Production and characterization of a cytotoxic monoclonal antibody reacting with rat islet cells.

We have produced a murine monoclonal antibody (F43 A1D2) that binds to the cell surface of both rat islet tumor cells (RINm clone 5F and RINm clone 14B) and normal rat islet cells. This antibody is cytotoxic in the presence of complement for RIN tumor cells as well as A, B, and D pancreatic polypeptide rat islet cells. Antibody A1D2 does not bind to rat thymus cells, pancreatic acinar cells, or fibroblasts. Antigen A1D2 (termed ICSAn-1 [islet cell surface antigen 1]) is a trypsin-sensitive glycoprotein with a molecular mass of approximately 24,000 daltons. In addition to purification of its islet cell antigen, antibody A1D2 can be used to identify and isolate living islet cells from pancreatic digests.