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O Tarutani

Publications and source records attributed to O Tarutani.

At least 19 recordsLinked to original sources
PubMed1994

Thyroglobulin-specific T cell line from a healthy individual does not produce proinflammatory cytokines on antigenic stimulation: an implication for possible fail-safe mechanism to avoid autoimmunity.

In order to investigate the regulation of autoimmune response to thyroglobulin (Tg), one of the thyroid autoantigens, we established a Tg-specific T cell line by stimulation of peripheral blood mononuclear cells from a healthy volunteer with Tg and characterized its cytokine production pattern. The Tg-specific T cell line, designated DH5D1, obtained from a limiting dilution culture bore alpha beta T cell receptor and was CD4 and CD45RO positive. Upon stimulation with Tg, DH5D1 secreted little or no titers of IL-2, TNF-alpha, and IFN-gamma, whereas activation with combination of phorbol myristate acetate and calcium ionophore produced measurable levels of these cytokines. These results indicate that the Tg-specific T cell line is not defective in its capacity to produce proinflammatory cytokines and suggest that the inability of cytokine production by autoreactive T cells of healthy individuals is one fail-safe mechanism for preventing aggression of harmful autoimmune response.

Antigens↗
PubMed1994

[Chemical iodination of hormonogenic tyrosine residues of human thyroglobulin is critical for the production of anti-thyroglobulin autoantibody and for the induction of experimental autoimmune thyroiditis in mice].

There is evidence from animal models that the iodine content of thyroglobulin (Tg) may influence its antigenicity in thyroid autoimmunity. To elucidate the effect of iodination of hormonogenic sites of human Tg (hTg) on its autoantigenicity, a synthetic peptide (TB: hTg 2546-2571), containing two hormonogenic tyrosine residues of hTg, and a chemically-iodinated peptide (TB-I) were prepared. We immunized C3H/He (H-2k) mice, a high responder strain to Tg, and BALB/c (H-2d), a low responder strain, with TB or TB-I plus lipopolysaccharide. Lymph node cells from the two strains immunized with TB or TB-I proliferated in response to both TB and TB-I. Anti-Tg autoantibodies were detected in both strains when immunized with TB-I, while immunization with TB failed to produce anti-Tg antibodies. Furthermore, one of the C3H/He mice immunized with TB-I developed diffuse thyroiditis, but BALB/c mice did not. These findings indicate that the iodination of the hormonogenic tyrosine residues of hTg, in other words, the synthesis of mono- and di-iodotyrosine (MIT and DIT) residues, is necessary for the production of anti-Tg autoantibodies in high and low responder mice and for the induction of autoimmune thyroiditis in high responder mice.

Amino Acid Sequence↗
PubMed1993

A common T-cell epitope between human thyroglobulin and human thyroid peroxidase is related to murine experimental autoimmune thyroiditis.

We have investigated functional common T-cell epitopes between human thyroglobulin (hTg) and human thyroid peroxidase (hTPO) in mice. Four hTg peptides, Tg-P1, Tg-P2, Tg-P3 and Tg-P4, in which 5 amino acid residues are identical to those of hTPO, and 1 hTPO peptide, TPO-P4 relevant to Tg-P4, were prepared. Among these peptides, only Tg-P4 (residues 2730-2743) and TPO-P4 (residues 118-131) were highly antigenic and both peptides shared the common T-cell epitope. In addition, when the spleen cells from mice immunized with mouse Tg (mTg) were restimulated in vitro by Tg-P4 or TPO-P4 as well as by mTg, these cells transferred thyroiditis to naive recipient mice. These findings indicate that this common T-cell epitope between hTg and hTPO is immunogenic and related to the development of murine experimental autoimmune thyroiditis.

Amino Acid Sequence↗
PubMed1993

Immune recognition of hormonogenic sites of human thyroglobulin: studies of Graves' sera and a murine monoclonal antibody with thyroid hormone antibody activity.

We synthesized four peptides (HTg-1, 1-10; HTg-2, 2547-2558; HTg-4, 2592-2603 and HTg-6, 2737-2748) and two peptides (HTg-3, 2582-2591 and HTg-5, 2687-2694) with or without hormonogenic acceptor tyrosine of human thyroglobulin (hTg). They were iodinated with 127I or 125I. 127I-labeled peptides were tested for their ability to displace 125I-T4 binding to thyroid hormone autoantibodies (THAA) in two cases of Graves' disease and to a murine anti-hTg monoclonal antibody with anti-T4 activity (mAb). 125I-labeled peptides were tested for the direct binding to the aforementioned antibodies. None of the peptides displaced 125I-T4 binding to THAA or to a mAb, or exhibited increased binding to THAA and to a mAb. 125I-T4 binding to a mAb was equally displaced by hTgs obtained from a normal thyroid gland (NTg) and a case of Hürthle cell adenoma with undetectable iodine content (CTg). 125I-T4 binding to serum gamma globulin in each patient's serum was completely displaced by NTg, but CTg displaced 125I-T4 binding 2% and 5% in Case 1 and Case 2, respectively. It was speculated that the mAb recognizes a topological epitope around the hormonogenic site of hTg, while that of THAA in our two cases recognizes only T4 or an iodine dependent topological epitope(s) of hTg.

Animals↗
PubMed1992

[Characterization of thyroglobulin in a patient with functioning and non-functioning benign thyroid tumors].

The chemical and immunological properties of thyroglobulin (Tg) in tissue obtained from a patient co-existed with two types of thyroid tumors, i.e., functioning and non-functioning, and were compared with the properties of Tg that was isolated from adjacent peripheral tissue. In the present observations, the Tg content was markedly increased in the non-functioning thyroid tumor. On the other hand, the Tg content in the functioning tumor was at the normal level. The iodine content of Tg was significantly lower in the non-functioning tumor than in peripheral tissues. Affinity with Lectins differed among Tg preparations, suggesting that the carbohydrate chain in the Tg was different in each nodule in a single individual.

Adenoma↗
PubMed1992

[Autoimmune response to thyroglobulin. Proliferative response to thyroglobulin fragments in low responder mice].

Thyroglobulin (Tg) is one of the major thyroid autoantigens involved in autoimmune thyroiditis. The immune response of mice to Tg is genetically controlled by H-2-linked genes. To elucidate the regulation mechanism of autoimmune response to Tg in low responder mice, we studied the proliferative response of lymph node cells (LNC) to mouse Tg (MTg) and enzyme-digested MTg fragments. MTg was treated with Staphylococcus aureus V8 protease followed by separation of the fragments into 6 fractions (Fr1-Fr6: 264,000-17,000) by high performance liquid chromatography (HPLC), LNC from MTg immunized CBA/N (H-2k) mice, a high responder strain, proliferated in response to MTg and all fractions (Fr1-Fr6) of MTg fragments in vitro. In contrast, LNC from MTg immunized BALB/c (H-2d) and B10 (H-2b) mice, low responder strains, did not respond to native Tg but responded well to some smaller Tg fractions (Fr3, 4, 5). In addition, when BALB/c mice were immunized with MTg Fr4 with a molecular weight of 63,000, LNC from BALB/c mice proliferated in response to MTg as well as MTg Fr4. These findings suggest that T cells which are capable of responding to Tg do exist even in low responder mice and that the activation of these autoreactive T cells is suppressed by a regulatory cell subpopulation in low responder mice.

Animals↗
PubMed1991

[Enzymatic iodination of thyroglobulins obtained from patients with thyroid disease].

Iodination of the isolated thyroglobulin (Tg) by peroxidase was compared with various Tg preparations obtained from patients with thyroid diseases. For the purpose, the iodination process was observed in the incubation medium containing Tg, iodide, H2O2-generating system, and thyroid peroxidase (TPO) or lactoperoxidase (LPO). During the incubation, iodination of Tg preparations increased gradually and reached a plateau after 90 min., and 5 min. incubation with 3mIU or 14mIU of TPO, respectively. The degree of iodination level at the plateau region was different in each Tg preparation, depending on the iodine content of the original starting (native) preparation before incubation. The iodination level of cancer Tg with a very low iodine content (less than 0.1%) was low compared with the normal Tg level (obtained from normal thyroid tissue which contained about 0.4% iodine). The above findings suggest the possible existence of some structural differences of Tg in terms of the susceptibility to the iodination between the preparations of normal and diseased Tgs. As far as the immunological aspect concerned, there was no significant difference in the affinity (avidity) of Tg with polyclonal anti-Tg antibody between the native Tg and the enzymatically iodinated one. These results suggest that the changes of iodine and thyroid hormone contents of Tg by in vitro iodination, has no significant effect on the immunological property of Tg molecule.

Antigen-Antibody Reactions↗
PubMed1991

Synthesis and examination of antigenicity of four hormonogenic sites and two non-hormonogenic sites of human thyroglobulin.

Four peptides (HTg-1, 1-10; HTg-2, 2547-2558; HTg-4, 2592-2603; HTg-6, 2737-2748) which contain hormonogenic acceptor tyrosine (Tyr) residues and two control peptides (HTg-3, 2582-2591; HTg-5, 2687-2694) of human thyroglobulin (Tg) were synthesized, radioiodinated and their binding with serial anti-human Tg antisera which had been raised in two rabbits (TG-1, TG-2) tested. Although increased binding of each of the six peptides was observed, HTg-4 and HTg-2 had higher binding whereas HTg-1 and HTg-6 showed lower binding with the immune gamma globulin from both rabbits. Each of the six peptides was iodinated with inorganic iodine (127I) using the chloramine-T method and the inhibitory activity of each peptide on the interaction between 125I-T4 and anti-Tg antibodies was tested. At the same time, Tg obtained from a normal thyroid tissue (NTg, iodine content 0.38%) and from a Hürthle cell adenoma (CTg, iodine content 0.000%) were also tested for inhibition of 125I-T4 binding. 125I-T4 binding with rabbit anti-Tg antisera was displaced not only by NTg and CTg but also by three out of four hormonogenic peptides. Among the three peptides, HTg-2 had the highest inhibitory activity, inhibiting 125I-T4 binding to the extent of 21.5% (TG-1) and 16.0% (TG-2). Two control peptides (HTg-3, HTg-5) did not inhibit 125I-T4 binding with anti-Tg antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1990

Two cases of Graves' disease with antithyroid hormone antibodies: implication on the role of thyroglobulin as an antigen.

We have experienced two cases of Graves' disease with antithyroid hormone autoantibodies (Case 1: anti-T4; Case 2: anti-T3) who finally underwent subtotal thyroidectomy after antithyroid drug treatment. Using serial sera obtained before and after operation, the correlation between titers of antithyroglobulin (anti-Tg) and anti-T4 or anti-T3 autoantibodies was examined in each case. There was a significant positive correlation between titers of anti-T4 (Case 1, r = 0.90, p less than 0.05), or anti-T3 (Case 2, r = 0.64, p less than 0.01) and anti-Tg antibodies. Using the homogenate of the thyroid tissue, it was found that the sole iodoprotein in the thyroid gland in each patient was 660 KDa Tg. In addition, Tg purified from the thyroid gland from Case 2 showed different immunological activity with normal Tg in two out of four murine monoclonal anti-Tg antibodies tested. On the other hand, Tg from Case 1 had identical immunological activity with normal Tg in every four monoclonal antibodies. These results are consistent with the view that the antigen responsible for the development of antithyroid hormone autoantibodies is Tg, at least in our two cases. The reason for the persistence of anti-T3 autoantibodies in Case 2, despite the subtotal thyroidectomy, could be due to some unidentified structural abnormalities of Tg which was detected only by the monoclonal anti-Tg antibodies.

Adenoma↗
PubMed1990

Autoimmune thyroiditis induced in mice depleted of particular T cell subsets. III. Analysis of regulatory cells suppressing the induction of thyroiditis.

It has previously been demonstrated that T cell clones with potentials to induce autoimmune thyroiditis exist in lymphoid organs from normal healthy individuals. The present study investigates the nature of regulatory cells co-existing in a normal lymphoid cell population to prevent the activation of these thyroiditis-inducing T cells. T cell-depleted (C57BL/6 x C3H/He) F1 mice (B cell mice) were prepared by adult thymectomy and injection of anti-thymocyte serum, followed by lethal X-irradiation and bone marrow reconstitution. Typical thyroiditis was induced in these B cell mice by i.v. administration of Lyt-1dull T cells but not of whole T cells from normal syngeneic mice. Additional injection of normal thymocytes into B cell mice which had been transferred with the Lyt-1 dull T cells resulted in complete prevention of thyroiditis induction. Mature thymocytes were responsible for this regulatory function and such regulatory cell activity was also found in peripheral lymphoid cells such as spleen cells. These regulatory cells exerted their capacity to prevent thyroiditis in cell dose-dependent and injection timing-dependent manners; thyroiditis was prevented when they were injected in cell doses of greater than 1.5 x 10(7)/mouse and before the initiation of the thyroiditis lesion. Most interestingly, the phenotypes of regulatory cells were Thy-1+ and L3T4+. Since the thyroiditis-inducing Lyt-1 dull T cells has previously been shown to be of L3T4+, these results indicate that there exist functionally heterogeneous subsets in an L3T4+ T cell population and that some L3T4+ T cells function as regulatory cells to prevent the activation of thyroiditis-inducing L3T4+ T cells co-existing in the normal lymphoid cell population.

Animals↗
PubMed1990

Anti-thyroglobulin autoantibodies in sera from patients with chronic thyroiditis and from healthy subjects: differences in cross-reactivity with thyroid peroxidase.

A significant portion (about 12.7%) of healthy subjects was found to contain anti-thyroglobulin (anti-Tg) antibodies in their sera. We compared the binding activities of these antibodies and of anti-Tg autoantibodies from sera of patients with chronic thyroiditis with human thyroid peroxidase (TPO). The results obtained by ELISA indicated that out of 10 healthy subjects with anti-Tg antibodies, only four had anti-Tg antibodies capable of binding to TPO, whereas anti-Tg autoantibodies from almost all patients with chronic thyroiditis possessed high binding activities to TPO. By use of the immunoprecipitation method, it was also shown that although all anti-Tg autoantibodies from patients precipitated TPO, a majority of anti-Tg antibodies from healthy subjects could not precipitate TPO. Such findings cannot be ascribed to the differences in levels of anti-Tg autoantibodies and anti-TPO autoantibodies in sera and the differences in avidities of anti-Tg antibodies in sera between healthy subjects and patients with chronic thyroiditis. Thus, it can be concluded that anti-Tg antibodies from healthy subjects differ from those of patients with chronic thyroiditis with respect to TPO binding, probably due to difference in fine specificities of these anti-Tg antibodies.

Adolescent↗
PubMed1989

Improved assay method for activity of thyroid peroxidase-catalysed coupling of iodotyrosine residues of thyroglobulin utilizing h.p.l.c. for analysis of iodothyronines.

The coupling of iodotyrosine residues of thyroglobulin (Tg) catalysed by thyroid peroxidase (TPO) has scarcely been studied with respect to the TPO of abnormal human thyroid glands. The present paper proposes a rapid and convenient assay method applicable for determining the coupling activity of a sample of less than 500 mg from each patient's thyroid. The main characteristics of the method are as follows: (i) mitochondrial/microsomal fractions of thyroid glands were treated with sodium cholate plus trypsin, and the supernatants obtained by ultracentrifugation were directly used for the assay of coupling and peroxidase activity of TPO; (ii) the formation of iodotyrosine residues catalysed by TPO was performed by using chemically iodinated Graves'-disease Tg containing 41 iodine atoms per molecule and with a high iodotyrosine and a low iodothyronine content; (iii) newly synthesized iodothyronine residues (thyroxine, 3,5,3'-tri-iodothyronine, and 3,3',5'-tri-iodothyronine) were analysed by h.p.l.c. after hydrolysis of Tg with proteinases and extraction of iodothyronines with ethyl acetate.

Chromatography, High Pressure Liquid↗
PubMed1988

Autoimmune thyroiditis induced in mice depleted of particular T cell subsets. I. Requirement of Lyt-1 dull L3T4 bright normal T cells for the induction of thyroiditis.

T cell-depleted C3H/He or (C57BL/6xC3H/He)F1 (B6C3F1) mice were prepared by adult thymectomy and injection of antithymocyte serum, followed 3 wk later by lethal x-irradiation and bone marrow reconstitution. When these T cell-depleted mice were not injected or injected i.v. with normal spleen and lymph node cells treated with either anti-Thy-1, -L3T4 or -Lyt-2 antibody plus C or C alone, none of the groups of mice developed thyroiditis. In contrast, the adoptive transfer of normal cells treated with anti-Lyt-1 plus C resulted in high incidence of the production of antithyroglobulin antibody and the induction of typical thyroiditis lesion. The thyroid was the sole organ involved, because neither typical inflammatory lesion in other organs nor autoantibody such as anti-DNA antibody was detected in mice that exhibited thyroiditis. Analyses of surface phenotypes of cells required for inducing thyroiditis by the adoptive transfer revealed that an appreciable percentage of Lyt-1 dull T cells remained after the treatment of normal lymphoid cells with anti-Lyt-1 plus C. Almost all of these Lyt-1 dull T cells expressed magnitudes of L3T4 or Lyt-2 Ag comparable to those detected on Lyt-1 bright T cells. More important, the induction of thyroiditis was almost completely prevented by either in vitro or in vivo elimination of Lyt-1 dull L3T4+(bright) but not of Lyt-1 dull Lyt-2+(bright) T cells. These results indicate that Lyt-1 dull L3T4+ T cells existing in normal healthy individuals have potential to induce typical thyroiditis which is associated with the production of antithyroglobulin autoantibody, and that the activation and/or function of this T cell subset is regulated by the Lyt-1 bright T cell population coexisting in normal lymphoid cell population.

Animals↗
PubMed1988

Enhanced thyroid iodine metabolism in patients with triiodothyronine-predominant Graves' disease.

Some patients with hyperthyroid Graves' disease have increased serum T3 and normal or even low serum T4 levels during treatment with antithyroid drugs. These patients with elevated serum T3 to T4 ratios rarely have a remission of their hyperthyroidism. The aim of this study was to investigate thyroid iodine metabolism in such patients, whom we termed T3-predominant Graves' disease. Mean thyroid radioactive iodine uptake was 51.0 +/- 18.1% ( +/- SD) at 3 h, and it decreased to 38.9 +/- 20.1% at 24 h in 31 patients with T3-predominant Graves' disease during treatment. It was 20.0 +/- 11.4% at 3 h and increased to 31.9 +/- 16.0% at 24 h in 17 other patients with hyperthyroid Graves' disease who had normal serum T3 and T4 levels and a normal serum T3 to T4 ratio during treatment (control Graves' disease). The activity of serum TSH receptor antibodies was significantly higher in the patients with T3-predominant Graves' disease than in control Graves' disease patients (60.5 +/- 19.2% vs. 20.4 +/- 18.2%; P less than 0.001). From in vitro studies of thyroid tissue obtained at surgery, both thyroglobulin content and iodine content in thyroglobulin were significantly lower in patients with T3-predominant Graves' disease than in the control Graves' disease patients. Thyroid peroxidase (TPO) activity determined by a guaiacol assay was 0.411 +/- 0.212 g.u./mg protein in the T3-predominant Graves' disease patients, significantly higher than that in the control Graves' disease patients (0.129 +/- 0.112 g.u./mg protein; P less than 0.01). Serum TPO autoantibody levels determined by immunoprecipitation also were greater in T3-predominant Graves' disease patients than in control Graves' disease patients (52.6 +/- 27.7% vs. 32.4 +/- 11.4%; P less than 0.05). Binding of this antibody to TPO slightly inhibited the enzyme activity of TPO, but this effect of the antibody was similar in the two groups of patients. The data suggest enhanced iodine metabolism in the thyroid gland of patients with T3-predominant Graves' disease, which may relate to the discordant T3 overproduction in patients with this type of Graves' disease.

Adolescent↗
PubMed1988

Antigenic determinants on thyroglobulin: comparison of the reactivities of different thyroglobulin preparations with serum antibodies and T cells of patients with chronic thyroiditis.

To delineate the antigenic determinants on thyroglobulin (Tg) recognized by serum autoantibodies and peripheral blood T cells from patients with chronic thyroiditis, we studied the reactivities of three different Tg preparations, i.e. enzyme-digested Tg fragments, physically or chemically denatured Tg, or Tg with differing iodine contents. Human Tg was digested with staphylococcal V8 protease, and the fragments were separated by high performance liquid chromatography. The autoantibodies reacted with the larger fragments, but their ability to bind to small fragments was limited. On the other hand, T cells reacted similarly with all fragments, regardless of mol wt. The autoantibodies bound little to denatured Tg after its disulfide bonds were destroyed with dithiothreitol or 2-mercaptoethanol, while the reactivity of heat-denatured Tg was partially decreased, and that of Tg denatured with sodium dodecyl sulfate was conserved. Conversely, T cells reacted with Tg denatured by heating or dithiothreitol treatment. These results indicate that autoantibodies recognize mainly a conformational structure of Tg, presumably containing disulfide bonds, whereas T cells recognize the primary structure of Tg. Variations in the iodine content of Tg were not associated with altered reactivity with autoantibodies or T cells. We propose that variations in Tg conformation related to iodination of the molecule do not contribute significantly to its reactivity with autoantibodies and T cells. In addition, T cells reacted with the smaller Tg fragments containing few T3 or T4 residues to a greater extent than they did with larger Tg fragments with the same amount of T3 or T4 as native Tg. Therefore, it appears that the Tg-reactive T cells predominantly recognize determinants on the Tg molecule that are unrelated to hormone-containing sites.

Adolescent↗
PubMed1988

Thyroglobulin and thyroid peroxidase share common epitopes recognized by autoantibodies in patients with chronic autoimmune thyroiditis.

Monoclonal antibodies specific for human thyroid peroxidase (TPO) were prepared by the hybridoma technique using hyperimmune spleen cells from mice immunized with TPO purified from thyroid glands from patients with Graves' disease. Use of the microenzyme-linked immunosorbent assay method revealed that some of the monoclonal antibodies cross-reacted strongly with human thyroglobulin (Tg). Conversely, monoclonal anti-Tg antibodies cross-reacted with TPO, albeit to a lesser degree. Some anti-Tg autoantibodies in serum from patients with chronic autoimmune thyroiditis purified by Tg affinity chromatography bound TPO, and such binding was completely inhibited by Tg. Western blotting experiments revealed that thyroid microsomal 103K proteins recognized by mouse monoclonal and polyclonal anti-TPO antibodies were recognized by some monoclonal anti-Tg antibodies and anti-Tg autoantibodies, and conversely, that 19S Tg was recognized by some monoclonal anti-TPO antibodies. TPO was immunoprecipitated by anti-Tg autoantibodies isolated by Tg affinity chromatography. On the other hand, the specificity for TPO of the anti-Tg autoantibodies was not identical with that of anti-TPO autoantibodies. These cross-reactivities were not due to contamination of TPO with Tg or vice versa, or to contamination of the anti-Tg autoantibody preparations with anti-TPO autoantibodies. Taken together, these data indicate that Tg and TPO share common antigenic determinants and that some of those determinants are recognized by autoantibodies in the serum of patients with chronic autoimmune thyroiditis.

Adolescent↗
PubMed1988

Peroxidase activity and thyroglobulin iodination activity of thyroid peroxidase in non-functioning thyroid tumours.

Both lesion (L) and adjacent normal (N) thyroid tissue from 48 patients with non-functioning adenomas and adenomatous goitres were assayed for peroxidase activity by the 'mini' assay method employing guaiacol or iodide as the second substrate. A considerable proportion of thyroids (46% of adenomas and 22% of adenomatous goitres) demonstrated no iodide oxidation activity in L although they had guaiacol oxidation activity, and these were grouped as subgroups A. The rest of these non-functioning tumours, termed subgroups B, had both guaiacol and iodide oxidation activity which was higher (3.0-4.6 times in guaiacol assay and 7.3-14.1 times in iodide assay) in L than in N. These data indicate that the non-functioning in subgroups A may be due to a lack of iodide oxidation activity and that some other defects such as an iodide transport defect may be involved in subgroups B. Furthermore, a precise and rapid assay method for thyroglobulin iodination activity of thyroid peroxidase was developed, with modifications of previous methods. On the basis of this method, we found that there is a good correlation (r = 0.94) between iodide oxidation assay and thyroglobulin iodination assay, leading to the conclusion that thyroglobulin iodination assay can be replaced by iodide oxidation assay.

Adenoma↗