Constitutive Changes in Circulating Follicular Helper T Cells and Their Subsets in Patients with Graves' Disease

Circular RNA circPHF16 enhances IL-17A expression and secretion by sequestering miR-378a-3p to activate the IL6ST axis in Graves' disease

Interleukin-17A (IL-17A) plays a pivotal role in the pathogenesis of Graves' disease (GD), an autoimmune disorder affecting thyroid function, but the detailed regulatory mechanisms remain elusive. Circular RNAs (circRNAs) have emerged as key regulators of IL-17A expression and secretion in autoimmune diseases, yet their specific role in GD, especially within CD4 + T lymphocytes, are not well understood. In this study, a circRNA, circPHF16 (hsa_circ_0090364) was found to be highly expressed in the peripheral blood mononuclear cells and serum of GD patients. In vitro experiments in Jurkat T cells revealed that silencing of circPHF16 suppressed IL-17A expression and secretion, while overexpression of circPHF16 had the opposite effect. Furthermore, bioinformatics analysis demonstrated a circPHF16/miR-378a-3p/IL6ST pathway, in which circPHF16 regulates IL6ST expression, which, in turn, influences IL-17A expression and secretion by interacting with miR-378a-3p. In vivo studies in a mouse model of GD showed similar trends in molecular expression levels, consistent with competitive endogenous RNA interactions. Together the results of the study identify circPHF16 as a potential target in the development of new strategies for GD diagnosis and treatment, and thus, offer a theoretical foundation for clinical therapeutic approaches in GD.

Targeting BTLA with the peptide inhibitor HVEM(14-39) - A new way to restore the activity of T cells in melanoma

The complex of B- and T-lymphocyte attenuator (BTLA) and herpes virus entry mediator (HVEM) plays a critical role in immune regulation and has emerged as a promising therapeutic target for cancer treatment. In this study, we investigated the potential of the peptide inhibitor HVEM(14-39) to restore peripheral T cell activity in patients with advanced melanoma. In these patients, CD8+ T cells downregulated BTLA expression and increased HVEM expression upon activation. The addition of HVEM(14-39) reduced the percentage of BTLA+ CD8+ T cells and increased the subpopulation of HVEM+ CD8+ T cells. Additionally, HVEM(14-39) enhanced T cell activation, proliferation, and the shift toward effector memory T cell subpopulations. Finally, this peptide affected the proliferation rate and late apoptosis of melanoma cell line in co-culture with T cells. These findings suggest that HVEM(14-39) can overcome T cell exhaustion and improve antitumor responses. Peptide-based immunotherapy targeting the BTLA-HVEM complex offers a promising alternative to monoclonal antibody-based therapies, with the potential for fewer side effects and higher treatment efficacy.

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.

T follicular helper cells in autoimmune diseases

T follicular helper (Tfh) cells with the phenotype of mainly expressing surface molecules C-X-C motif chemokine receptor type 5 (CXCR5), inducible co-stimulator (ICOS), secreting cytokine interleukin-21 (IL-21) and requiring the transcription factor B cell lymphoma 6 (BCL-6) have been recently defined as a new subset of CD4⁺ T cells. They exist in germinal centers (GCs) of lymphoid organs and in peripheral blood. With the ability to promote B cell development, GC formation and antibody production, Tfh cells play critical roles in the pathogenesis of many autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), etc. The aberrant proliferation and function of Tfh cells will cause the pathological process like autoantibody production and tissue injury. In this paper, we review the recent advances in Tfh cell biology and their roles in autoimmune diseases, with a mention of their use as therapeutic targets, which will shed more light on the pathogenesis and treatment of certain autoimmune diseases.

Elevated Expression and Activation of GPR15 in Immune Cells in Graves' Disease

GPR15 plays an important role in lymphocyte homing and is a key immune molecule to maintain organ immune homeostasis. Yet, no study on the association between GPR15 and Graves' disease (GD) is available. In this study, we systematically investigated the expression of GPR15 in different types of immune cells and different tissues of GD patients. We found that the expressions of GPR15 and GPR15L in peripheral blood of GD patients were increased compared with those in healthy controls. A flow cytometry analysis showed that GPR15 positive cells were mainly CD14+ monocytes and CD56+ natural killer cells (NK cells) of innate immunity, T helper cells and cytotoxic T cells of adaptive immunity. We also found that the expressions of GPR15 and GPR15L in the PBMC of GD patients were positively correlated with the Tfh-specific cytokines IL21 and IL4. In addition, immunohistochemistry showed that the level of GPR15 in thyroid tissue of GD patients was higher than that of the control group. Our results demonstrate for the first time that GPR15 is highly expressed in various immune cells in GD patients, suggesting that GPR15-GPR15L is associated with the activation and infiltration of proinflammatory immune cells in the thyroid tissue of GD patients.

Characterization of sex-related differences in allergen house dust mite-challenged airway inflammation, in two different strains of mice

Biological sex impacts disease prevalence, severity and response to therapy in asthma, however preclinical studies often use only one sex in murine models. Here, we detail sex-related differences in immune responses using a house dust mite (HDM)-challenge model of acute airway inflammation, in adult mice of two different strains (BALB/c and C57BL/6NJ). Female and male mice were challenged (intranasally) with HDM extract (~ 25 μg) for 2 weeks (N = 10 per group). Increase in serum HDM-specific IgE showed a female bias, which was statistically significant in BALB/c mice. We compared naïve and HDM-challenged mice to define immune responses in the lungs by assessing leukocyte accumulation in the bronchoalveolar lavage fluid (BALF), and profiling the abundance of 29 different cytokines in BALF and lung tissue lysates. Our results demonstrate specific sex-related and strain-dependent differences in airway inflammation. For example, HDM-driven accumulation of neutrophils, eosinophils and macrophages were significantly higher in females compared to males, in BALB/c mice. In contrast, HDM-mediated eosinophil accumulation was higher in males compared to females, in C57BL/6NJ mice. Differences in lung cytokine profiles indicated that HDM drives a T-helper (Th)17-biased response with higher IL-17 levels in female BALB/c mice compared to males, whereas female C57BL/6NJ mice elicit a mixed Th1/Th2-skewed response. Male mice of both strains showed higher levels of specific Th2-skewed cytokines, such as IL-21, IL-25 and IL-9, in response to HDM. Overall, this study details sex dimorphism in HDM-mediated airway inflammation in mice, which will be a valuable resource for preclinical studies in allergic airway inflammation and asthma.

Adoptive immunotherapy with natural killer cells from peripheral blood CD34+ stem cells to prevent hepatocellular carcinoma recurrence after curative hepatectomy: a study protocol for an open-label, single-arm phase I study

INTRODUCTION

Hepatocellular carcinoma (HCC) remains a major clinical problem as more than half of these cases recur after radical resection. Natural killer (NK) cells are at the forefront of the innate immune system and attack microcarcinomas and circulating tumour cells. The objective of this study was to evaluate the feasibility and toxicity of peripheral blood CD34⁺ stem cell-derived NK cell infusion after radical hepatectomy for HCC.

METHODS AND ANALYSIS

This is an open-label, single-arm, single-centre phase I study. Patients who have undergone initial hepatectomy for HCC with three or more risk factors for recurrence (≥10 ng/mL of Alpha fetoprotein (AFP), ≥360 mAU/mL of PIVKA-II, multiple tumours and ≥3 peripheral blood circulating tumour cells) will be enrolled and be treated with three peripheral blood CD34⁺ stem cell-derived NK cell infusions every 3 months. The primary endpoint will be safety assessment including the type and severity of adverse events, frequency of occurrence and duration of occurrence. The secondary endpoints will include survival, effect of immune response and clinical laboratory test results.

ETHICS AND DISSEMINATION

Ethical approval of the trial was obtained from the Certified Committee for Regenerative Medicine Hiroshima University in Japan. The trial results will be shared with the scientific community at international conferences and by publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

jRCTb060200020.

MiR-29a-3p negatively regulates circulating Tfh memory cells in patients with Graves’ disease by targeting ICOS

MicroRNAs (miRNAs) are small endogenous noncoding RNAs that regulate genome expression posttranscriptionally and are involved in autoimmune diseases. Previous studies have indicated that follicular helper T (Tfh) cells play a critical role in the pathogenesis of Graves' disease (GD). However, the molecular mechanisms that contribute to circulating Tfh memory cell response in GD patients remain incompletely understood. This study aimed to investigate the role of miRNAs on circulating Tfh memory cells in GD patients. Herein, our data showed that the proportion of circulating Tfh memory cells, the transcript levels of IL-21, and the plasma concentrations of IL-21 were increased in the peripheral blood from GD patients. We also found that inducible co-stimulator (ICOS) expression, an important molecule expressed on Tfh cells, were significantly augmented in the peripheral blood mononuclear cells (PBMCs) from GD patients and positively correlated with the percentage of circulating Tfh memory cells and the transcript levels of IL-21 in GD. Intriguingly, miRNA sequencing screened miR-29a-3p expression was downregulated and inversely correlated with ICOS expression and the frequency of circulating Tfh memory cells in patients with GD. Luciferase assay demonstrated that ICOS was the direct target gene of miR-29a-3p, and miR-29a-3p could inhibit ICOS at both transcriptional and translational levels. Overexpression of miR-29a-3p reduced the proportion of circulating Tfh memory cells. Moreover, miR-29a-3p expression negatively correlated with serum concentrations of TSH receptor antibody (TRAb) in GD patients. Collectively, our results demonstrate that miR-29a-3p emerges as a post-transcriptional brake to limit circulating Tfh memory cell response in GD patients and may be involved in the pathogenesis of GD.

The Frequency of Intrathyroidal Follicular Helper T Cells Varies with the Progression of Graves’ Disease and Hashimoto’s Thyroiditis

Objective

Autoimmune thyroid diseases (AITD), mainly Graves' disease (GD) and Hashimoto's thyroiditis (HT), are common organ-specific autoimmune diseases characterized by circulating antibodies and lymphocyte infiltration. Follicular helper T (Tfh) cell dysregulation is involved in the development of autoimmune pathologies. We aimed to explore the role of intrathyroidal and circulating Tfh cells in patients with GD and HT.

Methods

Ultrasound-guided thyroid fine-needle aspiration (FNA) was conducted in 35 patients with GD, 40 patients with HT, and 22 patients with nonautoimmune thyroid disease (nAITD). Peripheral blood samples were also obtained from 40 patients with GD, 40 patients with HT, and 40 healthy controls. The frequencies of intrathyroidal and circulating Tfh cells from FNA and peripheral blood samples were assessed by flow cytometry. Additionally, the correlations between the frequencies of the Tfh cells and the levels of autoantibodies and hormones or disease duration were analyzed.

Results

The frequency of intrathyroidal CD4⁺CXCR5⁺ICOS^high Tfh cells was higher in HT patients than in GD patients. Significant correlations were identified between the percentages of circulating and intrathyroidal Tfh cells and the serum concentrations of thyroid autoantibodies, especially thyroglobulin antibodies (TgAb), in AITD. Intrathyroidal CD4⁺CXCR5⁺ICOS^high Tfh cells were positively correlated with free triiodothyronine (FT3) in HT patients but negatively correlated with FT3 in GD patients. In addition, HT patients with a longer disease duration had an increased frequency of intrathyroidal CD4⁺CXCR5⁺ICOS^high and CD4⁺CXCR5⁺PD-1⁺ Tfh cells. In contrast, in the GD patients, a longer disease duration did not affect the frequency of intrathyroidal CD4⁺CXCR5⁺ICOS^high but was associated with a lower frequency of CD4⁺CXCR5⁺PD-1⁺ Tfh cells.

Conclusions

Our data suggest that intrathyroidal Tfh cells might play a role in the pathogenesis of AITD and they are potential immunobiomarkers for AITD.

Genetics, Epigenetics, Cellular Immunology, and Gut Microbiota: Emerging Links With Graves' Disease

Graves’ disease (GD) is a well-known organ-specific autoimmune disease characterized by hyperthyroidism, goiter, and exophthalmos. The incidence of GD is approximately 2.0–3.0% in China and 0.5–2.0% in Western countries. Due to the complex pathogenesis and etiology of GD, current treatment methods have great side effects that seriously endanger human health. Therefore, it is particularly important to understand the pathogenesis of GD. Various studies have shown that genetics, epigenetics, cellular immunology, and gut microbiota are all involved in the development of GD. Genetically, CD25 gene and VDR gene polymorphisms are involved in the development of GD by increasing the ratio of Th17/Treg cells. Epigenetically, miR-23a-3p and lncRNA-MEG3 lead to Th17/Treg imbalance and participate in the progression of GD. Moreover, commensal microbe deletion can disrupt Th17/Treg balance and participate in the occurrence of GD. The imbalance of Th17/Treg cells induced by genetics, epigenetics, and gut microbiota plays a vital role in the pathogenesis of GD. Therefore, this article reviews the role of genetics, epigenetics, cellular immunology, and gut microbiota in the pathogenic mechanism of GD. This may lead to the development of novel therapeutic strategies and providing promising therapeutic targets.

Identification of lncRNA and mRNA Expression Profile in Relapsed Graves' Disease

Background: Graves’ disease (GD) is a common autoimmune disease, and its pathogenesis is unclear. Studies have found that the occurrence of GD is related to the immune disorder caused by the interaction of genetic susceptibility and environmental factors. The CD4⁺ T cell subset is closely related to the immune disorder of GD. LncRNAs are RNA molecules with a length of more than 200 nt and are involved in a variety of autoimmune diseases. However, the roles of lncRNAs in recurrent GD are still elusive. The purpose of this study is to identify lncRNA and mRNA expression profile in relapsed Graves’ disease.

Method: CD4⁺ T cells from 12 recurrent GD and 8 healthy controls were collected for high-throughput sequencing. The gene-weighted co-expression network analysis (WGCNA) was used to construct the co-expression module relevant to recurrent GD, and the key genes in the module were verified by RT-PCR.

Results: There are 602 upregulated lncRNAs and 734 downregulated lncRNAs in CD4⁺ T cells in recurrent GD patients compared with the healthy controls. The module most relevant to GD recurrence was constructed using WGCNA, and the key genes in the module were verified by RT-PCR. We found that the expression of RPL8, OAS2, NFAT5, DROSHA, NONHSAT093153.2, NONHSAT118924.2, and NONHSAT209004.1 was significantly decreased in GD group (p < 0.001, p < 0.001, p < 0.01, p < 0.05, p < 0.001, p < 0.05, and p < 0.01, respectively).

Conclusion: LncRNAs are closely related to the recurrence of GD. For the first time, we constructed the expression profile of lncRNAs and mRNAs in CD4⁺ T cells in recurrent GD patients.

The OX40/OX40L Axis Regulates T Follicular Helper Cell Differentiation: Implications for Autoimmune Diseases

T Follicular helper (Tfh) cells, a unique subset of CD4+ T cells, play an essential role in B cell development and the formation of germinal centers (GCs). Tfh differentiation depends on various factors including cytokines, transcription factors and multiple costimulatory molecules. Given that OX40 signaling is critical for costimulating T cell activation and function, its roles in regulating Tfh cells have attracted widespread attention. Recent data have shown that OX40/OX40L signaling can not only promote Tfh cell differentiation and maintain cell survival, but also enhance the helper function of Tfh for B cells. Moreover, upregulated OX40 signaling is related to abnormal Tfh activity that causes autoimmune diseases. This review describes the roles of OX40/OX40L in Tfh biology, including the mechanisms by which OX40 signaling regulates Tfh cell differentiation and functions, and their close relationship with autoimmune diseases.

Follicular helper T cells: potential therapeutic targets in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease with joint and systemic inflammation that is accompanied by the production of autoantibodies, such as rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies. Follicular helper T (Tfh) cells, which are a subset of CD4+ T cells, facilitate germinal center (GC) reactions by providing signals required for high-affinity antibody production and the generation of long-lived antibody-secreting plasma cells. Uncontrolled expansion of Tfh cells is observed in various systemic autoimmune diseases. Particularly, the frequencies of circulating Tfh-like (cTfh-like) cells, their subtypes and synovial-infiltrated T helper cells correlate with disease activity in RA patients. Therefore, reducing autoantibody production and restricting excessive Tfh cell responses are ideal ways to control RA pathogenesis. The present review summarizes current knowledge of the involvement of Tfh cells in RA pathogenesis and highlights the potential of these cells as therapeutic targets.

Employing hypoxia characterization to predict tumour immune microenvironment, treatment sensitivity and prognosis in hepatocellular carcinoma

The hypoxic microenvironment was recognized as a major driving force of the malignant phenotype in hepatocellular carcinoma (HCC), which contributes to tumour immune microenvironment (TIM) remodeling and tumor progression. Dysregulated hypoxia-related genes (HRGs) result in treatment resistance and poor prognosis by reshaping tumor cellular activities and metabolism. Approaches to identify the relationship between hypoxia and tumor progression provided new sight for improving tumor treatment and prognosis. But, few practical tools, forecasting relationship between hypoxia, TIM, treatment sensitivity and prognosis in HCC were reported. Here, we pooled mRNA transcriptome and clinical pathology data from the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), and later developed a hypoxia risk model including four HRGs (DCN, DDIT4, PRKCA and NDRG1). The high-risk group displayed poor clinical characteristics, a malignant phenotype with carcinogenesis/proliferation pathways activation (MTORC1 and E2F) and immunosuppressive TIM (decreased immune cell infiltrations and upregulated immunosuppressive cytokines). Meanwhile, activated B cells, effector memory CD8 T cells and EZH2 deregulation were associated with patient’s survival, which might be the core changes of HCC hypoxia. Finally, we validated the ability of the hypoxia risk model to predict treatment sensitivity and found high hypoxia risk patients had poor responses to HCC treatment, including surgical resection, Sorafenib, Transarterial Chemoembolization (TACE) and immunotherapy. In conclusion, based on 4 HRGs, we developed and validated a hypoxia risk model to reflect pathological features, evaluate TIM landscape, predict treatment sensitivity and compounds specific to hypoxia signatures in HCC patients.

The potential role and status of IL-17 family cytokines in breast cancer

Breast cancer (BC) is currently the most common malignant tumor of women in the world. At present, the development of BC is accelerating and showing a younger trend, which may be due to the known and/or unknown risk factors (RFs) for BC are increasing. It has been reported that inflammatory factors promote the occurrence and development of BC. No doubt chronic inflammation could trigger a series of molecular events, which will lead to the malignant transformation of differentiated cells, inhibition of anti-tumor immunity, and finally, lead to the occurrence and metastasis of tumors. With the deepening of research, it has been found that pro-inflammatory cytokine-interleukin-17 (IL-17) is closely related to BC. It not only plays an important role in promoting tumor proliferation, invasion and metastasis, but also has a significant correlation with poor prognosis. Recently, it was reported that IL-17 is closely related to programmed death ligand 1 (PD-L1) in BC. Therefore, starting with the role of IL-17 family cytokines in BC, this paper briefly discusses the potential role and status of IL-17 and seeks to contribute to the development of targeted drugs for BC-related treatments and to the identification of prediction factors for the early detection and prognosis prediction of BC for laying a solid theoretical foundation.

lncRNA:mRNA expression profile in CD4+ T cells from patients with Graves' disease

Graves' disease (GD) is a common autoimmune disease that affects the thyroid gland. As a new class of modulators of gene expression, long noncoding RNAs (lncRNAs) have been reported to play a vital role in immune functions and in the development of autoimmunity and autoimmune disease. The aim of this study is to identify lncRNAs in CD4+ T cells as potential biomarkers of GD. lncRNA and mRNA microarrays were performed to identify differentially expressed lncRNAs and mRNAs in GD CD4+ T cells compared with healthy control CD4+ T cells. Quantitative PCR (qPCR) was used to validate the results, and correlation analysis was used to analyze the relationship between these aberrantly expressed lncRNAs and clinical parameters. The microarray identified 164 lncRNAs and 93 mRNAs in GD CD4+ T cells differentially expressed compared to healthy control CD4+ T cells (fold change >2.0 and a P < 0.05). Further analysis consistently showed that the expression of HMlincRNA1474 (P < 0.01) and TCONS_00012608 (P < 0.01) was suppressed, while the expression of AK021954 (P < 0.01) and AB075506 (P < 0.01) was upregulated from initial GD patients. In addition, their expression levels were recovered in euthyroid GD patients and GD patients in remission. Moreover, these four aberrantly expressed lncRNAs were correlated with GD clinical parameters. Moreover, the areas under the ROC curve were 0.8046, 0.7579, 0.8115 for AK021954, AB075506, HMlincRNA1474, respectively. The present work revealed that differentially expressed lncRNAs were associated with GD, which might serve as novel biomarkers of GD and potential targets for GD treatment.

Strategies for recombinant production of antimicrobial peptides with pharmacological potential

INTRODUCTION

The need to develop new drugs for the control of pathogenic microorganisms has redoubled efforts to prospect for antimicrobial peptides (AMPs) from natural sources and to characterize its structure and function. These molecules present a broad spectrum of action against different microorganisms and frequently present promiscuous action, with anticancer and immunomodulatory activities. Furthermore, AMPs can be used as biopharmaceuticals in the treatment of hospital-acquired infections and other serious diseases with relevant social and economic impacts.Areas covered: The low yield and the therefore difficult extraction and purification process in AMPs are problems that limit their industrial application and scientific research. Thus, optimized heterologous expression systems were developed to significantly boost AMP yields, allow high efficiency in purification and structural optimization for the increase of therapeutic activity.Expert opinion: This review provides an update on recent developments in the recombinant production of ribosomal and non-ribosomal synthesis of AMPs and on strategies to increase the expression of genes encoding AMPs at the transcriptional and translational levels and regulation of the post-translational modifications. Moreover, there are detailed reports of AMPs that have already reached marketable status or are in the pipeline under advanced stages of preclinical testing.

T Lymphocytes: A Promising Immunotherapeutic Target for Pancreatitis and Pancreatic Cancer?

Pancreatic disorders cause a broad spectrum of clinical diseases, mainly including acute and chronic pancreatitis and pancreatic cancer, and are associated with high global rates of morbidity and mortality. Unfortunately, the pathogenesis of pancreatic disease remains obscure, and there is a lack of specific treatments. T lymphocytes (T cells) play a vital role in the adaptive immune systems of multicellular organisms. During pancreatic disease development, local imbalances in T-cell subsets in inflammatory and tumor environments and the circulation have been observed. Furthermore, agents targeting T cells have been shown to reverse the natural course of pancreatic diseases. In this review, we have discussed the clinical relevance of T-cell alterations as a potential outcome predictor and the underlying mechanisms, as well as the present status of immunotherapy targeting T cells in pancreatitis and neoplasms. The breakthrough findings summarized in this review have important implications for innovative drug development and the prospective use of immunotherapy for pancreatitis and pancreatic cancer.

The frequency of Tim-3 on circulating Tfh cells was increased in type 2 diabetes mellitus patients

Type 2 diabetes mellitus (T2DM) is a chronic, low-grade inflammation disease. T follicular helper (Tfh) cells and T cell immunoglobulin and mucin domain 3 (Tim-3) are implicated in many immune diseases. This study aims to explore whether Tim-3 expression on Tfh cells is associated with T2DM progression. White blood cells (WBCs) were harvested from 30 patients with T2DM and 20 healthy donors. The abundance of circulating Tfh cells (cTfh) and the frequency of Tim-3 were analyzed by flow cytometry. Levels of fasting plasma glucose (FPG), insulin, hemoglobin A1C (HbA1C), and fasting plasma C-peptide were measured. Body mass index (BMI) and diabetes duration were also recorded. Patients with T2DM had higher numbers of cTfh cells. In addition, cTfh cells showed a negative correlation with HbA1C and diabetes duration, a positive correlation with fasting plasma C-peptide. The frequency of Tim-3 on cTfh cells was higher among T2DM patients compared with healthy donors. The in vitro experiment showed that high glucose levels increased the abundance cTfh cells but had no effect on Tim-3 expression. Our results suggest that cTfh cells and associated Tim-3 frequency may contribute to the progression of T2DM, and high glucose levels may influence cTfh cells directly.