Organ-specific autoimmune diseases induced in mice by elimination of T cell subset. I. Evidence for the active participation of T cells in natural self-tolerance; deficit of a T cell subset as a possible cause of autoimmune disease

Organ-specific autoimmune diseases such as oophoritis, gastritis, thyroiditis, and orchitis were induced in female or male nude (nu/nu) mice by the transfer of nu/+spleen cells from which particular Lyt T cell subset(s) had been removed: nu/+spleen cells treated with anti-Lyt-1 plus complement (C) caused disease in recipient nude mice; anti-Lyt-2 plus C-treated spleen cells, in contrast, did not. The cells responsible for disease induction are believed to be Thy-1+, Lyt-1-, 2,3- (Thy-1, Lyt-1, 2,3), since spleen cells treated with mixed antisera, including anti-Lyt-1 and anti-Lyt-2, plus C, could induce the disease with almost the same incidence as anti-Lyt-1 plus C-treated cells (oophoritis 50%, gastritis 25%, thyroiditis 10-20%, and orchitis 40%). Cells treated with mixed antisera of anti-Thy-1, anti-Lyt-1, and anti-Lyt-2, plus C, could not induce autoimmune disease. Each induced autoimmune disease could be adoptively transferred to other nude mice via spleen cells, with resulting histological lesion of corresponding organs and development of specific circulating autoantibodies. Since anti-Thy-1 plus C treatment of donor spleen cells abrogated the capacity to transfer the disease, we conclude that T cells are required as effector cells, and that these may develop from Lyt-1-, 2,3- cells. Lyt-1+, 2,3- cells were demonstrated to have suppressive activity upon the development of the diseases; induction of autoimmunity was completely inhibited by the cotransfer of Lyt-1+, 2,3- cells with Lyt-1-, 2,3- cells. When anti-Lyt-2 plus C-treated cells (i.e., Lyt-1+, 2,3- and Lyt-1-, 2,3- cells) were mixed with anti-Lyt-1 and anti-Lyt-2 plus C-treated cells (i.e., Lyt-1-, 2,3- cells) in various ratios, then transferred to nude mice, the development of each autoimmune disease was clearly inhibited, even by small doses of Lyt-1+, 2,3- cells. The autoimmune disease we were able to induce was quite similar to human organ-specific autoimmune disease in terms of the spectrum of organs involved, histopathological features, and the development of autoantibodies to corresponding organ components (oocytes, parietal cells, thyroid colloid, including thyroglobulin, and sperm).(ABSTRACT TRUNCATED AT 400 WORDS)

Autoimmune murine thyroiditis relation to histocompatibility (H-2) type

Immunization of 33 inbred strains of mice with thyroid extract emulsified in complete Freund's adjuvant showed differences in both thyroid autoantibody response and autoimmune thyroid damage, related to the histocompatibility (H-2) type of the strain. Congenic mice of the same H-2 type exhibited the same pattern of antibody response and thyroiditis, regardless of the strain's genetic background, thus showing a close relation between histocompatibility determinants and autoimmunity.

Regulatory T cells in the control of autoimmunity: the essential role of transforming growth factor beta and interleukin 4 in the prevention of autoimmune thyroiditis in rats by peripheral CD4(+)CD45RC- cells and CD4(+)CD8(-) thymocytes

Previous studies have shown that induction of autoimmune diabetes by adult thymectomy and split dose irradiation of PVG.RT1(u) rats can be prevented by their reconstitution with peripheral CD4(+)CD45RC-TCR-alpha/beta+RT6(+) cells and CD4(+)CD8(-) thymocytes from normal syngeneic donors. These data provide evidence for the role of regulatory T cells in the prevention of a tissue-specific autoimmune disease but the mode of action of these cells has not been reported previously. In this study, autoimmune thyroiditis was induced in PVG.RT1(c) rats using a similar protocol of thymectomy and irradiation. Although a cell-mediated mechanism has been implicated in the pathogenesis of diabetes in PVG.RT1(u) rats, development of thyroiditis is independent of CD8(+) T cells and is characterized by high titers of immunoglobulin (Ig)G1 antithyroglobulin antibodies, indicating a major humoral component in the pathogenesis of disease. As with autoimmune diabetes in PVG. RT1(u) rats, development of thyroiditis was prevented by the transfer of CD4(+)CD45RC- and CD4(+)CD8(-) thymocytes from normal donors but not by CD4(+)CD45RC+ peripheral T cells. We now show that transforming growth factor (TGF)-beta and interleukin (IL)-4 both play essential roles in the mechanism of this protection since administration of monoclonal antibodies that block the biological activity of either of these cytokines abrogates the protective effect of the donor cells in the recipient rats. The prevention of both diabetes and thyroiditis by CD4(+)CD45RC- peripheral cells and CD4(+)CD8(-) thymocytes therefore does not support the view that the mechanism of regulation involves a switch from a T helper cell type 1 (Th1) to a Th2-like response, but rather relies upon a specific suppression of the autoimmune responses involving TGF-beta and IL-4. The observation that the same two cytokines were implicated in the protective mechanism, whether thymocytes or peripheral cells were used to prevent autoimmunity, strongly suggests that the regulatory cells from both sources act in the same way and that the thymocytes are programmed in the periphery for their protective role. The implications of this result with respect to immunological homeostasis are discussed.

Pembrolizumab-Induced Thyroiditis: Comprehensive Clinical Review and Insights Into Underlying Involved Mechanisms

CONTEXT

Thyroid immune-related adverse events (irAEs) in patients treated with programmed death receptor-1 (PD-1) blockade are increasingly recognized as one of the most common adverse effects. Our aim was to determine the incidence and examine the potential mechanisms of anti-PD-1-induced thyroid irAEs.

DESIGN

Single-center, retrospective cohort study.

PATIENTS AND MEASUREMENTS

We studied 93 patients with advanced cancer (ages 24 to 82 years; 60% males) who received at least one infusion of pembrolizumab. Thyroid test results and thyroid imaging modalities were reviewed. Comprehensive 10-color flow cytometry of peripheral blood was performed.

RESULTS

Thirteen (14%) thyroid irAEs were observed. Thyroiditis occurred in seven patients (54%), from which four recovered. New onset of hypothyroidism overt/subclinical developed in three patients. Levothyroxine dosing required doubling in three patients with a known history of hypothyroidism. Thyroperoxidase antibodies were positive in the minority of the patients [4/13 (31%)] and diffuse increased 18fludeoxyglucose uptake of the thyroid gland was observed in the majority [7/11 (64%)] of patients. We observed more circulating CD56+CD16+ natural killer (NK) cells and an elevated HLA-DR surface expression in the inflammatory intermediate CD14+CD16+ monocytes in anti-PD-1-treated patients.

CONCLUSIONS

Thyroid dysfunction is common in cancer patients treated with pembrolizumab. Reversible destructive thyroiditis and overt hypothyroidism are the most common clinical presentations. The mechanism of thyroid destruction appears independent of thyroid autoantibodies and may include T cell, NK cell, and/or monocyte-mediated pathways. Because the thyroid is a frequent target of anti-PD-1 therapies, patients with therapeutically refractory thyroid cancer may be ideal candidates for this treatment.

A stable sheep cell preparation for detecing thyroglobulin auto-antibodies and its clinical applications

The preparation of stable formolized sheep cells coated with thyroglobulin and their use for the detection of auto-antibodies in human thyroiditis is described. This provides an easy laboratory test which gives results closely comparable with those using fresh tanned cells. The agglutination titres do not closely parallel the antibody content of the serum but a good correlation may be obtained by inhibiting agglutination with thyroglobulin. The diagnostic usefulness of the test in treating disorders of the thyroid is discussed and related to the results of tests for the other two immune systems involved in thyroiditis. The tanned red cell test may be used to differentiate Hashimoto's disease from thyroid cancer and non-toxic colloid goitre, and to assess the choice of treatment in patients with Graves' disease. It has proved of particular value in genetic studies of auto-immunity.

Natural history of autoimmune thyroiditis

One hundred and sixty-three asymptomatic people with thyroid antibodies or raised serum thyrotrophin (TSH) concentrations, or both, and 209 age-matched and sex-matched controls without either marker of thyroid disorder were followed up for four years to determine the natural history of autoimmune thyroiditis. Mildly raised TSH concentrations alone and the presence of thyroid antibodies alone did not significantly increase the risk of developing overt hypothyroidism during the four years compared with the controls. Overt hypothyroidism developed at the rate of 5% a year in women who initially had both raised TSH concentrations and thyroid antibodies. Prophylactic treatment with thyroxine may be justified in women found to have both markers of impending thyroid failure. The cost effectiveness of screening the adult population remains to be evaluated.

Induction of autoimmunity in good and poor responder mice with mouse thyroglobulin and lipopolysaccharide

The administration of soluble mouse thyroglobulin (MTg) in conjunction with bacterial lipopolysaccharide (LPS) led to the termination of natural tolerance to MTg in mice. The extent of autoimmunity correlated with responsiveness to MTg, previously shown by the injection of MTg in complete Freund's adjuvant (CFA) to be dependent upon the H-2 haplotype. In good responder B10.BR (H-2k) mice given MTg either with LPS or in CFA, high antibody levels to MTg and extensive mononuclear cell infiltration in the thyroid were observed. In contrast, congenic poor responder B10.D2 (H-2d) mice given MTg plus LPS showed low levels of antibody to MTg, compared to those receiving MTg in CFA, and insignificant cellular infiltration of the thyroid. In no instance did autoimmunity develop in either good or poor responder strain given MTg, LPS, or CFA along although LPS was antigenic in both of these congenic strains. Since the genetic difference in responsiveness to MTg is known to be T-cell based, the involvement of T cells in LPS-treated mice was suspected. This was further ascertained by the use of athymic poor responder (BALB/c) mice and thymectomized, irradiated, and bone marrow-reconstituted B10.BR mice. Antibodies to MTg were detected only in heterozygous (nu/+) mice and good responder mice reconstituted with both thymus and bone marrow cells. In addition, significant cellular infiltration in the thyroid occurred only in fully reconstituted good responder mice. Thus, the adjuvant effect of LPS on responsiveness to MTg required T cells. Since unmodified MTg and LPS abrogated selftolerance to MTg, the need for cross-reactive T cells could be excluded. These observations suggest the presence of self-reactive T cells.

Induction of autoimmune thyroiditis in chickens by dietary iodine

Clinical studies have suggested that excess dietary iodine promotes autoimmune thyroiditis; however, the lack of a suitable animal model has hampered investigation of the phenomenon. In this study, different amounts of potassium iodide were added to the diets of chicken strains known to be genetically susceptible to autoimmune thyroiditis. Administration of iodine during the first 10 weeks of life increased the incidence of the disease, as determined by histology and the measurement of autoantibodies to triiodothyronine, thyroxine, and thyroglobulin. Further support for the relation between iodine and autoimmune thyroiditis was provided by an experiment in which iodine-deficient regimens decreased the incidence of thyroid autoantibodies in a highly susceptible strain. These results suggest that excessive consumption of iodine in the United States may be responsible for the increased incidence of autoimmune thyroiditis.

Antibodies that promote thyroid growth. A distinct population of thyroid-stimulating autoantibodies

We used a strain of differentiated rat-thyroid cells in continuous culture (the FRTL-5 strain) to detect the presence of growth-promoting antibodies in serum samples from patients with autoimmune thyroid disease. We found that IgG preparations from 17 of 20 patients (85 per cent) with active Graves' disease and two of five patients (40 per cent) with Hashimoto's thyroiditis could augment thyroid-cell growth. In parallel with IgG-induced elevations in intracellular cyclic AMP levels in the same cell line, all 20 of the patients with active Graves' disease had thyroid-stimulatory antibodies. Patients' IgG preparations fell into three subclasses: those with both potent cyclic AMP stimulation and potent growth-promoting activity; those with potent cyclic AMP stimulation but low-level growth promotion; and those with potent growth promotion and low-level cyclic AMP action. Growth-promoting antibodies were not detected in patients with Graves' disease in remission (seven patients), nodular goiter (seven), subacute thyroiditis (five), or atrophic thyroiditis (one). Simultaneous assays of growth promotion and cyclic AMP stimulation may be useful in the care of patients with autoimmune thyroid disease.

The tight relationship between papillary thyroid cancer, autoimmunity and inflammation: clinical and molecular studies

OBJECTIVE

The recent concept that oncogenes responsible for thyroid neoplastic transformation are able to elicit an inflammatory protumourigenic microenvironment raises interest in further studies on papillary thyroid cancer (PTC) associated with thyroid autoimmunity.

PATIENTS

The clinical and molecular features, and the expression of inflammation-related genes, were investigated in a large series of PTCs with and without associated thyroiditis (groups A, n = 128 and B, n = 215).

RESULTS

The two groups did not show significant differences in clinical and prognostic features, whereas they harboured a significantly different genetic background (P = 0.001), with RET/PTC1 being more represented in PTCs associated with autoimmunity, and BRAF(V600E) in patients with PTC alone. A RET/PTC rearrangement was also found in 41% of non-neoplastic thyroiditis tissues, contralateral to tumours harbouring either RET/PTC or BRAF mutations. The expression of genes encoding CCL20, CXCL8 and l-selectin was significantly higher in PTC specimens (either with RET/PTC, BRAF(V600E) or unknown genetic lesion) compared with normal thyroid samples. On the contrary, thyroiditis showed l-selectin expression levels even higher than PTCs, but CCL20 and CXCL8 levels comparable with normal tissues.

CONCLUSIONS

The present data extend the knowledge about the tight relationships among oncogenes, thyroiditis and thyroid cancer. A different genetic background among PTCs with and without associated autoimmunity has been firstly demonstrated. The strong association between RET/PTC1 and thyroiditis points to a critical role of this oncoprotein in the modulation of the autoimmune response. Moreover, preliminary expression studies, indicating enhanced expression of inflammatory molecules in PTCs, suggest a proinflammatory, nonautoimmune relationship between thyroiditis and thyroid cancer.

The association of goitrous autoimmune thyroiditis with HLA-DR5

We found HLA-DR5 to be present among 53% of 40 patients with goitrous autoimmune (Hashimoto's ) thyroiditis compared to 26% of 80 controls. No deviations from those expected in the incidences of HLA-A, B, C antigens were seen. In contrast HLA-DR3 was increased among 50 patients with atrophic thyroiditis (65%) compared to controls (24%). These findings stress the immunogenetic heterogeneity between the goitrous and atrophic varieties of thyroiditis.

Induction of painless thyroiditis in patients receiving programmed death 1 receptor immunotherapy for metastatic malignancies

CONTEXT

Immunotherapies against immune checkpoints that inhibit T cell activation [cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death 1 (PD-1)] are emerging and promising treatments for several metastatic malignancies. However, the precise adverse effects of these therapies on thyroid gland function have not been well described.

CASE DESCRIPTION

We report on 10 cases of painless thyroiditis syndrome (PTS) from a novel etiology, following immunotherapy with anti-PD-1 monoclonal antibodies (mAb) during treatment for metastatic malignancies. Six patients presented with transient thyrotoxicosis in which thyrotropin binding inhibitory immunoglobulins (TBII) were absent for all, whereas four patients had evidence of positive antithyroid antibodies. All thyrotoxic patients required temporary beta-blocker therapy and had spontaneous resolution of thyrotoxicosis with subsequent hypothyroidism. Four patients presented with hypothyroidism without a detected preceding thyrotoxic phase, occurring 6-8 weeks after initial drug exposure. All of these patients had positive antithyroid antibodies and required thyroid hormone replacement therapy for a minimum of 6 months.

CONCLUSIONS

Patients receiving anti-PD-1 mAb therapy should be monitored for signs and symptoms of PTS which may require supportive treatment with beta-blockers or thyroid hormone replacement. The anti-PD-1 mAb is a novel exogenous cause of PTS and provides new insight into the possible perturbations of the immune network that may modulate the development of endogenous PTS, including cases of sporadic and postpartum thyroiditis.

Antithyroid antibodies in depressed patients

The presence of antithyroid (antimicrosomal and antithyroglobulin) antibodies was assessed in 45 psychiatric inpatients with prominent depressive symptoms (28 with DSM-III major depression). Nine patients (20%) had detectable titers of antithyroid antibodies, a rate considerably higher than the 5%-10% observed in the normal population. Each of these nine patients with symptomless autoimmune thyroiditis had normal baseline serum thyrotropin concentrations and normal thyroid function (as assessed by T4, T3 uptake, and free thyroxine index). These findings support the hypothesis of subtle thyroid dysfunction in a sizable sample of psychiatric inpatients with prominent depressive symptoms.