The appearance in thyroidectomized mice of immunoglobulins that bind TSH and stimulate FRTL-5 thyrocytes.
The purpose of these studies was to examine whether thyroid stimulating antibodies in Graves' patients could arise as auto-antiidiotypic antibodies to endogenous anti-TSH antibodies. The model system chosen was the thyroidectomized mouse, exhibiting an elevated level of endogenous, circulating TSH. Mice were thyroidectomized by 131I administration. Sera samples were drawn 1 to 14 months later. The following activities were measured in the immunoglobulin (Ig) fractions prepared: (a) TSH binding by elisa techniques, (b) iodide pump activity (as measured by 99mTcO4 uptake) and (c) increased [3H]thymidine incorporation into the DNA of FRTL-5 cells. TSH binding Igs were detected in 29/98 mice thyroidectomized for 7-14 months. Stimulation of technetium uptake was observed in 59/110 mice and stimulated labeled thymidine uptake in 37/102 mice, beginning eight and nine months after thyroidectomy, respectively. Of the positive animals, 51 showed a single stimulating activity. The incidence and the serum titers of Igs that stimulate technetium uptake increased significantly with time. Indeed, in the group tested 14 months post-thyroidectomy, 75% of the sera were positive for this antibody with a mean titer eightfold higher than the controls. Hybridomas were prepared from the spleen lymphocytes of thyroidectomized mice. Of these, 18 produced 99mTcO4 uptake stimulating Igs, 12 [3H]thymidine-uptake stimulating Igs and 18 TSH binding Igs. Most of the hybridomas secreted Igs with a single bioactivity. One monoclonal antibody was isolated which neutralized the bioactivity of bTSH on FRTL-5 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Gafny
M
M
Hubert H. Humphrey Department of Experimental Medicine, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Ben-David
C
C
Sirkis
N
N
Gordon
A
A
Gross
J
J
D000818:Animals; D000911:Antibodies, Monoclonal; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D005260:Female; D006111:Graves Disease / Q000276:immunology; D006825:Hybridomas / Q000378:metabolism / Q000473:pathology; D007136:Immunoglobulins / Q000378:metabolism* / Q000502:physiology*; D007457:Iodine Radioisotopes; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011485:Protein Binding; D013667:Technetium; D013936:Thymidine / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D007136:Immunoglobulins; D007457:Iodine Radioisotopes; D013667:Technetium; D013972:Thyrotropin; D004247:DNA; D013936:Thymidine