Pancreatic islet cell antigens obtained by molecular cloning

This invention relates to pancreatic islet cell antigens that bind with antibodies found in the sera of patients afflicted with insulin-dependent (Type I) diabetes mellitus (IDDM). More particularly, the invention relates to proteins and peptides that bind with islet cell antibodies (ICA) and that are prepared by recombinant DNA (rDNA) or synthetic methods. The invention also concerns cloned DNA encoding such ICA proteins and peptides. The ICA proteins and peptides of the present invention are useful as immunoassay reagents in the presymptomatic diagnosis of IDDM. Pancreatic islet cell antigens (ICA) that bind with antibodies found in the sera of patients afflicted with insulin-dependent (Type I) diabetes mellitus (IDDM). ICA proteins are expressed by recombinant cloning vehicles comprising DNA inserts isolated from islet cells. Full sequence native ICA proteins, or protein or peptide fragments thereof, can be used in the diagnosis of IDDM and in detecting or blocking human immunoglobulin, T-cells, or B-cells involved in IDDM.