic acinar cells by screening on cryosections. The antibody recognized a single polypeptide band on an immunoblot transferred from SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The polypeptide had a molecular weight of approximate ly 105-kDa and contained asparagine-linked carbohydrates. Light microscopic immunocytochemical study with rat pancreas, parotid gland, sublingual gland and gastric gland tissues indicated a staining pattern consistent with the Golgi apparatus but positive reaction was restricted to serous exocrine cells in these tissues. Immunoelectron microscopy with rat pancreatic and parotid acinar cells showed prominent staining of Golgi apparatus. The positive compartment of Golgi apparatus appeared to be its trans elements. It follows from these findings that monoclonal antibody GF-1 recognizes a glycopeptide of trans-Golgi membrane intimately related to specific functions of serous exocrine cells.