Localization of the discontinuous immunodominant region recognized by human anti-thyroperoxidase autoantibodies in autoimmune thyroid diseases.
The discontinuous immunodominant region (IDR) recognized by autoantibodies directed against the thyroperoxidase (TPO) molecule, a major autoantigen in autoimmune thyroid diseases, has not yet been completely localized. By using peptide phage-displayed technology, we identified three critical motifs, LXPEXD, QSYP, and EX(E/D)PPV, within selected mimotopes which interacted with the human recombinant anti-TPO autoantibody (aAb) T13, derived from an antibody phage-displayed library obtained from thyroid-infiltrating TPO-selected B cells of Graves' disease patients. Mimotope sequence alignment on the TPO molecule, together with the binding analysis of the T13 aAb on TPO mutants expressed by Chinese hamster ovary cells, demonstrated that regions 353-363, 377-386, and 713-720 from the myeloperoxidase-like domain and region 766-775 from the complement control protein-like domain are a part of the IDR recognized by the recombinant aAb T13. Furthermore, we demonstrated that these regions were involved in the binding to TPO of sera containing TPO-specific autoantibodies from patients suffering from Hashimoto's and Graves' autoimmune diseases. Identification of the IDR could lead to improved diagnosis of thyroid autoimmune diseases by engineering "mini-TPO" as a target autoantigen or designing therapeutic peptides able to block undesired autoimmune responses.
Bresson
Damien
D
CNRS Unité Mixte de Recherche (UMR) 5094, Faculté de Pharmacie, 15 avenue Charles Flahault, B. P. 14491, Montpellier 34093 Cedex 5, France. damienbresson@yahoo.fr
Cerutti
Martine
M
Devauchelle
Gérard
G
Pugnière
Martine
M
Roquet
Francoise
F
Bes
Cédric
C
Bossard
Carine
C
Chardès
Thierry
T
Péraldi-Roux
Sylvie
S
D000409:Alanine / Q000737:chemistry; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000737:chemistry; D000911:Antibodies, Monoclonal / Q000378:metabolism; D001323:Autoantibodies / Q000737:chemistry*; D001327:Autoimmune Diseases / Q000276:immunology*; D001402:B-Lymphocytes / Q000378:metabolism; D001667:Binding, Competitive; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D004305:Dose-Response Relationship, Drug; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006111:Graves Disease / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007118:Immunoassay; D016056:Immunodominant Epitopes; D007313:Insecta; D007453:Iodide Peroxidase / Q000737:chemistry* / Q000276:immunology*; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011489:Protein Denaturation; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid; D013959:Thyroid Diseases / Q000276:immunology*
D000906:Antibodies; D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D000939:Epitopes; D016056:Immunodominant Epitopes; D019151:Peptide Library; D010455:Peptides; D011994:Recombinant Proteins; D007453:Iodide Peroxidase; D000409:Alanine