Absolute reduction in peripheral regulatory T cells in patients with Graves’ disease and post-treatment recovery

Associations between immune cell traits and autoimmune thyroid diseases: a bidirectional two-sample mendelian randomization study

Autoimmune thyroid diseases (AITDs), mainly including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are common autoimmune disorders characterized by abnormal immune responses targeting the thyroid gland. We conducted a bidirectional two-sample MR analysis using the largest dataset of peripheral immune cell phenotypes from Sardinia, and the AITD dataset from the 10th round of the FinnGen and the UK Biobank project. Instrumental variables (IVs) were rigorously selected based on the three assumptions of MR and analyzed using the Wald ratio, inverse-variance weighted (IVW), MR-Egger, and weighted median methods. Additionally, sensitivity analyses were performed using Cochrane's Q, the Egger intercept, the MR-PRESSO, and the leave-one-out (LOO) method to ensure the robustness of the results. The Steiger test was utilized to identify and exclude potential reverse causation. The results showed that 3, 3, and 11 immune cell phenotypes were significantly associated with the risk of AITD. In GD, the proportion of naive CD4-CD8- (DN) T cells in T cells and the proportion of terminally differentiated CD4+T cells in T cells showed the strongest inducing and protective effects, respectively. In HT, lymphocyte count and CD45 on CD4+T cells showed the strongest inducing and protective effects, respectively. In autoimmune hypothyroidism, CD127 CD8+T cell count and terminally differentiated DN T cell count exhibited the strongest inducing and protective effects, respectively. Through MR analysis, our study provides direct genetic evidence of the impact of immune cell traits on AITD risk and lays the groundwork for potential therapeutic and diagnostic target discovery.

[Expression of miR-142 and its relationship with Th17/Treg imbalance in children with autoimmune thyroid disease]

OBJECTIVES

To investigate the expression of microRNA-142 (miR-142) in children with autoimmune thyroid disease (AITD) and its relationship with the imbalance of helper T cell 17 (Th17) and regulatory T cell (Treg).

METHODS

A total of 89 children hospitalized for AITD from January 2019 to December 2022 were prospectively selected as the study subjects, including 48 children with Graves' disease (GD group) and 41 children with Hashimoto's thyroiditis (HT group). Additionally, 55 healthy children undergoing physical examinations during the same period were selected as the control group. The differences in serum miR-142, antithyroglobulin antibody (TGAb), antithyroperoxidase antibody (TPOAb), Th17/Treg, and interleukin-17 (IL-17) expression were compared among the groups.

RESULTS

The expression of miR-142, TPOAb, TGAb, Th17, Th17/Treg, and IL-17 in the GD group and HT group was higher than that in the control group, while Treg was lower than that in the control group (P<0.05). Pearson correlation analysis revealed that in the GD group, miR-142 was positively correlated with TPOAb, TGAb, Th17, Th17/Treg, and IL-17 (r=0.711, 0.728, 0.785, 0.716, 0.709, respectively; P<0.001) and negatively correlated with Treg (r=-0.725, P<0.001); in the HT group, miR-142 was positively correlated with TPOAb and TGAb (r=0.752, 0.717, respectively; P<0.001).

CONCLUSIONS

miR-142 is highly expressed in children with AITD, and its expression may be related to the Th17/Treg imbalance in children with GD.

A role of NR4A2 in Graves' disease: regulation of Th17/Treg

PURPOSE

This study aimed to explore the molecular pathogenesis of Graves' disease (GD).

METHODS

The gene expression profile in CD4+ T cells from GD patients and healthy controls were analyzed through mRNA-sequencing. The expression of NR4A2 was determined by quantitative real-time PCR and western blot. The levels of Th17 and Treg were determined by flow cytometry. ELISA was employed to detect the levels of IL-10, IL-17A, IL-17F and IL-22.

RESULTS

In the CD4+ T cells from GD patients, there were 128 up-regulated and 510 down-regulated genes. Subsequently, we focused on the role of nuclear receptor 4 group A member 2 (NR4A2) in GD. NR4A2 was lowly expressed in the CD4+ T cells from GD patients. Its expression was negatively correlated with free triiodothyronine and tetraiodothyronine, but positively correlated with thyroid stimulating hormone. NR4A2 knockdown decreased the percentage of Treg cells, with a decreased IL-10 level. While its over-expression augmented the Treg differentiation, with an elevated IL-10 level. In addition, knockdown or over-expression of NR4A2 showed no significant influence on Th17 differentiation.

CONCLUSION

These results indicate that the low level of NR4A2 in GD patients may suppress Treg differentiation, but have no influence on Th17 differentiation, leading to the imbalance of Th17/Treg and contributing to the development of GD. Revealing the role of NR4A2 in GD provides a novel insight for the treatment of GD.

Regulatory T Cells in the Pathogenesis of Graves' Disease

Maintaining a delicate balance between the prompt immune response to pathogens and tolerance towards self-antigens and commensals is crucial for health. T regulatory (Treg) cells are pivotal in preserving self-tolerance, serving as negative regulators of inflammation through the secretion of anti-inflammatory cytokines, interleukin-2 neutralization, and direct suppression of effector T cells. Graves' disease (GD) is a thyroid-specific autoimmune disorder primarily attributed to the breakdown of tolerance to the thyroid-stimulating hormone receptor. Given the limitations of currently available GD treatments, identifying potential pathogenetic factors for pharmacological targeting is of paramount importance. Both functional impairment and frequency reduction of Tregs seem likely in GD pathogenesis. Genome-wide association studies in GD have identified polymorphisms of genes involved in Tregs' functions, such as CD25 (interleukin 2 receptor), and Forkhead box protein P3 (FOXP3). Clinical studies have reported both functional impairment and a reduction in Treg frequency or suppressive actions in GD, although their precise involvement remains a subject of debate. This review begins with an overview of Treg phenotype and functions, subsequently delves into the pathophysiology of GD and into the existing literature concerning the role of Tregs and the balance between Tregs and T helper 17 cells in GD, and finally explores the ongoing studies on target therapies for GD.

TSHR-based chimeric antigen receptor T cell specifically deplete auto-reactive B lymphocytes for treatment of autoimmune thyroid disease

Graves' disease (GD) is a prominent antibody-mediated autoimmune disorder characterized by stimulating antibodies (TRAb) that target the thyroid-stimulating hormone receptor (TSHR). Targeting and eliminating TRAb-producing B lymphocytes hold substantial therapeutic potential for GD. In this study, we engineered a novel chimeric antigen receptor T cell (CAR-T) therapy termed TSHR-CAR-T. This CAR-T construct incorporates the extracellular domain of the TSH receptor fused with the CD8 transmembrane and intracellular signal domain (4-1BB). TSHR-CAR-T cells demonstrated the ability to recognize and effectively eliminate TRAb-producing B lymphocytes both in vitro and in vivo. Leveraging this autoantigen-based chimeric receptor, our findings suggest that TSHR-CAR-T cells offer a promising and innovative immunotherapeutic approach for the treatment of antibody-mediated autoimmune diseases, including GD.

[The features of regulatory T-blood cells subpopulation and the level of CD25 expression in patients with Graves' disease in dynamics after radioactive iodine therapy]

BACKGROUND

The content of regulatory T cells (Treg) at different stages in formation of effector subpopulations and the level of CD25 expression on the membrane of their various fractions in Graves' disease can determine the long-term autoimmune process persistence and be the target of immunotropic therapy of the disease.

AIM

To study the features of regulatory T-blood cells subpopulation and the level of CD25 expression in patients with Graves' disease in dynamics after radioactive iodine therapy (RIT) to identify the specific Treg subpopulations for potential immunotropic therapy targets of the disease.

MATERIALS AND METHODS

A single-center, prospective, cohort, open, controlled study was conducted with the participation of women with laboratory-confirmed Graves' disease. The features of regulatory T-blood cells subpopulation and the level of expression (MFI) CD25 surface receptor were studied by flow cytometry using direct immunofluorescence using monoclonal antibodies.

RESULTS

The study included 36 women with recurrent Graves' disease, middle age 46.34±14.32 years. In patients with Graves' disease before and during the entire period after RIT a low percentage of naive (CD45R0-CD62L+) and terminally differentiated (CD45R0-CD62L-) Treg was established relative to the control, and on 3 and 6 months after RIT a significant decrease of cells with this phenotype was revealed relative to the values detected in patients before and 1 month after RIT (p&lt;0.001). Against the background of compensated hypothyroidism the most significant changes of expression CD25 receptor in patients with Graves' disease were found on 3 and 6 months after RIT: reduced levels of MFI CD25 on surface of naive and terminally differentiated Treg.

CONCLUSION

A decrease in the level of naive Treg was found (apparently due to a violation of differentiation processes in thymus) and terminally differentiated Tregs (due to maturation and survival processes), which are supplemented by a reduced expression of the CD25 receptor on the surface of these cells and do not depend on hyperthyroidism compensation, the titer of TSH receptor antibodies, previous conservative therapy with thiamazole and RIT. The obtained new data reveal the role of naive and terminally differentiated Treg subpopulations in immunopathogenesis and help to outline further ways to develop approaches for immunotropic therapy.

Characterizing the Interplay of Lymphocytes in Graves' Disease

Graves' disease (GD) is a thyroid-specific autoimmune disease with a high prevalence worldwide. The disease is primarily mediated by B cells, which produce autoantibodies against the thyroid-stimulating hormone receptor (TSHR), chronically stimulating it and leading to high levels of thyroid hormones in the body. Interest in characterizing the immune response in GD has motivated many phenotyping studies. The immunophenotype of the cells involved and the interplay between them and their secreted factors are crucial to understanding disease progression and future treatment options. T cell populations are markedly distinct, including increased levels of Th17 and follicular helper T cells (Tfh), while Treg cells appear to be impaired. Some B cells subsets are autoreactive, and anti-TSHR antibodies are the key disease-causing outcome of this interplay. Though some consensus across phenotyping studies will be discussed here, there are also complexities that are yet to be resolved. A better understanding of the immunophenotype of Graves' disease can lead to improved treatment strategies and novel drug targets.

Immunomodulatory role of vitamin D and selenium supplementation in newly diagnosed Graves' disease patients during methimazole treatment

Introduction

Methimazole (MMI) represents the conventional therapeutic agent for Graves' disease (GD) hyperthyroidism, but MMI efficacy is limited since it marginally affects the underlying autoimmune process. In a previous study, we randomly assigned 42 newly diagnosed GD patients with insufficient vitamin D (VitD) and selenium (Se) levels to treatment with MMI alone (standard) or combined with selenomethionine and cholecalciferol (intervention) and observed a prompter resolution of hyperthyroidism in the intervention group.

Methods

In the present study, we aimed to explore changes in peripheral T regulatory (Treg) and circulating natural killer (NK) cell frequency, circulating NK cell subset distribution and function, during treatment.

Results

At baseline, circulating total CD3^-CD56⁺NK cells and CD56^bright NK cells were significantly higher in GD patients than in healthy controls (HC) (15.7 ± 9.6% vs 9.9 ± 5.6%, p=0.001; 12.2 ± 10.3% vs 7.3 ± 4.1%, p=0.02, respectively); no differences emerged in Treg cell frequency. Frequencies of total NK cells and CD56^bright NK cells expressing the activation marker CD69 were significantly higher in GD patients than in HC, while total NK cells and CD56^dim NK cells expressing CD161 (inhibitory receptor) were significantly lower. When co-cultured with the K562 target cell, NK cells from GD patients had a significantly lower degranulation ability compared to HC (p<0.001). Following 6 months of treatment, NK cells decreased in both the intervention and MMI-alone groups, but significantly more in the intervention group (total NK: -10.3%, CI 95% -15.8; -4.8% vs -3.6%, CI 95% -9; 1.8%, p=0.09 and CD56^bright NK cells: -6.5%, CI 95% -10.1; -3 vs -0.9%, CI 95% -4.4; 2%, p=0.03). Compared to baseline, CD69⁺ NK cells significantly decreased, while degranulation ability slightly improved, although no differences emerged between the two treatment groups. Compared to baseline, Treg cell frequency increased exclusively in the intervention group (+1.1%, CI 95% 0.4; 1.7%).

Discussion

This pilot study suggested that VitD and Se supplementation, in GD patients receiving MMI treatment, modulates Treg and NK cell frequency, favoring a more pronounced reduction of NK cells and the increase of Treg cells, compared to MMI alone. Even if further studies are needed, it is possible to speculate that this immunomodulatory action might have facilitated the prompter and better control of hyperthyroidism in the supplemented group observed in the previous study.

Differential distribution and prognostic value of CD4+ T cell subsets before and after radioactive iodine therapy in differentiated thyroid cancer with varied curative outcomes

Differentiated thyroid cancer is the most frequently diagnosed endocrine tumor. While differentiated thyroid cancers often respond to initial treatment, little is known about the differences in circulating immune cells amongst patients who respond differently. A prospective study of 39 patients with differentiated thyroid cancer was conducted. Serum thyroglobulin levels and thyroid and immunological functions were tested before and after radioactive iodine treatment (RAIT). Efficacy assessments were performed 6 to 12 months after radioactive iodine treatment. Most patients showed an excellent response to radioactive iodine treatment. Before radioactive iodine treatment, the excellent response group had considerably fewer circulating CD4⁺ T cell subsets than the non-excellent response group. Both the excellent response and non-excellent response groups had considerably lower circulating CD4⁺ T lymphocyte subsets 30 days after radioactive iodine treatment, but those of the excellent response group were still lower than those of the non-excellent response group. All circulating CD4⁺ T cell subsets in the excellent response group rose by varying degrees by the 90th day, but only Treg cell amounts increased in the non-excellent response group. Interestingly, in the non-excellent response group, we noticed a steady drop in Th1 cells. However, the bulk of circulating CD4⁺ T cell subsets between the two groups did not differ appreciably by the 90th day. Finally, we discovered that CD4⁺ T cell subsets had strong predictive potential, and we thus developed high-predictive-performance models that deliver more dependable prognostic information. In conclusion, in individuals with differentiated thyroid cancer, there is great variation in circulating immune cells, resulting in distinct treatment outcomes. Low absolute CD4⁺ T cell counts is linked to improved clinical outcomes as well as stronger adaptive and resilience capacities.