Chaoming Mao

Increased frequency of circulating follicular helper T cells in patients with rheumatoid arthritis.

Follicular helper T (Tfh) cells are recognized as a distinct CD4+ helper T-cell subset, which provides for B-cell activation and production of specific antibody responses, and play a critical role in the development of autoimmune disease. So far, only one study investigated the circulating Tfh cells increased in a subset of SLE patients. Since relatively little is known about the Tfh cells in rheumatoid arthritis (RA) patients, in this study, Tfh-cell frequency, related cytokine IL-21, and transcription factor Bcl-6 were investigated in 53 patients with RA and 31 health controls. Firstly, we found that the frequency of CD4+CXCR5+ICOShigh Tfh cells was increased significantly in the peripheral blood of RA patients, compared with that in healthy controls. It is known that Tfh cells are critical for directing the development of an antibody response by germinal centers B cells; secondly, we observed that the Tfh-cell frequency is accompanied by the level of anti-CCP antibody in RA patients. Furthermore, expression of Bcl-6 mRNA and plasma IL-21 concentrations in RA patients was increased. Taken together, these findings have shown that the increased frequency of circulating Tfh cells is correlated with elevated levels of anti-CCP antibody, indicating the possible involvement of Tfh cells in the disease progression of RA.

ANRIL inhibits p15INK4b through the TGFβ1 signaling pathway in human esophageal squamous cell carcinoma

The INK4b-ARF-INK4a gene cluster encodes three tumor suppressors: p15(INK4b), p14(ARF), and p16(INK4a). Antisense non-coding RNA in the INK4 locus (ANRIL) is transcribed in the opposite direction from this gene cluster. Recent studies suggest that ANRIL represses the expression of p15(INK4b), p14(ARF), and p16(INK4a); however, the underlying mechanism is unclear. In this study, the expressions of ANRIL in human esophageal squamous cell carcinoma (ESCC) tissues and matched adjacent non-tumor tissues were examined by quantitative real-time polymerase chain reaction. Compared with matched adjacent non-tumor tissues, the expression levels of ANRIL in ESCC tissues were significantly increased. Furthermore, inhibition of ANRIL was found to increase the expression of p15(INK4b) and transforming growth factor β1 (TGFβ1) and depletion of ANRIL in ESCC cell lines may inhibit cellular proliferation. Thus, our findings suggest a significant role of ANRIL in the occurrence and development of ESCC through TGFβ1 signaling pathways.

MiR-346 regulates CD4+CXCR5+ T cells in the pathogenesis of Graves’ disease

Follicular helper T (Tfh) cells are increasingly recognized as participants in various autoimmune diseases, including Graves’ disease. Although many transcription factors and cytokines are known to regulate Tfh cells, the role of noncoding RNA in Tfh cells development and function is poorly understood. Twenty-three patients with GD, eleven patients with remitting GD, and twenty-four healthy controls were enrolled in the current study. The interaction of miRNA and target gene was predicted through software analysis and then validated by luciferase assay and Western blot. The levels of miR-346 in circulating CD4+ T cells and plasma were measured by qRT-PCR. The correlation of miR-346 levels with the percentages of CD4+CXCR5+T cells and autoantibody levels were also analyzed. Up-regulation of Bcl-6 and down-regulation of miR-346 in GD patients were observed, and miR-346 could inhibit Bcl-6 at both transcriptional and translational levels. Overexpression of miR-346 led to attenuating CD4+CXCR5+ T cells. The abnormal expression of miR-346 restored in GD patients after treatment. A negative correlation between levels of miR-346 and percentages of CD4+CXCR5+ T cells was confirmed in GD patients. Additionally, negative correlations between the levels of miR-346 in circulating CD4+ T cells and serum concentrations of TR-Ab, TG-Ab, and TPO-Ab were also revealed in GD patients. MiR-346 regulates CD4+CXCR5+ T cells by targeting Bcl-6, a positive regulator of Tfh cells, and might play an important role in the pathogenesis of Graves’ disease.

Glucocorticoid-Induced Tumor Necrosis Factor Receptor Family-Related Protein Exacerbates Collagen-Induced Arthritis by Enhancing the Expansion of Th17 Cells

Rheumatoid arthritis (RA), a chronic autoimmune form of inflammatory joint disease, progressively affects multiple joints with pathological changes in the synovia, cartilage, and bone. Numerous studies have suggested a critical role for glucocorticoid-induced tumor necrosis factor receptor family-related protein (GITR) in the pathogenesis of autoimmune arthritis by modulating both innate and adaptive immune reactions, but the underlying mechanisms by which GITR activation promotes arthritic progression remain largely unclear. In this study, we found that collagen-induced arthritis mice treated with the ligand of GITR (GITRL) displayed an earlier onset of arthritis with a markedly increased severity of arthritic symptoms and joint damage, in which significantly increased Th17 cells in both spleen and draining lymph nodes were observed. Notably, results showed that a marked expansion of Th17 cells with increased RORγt mRNA expression was induced from naïve CD4(+) T cells when cultured with GITRL. Consistently, normal mice that were treated with GITRL were found to display a substantial expansion of splenic Th17 cells. Furthermore, we detected elevated serum levels of GITRL in patients with RA, which were positively correlated with an increase in interleukin-17 production. Taken together, the results from this study have revealed a new function of GITRL in exacerbating autoimmune arthritis via the enhancement of the expansion of Th17 cells.

Increased CD4+CD25+FOXP3+ Regulatory T Cells in Cancer Patients from Conversion of CD4+CD25– T Cells through Tumor-Derived Factors

Background: CD4⁺CD25⁺ regulatory T (Treg) cells play a pivotal role in the maintenance of the homeostatic balance of the immune system. The current study was conducted to evaluate the prevalence of CD4⁺CD25⁺ Treg cells in cancer patients and to identify possible mechanisms contributing to Treg cell expansion. Materials and Methods: The frequencies of CD4⁺CD25⁺FOXP3⁺ T cells in the peripheral blood mononuclear cells (PBMCs) of 62 cancer patients and 25 healthy individuals were determined by flow cytometry. The purified CD4⁺CD25^– T cells were stimulated with malignant pleural effusion (MPE) or tumor cell-derived supernatants (TCS) from cancer patients in vitro. MPE/TCS-exposed CD4⁺ CD25^– T cells were also characterized in terms of phenotype (CD4, CD25, and FOXP3 expression) and function (i.e. suppression assays). Results: An increased population of CD4⁺ CD25⁺FOXP3⁺ T cells was detected in the peripheral blood of cancer patients, with no obvious difference between the adenocarcinoma group and the squamous carcinoma group. When stimulated with MPE or TCS, a fraction of natural CD4⁺CD25^– T cells was converted into CD4⁺CD25⁺ FOXP3⁺ T cells which had the functional activity resembling natural CD4⁺CD25⁺ Treg cells with anergy and imm unosuppression. Conclusion: The percentages of CD4⁺CD25⁺ FOXP3⁺ Treg cells in PBMCs of cancer patients are significantly increased. Tumor-derived factors such as TGF-βmay contribute to CD4⁺CD25⁺ Treg cell expansion in cancer patients.

The Long Noncoding RNA IFNG-AS1 Promotes T Helper Type 1 Cells Response in Patients with Hashimoto’s Thyroiditis

The long noncoding (lnc) RNA-Ifng-AS1 plays an essential role in the transcription of the gene encoding IFN-γ by Th1 cells, and its human ortholog, IFNG-AS1, is expressed in human Th1 cells. However, IFNG-AS1 contributing to Th1 cells’ response in Hashimoto’s thyroiditis (HT) patients has not been reported. Twenty-eight HT patients and 20 healthy controls were enrolled in the study. The proportion of circulating Th1 cells and the level of T-bet, IFNG mRNA were increased in HT patients, the expression of IFNG-AS1 was upregulated and positively correlated with the proportion of circulating Th1 cells or T-bet, and IFNG expression, or serum level of anti-thyroglobulin antibody/thyroperoxidase antibody in HT patients. IFNG-AS1 regulated the expression of IFNG at both transcriptional and translational level in human CD4+ T cells. Furthermore, strong positive correlations between the increased transcript level of IFNG-AS1 and the increased transcript level of T-bet or IFNG were revealed in thyroid tissues from HT patients. Our results indicate that enhanced expression of lncRNA-IFNG-AS1 contributes to Th1 cell response in HT patients and may be involved in the pathogenesis of HT.

Th17/Treg Cells Imbalance and GITRL Profile in Patients with Hashimoto’s Thyroiditis

Hashimoto’s thyroiditis (HT) is an organ-specific immune disease characterized by the presence of lymphocytic infiltration and serum autoantibodies. Previous studies have confirmed the critical role of Th17 cells in the pathopoiesis of HT patients. Additionally, regulatory T cells (Treg) display a dysregulatory function in autoimmune disease. The purpose of this study is to investigate the alteration of Th17 and Treg cells in HT patients and explore contributing factors. We found there was an increased ratio of Th17/Treg in HT patients and a positive correlation with autoantibodies (anti-TgAb). In addition, there was an increased level of GITRL, which has been demonstrated to be correlated with the increassement of Th17 cells in the serum and thyroid glands of HT patients; the upregulated serum level of GITRL has a positive correlation with the percentage of Th17 cells in HT patients. In summary, an increase in GITRL may impair the balance of Th17/Treg, and contribute to the pathopoiesis of Hashimoto’s thyroiditis.

Interleukin-23 promotes the epithelial-mesenchymal transition of oesophageal carcinoma cells via the Wnt/β-catenin pathway

As the eighth most common malignant tumour worldwide, oesophageal cancer (OC) is often diagnosed during the metastasis of its advanced stage. Interleukin (IL)-23 is an immunomodulatory cytokine that has recently been identified as a cancer-associated factor. However, the role of IL-23 in the evolution of OC remains unclear. In the present study, we found that IL-23 was significantly expressed in the tumours of OC patients suffering metastasis and demonstrated that IL-23 contributed to epithelial-mesenchymal transition (EMT) through the Wnt/β-catenin pathway, promoting the migration and invasion of OC cells. In conclusion, IL-23 plays a pivotal role in the development of OC via EMT.

Chemokine/chemokine receptor interactions contribute to the accumulation of Th17 cells in patients with esophageal squamous cell carcinoma.

Chemokine/chemokine receptor interactions play a critical role in lymphocyte infiltration of tumors. Recent studies suggest that Th17 cells accumulate within many types of tumors, although the mechanisms that control this are unclear. We studied the distribution and phenotypic features of Th17 cells chemokine receptors, as well as the mRNA levels of CCL2, CCL17, CCL20, and CCL22 in tumors of patients with esophageal squamous cell carcinoma. We found that Th17 cells accumulated in tumors, and high expressions of CCR4, CCR6 were detected in Th17 cells. Levels of the chemokines CCL17, CCL20, and CCL22 in tumors were significantly higher than in tumor-free tissues, and were positively correlated with the distribution of Th17 cells in tumors. Furthermore, an in vitro migration assay showed that CCL17, CCL20 and CCL22 had chemotactic effects on tumor-derived Th17 cells. In conclusion, the CCR4-CCL17/22 and CCR6-CCL20 axis might play an important role in Th17 cell infiltration of tumors.

Decreased expression of microRNA-125a-3p upregulates interleukin-23 receptor in patients with Hashimoto’s thyroiditis

Interleukin IL-23 receptor (IL-23R) is increasingly recognized as a key checkpoint in autoimmune diseases, including Hashimoto’s thyroiditis (HT). However, the molecular mechanisms regulating IL-23R expression are still unknown. MicroRNAs have emerged as key regulators of various biological events via suppressing target mRNAs at the posttranscriptional level. In this study, we found that the IL-23R mRNA expression was increased in peripheral blood mononuclear cells from HT patients, and there was a positive correlation between the level of IL-23R mRNA and the serum level of anti-thyroglobulin antibody (TgAb). The miR-125a-3p expression was decreased and inversely correlated with elevated level of IL-23R in patients with HT. MiR-125a-3p inhibited IL-23R expression through directly targeting 3′untranslated region of IL-23R. An inverse correlation was observed between the level of miR-125a-3p and serum level of TgAb. Furthermore, we also found upregulated IL-23R expression and downregulated miR-125a-3p expression in thyroid tissues from HT patients. Taken together, our results indicate that decreased expression of miR-125a-3p was involved in the pathogenesis of Hashimoto’s thyroiditis.