title: Thyroid-stimulating monoclonal antibodies.
abstract: Thyrotropin (TSH) receptor monoclonal antibodies (TSHR mAbs) were obtained from cDNA-immunized NMRI mice. Three mAb immunoglobulin Gs (IgGs) (TSmAbs 1-3) that had distinct V(H )and V(L) region sequences stimulated cyclic adenosine monophosphate (cAMP) production in isolated porcine thyroid cells greater than 10x basal and as little as 20 ng/mL (0.13 nmol/L) of TSmAb 1 IgG caused a 2x basal stimulation. TSmAb 1 and 2 Fab fragments were also effective stimulators and thyroid-stimulating activities of the IgGs and Fabs were confirmed using TSHR transfected Chinese hamster ovary (CHO) cells. The TSmAbs also inhibited (125)I-labeled TSH binding to TSHR-coated tubes by 50% or more at concentrations of 1 microg/mL or less and gave 15%-20% inhibition at 20-50 ng/mL. (125)I-labeled TSmAbs bound to TSHR-coated tubes with high affinity (approximately 10(10) L/mol) and this binding was inhibited by TSHR autoantibodies with both TSH agonist and antagonist activities. Inhibition of labeled TSmAb binding by Graves' sera correlated well with inhibition of TSH binding (r = 0.96; n = 18; p < 0.001 for TSmAb 2). The TSmAbs have considerable potential as (1) new probes for TSHR structure-function studies, (2) reagents for new assays for TSHR autoantibodies, and (3) alternatives to recombinant TSH in various in vivo applications.
authors.affiliation: FIRS Laboratories, RSR Ltd., Parc Ty Glas, Llanishen, Cardiff, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Sanders
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jeffreys
authors.forename: Hilde
authors.initials: H
authors.lastname: Depraetere
authors.forename: Tonya
authors.initials: T
authors.lastname: Richards
authors.forename: Michele
authors.initials: M
authors.lastname: Evans
authors.forename: Angela
authors.initials: A
authors.lastname: Kiddie
authors.forename: Karen
authors.initials: K
authors.lastname: Brereton
authors.forename: Marleen
authors.initials: M
authors.lastname: Groenen
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Oda
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Furmaniak
authors.forename: Bernard
authors.initials: B
authors.lastname: Rees Smith
mesh_terms: D000818:Animals; D021461:Animals, Outbred Strains; D000911:Antibodies, Monoclonal / Q000276:immunology* / Q000494:pharmacology; D001323:Autoantibodies / Q000276:immunology / Q000494:pharmacology; D001667:Binding, Competitive / Q000276:immunology; D016466:CHO Cells; D006224:Cricetinae; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D007114:Immunization; D007457:Iodine Radioisotopes; D051379:Mice; D011989:Receptors, Thyrotropin / Q000276:immunology / Q000378:metabolism; D013961:Thyroid Gland / Q000276:immunology*; D013972:Thyrotropin / Q000378:metabolism / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D001323:Autoantibodies; D007457:Iodine Radioisotopes; D011989:Receptors, Thyrotropin; D013972:Thyrotropin