Monoclonal antibodies raised against semi-purified preparations of human islets define subpopulations of pancreatic cells.

Monoclonal antibodies were produced from fusions between splenocytes from BALB/c mice immunised with purified human islets and the mouse myeloma cell line NS-0/Uncl. Supernatants from uncloned hybrids were screened by immunohistology on frozen sections of human pancreas. The range of specificities appeared to reflect the relative purity of the human islet preparations used. Eight monoclonal antibodies were investigated further, four of these bound to islet cells, two to acinar cells, one to ductal cells and one to occasional cells. The antigens recognised by these antibodies were characterised by immunohistology using a number of different tissues, as well as haemagglutination, immunoblotting and radioimmunoassay for insulin. Seven of the eight antibodies studied were IgM. One acinar cell antibody (IgG2a) precipitated proteins of 200Kd and 11OKd molecular weight. None of the antibodies bound directly to insulin. Seven of the antibodies appear to have defined previously unreported epitopes in the pancreas and will prove useful in further studies of human pancreatic cells.