concanavalin-a and Thyroid-Neoplasms

Topics: Adult; Antigen-Antibody Complex; Autoantibodies; Autoimmune Diseases; Child; Concanavalin A; Graves Disease; Humans; T-Lymphocytes, Regulatory; Thyroglobulin; Thyroid Gland; Thyroid Neoplasms

Interleukin-12 (IL12) is a heterodimeric cytokine that plays an important role in the development of cellular immunity. Studies have demonstrated antitumour activity after systemic administration of recombinant IL12. As with other cytokines, with increasing dosage and longer exposure, systemic toxicity is observed. To reduce systemic toxicity and obtain local production of IL12, we developed a replication defective adenovirus transducing two subunits of the murine IL12 (AdCMVmIL12) gene.. Two separate cassettes, expressing the p35 or p40 subunit of mIL12, under the control of human cytomeglavirus immediate early promoter, were inserted into the early1 (E1) region of adenovirus 5. Biological activity of virally expressed mIL12 was demonstrated in vitro through its ability to induce proliferation of mouse ConA blast cells.. Rat medullary thyroid carcinoma (MTC) cells infected with AdCMVmIL12 lost their tumorigenicity in their syngenic WAG/Rij rat hosts. Efficient antitumour activity was found after direct injection of the AdCMVmIL12 vector into rMTC tumours. After intratumoural treatment with AdCMVmIL12, 86% of tumour bearing animals were apparently cured, and almost all remaining tumours were stabilized. Challenge studies showed that most animals cured after the first treatment remained tumour free after reinjection of wild type rMTC cells, indicating that long-term antitumour immunity developed.. This study demonstrates the construction of an adenoviral vector expressing a functional heterodimeric mIL12 and its efficient antitumour activity after in vivo delivery in an animal model of medullary thyroid carcinoma.

Topics: Animals; Carcinoma, Medullary; Cell Division; Concanavalin A; Cytomegalovirus; Gene Expression; Genetic Therapy; Genetic Vectors; Humans; Immunotherapy, Active; Interleukin-12; Mice; Rats; Rats, Inbred Strains; Spleen; Thyroid Neoplasms; Transfection; Tumor Cells, Cultured

The composition of sugar chains on thyroglobulin (Tg) produced in thyroid carcinoma cells (C-Tg) is different from Tg produced in normal thyroid tissues (N-Tg). In this study, we designed a new method for detecting Tg derived from thyroid carcinoma based on the differences between C-Tg and N-Tg in the reactivity with lectins.. Thyroglobulin preparations obtained from various thyroid tissues were incubated with lectins, and the amount of lectin-unbound Tg (ub-Tg) in the supernatant relative to Tg untreated with lectin was determined by enzyme-linked immunosorbent assay and expressed as ub-Tg(%). In addition, to study further the differences in glycosylation between C-Tg and N-Tg, concanavalin A binding to Tg digested with Staphylococcus aureus V8 protease was analyzed on nitrocellulose membrane after Western blotting.. The ub-Tg(%) in C-Tg from papillary carcinoma was significantly higher than in Tg from Graves' disease, benign goiter, and normal thyroid tissue for both concanavalin A and ricinus communis agglutinin-120. Concanavalin A did not appear to bind to Tg from papillary carcinoma after V8 treatment by Western blot analysis. The ub-Tg(%) in Tg from follicular adenoma was significantly higher than C-Tg from follicular carcinoma, whereas there were no differences in ub-Tg(%) between follicular carcinoma and normal thyroid tissue in concanavalin A treatment.. These results suggest our new methods can distinguish both between C-Tg from papillary carcinoma and N-Tg, and between follicular carcinoma and follicular adenoma in thyroid tissue specimens. Thus, this type of analysis may be applicable to differentiate C-Tg from N-Tg in thyroid aspirates for the adjunctive cytodiagnosis of thyroid carcinoma.

Topics: Biomarkers; Blotting, Western; Concanavalin A; Histocytochemistry; Humans; Lectins; Plant Lectins; Sensitivity and Specificity; Thyroglobulin; Thyroid Diseases; Thyroid Gland; Thyroid Neoplasms; Wheat Germ Agglutinins

The immunological properties of thyroglobulins (Tg) of individual patients, obtained from a thyroid tumor and its adjacent tissue were compared, using conventional or monoclonal antibodies against human Tg. The thyroid tumors studied were non-functioning thyroid carcinomas and functioning thyroid adenomas. In contrast to non-functioning tumors, Tg from the functioning tumors was generally iodinated at a level close to that of normal tissue, and Tg from the tissue adjacent to the tumors had a very low iodine content. The conventional antiserum and monoclonal antibodies, B2F, seemed to recognize the conformation of Tg, while C6G showed a high affinity to Tg even when unfolded or denatured. In most cases, Tg isolated from the tissue adjacent to a tumor showed a higher affinity to antibodies than Tgs of the tumor tissue, as determined by the inhibitional effect of these Tgs against the binding of standard Tg and antibody. Furthermore, the Tg of the adjacent tissue was immunologically different in nature from the standard Tg obtained from a normal thyroid gland. From these results, Tgs of tumor and the adjacent tissue in individual patients were heterogeneous in immunological property, regardless of iodine content.

Topics: Adenocarcinoma; Adenoma; Antibodies, Monoclonal; Carcinoma, Papillary; Concanavalin A; Humans; Thyroglobulin; Thyroid Gland; Thyroid Neoplasms

Extracts of transplantable rat medullary thyroid carcinomas were fractionated by concanavalin A-agarose chromatography and SDS-polyacrylamide gel electrophoresis. While tumor extracts contained mostly (greater than 90%) native calcitonin, 4 distinct larger calcitonin species (Mr = 27,000, 17,000, 13,700, and 9,600) were also observed. Glycoprotein fractions from lectin-affinity chromatography of the tumor extracts contained 0.3-1.5% of the total immunoreactive calcitonin. Gel electrophoresis of the pooled glycoprotein fractions demonstrated that the predominant forms of immunoreactive calcitonin were larger than calcitonin monomer. One high molecular weight species (Mr = 9,600), isolated in sufficient quantity from the polyacrylamide gels for reapplication to concanavalin A-agarose, was specifically eluted from the lectin, indicating that it was a glycoprotein. These results are the first evidence that intact C-cells contain at lest one high molecular weight glycoprotein form of immunoreactive calcitonin and suggest that addition and removal of carbohydrate side chains occur during processing of calcitonin precursors to the native hormone.

Topics: Animals; Calcitonin; Carbohydrates; Chemical Phenomena; Chemistry; Concanavalin A; Neoplasm Transplantation; Neoplasms, Experimental; Rats; Thyroid Neoplasms; Transplantation, Homologous

Suppressor cell function of peripheral mononuclear cells has been examined in patients with Graves' disease, Hashimoto's thyroiditis, and thyroid cancer, as well as in healthy subjects. Suppressor cell function was assessed through two methods: 1) measurement of enhanced blastogenesis after 24-h preculture and 2) concanavalin A-inducible suppressor activity. The results from the two tests were coincident and indicate that suppressor cell function was significantly decreased in the Graves' disease population but not changed in either the Hashimoto's thyroiditis or the thyroid cancer groups compared to healthy controls. The impairment of suppressor cell function in the Graves' disease population was still observed when patients became euthyroid by treatment with antithyroid drugs, although the treated patients had improved suppressor cell function compared to untreated patients (P = NS). Low activity of suppressor cell function in the Graves' disease population might be a constitutional character based on an inherited abnormality specific for the disease population.

Topics: Adolescent; Adult; Cells, Cultured; Concanavalin A; DNA; Female; Graves Disease; Humans; Male; Propylthiouracil; T-Lymphocytes; Thyroid Neoplasms; Thyroiditis, Autoimmune; Time Factors