Journal of Clinical Endocrinology & Metabolism, Vol 75, 1425-1430, Copyright © 1992 by Endocrine Society

ARTICLES

Thyroid stimulatory autoantibodies in different patients with autoimmune thyroid disease do not all recognize the same components of the human thyrotropin receptor: selective role of receptor amino acids Ser25-Glu30

Y Nagayama and B Rapoport
Thyroid Molecular Biology Unit, Veterans Administration Medical Center, San Francisco, California 94121.

To study the interaction between TSH, autoantibodies and the amino- terminal half of the TSH receptor extracellular region (amino acids 1- 260; domains ABC), we constructed 20 LH/CG chimeric receptor cDNAs. The prototypic receptor for modification contained domains ABC of the TSH receptor and domains DE of the LH/CG receptor. Segments (6-13 amino acids) within the ABC domains were replaced with the corresponding amino acids of the rat LH/CG receptor. Fifteen of the 20 chimeric receptors could be expressed functionally in Chinese hamster ovary cells. Twelve retained both high affinity TSH binding and normal signal transduction. These 12 receptors were tested with a panel of 10 patients' immunoglobulin G (IgG) samples containing potent TSH receptor stimulatory activity. With 11 of the receptor variants, the cAMP responses were similar to those with the prototype receptor (TSH-LHR- 6). However, the -A1 variant of TSH-LHR-6 (Ser25-Glu30) responded poorly to 6 of 10 IgGs. The same pattern was observed when the IgGs were tested for their ability to inhibit [125I] TSH binding to the receptor variants, suggesting qualitative differences between the different stimulatory TSH receptor autoantibodies. Therefore, we examined the dose-response relationship of 2 IgGs that were approximately equipotent when tested with TSH-LHR-6 and its -A1 variant and another 2 IgGs that displayed greatly diminished potency with respect to the -A1 variant. Despite dilution to nearly undetectable levels, the relative potencies of the 4 IgG samples for both types of receptors remained similar. These data demonstrate directly that stimulatory TSH receptor autoantibodies do not all recognize the same components of the TSH receptor. The segment of the TSH receptor discriminated by these autoantibodies is between amino acids Ser25- Glu30.

This article has been cited by other articles:

				C.-R. Chen, S. M. McLachlan, and B. Rapoport Suppression of Thyrotropin Receptor Constitutive Activity by a Monoclonal Antibody with Inverse Agonist Activity Endocrinology, May 1, 2007; 148(5): 2375 - 2382. [Abstract] [Full Text] [PDF]

				S. M. McLachlan, Y. Nagayama, and B. Rapoport Insight into Graves' Hyperthyroidism from Animal Models Endocr. Rev., October 1, 2005; 26(6): 800 - 832. [Abstract] [Full Text] [PDF]

				G. D. Chazenbalk, F. Latrofa, S. M. McLachlan, and B. Rapoport Thyroid Stimulation Does Not Require Antibodies with Identical Epitopes But Does Involve Recognition of a Critical Conformation at the N Terminus of the Thyrotropin Receptor A-Subunit J. Clin. Endocrinol. Metab., April 1, 2004; 89(4): 1788 - 1793. [Abstract] [Full Text] [PDF]

				W. B. Minich, C. Lenzner, A. Bergmann, and N. G. Morgenthaler A Coated Tube Assay for the Detection of Blocking Thyrotropin Receptor Autoantibodies J. Clin. Endocrinol. Metab., January 1, 2004; 89(1): 352 - 356. [Abstract] [Full Text] [PDF]

				L. Schwarz-Lauer, P. N. Pichurin, C.-R. Chen, Y. Nagayama, C. Paras, J. C. Morris, B. Rapoport, and S. M. McLachlan The Cysteine-Rich Amino Terminus of the Thyrotropin Receptor Is the Immunodominant Linear Antibody Epitope in Mice Immunized Using Naked Deoxyribonucleic Acid or Adenovirus Vectors Endocrinology, May 1, 2003; 144(5): 1718 - 1725. [Abstract] [Full Text] [PDF]

				C. H. Byun, J. Y. Park, T. Akamizu, and C.-B. Chae Identification of the Peptides That Inhibit the Function of Human Monoclonal Thyroid-Stimulating Antibodies from Phage-Displayed Peptide Library J. Clin. Endocrinol. Metab., July 1, 2001; 86(7): 3311 - 3318. [Abstract] [Full Text] [PDF]

				G. D. Chazenbalk, S. M. McLachlan, P. Pichurin, X.-M. Yan, and B. Rapoport A Prion-Like Shift between Two Conformational Forms of a Recombinant Thyrotropin Receptor A-Subunit Module: Purification and Stabilization Using Chemical Chaperones of the Form Reactive with Graves' Autoantibodies J. Clin. Endocrinol. Metab., March 1, 2001; 86(3): 1287 - 1293. [Abstract] [Full Text]

				M. H. Lee, J. Y. Park, B. Y. Cho, and C.-B. Chae Expression of the Functional Extracellular Domain of Human Thyrotropin Receptor Using a Vaccinia Virus System: Its Purification and Analysis of Autoantibody Binding J. Clin. Endocrinol. Metab., April 1, 1999; 84(4): 1391 - 1397. [Abstract] [Full Text]

				G. D. Chazenbalk, Y. Wang, J. Guo, J. S. Hutchison, D. Segal, J. C. Jaume, S. M. McLachlan, and B. Rapoport A Mouse Monoclonal Antibody to a Thyrotropin Receptor Ectodomain Variant Provides Insight into the Exquisite Antigenic Conformational Requirement, Epitopes and in Vivo Concentration of Human Autoantibodies J. Clin. Endocrinol. Metab., February 1, 1999; 84(2): 702 - 710. [Abstract] [Full Text]

				B. Rapoport, G. D. Chazenbalk, J. C. Jaume, and S. M. McLachlan The Thyrotropin (TSH)-Releasing Hormone Receptor: Interaction with TSH and Autoantibodies Endocr. Rev., December 1, 1998; 19(6): 673 - 716. [Abstract] [Full Text]

				S. Kikuoka, N. Shimojo, K.-I. Yamaguchi, Y. Watanabe, A. Hoshioka, A. Hirai, Y. Saito, K. Tahara, L. D. Kohn, N. Maruyama, et al. The Formation of Thyrotropin Receptor (TSHR) Antibodies in a Graves' Animal Model Requires the N-Terminal Segment of the TSHR Extracellular Domain Endocrinology, April 1, 1998; 139(4): 1891 - 1898. [Abstract] [Full Text] [PDF]

				W. B. Kim, H. K. Chung, H. K. Lee, L. D. Kohn, K. Tahara, and B. Y. Cho Changes in Epitopes for Thyroid-Stimulating Antibodies in Graves' Disease Sera During Treatment of Hyperthyroidism: Therapeutic Implications J. Clin. Endocrinol. Metab., June 1, 1997; 82(6): 1953 - 1959. [Abstract] [Full Text] [PDF]

				T. Sunthornthepvarakul, M. E. Gottschalk, Y. Hayashi, and S. Refetoff Resistance to Thyrotropin Caused by Mutations in the Thyrotropin-Receptor Gene N. Engl. J. Med., January 19, 1995; 332(3): 155 - 160. [Full Text] [PDF]

				C.-R. Chen, K. Tanaka, G. D. Chazenbalk, S. M. McLachlan, and B. Rapoport A Full Biological Response to Autoantibodies in Graves' Disease Requires a Disulfide-bonded Loop in the Thyrotropin Receptor N Terminus Homologous to a Laminin Epidermal Growth Factor-like Domain J. Biol. Chem., April 27, 2001; 276(18): 14767 - 14772. [Abstract] [Full Text] [PDF]