Levels of regulatory T cells CD69(+)NKG2D(+)IL-10(+) are increased in patients with autoimmune thyroid disorders

Redox mechanisms in autoimmune thyroid eye disease

Thyroid eye disease (TED) is an autoimmune condition affecting the orbit and the eye with its adnexa, often occurring as an extrathyroidal complication of Graves' disease (GD). Orbital inflammatory infiltration and the stimulation of orbital fibroblasts, triggering de novo adipogenesis, an overproduction of hyaluronan, myofibroblast differentiation, and eventual tissue fibrosis are hallmarks of the disease. Notably, several redox signaling pathways have been shown to intensify inflammation and to promote adipogenesis, myofibroblast differentiation, and fibrogenesis by upregulating potent cytokines, such as interleukin (IL)-1β, IL-6, and transforming growth factor (TGF)-β. While existing treatment options can manage symptoms and potentially halt disease progression, they come with drawbacks such as relapses, side effects, and chronic adverse effects on the optic nerve. Currently, several studies shed light on the pathogenetic contributions of emerging factors within immunological cascades and chronic oxidative stress. This review article provides an overview on the latest advancements in understanding the pathophysiology of TED, with a special focus of the interplay between oxidative stress, immunological mechanisms and environmental factors. Furthermore, cutting-edge therapeutic approaches targeting redox mechanisms will be presented and discussed.

The relationship between migraine and Hashimoto's thyroiditis: a single center experience

Introduction

Hashimoto's thyroiditis (HT) is nowadays the leading cause of hypothyroidism with high and still growing prevalence in general population, but there are lack of data regarding migraine and HT connection.

Methods

The aim of this study was to analyze the prevalence of HT in migraine and to check if the presence of HT influence migraine severity. This retrospective observational cohort study involved consecutive migraine patients consulted at our Headache Center with diagnosis of migraine. Electronic charts of patients were collected, including data on migraine type, presence of cranial autonomic symptoms (CAS), monthly migraine days (MMD), medication overuse headache (MOH), and the presence of comorbidities including HT.

Results

We found 928 eligible migraine patients, 88.7% were women. The mean age was 36.09 years. 592 (63.8%) were diagnosed with episodic migraine (EM), the rest with chronic migraine (CM). MOH was additionally diagnosed in 258 (27.8%) patients. The duration of migraine was 15.99 years. 106 (11.4%) was diagnosed with HT, 148 (15.9%) with hypothyroidisms, while 84 (9.05%) had both diagnosis. Migraine patients with HT were significantly older (p < 0.001), were more frequently women (p = 0.0017), had longer duration of migraine (p < 0.001), had CAS more frequently (<0.001), developed CM (p = 0.0169) and depression more frequently (p = 0.0047) and had more MMD (p = 0.0195) as compared with individuals without HT. According to our multivariate logistic model, the presence CM was positively associated with HT (OR 1.76, p = 0.045), MOH and duration of migraine, while negatively associated with aura.

Conclusion

HT is very prevalent in migraine patients. This is the first study considering migraine and HT to be comorbid and suggesting that HT may influence the course of migraine causing its chronification.

Molecular Biomarkers in Thyroid Eye Disease: A Literature Review

PURPOSE

Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves disease. Patients may be severely affected with eyelid retraction, exophthalmos, diplopia, pain, and threatened vision. Autoantibodies against thyroid-stimulating hormone receptor and insulin-like growth factor 1 receptor have shown associations with pathophysiological and clinical traits. Autoantibodies against thyroid-stimulating hormone receptor is in current clinical use as biomarker, but not with unambiguous diagnostic performance. A biomarker with high diagnostic accuracy and/or prognostic capability would be of immense value in diagnosing TED, especially in subclinical cases or when TED precedes the thyroid dysfunction. This article is a literature review on molecular biomarkers of TED.

METHODS

A literature search was performed using PubMed and Embase. Studies on molecular biomarkers in blood, tear fluid, and urine were included in the review.

RESULTS

Forty-six papers were included, of which 30, 14, and 2 studies on biomarkers in blood, tears, and urine, respectively. Fourteen of the papers evaluated the diagnostic performance of various biomarkers, 12 in blood and 2 in tears. Most studies evaluated single biomarkers, but 3 tested a panel of several markers. Except for autoantibodies against thyroid-stimulating hormone receptor, the reported diagnostic performances for the biomarkers were not confirmed in independent cohorts. In 32 studies, no or insufficient performance data were given, but the findings indicated involvement of various biologic mechanisms in TED including inflammation, oxidative stress, fibrosis, lipid metabolism, and ocular surface microflora.

CONCLUSIONS

Currently, serum autoantibodies against thyroid-stimulating hormone receptor is the only molecular biomarker with clinical utility in patients with TED. Several potential biomarkers have been investigated, and particularly panels of multiple biomarkers in tears are promising. To improve patient care, biomarkers in TED should be studied further.

Th17 cytokines and factors modulating their activity in patients with pernicious anemia

The effects of specific cytokines produced by T cell subsets (such as Th1, Th2, and newly discovered Th17, Treg, Tfh, or Th22) are diverse, depending on interactions with other cytokines, distinct signaling pathways, phase of the disease, or etiological factor. The immunity equilibrium of the immune cells, such as the Th1/Th2, the Th17/Treg, and the Th17/Th1 balance is necessary for the maintenance of the immune homeostasis. If the balance of the T cells subsets is damaged, the autoimmune response becomes enhanced which leads to autoimmune diseases. Indeed, both the Th1/Th2 and the Th17/Treg dichotomies are involved in the pathomechanism of autoimmune diseases. The aim of the study was to determine the cytokines of Th17 lymphocytes as well as the factors modulating their activity in patients with pernicious anemia. The magnetic bead-based immunoassays used (Bio-Plex) allow simultaneous detection of multiple immune mediators from one serum sample. In our study, we showed that patients suffering from pernicious anemia develop the Th1/Th2 imbalance with a quantitative advantage of cytokines participating in Th1-related immune response, the Th17/Treg imbalance with a quantitative advantage of cytokines participating in Treg-related response, as well as the Th17/Th1 imbalance with a quantitative predominance of cytokines participating in Th1-related immune response. Our study results indicate that T lymphocytes and their specific cytokines play an role in the course of pernicious anemia. The observed changes may indicate the immune response to pernicious anemia or be an element of the pernicious anemia pathomechanism.

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.

BIGKnock: fine-mapping gene-based associations via knockoff analysis of biobank-scale data

We propose BIGKnock (BIobank-scale Gene-based association test via Knockoffs), a computationally efficient gene-based testing approach for biobank-scale data, that leverages long-range chromatin interaction data, and performs conditional genome-wide testing via knockoffs. BIGKnock can prioritize causal genes over proxy associations at a locus. We apply BIGKnock to the UK Biobank data with 405,296 participants for multiple binary and quantitative traits, and show that relative to conventional gene-based tests, BIGKnock produces smaller sets of significant genes that contain the causal gene(s) with high probability. We further illustrate its ability to pinpoint potential causal genes at [Formula: see text] of the associated loci.

Evaluation of Epithelial-Mesenchymal Transition Markers in Autoimmune Thyroid Diseases

A state of chronic inflammation is common in organs affected by autoimmune disorders, such as autoimmune thyroid diseases (AITD). Epithelial cells, such as thyroid follicular cells (TFCs), can experience a total or partial transition to a mesenchymal phenotype under these conditions. One of the major cytokines involved in this phenomenon is transforming growth factor beta (TGF-β), which, at the initial stages of autoimmune disorders, plays an immunosuppressive role. However, at chronic stages, TGF- β contributes to fibrosis and/or transition to mesenchymal phenotypes. The importance of primary cilia (PC) has grown in recent decades as they have been shown to play a key role in cell signaling and maintaining cell structure and function as mechanoreceptors. Deficiencies of PC can trigger epithelial-mesenchymal transition (EMT) and exacerbate autoimmune diseases. A set of EMT markers (E-cadherin, vimentin, α-SMA, and fibronectin) were evaluated in thyroid tissues from AITD patients and controls through RT-qPCR, immunohistochemistry (IHC), and western blot (WB). We established an in vitro TGF-β-stimulation assay in a human thyroid cell line to assess EMT and PC disruption. EMT markers were evaluated in this model using RT-qPCR and WB, and PC was evaluated with a time-course immunofluorescence assay. We found an increased expression of the mesenchymal markers α-SMA and fibronectin in TFCs in the thyroid glands of AITD patients. Furthermore, E-cadherin expression was maintained in these patients compared to the controls. The TGF-β-stimulation assay showed an increase in EMT markers, including vimentin, α-SMA, and fibronectin in thyroid cells, as well as a disruption of PC. The TFCs from the AITD patients experienced a partial transition to a mesenchymal phenotype, preserving epithelial characteristics associated with a disruption in PC, which might contribute to AITD pathogenesis.

Role of Peripheral Regulatory T Lymphocytes in Patients with Thyroid Associated Ophthalmopathy During Systemic Glucocorticoid Treatment: A Prospective Observational Study

OBJECTIVE

Thyroid-associated ophthalmopathy (TAO) is an autoimmune disorder involving the orbital tissue. This study aimed to understand the role of regulatory T cells (Tregs) in TAO during 12-week systemic glucocorticoid (GC) treatment.

METHODS

Thirty-two moderate-severe TAO patients with a clinical activity score (CAS) ≥3/7 or with prolonged T2 relaxation time (T2RT) on at least one side of extraocular muscle (EOM) were enrolled. The percentage of the peripheral CD4⁺CD25(high)CD127(-/low) Tregs was analyzed using flow cytometry before and after the GC treatment. The activity and severity of TAO, T2RT, and the clinical outcomes after the GC treatment were assessed. Their correlation with the peripheral Tregs was investigated.

RESULTS

There was no significant association between the baseline Treg fraction and the activity and severity of TAO or the treatment response. A significant reduction of Tregs was observed after the GC therapy merely in patients without any clinical improvement.

CONCLUSION

Treg reduction after systemic GC therapy is indicative of a poor therapeutic response. Accordingly, dynamic alterations of Tregs could help to evaluate the effectiveness of the GC treatment.

Anti-thyroid antibodies and underlying generalized immunologic aberrations in patients with reproductive failures

The link between autoimmune thyroid diseases and reproductive failures, including implantation failure and pregnancy loss, has been attracted a great deal of attention in the last two decades. In this regard, a considerable progress has been achieved in understanding the etiopathogenesis of the adverse pregnancy consequences related to the presence of anti-thyroid antibodies, however, the exact action mechanisms of these antibodies are not fully comprehended. Thyroid peroxidase antibodies (TPOAbs), thyroglobulin antibodies (TgAbs) and TSH receptor antibodies (TRAbs) are the anti-thyroid antibodies which are present in autoimmune thyroid disorder (AITD) patients, such as Hashimoto's thyroiditis. In this condition, the thyroid hormones production, which are essential for normal implantation and pregnancy, are disrupted, and compromise the embryo or fetus development. In addition, a hypothesis suggests that there is underlying generalized immune abnormalities behind the presence of these antibodies. On the other hand, similar immunologic aberrations have been observed in thyroid autoimmunity and reproductive complications, which are postulated to be the proper answer for the scientists who seek for the pathophysiology behind the presence of these antibodies. Elevated inflammatory responses and decreased immunoregulatory actions, seem to be the main interfering pathologic factors in maternal tolerance toward fetus. In addition, cross reactivity of these antibodies with antigenic determinants of egg, embryo and placenta is another suggested mechanism, causing implantation and pregnancy complications. The ability of anti-thyroid antibodies in passing through the placental barrier and affecting the fetal thyroid gland, makes them more threatening for maintenance of a pregnancy.

The role of PET/CT in thyroid autoimmune diseases

Autoimmune thyroid diseases (AITD) are a heterogeneous group of disorders. They include, in particular, Graves' disease and Hashimoto's thyroiditis with a wide range of different functional status ranging from subclinical biochemical abnormalities to severe hyperthyroidism or severe hypothyroidism respectively. Furthermore, other conditions more frequently infectious or drug related can cause an immune reaction in the thyroid tissue. In AITDs, positron emission tomography/computed tomography (PET/CT) does not play a primary role for disease diagnosis or management, but accidental findings can occur in both symptomatic and asymptomatic patients, and they should be recognized and well interpreted. A comprehensive literature search of the PubMed databases was conducted to identify papers (systematic review, prospective and retrospective study, case report) evaluating the role of PET/CT in thyroid autoimmune diseases. Thyroid diffuse uptake of 18F-fluoro-2-deoxy-2-d-glucose ([18F]FDG) has been shown to be frequently associated with AITDs, but also with immune-induced thyroid disorders related to SARS-CoV-2 or immunotherapy, while malignant lesions more often have a focal aspect. Other radiopharmaceuticals as [68Ga]-DOTA-peptides, [68Ga]-fibroblast activation protein inhibitors (FAPIs) and [68Ga]-prostate specific membrane antigen ([68Ga]-PSMA) showed similar findings. In conclusion, PET/CT scan in AITDs does not play a primary role in the diagnosis, but the occasional finding of a thyroid uptake must always be described in the report and possibly investigated for a better patient's management.

Research progress on the pathogenesis of Graves’ ophthalmopathy: Based on immunity, noncoding RNA and exosomes

Graves’ ophthalmopathy (GO), also known as thyroid-associated ophthalmopathy, is a common potentially vision-threatening organ-specific autoimmune disease and the most common extrathyroidal manifestation of Graves’ disease. It can happen to those who have hyperthyroidism or euthyroidism. At present, the pathogenesis of GO has not been fully elucidated, and the majority of clinical treatments are symptomatic. Therefore, we are eager to discover any new therapeutic strategies that target the etiology of GO. To provide fresh ideas for the creation of new therapeutic techniques, this study primarily discusses the research state and progress of GO-related pathogenesis from the perspectives of GO’s cellular immunity, autoantigens, non-coding RNAs, and exosomes.

Effect of different cytokines in combination with IL-15 on the expression of activating receptors in NK cells of patients with Behçet's disease

Behçet's disease (BD) is a systemic, autoinflammatory, chronic disorder which affects various parts of the body in genetically susceptible individuals. BD has a multi-factorial etiopathogenesis which encompasses both innate and adaptive arms of immunity. NK cells, which kill virus-infected or malign cells and provide interaction between adaptive and innate immune system, are also known to involve in the pathogenesis of autoimmune/autoinflammatory diseases including BD. NK cells function in immune responses via the signals obtained from surface-expressed activating and inhibitory receptors. In this study, we aimed to explore NK cell activation status by measuring the levels of activation marker CD69 and activating receptors NKG2D, NKp30, and NKp46 as well as proliferative and cytotoxic capacities in response to stimulation with interleukin (IL)-15-combined cytokines in BD patients. CD4⁺ and CD8⁺ T cell responses were also evaluated to compare with those of NK cells. As a result, the expression of activating receptors on NK cells was demonstrated to be varied among patients with active and inactive BD and healthy controls. The proliferation levels of NK cells were elevated in BD patients, especially in inactive phase of disease compared to healthy controls. Additionally, CD107a levels of inactive BD patients were detected to be lower in comparison with healthy controls and active BD patients. These findings suggest that BD patients in active and inactive phases display different activation status of NK cells which indicate NK cells might be associated with immune attacks and remissions during the course of BD.

Increased levels of pathogenic Th17 cells and diminished function of CD69 + Treg lymphocytes in patients with overweight

A low-grade inflammatory phenomenon is a feature of overweight and metabolic syndrome. The involvement of a pro-inflammatory Th17 lymphocyte subset and the CD69 + T regulatory (Treg) cell subtype in patients with metabolic dysfunction associated or not to overweight has not been fully elucidated. The aim of this study was to perform a quantitative and functional analysis of pathogenic Th17 lymphocytes and CD69 + Treg cells in patients with metabolic dysfunction (insulin resistance and dyslipidemia). The number of pathogenic Th17 cells and the levels and function of CD69 + Treg cells were analyzed in blood samples from individuals with metabolic dysfunction, associated or not to overweight. Pathogenic and non-pathogenic Th17 lymphocytes as well as Th22 cells were determined by eight-color flow cytometry analysis, whereas the levels and the suppressive function of CD69 + Treg cells were also analyzed by multiparametric flow cytometry. We detected increased levels of pro-inflammatory Th17 pathogenic cells and Th22 lymphocytes in overweight unhealthy individuals (p<0.001, compared to normal weight healthy). Conversely, diminished numbers of CD69 + Treg lymphocytes were observed in metabolically unhealthy individuals, with or without overweight. Likewise, the immunosuppressive function of CD69 + Treg cells was also defective in these patients. The increased levels of pathogenic Th17 cells along with a diminished number and function of CD69 + Treg lymphocytes may significantly contribute to the low-grade inflammatory phenomenon of metabolically unhealthy patients.

The Frequency of CD4+ T Cells in Women with Hashimoto's Thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune disease, and there is no definitive treatment available for this disease. To find the appropriate therapeutic approach, it is necessary to determine the mechanism of this disease. To achieve this purpose, the frequency of CD4⁺ T cells was evaluated in patients with HT and compared with healthy individuals.

METHODS

Twenty-six female patients with HT, aged 20 - 45 years, enrolled in this study. Based on the level of thyroglobulin antibody (anti-TG) and anti-thyroid peroxidase antibody (anti-TPO) in serum of patients with HT, they were divided into two groups. The serum level of anti-TPO was above 100 IU/mL in the group 1 (n = 13), whereas the serum levels of both anti-TPO and anti-TG were above 100 IU/mL in the group 2 (n = 13). Eleven healthy women were considered control group, or group 3. Using flow cytometry, the frequency of T helper (Th)1, Th2, Th17, T regulatory type 1 (Tr1), and LT CD4⁺IL-4⁺IL-17⁺ cells and mean fluorescent intensity (MFI) of their related cytokines were evaluated.

RESULTS

The frequency of Th2 cells in the groups 1 (anti-TPO > 100) and 2 (anti-TPO > 100 and anti-TG > 100) were more than control group. Only the difference between groups 3 (healthy control) and 2 was significant (P = 0.022). The frequency of LT CD4⁺IL-4⁺IL-17⁺ cells in the group 1 was significantly more than group 3 (P = 0.027); However, the difference between group 2 and 3 was not significant (P = 0.126). The expression of interferon-gamma (IFN-γ) in the group 2 (P = 0.001) and group 1 (P = 0.001) was significantly higher than group 3. The frequency of Th17, Th1, and Tr1 cells and MFI of IL-17 and IL-10 were not significantly different between the study groups.

CONCLUSIONS

In the present study, no significant differences were observed in the frequency of Th17 and Tr1 cells and in MFI of IL-17 and IL-10 in comparison to healthy individuals. Therefore, trying to make a change in the population of these cells probably does not have a significant therapeutic effect. Since Th2 cells and the expression of IFN-γ increased in women with HT, reducing the frequency of Th2 cells or the expression of IFN-γ may be effective in controlling the disease progression. It may be helpful for these patients to prevent the progression of the disease.

An update on the pathogenesis of Hashimoto's thyroiditis

It is 70 years since Noel Rose embarked on his pioneering studies that lead to the discovery of autoimmune thyroiditis and the elucidation of Hashimoto's thyroiditis. This short review to honour his passing focuses on the developments in our understanding of the causes and pathogenesis of HT over the last five years. Recent genetic studies have reported heritability estimates for HT and associated diseases for the first time, and emphasised the complexity of the genetic factors involved, including monogenic forms of HT. Environmental factors continue to be elucidated, especially as a side effect of drugs which modulate the immune system therapeutically. Regarding pathogenetic mechanisms, multiple cytokine networks have been identified which involve the thyroid cells in a circuit of escalating proinflammatory effects, such as the expression of inflammasome components, and an array of different defects in T regulatory cells may underlie the loss of self-tolerance to thyroid autoantigens. Finally, a number of studies have revealed fresh insights into disease associations with HT which may have both pathological and clinical significance, the most intriguing of which is a possible direct role of the autoimmune process itself in causing some of the persistent symptoms reported by a minority of patients with levothyroxine-treated HT.

Ursolic acid ameliorates Nthy-ori 3-1 cells injury induced by IL-1β through limiting MALAT1/miR-206/PTGS1 ceRNA network and NF-κB signaling pathway

RATIONALE

Ursolic acid (UA) has exhibited anti-inflammatory and anti-oxidative drug effects.

OBJECTIVES

In the research, we assessed the effects of UA on Nthy-ori 3-1 cells stimulated by IL-1β and attempted to elucidate the mechanisms underlying the effects.

METHODS

Autoimmune thyroiditis (AIT) was simulated using Nthy-ori 3-1 cells by IL-1β (10 μM) treatment. UA (20 μM) was applied to ameliorate the injury of Nthy-ori 3-1 cells. The target of UA was predicted by TCMSP, BATMAN, and GEO database. Targeted relationship between lncRNA MALAT1 and miR-206, as well as miR-206 and PTGS1, was predicted by bioinformatics software and identified by dual luciferase assays. Cytokines in the cell supernatant and the apoptosis of cells were detected by ELISAs and flow cytometry assays, respectively. Expression levels of NF-κB signaling pathway-related proteins were estimated by western blot.

RESULTS

By enquiring TCMSP, BATMAN, and GEO database, PTGS1 was identified as a target of UA. Afterward, a ceRNA network among MALAT1, miR-206, and PTGS1 was constructed. The expression levels of MALAT1 and PTGS1 in AIT tissues were obviously enhanced. Moreover, the ceRNA network formed by MALAT1/miR-206/PTGS1 contributed to the damage of Nthy-ori 3-1 cells induced by IL-1β. However, UA ameliorated the Nthy-ori 3-1 cells injury induced by IL-1β through mediating the MALAT1/miR-206/PTGS1 ceRNA network and NF-κB signaling pathway.

CONCLUSIONS

UA treatment significantly relieved the injury of Nthy-ori 3-1 cells via inhibiting the ceRNA mechanism of MALAT1/miR-206/PTGS1 and inflammatory pathways, insinuating that UA may be helpful for the treatment of AIT.

Novel human immunomodulatory T cell receptors and their double-edged potential in autoimmunity, cardiovascular disease and cancer

In the last decade, approaches based on T cells and their immunomodulatory receptors have emerged as a solid improvement in treatments for various types of cancer. However, the roles of these molecules in the therapeutic context of autoimmune and cardiovascular diseases are still relatively unexplored. Here, we review the best known and most commonly used immunomodulatory T cell receptors in clinical practice (PD-1 and CTLA-4), along with the rest of the receptors with known functions in animal models, which have great potential as modulators in human pathologies in the medium term. Among these other receptors is the receptor CD69, which has recently been described to be expressed in mouse and human T cells in autoimmune and cardiovascular diseases and cancer. However, inhibition of these receptors individually or in combination by drugs or monoclonal antibodies generates a loss of immunological tolerance and can trigger multiple autoimmune disorders in different organs and immune-related adverse effects. In the coming decades, knowledge on the functions of different immunomodulatory receptors will be pivotal for the development of new and better therapies with less harmful side effects. In this review, we discuss the roles of these receptors in the control of immunity from a perspective focused on therapeutic potential in not only cancer but also autoimmune diseases, such as systemic lupus erythematosus, autoimmune diabetes and rheumatoid arthritis, and cardiovascular diseases, such as atherosclerosis, acute myocardial infarction, and myocarditis.

The pivotal role of CD69 in autoimmunity

Autoimmune disorders are outcomes of impaired activity of the immune system regarding the maintenance of tolerance, which results in tissue damage secondary to an excess in the inflammatory response. Under normal conditions, the cells in the adaptive immune system are highly controlled to remain unresponsive against self-antigens (self-Ags) through various mechanisms and during different stages of maturation. CD69 (cluster of differentiation 69), a C-type lectin disulfide-linked homodimer, is expressed on different leukocytes, including newly-activated lymphocytes, certain subtypes of memory T-cells, infiltrating lymphocytes isolated from patients with chronic inflammatory disorders, and regulatory T-cells (Tregs). Cumulative evidence from in vitro and in vivo studies has revealed an immunoregulatory role for CD69. This marker has been reported to play a controversial role in chronic human inflammatory disorders. Many investigations have linked the absence of CD69 with a predisposition to inflammatory and/or autoimmune conditions, which indicates an immunoregulatory function for CD69 by mechanisms such as controlling the balance between differentiation of Th/Treg cells and enhancing the suppressive activity of Tregs. However, some reports from human studies have indicated that CD69 may exert a stimulatory effect on the inflammatory response. In this review, we first present a brief summary of the concept of 'immune tolerance' and, subsequently, review previous studies to uncover the details that underlie the immunoregulatory effects of CD69.

Tissue Infiltrating LTi-Like Group 3 Innate Lymphoid Cells and T Follicular Helper Cells in Graves' and Hashimoto's Thyroiditis

Background: Hashimoto's thyroiditis (HT) and Graves' disease (GD) are autoimmune thyroid disorders (AITDs). These conditions have been associated to abnormalities in circulating regulatory T cells (Tregs). We postulated that immune perturbations could be more pronounced at the thyroid tissue level.

Methods: The phenotype of PBMCs and immune cells infiltrating thyroid tissue from 19 patients with HT, 21 patients with GD, and 30 controls has been analyzed by flow cytometry.

Results: We report that blood and thyroid Treg cell subsets are similarly represented in all AITDs patients and controls. Increased Lymphoid tissue inducer (LTi)-like ILC3 and CXCR5⁺ PD-1^hi CD4⁺ T follicular helper cells (Tfh) tissue-infiltrating cells, together with the prevalence of tertiary lymphoid structures (TLS) and germinal centers (GCs) represented a typical immune signature in all HT and 60% of GD patients. In the remaining group of GD patients, the absence of the aforementioned abnormalities was associated with a higher prevalence of ophthalmopathy.

Conclusion: Tissue infiltrating Lymphoid Tissue inducer—like group 3 Innate Lymphoid cells and T follicular helper cells are increased in most thyroid autoimmune disease.

Astilbin promotes the induction of regulatory NK1.1- CD4+ NKG2D+ T cells through the PI3K, STAT3, and MAPK signaling pathways

Astilbin is a potential agent for autoimmune and inflammatory diseases and has a protective effect in mice with DSS-induced colitis. NK1.1^- CD4⁺ NKG2D⁺ T cells are a subpopulation of regulatory T cells that produce TGF-β1 and IL-10. Whether astilbin directly promotes the induction of NK1.1^- CD4⁺ NKG2D⁺ T cells and whether these astilbin-stimulated T cells exert an immune-regulatory role remain unclear. Here, we show that astilbin efficiently induces the production of NK1.1^- CD4⁺ NKG2D⁺ T cells with high expressions of TGF-β1, IL-10, CCR6, and CCR9 in a dose-dependent manner ex vivo. These regulatory T cells also substantially inhibit the activities of CD8⁺ T cells and macrophages. Intraperitoneal injection of astilbin ameliorates the severity of colitis with an increase in the frequency of NK1.1^- CD4⁺ NKG2D⁺ T cells in the colon tissue of DSS-treated mice. Moreover, adoptive transfer of NK1.1^- CD4⁺ NKG2D⁺ T cells induced by astilbin remarkably protects against the onset of DSS-induced colitis. Finally, the PI3K, STAT3, and MAPK signaling pathways are involved in the induction of NK1.1^- CD4⁺ NKG2D⁺ T cells by astilbin. Taken together, our study elucidates a new immune-regulatory mechanism of astilbin by inducing the regulatory NK1.1^- CD4⁺ NKG2D⁺ T cells and indicates a potential clinical use of astilbin for patients with inflammatory bowel diseases.

The exploration of Hashimoto's Thyroiditis related miscarriage for better treatment modalities

Hashimoto's thyroiditis (HT) is the most prevalent autoimmune thyroid disease (ATD) worldwide and is strongly associated with miscarriage and even recurrent miscarriage (RM). Moreover, with a deepening understanding, emerging evidence has shown that immune dysfunctions caused by HT conditions, including imbalanced subsets of CD4+ T-helper cells, B regulatory (Breg) cells, high expression levels of CD56dim natural killer (NK) cells, and cytokines, possibly play an important role in impairing maternal tolerance to the fetus. In recent years, unprecedented progress has been made in recognizing the specific changes in immune cells and molecules in patients with HT, which will be helpful in exploring the mechanism of HT-related miscarriage. Based on these findings, research investigating some potentially more effective treatments, such as selenium (Se), vitamin D3, and intravenous immunoglobulin (IVIG), has been well developed over the past few years. In this review, we highlight some of the latest advances in the possible immunological pathogenesis of HT-related miscarriage and focus on the efficacies of treatments that have been widely introduced to clinical trials or practice described in the most recent literature.

Seminal Plasma Modifies the Transcriptional Pattern of the Endometrium and Advances Embryo Development in Pigs

Background: Seminal plasma (SP) promotes sperm survival and fertilizing capacity, and potentially affects embryo development, presumably via specific signaling pathways to the internal female genital tract.

Objectives: This study evaluated how heterologous SP, infused immediately before postcervical artificial insemination (AI) affected embryo development and the transcriptional pattern of the pig endometria containing embryos.

Materials and Methods: Postweaning estrus sows (n = 34) received 40-mL intrauterine infusions of either heterologous pooled SP or Beltsville Thawing Solution (BTS; control) 30 min before AI of semen extended to 10% of homologous SP. Embryos (all sows) and endometrium samples (3 sows/group) were removed during laparotomy 6 days after the infusion of SP or BTS to morphologically evaluate the embryos to determine their developmental stage and to analyze the endometrial transcriptome using microarrays (PORGENE 1.0 ST GeneChip array, Affymetrix) followed by qPCR for further validation.

Results: Embryo viability was equal between the groups (~93%), but embryo development was significantly (P < 0.05) more advanced in the SP-treated group compared to control. A total of 1,604 endometrium transcripts were differentially expressed in the SP group compared to the control group. An enrichment analysis showed an overrepresentation of genes and pathways associated with the immune response, cytokine signaling, cell cycle, cell adhesion, and hormone response, among others.

Conclusions: SP infusions prior to AI positively impacted the preimplantation embryo development and altered the expression of the endometrial genes and pathways potentially involved in embryo development.

Changes in glucose-lipid metabolism, insulin resistance, and inflammatory factors in patients with autoimmune thyroid disease

Background

Autoimmune thyroid disease (AITD) is a common organ‐specific autoimmune disorder, and genetic, environmental, and endogenous factors are responsible for initiation of thyroid autoimmunity. Some AITD patients suffer from a certain degree of glucose‐lipid metabolism disorder. This study aims to explore the changes in glucose‐lipid metabolism, insulin resistance, and inflammatory factors in patients with AITD.

Methods

A total of 91 patients with Hashimoto's thyroiditis were retrospectively analyzed and divided into hypothyroidism group (n = 42) and normal thyroid group (n = 49), while 50 healthy people were selected as control group. The changes in glucose‐lipid metabolism, insulin resistance, and inflammatory factors in each group were compared, and their correlations with the thyroid function were analyzed.

Results

The levels of serum interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α), IL‐12, IL‐10, (FINS), and homeostasis model assessment of insulin resistance (HOMA‐IR) were gradually declined in sequence of hypothyroidism group, normal thyroid group, and control group (P < 0.05). In hypothyroidism group, the levels of serum‐free triiodothyronine (FT3), free thyroxine (FT4), (TC), triglyceride (TG), and low‐density lipoprotein cholesterol (LDL‐C) were significantly lower than those in normal thyroid group (P < 0.05), while the level of serum thyroid stimulating hormone (TSH) was significantly higher than that in normal thyroid group (P < 0.05). However, the fasting blood glucose and 2‐hour postprandial blood glucose levels had no statistically significant differences among the three groups (P > 0.05).

Conclusion

Autoimmune thyroid disease patients are prone to fat metabolism disorder, and the serum thyroid hormone level has a close correlation with blood lipid metabolism, insulin metabolism, and inflammatory factors.

Analysis of Regulatory T Cell Subsets and Their Expression of Helios and PD-1 in Patients with Hashimoto Thyroiditis

Hashimoto thyroiditis (HT) is an autoimmune disease that presumably arises consequent to loss of immune tolerance to autoantigen in thyroid. Regulatory T cells (Tregs) are considered to play a vital role in maintaining the immune balance, as they own intensive suppressive function. This study was undertaken to analyze numbers of Tregs and their expressions of Helios and PD-1 in HT patients. It also aimed to explore the relationship of these with thyroid function and specific autoantibodies. Peripheral blood mononuclear cells (PBMCs) were extracted from blood of 20 healthy controls (HC) and 42 HT patients with varying thyroid functions (10 overt hypothyroidism, 12 subclinical hypothyroidism, and 20 euthyroidism). We performed flow cytometry analysis in PBMCs to detect CD4⁺CD25⁺Foxp3⁺Tregs and their subsets, including CD45RO⁺Foxp3^high activated Treg cells (aTregs), CD45RO^-Foxp3^low resting Tregs cells (rTregs), and CD45RO⁺Foxp3^low secreting Treg cells (sTregs), as well as the expression of Helios and PD-1 on these cells. The results showed that the percentage of Tregs, aTregs was significantly lower in HT patients and it showed inverse correlation to thyroid function states, in comparison with these in healthy controls. In addition, patients with HT showed decreased expression of Helios in aTregs, while having increased expression of PD-1 in Tregs and sTregs. The levels of Tregs, aTregs, and Helios expressing aTregs were all negatively correlated with antithyroid antibodies. In conclusion, the deficiency of Tregs frequency and aberrant expressions of Helios and PD-1 may possibly contribute to thyroid immune damage in HT.

Patients With Autoimmune Thyroiditis Show Diminished Levels and Defective Suppressive Function of Tr1 Regulatory Lymphocytes

CONTEXT

T regulatory type 1 (Tr1) cells are a subpopulation of T lymphocytes (CD4+CD49+LAG-3+IL-10+) that exert a considerable immunosuppressive effect. However, their possible role in autoimmune thyroid disease (AITD) has not been explored so far.

PURPOSE

To analyze the levels and function of Tr1 cells in peripheral blood and thyroid tissue of patients with AITD.

DESIGN

Cases and controls, observational study.

SETTING

Department of Endocrinology, Hospital Universitario de la Princesa, Madrid, Spain.

PATIENTS

Thirty-eight patients with AITD (23 with Graves disease and 15 with Hashimoto thyroiditis) and 26 controls.

INTERVENTION

Multiparametric flow cytometry and immunofluorescence techniques were used to analyze the levels in peripheral blood (n = 38) and thyroid mononuclear cells (n = 5). An in vitro assay of suppression of cellular activation and cytokine release was performed to study the function of Tr1 cells.

MAIN OUTCOME MEASURE

Levels and function of Tr1 cells in patients with AITD and controls.

RESULTS

Levels of Tr1 cells were significantly diminished in peripheral blood from patients with AITD. Functional studies showed that Tr1 cells from patients with AITD exhibit a diminished suppressive function compared with healthy controls. Tr1 levels were associated with disease severity, including longer duration of the disease and ophthalmopathy activity, and with autoantibody titers.

CONCLUSIONS

The low levels of Tr1 cells and their diminished function may have a relevant role in the defective immune-regulatory function characteristic of patients with AITD.

Analysis of Sodium Chloride Intake and Treg/Th17 Lymphocytes in Healthy Individuals and Patients with Rheumatoid Arthritis or Systemic Lupus Erythematosus

We assessed different immune parameters in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) with low (LSI) and high (HSI) sodium intake. Thirty-eight patients with RA, thirty-seven with SLE, and twenty-eight healthy subjects were studied and classified as LSI or HSI. Levels and suppressive function of CD4+CD25+Foxp3+ and CD4+CD69+Foxp3- Treg cells were determined by flow cytometry in blood samples. Levels and in vitro differentiation of Th17 cells were also assessed. Similar levels of CD4+CD25+Foxp3+ and CD4+CD69+Foxp3- Treg cells were observed in LSI and HSI patients or controls. However, a positive correlation was detected between sodium intake and levels of CD4+CD25+Foxp3+ Treg cells in SLE and a negative association between CD4+CD69+Foxp3- Treg cells and sodium intake in RA. No other significant associations were detected, including disease activity and sodium intake. Moreover, the suppressor activity of CD4+CD25+Foxp3+ and CD4+CD69+Foxp3- Treg cells was similar in LSI and HSI patients or controls. The levels and in vitro differentiation of Th17 cells were also similar in LSI and HSI individuals. Our results suggest that, in the population studied (Mexican mestizo), the level of sodium intake is not apparently associated with different relevant immune parameters in healthy subjects or patients with SLE or RA.

Association of T and NK Cell Phenotype With the Diagnosis of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a pathological condition characterized by incapacitating fatigue and a combination of neurologic, immunologic, and endocrine symptoms. At present its diagnosis is based exclusively on clinical criteria. Several studies have described altered immunologic profiles; therefore, we proposed to further examine the more significant differences, particularly T and NK cell subpopulations that could be conditioned by viral infections, to discern their utility in improving the diagnosis and characterization of the patients. The study included 76 patients that fulfilled the revised Canadian Consensus Criteria (CCC 2010) for ME/CFS and 73 healthy controls, matched for age and gender. Immunophenotyping of different T cell and natural killer cell subpopulations in peripheral blood was determined by flow cytometry. ME/CFS patients showed significantly lower values of T regulatory cells (CD4⁺CD25^++(high)FOXP3⁺) and higher NKT-like cells (CD3⁺CD16^+/-CD56⁺) than the healthy individuals. Regarding NK phenotypes, NKG2C was significantly lower and NKCD69 and NKCD56 bright were significantly higher in the patients group. A classification model was generated using the more relevant cell phenotype differences (NKG2C and T regulatory cells) that was able to classify the individuals as ME/CFS patients or healthy in a 70% of cases. The observed differences in some of the subpopulations of T and NK cells between patients and healthy controls could define a distinct immunological profile that can help in the diagnostic process of ME/CFS patients, contribute to the recognition of the disease and to the search of more specific treatments. However, more studies are needed to corroborate these findings and to contribute to establish a consensus in diagnosis.

Depletion of Regulatory T Cells in Visceral Adipose Tissues Contributes to Insulin Resistance in Hashimoto's Thyroiditis

Hashimoto's Thyroiditis (HT) is a common organ-specific autoimmune disorder associated with a high incidence, and insulin resistance is highly related to autoimmune. Here, we examined the insulin sensitivity in HT patients and found decreased insulin sensitivity occurred in HT patients. To explore the relationship between impaired insulin sensitivity and immune status, we established HT model mice which showed similar pathological features and immune features to HT patients. In HT model mice, reinfusion of regulatory T cells (Tregs) from peripheral blood of normal mice could improve insulin sensitivity and decrease the inflammation. Anti-CD25 antibodies blocked beneficial effects from reinfusion of Tregs, but delayed administration of anti-CD25 antibodies could not abolished the effect from Tregs. Delayed administration of anti-CD25 antibodies abolished exogenous Tregs in peripheral blood, but there were increased exogenous Tregs located to visceral adipose tissues (VATs) which modulated the expression of cytokines in VATs. These findings suggest that insulin resistance exists in HT patients and it associates with the decreased Tregs and increased inflammation in the VATs.

Role of the T and B lymphocytes in pathogenesis of autoimmune thyroid diseases

Autoimmune thyroid disorders (AITD) broadly include Graves' disease and Hashimoto's thyroiditis which are the most common causes of thyroid gland dysfunctions. These disorders develop due to complex interactions between environmental and genetic factors and are characterized by reactivity to self-thyroid antigens due to autoreactive lymphocytes escaping tolerance. Both cell-mediated and humoral responses lead to tissue injury in autoimmune thyroid disease. The differentiation of CD4+ cells in the specific setting of immune mediators (for example cytokines, chemokines) results in differentiation of various T cell subsets. T cell identification has shown a mixed pattern of cytokine production indicating that both subtypes of T helper, Th1 and Th2, responses are involved in all types of AITD. Furthermore, recent studies described T cell subtypes Th17 and Treg which also play an essential role in pathogenesis of AITD. This review will focus on the role of the T regulatory (Treg) and T helper (Th) (especially Th17) lymphocytes, and also of B lymphocytes in AITD pathogenesis. However, we have much more to learn about cellular mechanisms and interactions in AITD before we can develop complete understanding of AITD pathophysiology.

Autoimmune thyroid diseases and Th17/Treg lymphocytes

Years of researches have demonstrated that the imbalance of Th17 and Tregs contribute to the thyroid autoimmunity and the severity of autoimmune thyroid disease (AITD). The underlying mechanism comprises inherent genetic predisposition, abnormality of Th17 and Treg related biological molecules, and gut microbiota disorder. New therapeutic strategies have been developed to improve the Th17/Treg equilibrium, including regulation of intracellular signaling pathways, neutralization of Th17-related cytokines, as well as manipulation of Th17 and Treg specific transcription factors. Although a few of these agents are applied into AITD, the clinic prospect is promising.

Patients with Systemic Lupus Erythematosus Show Increased Levels and Defective Function of CD69+ T Regulatory Cells

T regulatory (Treg) cells have a key role in the pathogenesis of chronic inflammatory and autoimmune diseases. A CD4⁺CD69⁺ T cell subset has been described that behaves as Treg lymphocytes, exerting an important immune suppressive effect. In this study, we analyzed the levels and function of CD4⁺CD69⁺ Treg cells in patients with systemic lupus erythematosus (SLE). Blood samples were obtained from 22 patients with SLE and 25 healthy subjects. Levels of CD4⁺CD69⁺ Treg cells were analyzed by multiparametric flow cytometry, and their function was measured by an assay of suppression of lymphocyte activation and through the inhibition of cytokine synthesis. We found an increased percent of CD4⁺CD25^varCD69⁺TGF-β⁺IL-10⁺Foxp3⁻ lymphocytes in patients with SLE compared to controls. In addition, a significant diminution in the suppressive effect of these cells on the activation of autologous T lymphocytes was observed in most patients with SLE. Accordingly, CD69⁺ Treg cells from SLE patients showed a defective capability to inhibit the release of IL-2, IL-6, IL-10, and IL-17A by autologous lymphocytes. Our findings suggest that while CD4⁺CD69⁺ Treg lymphocyte levels are increased in SLE patients, these cells are apparently unable to contribute to the downmodulation of the autoimmune response and the tissue damage seen in this condition.

Expression and Function of the Costimulatory Receptor SLAMF1 Is Altered in Lymphocytes From Patients With Autoimmune Thyroiditis

CONTEXT

Signaling lymphocytic activation molecule family 1 (SLAMF1) is a costimulatory receptor expressed by most immune cells. Its role in autoimmune thyroid disease (AITD) is not well known.

OBJECTIVE

To analyze the expression and function of the costimulatory receptor SLAMF1 in lymphocytes of patients with AITD.

DESIGN

Cross-sectional, prospective, single-center study.

SETTING

Department of Endocrinology, Hospital Universitario de la Princesa, Madrid.

PATIENTS

Twenty-eight patients with AITD (17 with Graves disease and 11 with Hashimoto thyroiditis) and 21 controls.

INTERVENTION

Multiparametric flow cytometry and immunofluorescence techniques to analyze the expression of SLAMF1 in peripheral blood (n = 28) and thyroid tissue (n = 5) mononuclear cells. Assay of inhibition of cellular proliferation to study the function of SLAMF1 in CD4+CD25+ T regulatory (Treg) cells.

MAIN OUTCOME MEASURE

Expression levels and the function of SLAMF1 in lymphocytes in AITD patients and controls.

RESULTS

Expression of SLAMF1 was significantly increased in peripheral blood CD4+, T helper 17, and CD19+ B cells from AITD patients. Immunofluorescence microscopy detected the presence of SLAMF1+ lymphocytes in thyroid inflammatory cell infiltrate. Functional studies showed that SLAMF1 engagement in Treg cells increased their suppressive function in healthy controls but not in AITD patients.

CONCLUSIONS

The altered expression of SLAMF1, as well as its defective function observed in patients with AITD, may have a relevant role in the defective immune-regulatory function observed in this condition.

Quantitative and functional analysis of CD69+ T regulatory lymphocytes in patients with periodontal disease

BACKGROUND

Periodontal disease is chronic inflammatory process that affects the attachment structures of the teeth and constitutes a significant cause of tooth loss in adults. Although different bacteria play an important role in the triggering of this condition, the progression and severity of the disease are strongly affected by the host immune response, which is under the control of different immune regulatory mechanisms, including T regulatory (Treg) cells. The aim of this study was to assess the frequency and function of CD69⁺ Treg lymphocytes in patients with chronic periodontal disease.

METHODS

Peripheral blood samples (n = 33) and gingival tissue (n = 9) were obtained from patients with chronic periodontal disease. Blood samples from 25 healthy individuals were also studied. Levels of CD69⁺ Treg lymphocytes in peripheral blood and gingival tissue were determined by six-color multiparametric flow cytometry, immunofluorescence, and immunohistochemistry. The immune regulatory function of CD69⁺ Treg cells was tested by an in vitro assay of inhibition of lymphocyte activation.

RESULTS

Percentages of CD69⁺ Treg cells were significantly higher in the peripheral blood from patients with active periodontal disease compared to healthy controls, and these percentages inversely correlated with the periodontal attachment loss. Increased numbers of these Treg cells were detected in the gingival tissue from active PD patients compared to their peripheral blood. However, the suppressive function of CD69⁺ Treg cells was significantly diminished in patients with periodontal disease compared to healthy controls.

CONCLUSIONS

Our data suggest that CD69⁺ Treg cells seem to be another important piece in the complex immunopathogenesis of periodontal disease.

Impaired immune regulation after radioiodine therapy for Graves' disease and the protective effect of Methimazole

Both therapies for Graves' disease (GD), radioactive iodine (RAI) and antithyroid drugs (ATD), were reported to have specific immune effects. We aimed at investigating the effects of RAI therapy on cellular subsets involved in immune regulation. We conducted a thirty day follow-up prospective cohort study of adult patients. Patients eligible for RAI therapy at our centre were approached. Twenty seven patients with GD were recruited, among whom 11 were treated with ATD. Twenty-two healthy subjects (HS) were also studied. Over time, frequency of regulatory T cells (Treg) and of invariant natural killer T cells (iNKT), along with Treg cell-mediated suppression and underlying mechanisms, were monitored in the peripheral blood. Variance in frequency of Treg and iNKT after RAI therapy was higher in GD patients than in HS over time (p < 0.0001). Reduced Treg suppressive function was observed after RAI therapy in GD patients (p = 0.002). ATD medication prior to RAI dampened these outcomes: less variation of Treg frequency (p = 0.0394), a trend toward less impaired Treg function, and prevention of reduced levels of suppressive cytokines (p < 0.05). Shortly after RAI therapy, alterations in immunoregulatory cells in patients with GD were observed and partially prevented by an ATD pretreatment. Worsening of autoimmunity after RAI was explained in previous studies by enhanced immune activity. This study adds new highlights on immune regulation deficiencies after therapeutic interventions in thyroid autoimmunity.

Pathogenesis of thyroid autoimmune disease: the role of cellular mechanisms

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are two very common organ-specific autoimmune diseases which are characterized by circulating antibodies and lymphocyte infiltration. Although humoral and cellular mechanisms have been classically considered separately in the pathogenesis of autoimmune thyroid diseases (AITD), recent research suggests a close reciprocal relationship between these two immune pathways. Several B- and T-cell activation pathways through antigen-presenting cells (APCs) and cytokine production lead to specific differentiation of T helper (Th) and T regulatory (Treg) cells. This review will focus on the cellular mechanisms involved in the pathogenesis of AITD. Specifically, it will provide reasons for discarding the traditional simplistic dichotomous view of the T helper type 1 and 2 pathways (Th1/Th2) and will focus on the role of the recently characterized T cells, Treg and Th17 lymphocytes, as well as B lymphocytes and APCs, especially dendritic cells (DCs).