The use of monoclonal antibodies against thyroglobulin in immunoperoxidase techniques

Monoclonal antibodies to human thyroglobulin: evaluation of immunoreactivity

We have earlier reported production and characterization of monoclonal antibodies (MAbs) to human thyroglobulin (h-tg). In the present study H10 I MAb was evaluated for its immunoreactivity towards different forms of tg and various human thyroid tumours. The specificity of H10 I MAb was validated by the absence of cross reaction with tri-iodothyronine (T3) Thyroxine (T4) and human gamma globulins. Sodium-dodicyl-sulphate polyacrylamide gel electrophoresed (SDS-PAGE) immunoblot of h-tg on the nitrocellulose membrane revealed multiple immunoreactive bands on reaction with polyclonal antibody (PAb) in comparison with total lack of reactivity with H10 I MAb. The absence of immunoreactivity of H10 I MAb was demonstrated with SDS treated, Dithiothreitol (DT) treated and heat denatured tg using dot immunobinding technique. However, the H10 I MAb was able to react with tg treated with unfolding agents such as urea and guanidine hydrochloride. All the treated forms of tg were equally recognized by PAb. The immunoreactivity of the oxidized/reduced tg towards H10 I MAb was markedly reduced (60.0%) as compared to that obtained with native tg. It appears that H10 I MAb is directed towards conformational epitope involving sulphydryl bonds. Immunohistochemically, a comparable immunoreactivity between PAb and MAb was observed with normal thyroid tissues, follicular thyroid tissues, Hurthle cell carcinoma tissues and poorly differentiated thyroid tumor tissues using immunoperoxidase staining. The sections from papillary carcinoma tissue (thyroid as well as metastatic lymph node) exhibited intense immunoreactivity with PAb. Thyroglobulin present on these sections was not recognized by H10 I MAb. Nonetheless, H10 I MAb was able to detect tg in follicular differentiation wherever present. The absence of immunoreactivity of H10 I MAb in papillary carcinoma strongly suggests that this neoplasm produces tg which is antigenically different from the protein present in the normal tissue. The reactivity of H10 I MAb with metastatic lymph node of an unknown primary origin suggests its usefulness in the identification of prevalent metastasis of differentiated thyroid carcinoma other than papillary type.

Immunohistochemical study of thyroglobulin in thyroid carcinomas with monoclonal antibodies

The effectiveness of an immunoperoxidase technique using four monoclonal antibodies (mAb) is compared to a technique using one polyclonal antibody (pAb) to detect human thyroglobulin (Tg) in paraffin sections of 55 thyroid carcinomas. With the pAb, a positive reaction was found in 82% of the cases. With the four mAb, the presence of Tg was demonstrated in 96.5% of the cases. The mAb gave better results than the pAb on poorly differentiated and anaplastic thyroid carcinomas. Many of the thyroid carcinomas in this study, especially the poorly differentiated and anaplastic type, failed to react with all four mAb to Tg. These results confirm the notion of the heterogeneity of Tg in thyroid carcinomas and indicate that a battery of carefully selected mAb can be successfully used for routine histopathologic detection of Tg in these tumors.

The immunohistochemical demonstration of thyroglobulin in human thyroid tumour xenografts using a monoclonal antibody

A monoclonal antibody (RBU/01) was raised against human thyroglobulin and its suitability for the immunohistochemical staining of thyroglobulin was determined on fixed, wax-embedded tissue, using the peroxidase anti-peroxidase (PAP) method. The antibody was then used to demonstrate the expression of human thyroglobulin in sections of a human follicular carcinoma of the thyroid which had been grown in immunodeficient mice. It is concluded that the immunohistochemical evaluation of the xenografts with the antibody provides useful information on this xenograft system as a potential model for thyroid carcinoma.

An immuno-electron microscopic study on intracellular localization of thyroglobulin (TG) in the thyroid gland in Grave's disease

Intracellular localization of thyroglobulin (TG) using a pre-embedding diffusion technique and an indirect localization sequence has been made in human thyroid obtained from 20 patients with treated Grave's disease. Both antibodies, anti-human TG-rabbit IgG F(ab')2 and anti-rabbit IgG F(ab')2-goat IgG F(ab')2 fragments easily penetrated the cytoplasm of follicular cells which were dissociated by RPMI-1640 solution containing collagenase, dispase, and deoxyribonuclease. With light microscopic observation of semithin sections positive immuno-reaction for TG was demonstrated as fine granular deposits in the cytoplasm of the dissociated cells. In electron microscopic studies, intracellular antigen was well circumscribed within certain cell organelles in all cases with the positive immuno-reaction for TG being observed in perinuclear space, rough endoplasmic reticulum, Golgi complexes, secretory granules, and reabsorbed colloid droplets. Content of positive immuno-reaction product differed somewhat from one case to another and from one follicle to another even in the same case. There was no immunoreaction product in nuclei, mitochondria, lysosomes, and lipofuscin-like granules.

Use of the peroxidase-antiperoxidase technique for differential staining of multiple cell types in the rat pancreatic islet

Multiple staining of the endocrine cells of the pancreatic islet was studied in tissue obtained from adult rats. After fixation in Bouin's fluid and processing for light microscopy, the unlabeled peroxidase-antiperoxidase (PAP) technique was performed. Successful staining procedures used variations of the PAP technique with 3,3'-diaminobenzidine (DAB) and 4-chloro-1-naphthol (CN) as chromagens. The purpose of this study was to stain as many of the four primary cell types (A-cells, B-cells, D-cells, PP-cells) as possible either simultaneously or sequentially using photomicroscopy. At optimum antibody titer, there was minimal nonspecific background staining which made it possible to differentiate cell types by intensity of the chromagen. Any two cell types can be shown by using DAB with the first antibody and CN with the second. To demonstrate three cell types simultaneously, three methods which altered dilutions and chromagens were used. The first method consisted of decreasing dilutions of primary antibody with DAB and CN as the chromagens. The second method involved repetitive DAB applications resulting in three intensities of brown. The third method used a DAB immersion after the second cell type was stained. This produced a color differential so the third cell type could be distinguished with CN. To demonstrate the three cell types sequentially, a masking technique was introduced with photomicroscopy. In order to block the preceding complex, the previous cell type (demonstrated by CN) was restained with DAB at an increased dilution. The next cell type was then stained with CN. These four methods were tried in attempts to stain four cell types in the same tissue section.