γδ Τ cells enhance B cells for antibody production in Hashimoto's thyroiditis, and retinoic acid induces apoptosis of the γδ Τ cell

Circulating immunophenotypes are potentially prognostic in follicular cell-derived thyroid cancer

Background

Exploring the immune interface of follicular cell-derived thyroid cancer has prognostic and therapeutic potential. The available literature is lacking for comprehensive immunophenotyping in relation to clinical outcomes. In this study, we identify circulating immunophenotypes associated with thyroid cancer prognosis.

Methods

We conducted a pilot observational study of adults with follicular cell-derived thyroid cancer who underwent surgery at our tertiary care referral center and had consented for flow cytometry on peripheral blood collected at the time of thyroidectomy.

Results

Of the 32 included subjects, 20 (62%) had well differentiated, 5 (16%) had poorly differentiated, and 7 (22%) had anaplastic thyroid cancer. The most frequent AJCC stage was 4 (59%) and the ATA risk of recurrence category was high (56%). Patients with AJCC stage 3/4 demonstrated fewer circulating mononuclear cells (CD45+), more monocytes (CD14+), fewer total lymphocytes (CD14-), fewer T cells (CD3+), fewer CD4+ T cells, fewer gamma-delta T cells, fewer natural killer (NK) T-like cells, more myeloid-derived suppressor cells (MDSCs; Lin-CD33+HLADR-), and more effector memory T cells but similar CD8+ T cells compared to stage1/2. Immunophenotype comparisons by ATA risk stratification and course of thyroid cancer were comparable to those observed for stage, except for significant differences in memory T cell subtypes. The median follow-up was 58 months.

Conclusions

Aggressive follicular cell-derived thyroid cancer either at presentation or during follow-up is associated with down-regulation of the T cell populations specifically CD4+ T cells, gamma-delta T cells, and NK T-like cells but up-regulation of MDSCs and altered memory T cells. These immunophenotypes are potential prognostic biomarkers supporting future investigation for developing targeted immunotherapies against advanced thyroid cancer.

A new method for the treatment of myocardial ischemia-reperfusion injury based on γδT cell-mediated immune response

Acute myocardial ischemia is a disease with high morbidity and mortality, and re-perfusion is currently the best intervention. However, re-perfusion may lead to further myocardial injury and increase the area of myocardial infarction. The mechanism of myocardial ischemia-re-perfusion injury is complex, but with more in-depth study, it has been proved that the immune system plays an important role in the process of MIRI. Among them, the γδT cell population has received increasing attention as the main early source of IL-17A in many immune response models. Because γδT cells have the characteristics of linking innate immunity and adaptive immunity,they can rapidly produce IL-17A and produce subsequent immune killing of cardiomyocytes. It can be seen that γδT cells play an important role in MIRI. Therefore, here we review the research progress of immune response in myocardial ischemia-re-perfusion injury, the key characteristics of γδT cells and the role of rapidly produced IL-17 in myocardial ischemia-re-perfusion injury, and propose relevant treatment strategies and prospects for myocardial repair, in order to provide new ideas and methods for clinical treatment of myocardial ischemia-re-perfusion injury.

Non-Apoptotic Programmed Cell Death in Thyroid Diseases

Thyroid disorders are among the most common endocrinological conditions. As the prevalence of thyroid diseases increases annually, the exploration of thyroid disease mechanisms and the development of treatments are also gradually improving. With the gradual advancement of therapies, non-apoptotic programmed cell death (NAPCD) has immense potential in inflammatory and neoplastic diseases. Autophagy, pyroptosis, ferroptosis, and immunogenic cell death are all classical NAPCD. In this paper, we have compiled the recent mechanistic investigations of thyroid diseases and established the considerable progress by NAPCD in thyroid diseases. Furthermore, we have elucidated the role of various types of NAPCD in different thyroid disorders. This will help us to better understand the pathophysiology of thyroid-related disorders and identify new targets and mechanisms of drug resistance, which may facilitate the development of novel diagnostic and therapeutic strategies for patients with thyroid diseases. Here, we have reviewed the advances in the role of NAPCD in the occurrence, progression, and prognosis of thyroid diseases, and highlighted future research prospects in this area.

Decreased β-catenin expression contributes to IFNγ-induced chemokine secretion and lymphocyte infiltration in Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) is a very common organ-specific autoimmune disease characterized by lymphocyte infiltration and the destruction of thyroid follicular cells (TFCs), in which IFN-γ and chemokines play pivotal roles. Moreover, β-catenin has been implicated in the regulation of T cell infiltration. However, whether β-catenin is involved in Hashimoto's thyroiditis is unknown. Here, we examined β-catenin expression in thyroid tissues and investigated its role in the pathogenesis of HT. The results showed that β-catenin expression was markedly reduced in the thyroid tissues of HT patients; more importantly, IFN-γ treatment markedly reduced the expression of β-catenin and was accompanied by the secretion of chemokines such as CCL5, CXCL16, GRO-β, and GRO-γ in TFCs in vitro, which was attributed to GSK-3β/β-catenin signaling pathway activation. Collectively, the decreased expression of β-catenin might contribute to IFNγ-induced chemokine secretion and lymphocyte infiltration in the development of HT.

Immune Checkpoint Inhibitor-Induced Thyroiditis Is Associated with Increased Intrathyroidal T Lymphocyte Subpopulations

Background: Immune checkpoint inhibitors (ICIs) frequently cause thyroid dysfunction but their underlying mechanism remains unclear. We have previously demonstrated increased circulating natural killer (NK) cells and human leukocyte antigen (HLA)-DR surface expression on inflammatory intermediate CD14⁺CD16⁺ monocytes in programmed cell death protein-1 (PD-1) inhibitor-treated patients. This study characterizes intrathyroidal and circulating immune cells and class II HLA in ICI-induced thyroiditis. Methods: This is a single-center prospective cohort study of 10 patients with ICI-induced thyroiditis by flow cytometry of thyroid fine needle aspirates (n = 9) and peripheral blood (n = 7) as compared with healthy thyroid samples (n = 5) and healthy volunteer blood samples (n = 44); HLA class II was tested in n = 9. Results: ICI-induced thyroiditis samples demonstrated overall increased T lymphocytes (61.3% vs. 20.1%, p = 0.00006), CD4^-CD8^- T lymphocytes (1.9% vs. 0.7%, p = 0.006), and, as a percent of T lymphocytes, increased CD8⁺T lymphocytes (38.6% vs. 25.7%; p = 0.0259) as compared with healthy thyroid samples. PD-1 inhibitor-induced thyroiditis had increased CD4⁺PD1⁺ T lymphocytes (40.4% vs. 0.8%; p = 0.021) and CD8⁺PD1⁺ T lymphocytes (28.8% vs. 1.5%; p = 0.038) in the thyroid compared with the blood. Circulating NK cells, certain T lymphocytes (CD4⁺CD8⁺, CD4^-CD8^- T, gamma-delta), and intermediate monocytes were increased in ICI-induced thyroiditis. Six patients typed as HLA-DR4-DR53 and three as HLA-DR15. Conclusions: ICI-induced thyroiditis is a T lymphocyte-mediated process with intra-thyroidal predominance of CD8⁺ and CD4^-CD8^- T lymphocytes. The HLA haplotypes may be involved but need further evaluation. These findings expand the limited understanding of ICI-induced thyroiditis, which could be further translated to guide immunomodulatory therapies for advanced thyroid cancer.

Caveolin-1 Regulates CCL5 and PPARγ Expression in Nthy-ori 3-1 Cells: Possible Involvement of Caveolin-1 and CCL5 in the Pathogenesis of Hashimoto's Thyroiditis

BACKGROUND

Hashimoto's thyroiditis (HT) is characterized by lymphocytic infiltration of the thyroid parenchyma, which ultimately leads to tissue destruction and loss of function. Caveolin-1 (Cav-1) is an essential structural constituent of lipid rafts in the plasma membrane of cells and is reported to be significantly reduced in thyrocytes from HT patients. However, the mechanism of Cav-1 involvement in HT pathogenesis is still largely unclear.

METHODS

Cav-1 expression in thyroid tissues from HT patients and euthyroid nodular goiter tissues was detected by immunohistochemistry staining. Cav-1 knockdown and overexpression were constructed by lentiviral transfection in the human thyroid follicular epithelial cell (TFC) line of Nthy-ori 3-1. The mRNA expression levels of chemokines in TFCs were determined by quantitative real-time PCR (qPCR). Cav-1 and peroxisome proliferator-activated receptor gamma (PPARγ) levels were analysed by qPCR and Western blot analysis. The migration ability of peripheral blood mononuclear cells (PBMCs) was detected by the Transwell assay.

RESULTS

In this study, Cav-1 and PPARγ expression was reduced in the thyroid tissues from HT patients. In vitro experiments showed that the expressions of chemokine (C-C motif) ligand 5 (CCL5) and migration of PBMCs were markedly increased, while the level of PPARγ was significantly decreased after the lentivirus-mediated knockdown of Cav-1 in Nthy-ori 3-1 cells. Interestingly, pioglitazone, a PPARγ agonist, not only upregulated PPARγ and Cav-1 proteins significantly, but also effectively reversed the Cav-1-knockdown-induced upregulation of CCL5 in Nthy-ori 3-1 cells and reduced the infiltration of lymphocytes.

CONCLUSION

The inhibition of Cav-1 upregulated the CCL5 expression and downregulated the PPARγ expression in TFC while pioglitazone, a PPARγ agonist, reversed the detrimental consequence. This outcome might be a potential target for the treatment of lymphocyte infiltration into the thyroid gland and HT development.

Caveolin-1 regulates autophagy activity in thyroid follicular cells and is involved in Hashimoto's thyroiditis disease

Hashimoto's thyroiditis (HT) is considered a T helper-type 1 (Th1) cytokine-dominant autoimmune thyroid disease. Caveolin-1 (Cav-1), a part of the thyroxisome multiprotein complex, is localized at the apical pole of thyrocytes and is indispensable for synthesis of thyroid hormones and modulation of oxidative stress in order to avoid cell damage and apoptosis. Reduced autophagy induces thyroid follicular cells (TFC) apoptosis by activating reactive oxygen species (ROS) in HT patients. Nevertheless, whether Cav-1 has roles in the regulation of autophagy remains largely unclear. In this study, we examined Th1 cytokines and Cav-1 expression in HT thyroid tissues, determined the effects of interleukin-1beta (IL-1β) and interferon-gamma (IFN-γ) on Cav-1 and autophagy activity in TFC, and investigated the association between Cav-1 and autophagy activity in vitro. Our results indicate that higher levels of IL-1β and IFN-γ and lower levels of Cav-1 were expressed in thyroid tissues of HT patients than in those of normal controls. Cav-1 mRNA and protein levels were significantly decreased in TFC exposed to IL-1β and IFN-γ, accompanied by decreased expression of autophagy-related protein LC3B-II. Interestingly, small interfering RNA (siRNA)-mediated Cav-1 knockdown in TFC reduced LC3B-II protein expression. Taken together, these results suggest that lack of Cav-1 expression inhibited autophagy activity in TFC exposed to Th1 cytokines (IL-1β and IFN-γ), which might be a novel pathogenetic mechanism of HT.

IL-17 and limits of success

Interleukin-17 (IL-17) is a potent proinflammatory cytokine that protects a host against fungal and extracellular bacterial infections. On the other hand, excessive or dysregulated production of IL-17 underlines susceptibility to autoimmune disease. Consequently, blocking IL-17 has become an effective strategy for modulating several autoimmune diseases, including multiple sclerosis (MS), psoriasis, and rheumatoid arthritis (RA). Notably, however, IL-17 blockade remains ineffective or even pathogenic against important autoimmune diseases such as inflammatory bowel disease (IBD). Furthermore, the efficacy of IL-17 blockade against other autoimmune diseases, including type 1 diabetes (T1D) is currently unknown and waiting results of ongoing clinical trials. Coming years will determine whether the efficacy of IL-17 blockade is limited to certain autoimmune diseases or can be expanded to other autoimmune diseases. These efforts include new clinical trials aimed at testing second-generation agents with the goal of increasing the efficiency, spectrum, and ameliorating side effects of IL-17 blockade. Here we briefly review the roles of IL-17 in the pathogenesis of selected autoimmune diseases and provide updates on ongoing and recently completed trials of IL-17 based immunotherapies.

Aberrant MRP14 expression in thyroid follicular cells mediates chemokine secretion through the IL-1β/MAPK pathway in Hashimoto's thyroiditis

Myeloid-related protein 14 (MRP14) is responsible for inflammatory reactions. However, the correlation between MRP14 and Hashimoto's thyroiditis (HT) is still not clear. In this study, we examined the status of MRP14 in thyroid tissues and sera of HT patients and explored the mechanism of IL-1β-mediated regulation of MRP14 expression, as well as the effects of MRP14 on pro-inflammatory chemokine secretion in thyroid follicular cells (TFCs), to elucidate the role of MRP14 in HT development. Our results showed dramatically increased MRP14 expression in thyroid tissues and sera from HT patients. In addition, IL-1β significantly promoted the expression of MRP14 in TFCs, which was mediated by activation of the MAPK/NF-κB signalling pathway. More importantly, IL-1β induced the secretion of the chemokines GRO-2, CXCL9 and CCL22, which was dependent on the regulation of MRP14 in TFCs. Therefore, these findings suggested that under pro-inflammatory conditions, TFCs secreted chemokines with the help of MRP14 regulation, which might suggest a potential pathological mechanism of lymphocyte infiltration into the thyroid gland in HT.

Increased Interleukin-23 in Hashimoto's Thyroiditis Disease Induces Autophagy Suppression and Reactive Oxygen Species Accumulation

Hashimoto’s thyroiditis (HT) represents the most common organ-specific autoimmune disease. Inflammatory factors and reactive oxygen species (ROS) play detrimental roles during the pathogenesis of HT. In this study, we found that thyroid follicular cells (TFCs) from HT patients expressed an elevated level of interleukin-23 (IL-23), which contributed to autophagy suppression and ROS accumulation. Additionally, IL-23-induced autophagy suppression and ROS accumulation in human TFCs was attributed to AKT/mTOR/NF-κB signaling pathway activation. Inhibition of either IL-23 by a specific neutralization antibody, or mTOR by rapamycin, or NF-κB by IKK-16, significantly reversed the autophagy suppression and ROS accumulation. These results demonstrate a key role for IL-23 in HT pathogenesis and provide a potential therapeutic strategy against IL-23 or its signaling pathway in HT.

Association of increased eomesodermin, BCL6, and granzyme B expression with major clinical manifestations of Hashimoto's thyroiditis - an observational study

PURPOSE

Studies of cytotoxic T cells and their respective lineage master regulators have been limited in Hashimoto's thyroiditis (HT). It is unclear whether their transcriptomes are changed in HT patients and how these changes are associated with the thyroid damage, major clinical manifestations, and disease progression.

METHODS

We explored the gene expression patterns of selected transcription factors [eomesodermin (EOMES), BACH2, BCL6, TCF1] and cytolytic molecules [granzyme B (GZMB)] in peripheral blood (PB) T cells of 10 healthy controls and 30 HT patients of various subtypes (hypothyroid, untreated HT; L-thyroxine (T4)-treated HT, and spontaneously euthyroid HT) using real-time quantitative PCR.

RESULTS

EOMES (Mann-Whitney P = 0.044), GZMB (P = 0.028), and BCL6 mRNA (P = 0.001) were overrepresented in PB T cells from HT and showed levels varying by age, thyroid volume and disease severity. BCL6 transcripts were predominantly enriched in severely affected, hypothyroid cases, both on and off LT4. Increased EOMES RNA expression was associated with advancing age, lower thyroid volumes and higher peak adjusted TSH levels over the course of the disease. The body mass-adjusted, steady-state maintenance dose of LT4 increased with GZMB and BCL6 levels in PB T cells of hypothyroid cases, mostly postmenopausal women having long-standing, non-goitrous and atrophic disease form.

CONCLUSIONS

Our exploratory results suggest a role for GZMB, EOMES, and BCL6 in the context of HT, thyroid injury, and aggressive/advanced disease forms. Functions enriched within differentially expressed transcripts could be an important new target in understanding the pathogenesis of HT.

Neuroprotective effect of (-)-epigallocatechin-3-gallate on autoimmune thyroiditis in a rat model by an anti-inflammation effect, anti-apoptosis and inhibition of TRAIL signaling pathway

(-)-Epigallocatechin-3-gallate (EGCG) is a polyphenol monomer compound extracted and separated from green tea, and is a key catechin in green tea. Recent research has identified that EGCG is equipped with important biological activities, including antitumor, antioxidant, anti-inflammation, blood fat reduction and radiation protection abilities. In the current study, it was investigated whether EGCG exerts a neuroprotective effect on AIT and examined the possible underlying mechanism. The present study sought to establish an experimental autoimmune thyroiditis (AIT) rat model and to investigate the neuroprotective effect of EGCG in this model. EGCG was demonstrated to inhibit urinary iodine values and thyroid pathological features in AIT model rats. Treatment with EGCG significantly reduced interleukin-1β, interferon-γ (INF-γ) and tumor necrosis factor-α (TNF-α) levels in the AIT rats through suppression of nuclear factor-κB (NF-κB) pathway. In addition, pretreatment with EGCG significantly increased B-cell lymphoma-2 protein expression, and suppressed caspase-3 activity and TNF-α-related apoptosis-inducing ligand (TRAIL) protein expression levels in the AIT model rats. In conclusion, these results suggested that the neuroprotective effect of EGCG protects against AIT through its anti-inflammatory ability, anti-apoptosis and TRAIL signaling pathway in model rats, and it may be used as a therapeutic agent against AIT caused by inflammation.

Excess iodine promotes apoptosis of thyroid follicular epithelial cells by inducing autophagy suppression and is associated with Hashimoto thyroiditis disease

The incidence of the autoimmune thyroid disease Hashimoto thyroiditis (HT) has increased in recent years, and increasing evidence supports the contribution of excess iodine intake to thyroid disease. In this study, we examined the status of autophagy and apoptosis in thyroid tissues obtained from patients with HT, and we determined the effects of excessive iodine on the autophagy and apoptosis of thyroid follicular cells (TFCs) in an attempt to elucidate the effects of excess iodine on HT development. Our results showed decreases in the autophagy-related protein LC3B-II, and increases in caspase-3 were observed in thyroid tissues from HT patients. Interestingly, the suppression of autophagy activity in TFCs was induced by excess iodine in vitro, and this process is mediated through transforming growth factor-β1 downregulation and activation of the Akt/mTOR signaling pathway. In addition, excess iodine induced autophagy suppression and enhanced reactive oxygen species (ROS) production and apoptosis of TFCs, which could be rescued by the activation of autophagy. Taken together, our results demonstrated that excess iodine contributed to autophagy suppression and apoptosis of TFCs, which could be important factors predisposing to increased risk of HT development.