title: Antigen mimicry in autoimmune disease sharing of amino acid residues critical for pathogenic T cell activation.
abstract: A nonamer peptide from murine nicotinic acetylcholine receptor delta chain (ACR delta), which shared four amino acid residues with a nonamer peptide of murine ovarian zona pellucida glycoprotein ZP3, induced murine autoimmune oophoritis and IgG autoantibody to the zona pellucida. Crossreaction between the ACR delta and ZP3 peptides was established by the response of a ZP3 peptide-specific, oophoritogenic T cell clone to both peptides in association with IA (alpha k beta b). By substituting the ZP3 peptides with a single alanine, four amino acids within the ZP3 peptide were found to be important for ovarian autoimmune disease, autoantibody response, and stimulation of the ZP3-specific T cell clone. Substitution with conservative amino acids of three residues also ablated activity, whereas the fourth, a phenylalanine, was replaceable by tyrosine without loss of activity. Of the four critical amino acids, three were shared between the ZP3 peptide and the ACR delta peptide. Moreover, polyalanine peptides with the four critical ZP3 amino acids or the four amino acids common to the ZP3 and ACR delta peptides induced immune response to ZP3 and elicited severe ovarian autoimmune disease. Thus, organ-specific autoimmune disease can occur through immune response against unrelated self (or foreign) peptides that share with a self-peptide sufficient common amino acid residues critical for activation of pathogenic, autoreactive T cells.
authors.affiliation: Department of Pathology, University of Virginia, Charlottesville 22908.
authors.forename: A M
authors.initials: AM
authors.lastname: Luo
authors.forename: K M
authors.initials: KM
authors.lastname: Garza
authors.forename: D
authors.initials: D
authors.lastname: Hunt
authors.forename: K S
authors.initials: KS
authors.lastname: Tung
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001323:Autoantibodies / Q000096:biosynthesis; D001327:Autoimmune Diseases / Q000209:etiology / Q000276:immunology*; D002999:Clone Cells; D003429:Cross Reactions; D004527:Egg Proteins; D005260:Female; D007116:Immunization, Passive; D008213:Lymphocyte Activation / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D009869:Oophoritis / Q000209:etiology / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology; D011956:Receptors, Cell Surface; D011978:Receptors, Nicotinic / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D000072216:Zona Pellucida Glycoproteins
chemical_list: D001323:Autoantibodies; D004527:Egg Proteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D011978:Receptors, Nicotinic; D000072216:Zona Pellucida Glycoproteins; C000606521:Zp3 protein, mouse