title: Production of a monoclonal antibody 14A20 that reacts with a 220-kDa protein in the islet cells.
abstract: To study the target antigens of the islet cell cytoplasmic antibodies (ICA), we tried to make a monoclonal islet cell antibody. We made a monoclonal antibody 14A20 (IgM, kappa) that reacted strongly with Wistar and BB rat islet cells and weakly with pancreatic acinar cells. The immunoreactivity of the 14A20 was also found to react extensively in neuroendocrine cells. Immunostaining showed a granular pattern in both neurons and islet cells. Chemical and enzymic studies revealed that the antigen has the property of a protein. We compared immunoreactivity of the monoclonal antibody 14A20 with anti-insulin, -glucagon or -somatostatin antibodies. The antigen recognized by the monoclonal antibody 14A20 was equally present in the alpha, beta, and delta cells of islet, which mimicked the immunoreactivity of the ICA in the pancreas. The recognized protein had a relative molecular weight of 220,000, indicating that it is different from the previously identified target antigen of the ICA.
authors.affiliation: Third Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Sudo
authors.forename: M
authors.initials: M
authors.lastname: Itoh
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000378:metabolism; D000917:Antibody Formation; D001323:Autoantibodies / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D004797:Enzyme-Linked Immunosorbent Assay; D005557:Formaldehyde / Q000494:pharmacology; D005934:Glucagon / Q000276:immunology; D007150:Immunohistochemistry; D007328:Insulin / Q000276:immunology; D007515:Islets of Langerhans / Q000737:chemistry / Q000166:cytology* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D051381:Rats; D011913:Rats, Inbred BB; D017208:Rats, Wistar; D013004:Somatostatin / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D007328:Insulin; C024211:islet cell antibody; D005557:Formaldehyde; D013004:Somatostatin; D005934:Glucagon