Foxp3, Regulatory T Cell, and Autoimmune Diseases

Induction of FoxP3 Pre-mRNA Alternative Splicing to Enhance the Suppressive Activity of Regulatory T Cells from Amyotrophic Lateral Sclerosis Patients

Forkhead box protein 3 (FoxP3) is a key transcription factor responsible for the development, maturation, and function of regulatory T cells (Tregs). The FoxP3 pre-mRNA is subject to alternative splicing, resulting in the translation of multiple splice variants. We have shown that Tregs from patients with amyotrophic lateral sclerosis (ALS) have reduced expression of full-length (FL) FoxP3, while other truncated splice variants are expressed predominantly. A correlation was observed between the reduced number of Tregs in the peripheral blood of ALS patients, reduced total FoxP3 mRNA, and reduced mRNA of its FL splice variant. Induction of FL FoxP3 was achieved using splice-switching oligonucleotides capable of base pairing with FoxP3 pre-mRNA and selectively modulating the inclusion of exons 2 and 7 in the mature mRNA. Selective expression of FL FoxP3 resulted in the induction of CD127low, CD152, and Helios-positive cells, while the cell markers CD4 and CD25 were not altered. Such Tregs had an increased proliferative activity and a higher frequency of cell divisions per day. The increased suppressive activity of Tregs with the induced FL FoxP3 splice variant was associated with the increased synthesis of the pro-apoptotic granzymes A and B, and perforin, IL-10, and IL-35, which are responsible for contact-independent suppression, and with the increased ability to suppress telomerase in target cells. The upregulation of Treg suppressive and proliferative activity using splice-switching oligonucleotides to induce the predominant expression of the FoxP3 FL variant is a promising approach for regenerative cell therapy in Treg-associated diseases.

Immunomodulatory effects of Diospyros peregrina fruit preparation (DFP) in non-small cell lung cancer (NSCLC) by utilizing dendritic cell-mediated antigen presentation and T helper (TH) cell differentiation

Diospyros peregrina is a dioecious plant which is native to India. It belongs to the family of Ebenaceae and is extensively used to treat various ailments, such as leucorrhoea and other uterine-related problems. Though few studies have been on D. peregrina for their anti-tumour response, little is known. Therefore, this intrigued us to understand its immunomodulator capabilities on various types of cancer extensively. Our primary focus is on NSCLC (Non-Small Cell Lung Cancer), which is ranked as the second largest form of cancer in the world, and the treatments demand non-invasive agents to target NSCLC effectively. In an objective to generate an efficient Lung Cancer Associated Antigen (LCA) specific anti-tumour immune response, LCA was presented using dendritic cells (DCs) in the presence of D. peregrina fruit preparation (DFP). Moreover, we also investigated DFP's role in the differentiation of T-helper (TH) cells. Therefore, this study aimed at better LCA presentation mediated by DFP by activating the LCA pulsed DCs and T helper cell differentiation for better immune response. DCs were pulsed with LCA for tumour antigen presentation in vitro, with and without DFP. Differentially pulsed DCs were irradiated to co-culture with autologous and allogeneic lymphocytes. Extracellular supernatants were collected for the estimation of cytokine levels by ELISA. LDH release assay was performed to test Cytotoxic T lymphocytes (CTLs) mediated lung tumour cell cytotoxicity. Thus, DFP may be a potential vaccine to generate anti-LCA immune responses to restrict NSCLC.

Regulation of lipid metabolism by E3 ubiquitin ligases in lipid-associated metabolic diseases

Previous studies have progressively elucidated the involvement of E3 ubiquitin (Ub) ligases in regulating lipid metabolism. Ubiquitination, facilitated by E3 Ub ligases, modifies critical enzymes in lipid metabolism, enabling them to respond to specific signals. In this review, we aim to present a comprehensive analysis of the role of E3 Ub ligases in lipid metabolism, which includes lipid synthesis and lipolysis, and their influence on cellular lipid homeostasis through the modulation of lipid uptake and efflux. Furthermore, it explores how the ubiquitination process governs the degradation or activation of pivotal enzymes, thereby regulating lipid metabolism at the transcriptional level. Perturbations in lipid metabolism have been implicated in various diseases, including hepatic lipid metabolism disorders, atherosclerosis, diabetes, and cancer. Therefore, this review focuses on the association between E3 Ub ligases and lipid metabolism in lipid-related diseases, highlighting enzymes critically involved in lipid synthesis and catabolism, transcriptional regulators, lipid uptake translocators, and transporters. Overall, this review aims to identify gaps in current knowledge, highlight areas requiring further research, offer potential targeted therapeutic approaches, and provide a comprehensive outlook on clinical conditions associated with lipid metabolic diseases.

Radiomics Model for Predicting FOXP3 Expression Level and Survival in Clear Cell Renal Carcinoma

RATIONALE AND OBJECTIVES

We aimed to evaluate the predictive significance of forkhead box protein 3 (FOXP3) expression levels among individuals with clear cell renal carcinoma (ccRCC) and establish a radiomics model for predicting FOXP3 expression.

MATERIALS AND METHODS

430 patients with ccRCC were included in the gene-based prognostic analyses; 100 samples were used for radiomics feature generation, model development, and evaluation. A gradient boosting machine was employed to model the selected radiomics features. The developed model generated radiomics scores (RS) that predicted FOXP3 expression. The FOXP3 prognostic model combining imaging features was applied for survival and clinical indicator correlation analyses.

RESULTS

FOXP3 was highly expressed in patients with ccRCC and served as an independent predictive marker (hazard ratio [HR]=2.357, 95% CI [confidence interval]: 1.582-3.511, p < 0.001). The radiomics model formed by three radiomics characteristics was identified as a strong prognostic indicator of overall survival (OS). The predictive power of the model was commendable (areas under the curve: 0.835 and 0.809 for training and validation sets, respectively). Significant between-group variations in RS distribution were identified, as indicated by gene expression levels (p < 0.05). Disparities were observed in pathological stage, pharmaceutical therapy, and neoplasm status between low and high RS cohorts (p < 0.001). Kaplan-Meier curves revealed a significant correlation between increased RS and decreased OS (p = 0.001), which was also observed in the multivariate analyses (HR=3.411, 95% CI: 1.039-11.196, p = 0.043).

CONCLUSION

Prognostic outcome of ccRCC is closely linked to FOXP3 expression level. Computed tomography-based radiomics shows promise for prognostic prediction in ccRCC.

Study on the expression changes of lncRNA in patients with systemic lupus erythematosus and its correlation with Treg cells

OBJECTIVES

We initially explored the link between the differentially expressed long non-coding RNAs (lncRNAs) and the number of regulatory T (Treg) cells by detecting the lncRNA expression profiles in patients with systemic lupus erythematosus (SLE), then analyzed the correlation between Treg-related lncRNAs and the clinical features of SLE patients, predicting the mechanism by which lncRNAs regulate the differentiation and development of Treg cells, and provided new ideas for the treatment of SLE.

METHODS

Peripheral blood of 9 active SLE patients were collected and mononuclear cells (PBMCs) were extracted; the lncRNA expression profiles of PBMCs were analyzed by whole transcriptome sequencing. Nine healthy people were used as controls to screen the differentially expressed lncRNAs, to analyze the correlation between lncRNAs and Treg cell number. Pearson test was used to analyze the correlation between lncRNAs and the number of Treg cell, and the correlation between Treg-associated lncRNA and SLEDAI score, ESR, C3, and C4 in SLE patients. The targeted genes of Treg-associated lncRNAs were predicted with miRcode and Targetscan databases and coexpression network.

RESULTS

There were 240 differentially expressed lncRNAs in SLE patients compared with healthy controls, including 134 highly expressed lncRNAs (p < 0.05) and 106 lowly expressed lncRNAs (p < 0.05). The expression of ANKRD44-AS1 (r = 0.7417, p = 0.0222), LINC00200 (r = 0.6960, p = 0.0373), AP001363.2 (r = 0.7766, p = 0.0138), and LINC02824 (r = 0.7893, p = 0.0114) were positively correlated with the number of Treg cell, and the expression of AP000640.1 (r = - 0.7225, p = 0.0279), AC124248.1 (r = - 0.7653, p = 0.0163), LINC00482 (r = - 0.8317, p = 0.0054), and MIR503HG (r = - 0.7617, p < 0.05) were negatively correlated with the number of Treg cell. Among these Treg-associated lncRNAs, the expression of LINC00482 (r = - 0.7348, p < 0.05) and MIR503 HG (r = - 0.7617, p < 0.05) were negatively correlated with C3. LINC00200, ANKRD44 - AS1, and AP000640.1 related to Treg cells regulate the expression of signal transducer and activator of transcription 5 (STAT5), phospholipase D1 (PLD1), homeodomain-only protein X (HOPX), and runt-related transcription factor 3 (RUNX3) through competitive binding of miRNA or trans-regulatory mechanism, thereby regulating the differentiation and development of Treg cell.

CONCLUSIONS

The lncRNA expression profiles were changed in SLE patients, the differentially expressed lncRNAs were associated with abnormal number and function of Treg cells in SLE, and Treg-associated lncRNAs were associated with SLE-disease activity, which may affect the expression of STAT5, PLD1, HOPX, RUNX3 and regulate Treg cell function and participate in the pathogenesis and progression of SLE by competitively binding to miRNAs or trans-regulatory mechanism. Key points • Systemic lupus erythematosus (SLE) is an autoimmune disease involving multiple organs and systems. lncRNAs may affect Treg cells function by regulating genes expression, which may be an important pathogenesis of SLE. • This study, taking SLE as an example, preliminarily analyzed the correlation between lncRNA and Treg cells in SLE patients, analyzed the correlation between Treg-related lncRNA and the clinical characteristics of SLE, and speculated that lncRNA could regulate the differentiation and development of Treg cells through competitive combination with miRNA or trans-regulatory mechanisms. • It is possible to target epigenetic therapy for SLE.

Augmenting regulatory T cells: new therapeutic strategy for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune condition marked by inflammation of the joints, degradation of the articular cartilage, and bone resorption. Recent studies found the absolute and relative decreases in circulating regulatory T cells (Tregs) in RA patients. Tregs are a unique type of cells exhibiting immunosuppressive functions, known for expressing the Foxp3 gene. They are instrumental in maintaining immunological tolerance and preventing autoimmunity. Increasing the absolute number and/or enhancing the function of Tregs are effective strategies for treating RA. This article reviews the studies on the mechanisms and targeted therapies related to Tregs in RA, with a view to provide better ideas for the treatment of RA.

Pathogenesis and novel therapeutics of regulatory T cell subsets and interleukin-2 therapy in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous multisystem inflammatory disease with wide variability in clinical manifestations. Natural arising CD4+ regulatory T cells (Tregs) play a critical role in maintaining peripheral tolerance by suppressing inflammation and preventing autoimmune responses in SLE. Additionally, CD8+ regulatory T cells, type 1 regulatory T cells (Tr1), and B regulatory cells also have a less well-defined role in the pathogenesis of SLE. Elucidation of the roles of various Treg subsets dedicated to immune homeostasis will provide a novel therapeutic approach that governs immune tolerance for the remission of active lupus. Diminished interleukin (IL)-2 production is associated with a depleted Treg cell population, and its reversibility by IL-2 therapy provides important reasons for the treatment of lupus. This review focuses on the pathogenesis and new therapeutics of human Treg subsets and low-dose IL-2 therapy in clinical benefits with SLE.

Investigating the Role of FoxP3 in Renal Cell Carcinoma Metastasis with BAP1 or SEDT2 Mutation

Forkhead box protein P3 (FoxP3) primarily functions as the master regulator in regulatory T cells (Tregs) differentiation, but its high level of expression has also been found in tumor cells recently. The aim of our study was to clarify the role of FoxP3 in renal cell carcinoma (RCC) progression and metastasis. We verified the FoxP3 characteristic clinicopathological data from The Cancer Genome Atlas (TCGA) database using bioinformatics tools. Meanwhile, RNA sequencing was performed to determine the FoxP3 biofunction in RCC progression. Our results showed that high expression of FoxP3 was found in BAP1- or SETD2-mutant patients with RCC, and a higher FoxP3 expression was related to worse prognosis. However, there was no statistically significant relationship between the FoxP3 IHC score and RCC malignant progression owning to the limited number of patients in our tissue microarray. Using in vitro FoxP3 loss-of-function assays, we verified that silencing FoxP3 in 786-O and ACHN cells could inhibit the cell migration/invasion capability, which was consistent with the data from RNA sequencing in 786-O cells and from the TCGA datasets. Using an in vivo nude mice orthotopic kidney cancer model, we found that silencing FoxP3 could inhibit tumor growth. In conclusion, our study demonstrated that BAP1 or SEDT2 mutation could lead to higher expression of FoxP3 in RCC patients, and FoxP3 could eventually stimulate RCC cells' invasion and metastasis, which might indicate that FoxP3 could function as a potential oncogene in RCC progression.

Role of Fork-Head Box Genes in Breast Cancer: From Drug Resistance to Therapeutic Targets

Breast cancer has been acknowledged as one of the most notorious cancers, responsible for millions of deaths around the globe. Understanding the various factors, genetic mutations, comprehensive pathways, etc., that are involved in the development of breast cancer and how these affect the development of the disease is very important for improving and revitalizing the treatment of this global health issue. The forkhead-box gene family, comprising 19 subfamilies, is known to have a significant impact on the growth and progression of this cancer. The article looks into the various forkhead genes and how they play a role in different types of cancer. It also covers their impact on cancer drug resistance, interaction with microRNAs, explores their potential as targets for drug therapies, and their association with stem cells.

Identifying shared genetic loci and common risk genes of rheumatoid arthritis associated with three autoimmune diseases based on large-scale cross-trait genome-wide association studies

Introduction

Substantial links between autoimmune diseases have been shown by an increasing number of studies, and one hypothesis for this comorbidity is that there is a common genetic cause.

Methods

In this paper, a large-scale cross-trait Genome-wide Association Studies (GWAS) was conducted to investigate the genetic overlap among rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease and type 1 diabetes.

Results and discussion

Through the local genetic correlation analysis, 2 regions with locally significant genetic associations between rheumatoid arthritis and multiple sclerosis, and 4 regions with locally significant genetic associations between rheumatoid arthritis and type 1 diabetes were discovered. By cross-trait meta-analysis, 58 independent loci associated with rheumatoid arthritis and multiple sclerosis, 86 independent loci associated with rheumatoid arthritis and inflammatory bowel disease, and 107 independent loci associated with rheumatoid arthritis and type 1 diabetes were identified with genome-wide significance. In addition, 82 common risk genes were found through genetic identification. Based on gene set enrichment analysis, it was found that shared genes are enriched in exposed dermal system, calf, musculoskeletal, subcutaneous fat, thyroid and other tissues, and are also significantly enriched in 35 biological pathways. To verify the association between diseases, Mendelian randomized analysis was performed, which shows possible causal associations between rheumatoid arthritis and multiple sclerosis, and between rheumatoid arthritis and type 1 diabetes. The common genetic structure of rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease and type 1 diabetes was explored by these studies, and it is believed that this important discovery will lead to new ideas for clinical treatment.

Mechanism underlying the action of Duanteng-Yimu Tang in regulating Treg/Th17 imbalance and anti-rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a chronic immune disease characterised by synovitis and cartilage destruction. Currently, many patients experience poor remission after new antirheumatic drug treatments. Duanteng-Yimu Tang (DTYMT), a traditional Chinese medicine, is effective in the treatment of RA. In this research, we designed to investigate the anti-RA effects of DTYMT and explore its potential mechanisms.

Methods

Network pharmacology was adopted to explore the main pathways of DTYMT in patients with RA. Collagen-induced arthritis models of male DBA/1 mice were established, and their histopathological changes were observed by hematoxylin-eosin staining and micro-CT. qRT-PCR was performed to detect the expression of Foxp3 and RORγt in the serum and synovial tissue and IL-17, IL-1β, TNF-α, and IL-10 mRNA in vivo. The proliferation and invasion of synovial cells were analyzed using Cell Counting Kit-8 and transwell assays, respectively. The ratio of T helper 17 (Th17) to regulatory T (Treg) cells was analyzed by flow cytometry.

Results

Network pharmacology analysis revealed that Th17 cell differentiation may be the key pathway of DTYMT in RA. DTYMT ameliorated joint damage, inhibited RORγt expression, and increased Foxp3 expression in CIA mice. DTYMT significantly decreased IL-1β, IL-17, and TNF-α mRNA levels, and increased IL-10 mRNA levels in IL-6-induced cells. Additionally, DTYMT inhibited Th17 cell differentiation and promoted Treg cell production, thus improving the Treg/Th17 imbalance. DTYMT also inhibited the proliferation, migration, and invasion of RA fibroblast-like synovial cells.

Conclusions

These results indicate that DTYMT could regulate the Treg/Th17 cell balance, which is a possible mechanism of DTYMT in treating RA.

Investigating the correlation of the NF-κB and FoxP3 gene expression with the plasma levels of pro- and anti-inflammatory cytokines in rheumatoid arthritis patients

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic inflammatory systemic autoimmune disease. Cytokines regulate a wide range of inflammatory processes involved in RA pathogenesis. Anti-inflammatory cytokines (i.e., TGF-β and lL-10) and pro-inflammatory cytokines, like IL-6, were found to be potentially implicated in RA pathogenesis. Besides, NF-κB and FoxP3 are critical transcription factors regulating the inflammatory events occurring in RA patients. This study intends to assess the plasma levels of IL-6, IL-10, and TGF-β1 cytokines, as well as the expression of NF-κB and FoxP3 genes in RA patients, compared to the healthy controls.

METHODS

Peripheral blood was collected from 50 RA patients (25 new case and 25 under-treatment) and 25 age- and gender-matched healthy subjects. The disease activity was determined using the DAS-28 and ESR criteria. Also, plasma levels of TGF-β1, lL-10, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA) technique, and the gene expression of NF-κB and FoxP3 was evaluated using the real-time PCR method.

RESULTS

Our results showed a significant up-regulation of Rel-A and NF-κB1, and also a down-regulation of FoxP3 gene expression in under-treatment RA patients compared to the controls (P=0.031, P=0.014, and P=0.011, respectively). Moreover, there was a significant reduction of Rel-A and FoxP3 in the under-treatment RA patients compared to new case RA patients (P=0.005 and P=0.015, respectively). Also, plasma levels of TGF-β1 were significantly increased in both the new case and under-treatment RA patients relative to controls (P<0.001).

CONCLUSION

In conclusion, classical NF-κB (P65/P50) and FoxP3 may have significant pro- and anti-inflammatory roles in RA pathogenesis, respectively. Key Point • NF-κB (P65/P50) has a contribution to the early phase of RA.

CD83 Regulates the Immune Responses in Inflammatory Disorders

Activating the immune system plays an important role in maintaining physiological homeostasis and defending the body against harmful infections. However, abnormalities in the immune response can lead to various immunopathological responses and severe inflammation. The activation of dendritic cells (DCs) can influence immunological responses by promoting the differentiation of T cells into various functional subtypes crucial for the eradication of pathogens. CD83 is a molecule known to be expressed on mature DCs, activated B cells, and T cells. Two isotypes of CD83, a membrane-bound form and a soluble form, are subjects of extensive scientific research. It has been suggested that CD83 is not only a ubiquitous co-stimulatory molecule but also a crucial player in monitoring and resolving inflammatory reactions. Although CD83 has been involved in immunological responses, its functions in autoimmune diseases and effects on pathogen immune evasion remain unclear. Herein, we outline current immunological findings and the proposed function of CD83 in inflammatory disorders.

0.1% Nano-silver mediates PD-1/PD-L1 pathway and alleviates chronic apical periodontitis in rats

This study was to investigate whether the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) and T-helper 17 (Th17)/regulatory T (Treg) balance are associated with chronic apical periodontitis (CAP) relived by 0.1% nano-silver. CAP rat models were established by opening the first molars of the right and left mandible and exposing the pulp cavity to the oral cavity. CAP model was verified by cone-beam computed tomography, X-ray digital radiovisiography, and hematoxylin-eosin (H and E) staining. The rats were randomly divided into the sham, Ca(OH)₂, and 0.1% nano-silver groups (n = 12 in each group) 2 weeks after surgery. The pathological changes in the apical area were detected by H and E staining. PD-1, PD-L1, RORγT, IL-17, and Foxp3 in periapical tissues were detected by qRT-PCR and immunohistochemistry. Th17/Treg and PD-1/PD-L1 were analyzed by flow cytometry. After 7, 14, and 21 days of 0.1% nano-silver treatment, inflammatory cells in the apical region were slightly reduced and inflammatory infiltration was relieved compared with the sham group. RORγT, IL-17, PD-1, and PD-L1 decreased and Foxp3 increased after 7, 14, and 21 days of 0.1% nano-silver treatment compared with the sham group (p < 0.05); however, there were no significant differences with Ca(OH)₂ group (p > 0.05). Flow cytometry revealed that 0.1% nano-silver solution decreased Th17/Treg and PD-1/PD-L1 ratio. 0.1% Nano-silver significantly reduced the inflammation of CAP in rats. PD-1/PD-L1 was included in Th17/Treg balance restored by 0.1% nano-silver.

The role of FOXP3 in non-small cell lung cancer and its therapeutic potentials

Although in the last few decades we have witnessed the rapid development of treatments for non-small cell lung cancer (NSCLC), it still remains the leading cause of cancer-related death. Increasing efforts have been devoted to exploring potential biomarkers and molecular targets for NSCLC. Foxp3, a transcription factor that was discovered as a master regulator of regulatory T cells (Tregs), has been found to express abnormally in tumoral cells including lung cancer cells. In recent years, increasing evidence have surfaced, revealing the carcinogenic effect of FOXP3 in lung cancer. In this review, we analyzed and summarized the function of FOXP3, its regulation and therapeutic potentials in NSCLC, with a hope to facilitate the development of novel treatments for NSCLC.

T cells in ocular autoimmune uveitis: Pathways and therapeutic approaches

Autoimmune uveitis is a non-infectious intraocular condition that affects the uveal tract of the eye and threatens vision if not treated properly. Increasing evidence suggests that activated CD4⁺ T cells are associated with progressive and permanent destruction of photoreceptors in ocular autoimmune diseases. As such, the purpose of this review is to offer an overview of the role of CD4⁺ T cells in autoimmune uveitis as well as a justification for the current development and assessment of innovative autoimmune uveitis medications targeting CD4⁺ T cells. With an emphasis on T helper (Th)17, Th1, and Th2 cells, follicular helper CD4⁺ T cells, and regulatory T cells, this review presents a summary of recent research related to the pathways and signaling that encourage CD4⁺ T cells to develop into specialized effector cells. We also describe immunotherapeutic approaches based on CD4⁺ T cell subsets and their potential as therapeutic agents for autoimmune disorders.

The role of immune checkpoint receptors in the malignant phenotype of cutaneous T cell lymphoma

Immune checkpoint receptors (ICR) modulate the immune response and are critical hubs for immunotherapy. However, data on their role in T lymphoid malignancies, such as cutaneous T cell lymphoma (CTCL), is sparse. We aimed to explore the role of ICR in the malignant features of transformed T lymphocytes and evaluate the effect of ICR-targeting monoclonal antibodies, often used as immunotherapy for solid tumors. We used the CTCL cell line HH and the Sézary cell line Hut78 to examine ICR expression and the effects of ICR inhibition on cell viability and proliferation. Despite their shared T cell progeny, the different CTCL cell lines exhibit markedly different ICR expression profiles. Programmed cell death-ligand 1 (PD-L1) was expressed by both cell lines, while programmed death-1 (PD-1) was expressed only by the HH cell line. Common to all malignant T cells was an autonomous hyper-proliferative state that did not require T cell receptor stimulation. A monoclonal antibody blocking PD-1 had a small but statistically significant augmenting effect on T cell proliferation. Of note, when the cells were exposed to ionizing radiation, healthy lymphocytes and those derived from the HH cell line were salvaged by anti-PD-L1. We show a regulatory role of ICR, mainly PD-1 and its ligand PD-L1, on cutaneous T cell malignancy.

High-throughput T cell receptor sequencing reveals differential immune repertoires in autoimmune thyroid diseases

BACKGROUND

Autoimmune thyroid diseases (AITDs) are chronic autoimmune diseases specific to thyroid and mainly include Graves' disease (GD) and Hashimoto' thyroiditis (HT). The adaptive immunoreactivity of CD4⁺ T cells plays a crucial role in the pathogenesis of AITDs, but very little has been known about its changes in disease status.

METHODS

We collected peripheral CD4⁺ T cells from 12 GD patients, including 6 newly diagnosed GD (NGD) and 6 refractory GD (RGD) patients, 6 HT patients and 6 healthy controls, and examined the gene expression profiles and colon types of T cells receptor (TCR) β chain complementarity determining region 3 (CDR3) using high-throughput sequencing.

RESULTS

The TCR repertoire were significantly expanded in AITDs groups, and some TCR genes were expressed more preferentially in AITDs group than in the healthy control group, including TRBV15 (P = 0.001), TRBV4-2 (P = 0.003), TRBV9 (P = 0.007), TRBV3-2 (P = 0.012), TRBV7-8 (P = 0.015), TRBV25-1 (P = 0.019), TRBV12-4 (P = 0.019) and TRBV27 (P = 0.02) in GD patients as well as TRBV29-1 (P = 0.004), TRBV12-4 (P = 0.004), TRBV6-5 (P = 0.011), TRBV7-2 (P = 0.012), TRBV27 (P = 0.012), TRBV9 (P = 0.031) and TRBV4-2 (P = 0.032) in HT patients. Moreover, subgroup analysis showed that the difference in the TCR spectrum between the normal group and NGD was not obvious, but a large number of differential genes appeared in the RGD group.

CONCLUSION

TCR spectrum has changed in patients with AITDs with expanded repertoire and many upregulated TRBV genes. Moreover, this difference is not apparent in GD patients at the initial stage, but as the disease progresses, the differences in TCR profiles became more pronounced.

Small extracellular vesicles derived from PD-L1-modified mesenchymal stem cell promote Tregs differentiation and prolong allograft survival

We aimed to explore whether programmed cell death protein-1 ligand (PD-L1) modification on small extracellular vesicles (sEVs) could promote T regulatory cells (Tregs) differentiation. In this study, it was confirmed that under physiological conditions, PD-L1 expression was minimal in the MSCs and absent in the MSC-sEVs. A vector harboring the PD-L1 gene was constructed and transfected into bone marrow mesenchymal stem cells (BM-MSCs). By extracting the sEVs of these modified BM-MSCs and monitoring the expression of the PD-L1 protein, however, PD-L1 expression was substantially increased in the MSCs and concentrated in the sEVs. Then, the rat naïve CD4 + T cells were cocultured with the sEVs derived from the PD-L1-modified MSCs (sEVs^PD-L1). By flow cytometry, a higher percentage of Tregs and anti-inflammatory downstream cytokines (including IL-2, IFN-γ, TGF-β, IL-10) was detected in the sEVs^PD-L1 group than that in the control group treated by either sEVs in wild type, modified by empty vector, or blank control. Suppressive effect on CD4 + T cell proliferation serves as additional evidence to support the immunoregulation capacity of sEVs^PD-L1. The animal model of vascularized composite allograft further confirmed that PD-L1-modified sEVs induce an immune tolerance, by clinically observation, histopathology, T cell fate and cell product. In conclusion, sEVs^PD-L1 efficiently promotes Treg cell differentiation in vitro and in vivo, which suggests their therapeutic potential in the treatment of allograft rejection.

The positive feedback loop of furin and TGFβ1 enhances the immune responses of Tregs to hepatocellular carcinoma cells and hepatitis B virus in vitro

Regulatory T cells (Tregs) can exert immunosuppressive activity. Furin can regulate Treg functions, hepatitis B virus (HBV) persistent infection, and hepatocellular carcinoma (HCC) development. However, it remains unknown whether furin can regulate the immune responses of Tregs to HBV and HCC cells. Here, coculture systems of HBV1.3P-HepG2.3P-HepG2 cells and Tregs transduced with or without lentiviral particles that could overexpress furin or knockdown furin/transforming growth factor β1 (TGFβ1) were established to investigate the regulatory relationship between furin and TGFβ1 and the effect of furin/TGFβ1 on Treg activity. Also, the effects of furin overexpression or furin/TGFβ1 knockdown in Tregs on the immunological activity of effector T cells (Teffs)/cytotoxic T lymphocytes (CTLs) and HBV replication/expression were explored in the coculture system of Teff/CTL, Treg, and HBV1.3P-HepG2 cells. Our results showed that furin expression and TGFβ1 secretion were notably increased in Tregs, and Furin and TGFβ1 formed a positive feedback loop to activate Tregs in the coculture system of Tregs and HBV1.3P-HepG2 cells. Furin or TGFβ1 knockdown in Tregs promoted Teff cell proliferation, stimulated interleukin-2 and interferon-γ secretion, and inhibited HBV replication/gene expression in the coculture system of Teff, Treg, and HBV1.3P-HepG2 cells. Moreover, furin or TGFβ1 depletion in Tregs enhanced the killing activity of CTLs against HBV1.3P-HepG2 cells and curbed HBV replication/gene expression in the coculture system of Tregs, CTLs, and HBV1.3P-HepG2 cells. In conclusion, the positive feedback loop of furin and TGFβ1 enhanced the immune responses of Tregs to HCC cells and HBV in vitro.

The relation of CD4+CD25+Foxp3+ regulatory T cells concentration with disease activity and damage index in systemic lupus erythematosus

Introduction

Regulatory T cells (Treg) deficits, both quantitative and qualitative, are known to be possible triggers for the development of autoimmune disorders by causing T and B cells dysfunction. The contribution of Treg deficiency in the etiology of systemic lupus erythematosus (SLE) is still being debated. The aim of the present study is to evaluate the percentage of circulating CD4+CD25+Foxp3+ Treg cells in a cohort of Egyptian SLE patients and to correlate this value with the activity and damage index of these patients.

Methods

50 female patients with SLE together with an equal number of age- and sex-matched healthy controls were enrolled in the study. Flow cytometric determination of peripheral Treg cells was carried out for all participants by detecting the percentage of CD4+CD25+Foxp3+ cells to compare cases with the control group. Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), while disease damage was assessed using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SLICC/ACR DI). Both indices were correlated with the percentage of CD4+CD25+Foxp3 T regulatory cells.

Results

CD4+CD25+Foxp3+ Treg cells percentage was significantly decreased in patients with SLE as compared to healthy controls. On correlating CD4+CD25+Foxp3+ Treg percentage with SLEDAI-2K, a significantly negative correlation was found. Also, there was a negative significant correlation between CD4+CD25+Foxp3+ Treg cells percentage and SLICC/ACR DI. On correlating SLEDAI-2K with damage index (SLICC/ACR DI), we found highly significant positive correlation.

Conclusion

Our study showed impaired production of CD4+CD25+Foxp3+ Tregs in SLE patients, which can play a reciprocal role with some cytokines to affect the activity of the disease and organ damage. CD4+CD25+Foxp3+ Tregs cells should be the target to determine the clinical effectiveness of new therapy to modulate Tregs besides the traditional treatments.

The Effect of α7nAChR Signaling on T Cells and Macrophages and Their Clinical Implication in the Treatment of Rheumatic Diseases

Rheumatoid arthritis (RA) is one of the most common autoimmune disease and until now, the etiology and pathogenesis of RA is not fully understood, although dysregulation of immune cells is one of the leading cause of RA-related pathological changes. Based on current understanding, the priority of anti-rheumatic treatments is to restore immune homeostasis. There are several anti-rheumatic drugs with immunomodulatory effects available nowadays, but most of them have obvious safety or efficacy shortcomings. Therefore, the development of novel anti-rheumatic drugs is still in urgently needed. Cholinergic anti-inflammatory pathway (CAP) has been identified as an important aspect of the so-called neuro-immune regulation feedback, and the interaction between acetylcholine and alpha 7 nicotinic acetylcholine receptor (α7nAChR) serves as the foundation for this signaling. Consistent to its immunomodulatory functions, α7nAChR is extensively expressed by immune cells. Accordingly, CAP activation greatly affects the differentiation and function of α7nAChR-expressing immune cells. As a result, targeting α7nAChR will bring profound therapeutic impacts on the treatment of inflammatory diseases like RA. RA is widely recognized as a CD4+ T cells-driven disease. As a major component of innate immunity, macrophages also significantly contribute to RA-related immune abnormalities. Theoretically, manipulation of CAP in immune cells is a feasible way to treat RA. In this review, we summarized the roles of different T cells and macrophages subsets in the occurrence and progression of RA, and highlighted the immune consequences of CAP activation in these cells under RA circumstances. The in-depth discussion is supposed to inspire the development of novel cell-specific CAP-targeting anti-rheumatic regimens.

Immunohistochemical Expression of Regulatory T Cells (CD4 + CD25 + bright FOXP3 + ) in Pemphigus patients

BACKGROUND

Pemphigus is a series of autoimmune skin disorders caused by IgG. Regulatory T cells (Tregs) are a subset of CD4+ T cells that mostly block pathogenic immune responses mediated by self-reactive cells, therefore a lack of Tregs or a malfunction in their activity could lead to a loss of tolerance and the development of autoimmunity. .

AIMS

to evaluate the expression of lesional and perilesional Treg markers (CD4+ CD25+ bright FOXP3+) in pemphigus patients.

PATIENTS AND METHODS

Twenty three pemphigus patients and 20 healthy controls were included in this study. The expression of CD4, CD25 and Foxp3 were evaluated by immunohistochemistry.

RESULTS

There was statistically significant increase in CD4+ T lymphocytes in lesional skin of pemphigus compared to perilesional skin and control group (P-value: 0.001). There was statistically significant decrease in CD25+ and Foxp3+ cells in lesional skin compared to perilesional and control group (P-value: <0.001, 0.025 respectively ).

CONCLUSION

The reduction of lesional skin Tregs may play an important role in the pemphigus pathogenesis.

Low-Dose Interleukin-2 Altered Gut Microbiota and Ameliorated Collagen-Induced Arthritis

Purpose

Low-dose interleukin-2 (ld-IL-2) has been shown to regulate the balance between effector T and regulatory T (Treg) cells and has been used in several clinical trials to treat autoimmune diseases including rheumatoid arthritis (RA). In this study, we investigated the effects of ld-IL-2 on collagen-induced arthritis (CIA) in mice.

Methods

Arthritis severity in CIA mice was measured using the arthritis index (AI), radiographs, and hematoxylin and eosin staining. Cytokines were detected using enzyme-linked immunosorbent assay. Gut microbiota alterations and short-chain fatty acid production were analyzed through 16S rRNA sequencing and gas chromatography.

Results

The AI scores of CIA mice treated with ld-IL-2 were significantly lower compared to the model group, which significantly reduced the severity of arthritis. Ld-IL-2 also altered the gut microbiota in CIA mice. The diversity, composition, and dominant species of gut microbiota were altered by ld-IL-2 treatment. Ld-IL-2 also increased short-chain fatty acid levels. There was a strong correlation between ld-IL-2 treatment and improved gut microbiota.

Conclusion

Ld-IL-2 significantly ameliorated joint inflammation and bone damage and improved gut microbial dysbiosis in CIA, indicating that it may be a promising therapy for RA patients.

Progranulin as a Potential Therapeutic Target in Immune-Mediated Diseases

Progranulin (PGRN), a secretory glycoprotein consisting of 593 amino acid residues, is a key actor and regulator of multiple system functions such as innate immune response and inflammation, as well as tissue regeneration. Recently, there is emerging evidence that PGRN is protective in the development of a variety of immune-mediated diseases, including rheumatoid arthritis (RA), inflammatory bowel disease (IBD), type 1 diabetes mellitus (T1DM) and multiple sclerosis (MS) by regulating signaling pathways known to be critical for immunology, particularly the tumor necrosis factor alpha/TNF receptor (TNF-α/TNFR) signaling pathway. Whereas, the role of PGRN in psoriasis, systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) is controversial. This review summarizes the immunological functions of PGRN and its role in the pathogenesis of several immune-mediated diseases, in order to provide new ideas for developing therapeutic strategies for these diseases.

Knockout of the KH-Type Splicing Regulatory Protein Drives Glomerulonephritis in MRL-Faslpr Mice

KH-type splicing regulatory protein (KSRP) is an RNA-binding protein that promotes mRNA decay and thereby negatively regulates cytokine expression at the post-transcriptional level. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated cytokine expression causing multiple organ manifestations; MRL-Faslpr mice are an established mouse model to study lupus disease pathogenesis. To investigate the impact of KSRP on lupus disease progression, we generated KSRP-deficient MRL-Faslpr mice (MRL-Faslpr/KSRP-/- mice). In line with the predicted role of KSRP as a negative regulator of cytokine expression, lupus nephritis was augmented in MRL-Faslpr/KSRP-/- mice. Increased infiltration of immune cells, especially of IFN-γ producing T cells and macrophages, driven by enhanced expression of T cell-attracting chemokines and adhesion molecules, seems to be responsible for worsened kidney morphology. Reduced expression of the anti-inflammatory interleukin-1 receptor antagonist may be another reason for severe inflammation. The increase of FoxP3+ T cells detected in the kidney seems unable to dampen the massive kidney inflammation. Interestingly, lymphadenopathy was reduced in MRL-Faslpr/KSRP-/- mice. Altogether, KSRP appears to have a complex role in immune regulation; however, it is clearly able to ameliorate lupus nephritis.

The molecular structure and biological functions of RNA methylation, with special emphasis on the roles of RNA methylation in autoimmune diseases

Autoimmune diseases such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and systemic vasculitis are caused by the body's immune response to autoantigens. The pathogenesis of autoimmune diseases is complex. RNA methylation is known to play a key role in disease progression as it regulates almost all aspects of RNA processing, including RNA nuclear export, translation, splicing, and noncoding RNA processing. This review summarizes the mechanisms, molecular structures of RNA methylations and their roles in biological functions. Similar to the roles of RNA methylation in cancers, RNA methylation in RA and SLE involves "writers" that deposit methyl groups to form N6-methyladenosine (m6A) and 5-methylcytosine (m5C), "erasers" that remove these modifications, and "readers" that further affect mRNA splicing, export, translation, and degradation. Recent advances in detection methods have identified N1-methyladenosine (m1A), N6,2-O-dimethyladenosine (m6Am), and 7-methylguanosine (m7G) RNA modifications, and their roles in RA and SLE need to be further studied. The relationship between RNA methylation and other autoimmune diseases has not been reported, and the roles and mechanisms of RNA modifications in these diseases need to be explored in the future.

Bortezomib alleviates antibody-mediated rejection in kidney transplantation by facilitating Atg5 expression

Antibody‐mediated rejection (AMR) is one of the most dominant mechanisms responsible for the loss of kidney grafts. Previous researches have shown that donor‐specific antibodies (DSAs) are the major mediators of AMR. In order to prolong the survival time of grafts, it is vital to reduce the incidence of AMR and inhibit the generation of DSAs. We established an animal model of AMR by performing kidney transplantation in pre‐sensitized rats. Then, we investigated the effect of bortezomib (BTZ) on AMR. We found that BTZ could reduce the serum level of DSAs and alleviate post‐transplantation inflammation in peritubular capillaries (PTCs) and glomeruli, which was demonstrated by the reduction of C4d and IgG deposition in PTCs, and the reduced number of B cell and plasma cell in peripheral blood and the transplanted kidney (p < 0.05). Our results also suggested that BTZ increased the number of regulatory T cell (Treg) and significantly reduced the proportion of T helper (Th17) cell (p < 0.05). Besides, BTZ induced the significant upregulation of anti‐inflammatory cytokines but downregulated pro‐inflammatory cytokines (p < 0.05). After dealing with Atg5 siRNA‐lentivirus, the effect of BTZ alleviating AMR was reversed and Th17/Treg proportions were also significantly modulated. Collectively, these findings show that BTZ slows down the process of AMR and Atg5 may be the key mechanism. Furthermore, Atg5 silencing results may be demonstrated that Atg5 alleviated AMR by modulating the ratio of Th17/Treg.

ACLY ubiquitination by CUL3-KLHL25 induces the reprogramming of fatty acid metabolism to facilitate iTreg differentiation

Inducible regulatory T (iTreg) cells play a central role in immune suppression. As iTreg cells are differentiated from activated T (Th0) cells, cell metabolism undergoes dramatic changes, including a shift from fatty acid synthesis (FAS) to fatty acid oxidation (FAO). Although the reprogramming in fatty acid metabolism is critical, the mechanism regulating this process during iTreg differentiation is still unclear. Here we have revealed that the enzymatic activity of ATP-citrate lyase (ACLY) declined significantly during iTreg differentiation upon transforming growth factor β1 (TGFβ1) stimulation. This reduction was due to CUL3-KLHL25-mediated ACLY ubiquitination and degradation. As a consequence, malonyl-CoA, a metabolic intermediate in FAS that is capable of inhibiting the rate-limiting enzyme in FAO, carnitine palmitoyltransferase 1 (CPT1), was decreased. Therefore, ACLY ubiquitination and degradation facilitate FAO and thereby iTreg differentiation. Together, we suggest TGFβ1-CUL3-KLHL25-ACLY axis as an important means regulating iTreg differentiation and bring insights into the maintenance of immune homeostasis for the prevention of immune diseases.

High Levels of Thyroid Hormone Impair Regulatory T Cell Function Via Reduced PD-1 Expression

CONTEXT

Regulatory T cell (Treg) dysfunction plays an important role in the development and progression of Graves' disease (GD). Programmed cell death 1 (PD-1) prompts FoxP3 in Treg expression and enhances the suppressive activity of Tregs. Whether abnormal expression of PD-1 contributes to the breakdown of Tregs and the role of thyroid hormone in the PD-1 expression of Tregs in GD remain substantially undefined.

OBJECTIVE

To evaluate the role of PD-1 in Treg function and triiodothyronine (T3) in PD-1 expression in patients with GD and mice treated with T3.

METHODS

We recruited 30 patients with GD and 30 healthy donors. PD-1 expression in Tregs and Treg function were determined. To evaluate the effects of thyroid hormone on PD-1 expression in Tregs, we used T3 for the treatment of human peripheral blood mononuclear cells (PBMCs). We then treated mice with T3 to confirm the effect of thyroid hormone on PD-1 expression in Tregs and Tregs function in vivo.

RESULTS

PD-1 expression in Tregs and the suppressive function of Tregs significantly decreased in patients with GD. T3 reduced PD-1 expression in human Tregs in a concentration- and time-dependent manner in vitro. High levels of circulating T3 reduced PD-1 expression in Tregs, impaired Treg function, and disrupted T-helper cell (Th1 and Th2) balance in mice treated with T3.

CONCLUSION

Treg dysfunction in GD patients might be due to downregulation of PD-1 expression in Tregs induced by high levels of serum T3.

T cell receptor revision and immune repertoire changes in autoimmune diseases

Autoimmune disease (AID) is a condition in which the immune system breaks down and starts to attack the body. Some common AIDs include systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes mellitus and so forth. The changes in T-cell receptor (TCR) repertoire have been found in several autoimmune diseases, and may be responsible for the breakdown of peripheral immune tolerance. In this review, we discussed the processes of TCR revision in peripheral immune environment, the changes in TCR repertoire that occurred in various AIDs, and the specifically expanded T cell clones. We hope our discussion can provide insights for the future studies, helping with the discovery of disease biomarkers and expanding the strategies of immune-targeted therapy. HighlightsRestricted TCR repertoire and biased TCR-usage are found in a variety of AIDs.TCR repertoire shows tissue specificity in a variety of AID diseases.The relationship between TCR repertoire diversity and disease activity is still controversial in AIDs.Dominant TCR clonotypes may help to discover new disease biomarkers and expand the strategies of immune-targeted therapy.

Epithelial cell-derived CD83 restores immune tolerance in the airway mucosa by inducing regulatory T-cell differentiation

The mechanism of generation of regulatory T cells (Treg) remains incompletely understood. Recent studies show that CD83 has immune regulatory functions. This study aims to investigate the role of epithelial cell-derived CD83 in the restoration of immune tolerance in the airway mucosa by inducing the Treg differentiation. In this study, CD83 and ovalbumin (OVA)-carrying exosomes were generated from airway epithelial cells. An airway allergy mouse model was developed to test the role of CD83/OVA-carrying exosomes in the suppression of airway allergy by inducing Treg generation. We observed that mouse airway epithelial cells expressed CD83 that could be up-regulated by CD40 ligand. The CD83 deficiency in epithelial cells retarded the Treg generation in the airway mucosa. CD83 up-regulated transforming growth factor-β-inducible early gene 1 expression in CD4+ T cells to promote Foxp3 expression. Exposure of primed CD4+ T cells to CD83/OVA-carrying exosomes promoted antigen-specific Treg generation. Administration of CD83/OVA-carrying exosomes inhibited experimental airway allergic response. In summary, airway epithelial cells express CD83 that is required in the Treg differentiation in the airway mucosa. Administration of CD83/OVA-carrying exosomes can inhibit airway allergy that has the translation potential in the treatment of airway allergic disorders.

Sex Differences in the Immune System Become Evident in the Perinatal Period in the Four Core Genotypes Mouse

We have used the four core genotypes (FCG) mouse model, which allows a distinction between effects of gonadal secretions and chromosomal complement, to determine when sex differences in the immune system first appear and what influences their development. Using splenic T cell number as a measure that could be applied to neonates with as yet immature immune responses, we found no differences among the four genotypes at postnatal day 1, but by day 7, clear sex differences were observed. These sex differences were unexpectedly independent of chromosomal complement and similar in degree to gonadectomized FCG adults: both neonatal and gonadectomized adult females (XX and XY) showed 2-fold the number of CD4+ and 7-fold the number of CD8+ T cells versus their male (XX and XY) counterparts. Appearance of this long-lived sex difference between days 1 and 7 suggested a role for the male-specific perinatal surge of testicular testosterone. Interference with the testosterone surge significantly de-masculinized the male CD4+, but not CD8+ splenic profile. Treatment of neonates demonstrated elevated testosterone limited mature cell egress from the thymus, whereas estradiol reduced splenic T cell seeding in females. Neonatal male splenic epithelium/stroma expressed aromatase mRNA, suggesting capacity for splenic conversion of perinatal testosterone into estradiol in males, which, similar to administration of estradiol in females, would result in reduced splenic T cell seeding. These sex steroid effects affected both CD4+ and CD8+ cells and yet interference with the testosterone surge only significantly de-masculinized the splenic content of CD4+ cells. For CD8+ cells, male cells in the thymus were also found to express one third the density of sphingosine-1-phosphate thymic egress receptors per cell compared to female, a male characteristic most likely an indirect result of Sry expression. Interestingly, the data also support a previously unrecognized role for non-gonadal estradiol in the promotion of intra-thymic cell proliferation in neonates of both sexes. Microarray analysis suggested the thymic epithelium/stroma as the source of this hormone. We conclude that some immune sex differences appear long before puberty and more than one mechanism contributes to differential numbers and distribution of T cells.

Advances in targeting 'undruggable' transcription factors with small molecules

Transcription factors (TFs) represent key biological players in diseases including cancer, autoimmunity, diabetes and cardiovascular disease. However, outside nuclear receptors, TFs have traditionally been considered 'undruggable' by small-molecule ligands due to significant structural disorder and lack of defined small-molecule binding pockets. Renewed interest in the field has been ignited by significant progress in chemical biology approaches to ligand discovery and optimization, especially the advent of targeted protein degradation approaches, along with increasing appreciation of the critical role a limited number of collaborators play in the regulation of key TF effector genes. Here, we review current understanding of TF-mediated gene regulation, discuss successful targeting strategies and highlight ongoing challenges and emerging approaches to address them.

Effect of intraoperative blood transfusion on Treg and FOXP3 in patients with digestive tract malignancies and different ABO blood types

Background

Blood transfusion can cause immunosuppression and lead to worse outcomes in patients with digestive tract malignancies; however, the specific mechanism behind this is not completely understood. One theory is that increased numbers of regulatory CD3⁺CD4⁺CD25⁺FOXP3⁺ T cells (Tregs) and forkhead box protein-3 mRNA (FOXP3) expression in the blood after transfusion contribute to these outcomes. The effect of blood transfusion on immune function in patients with different ABO blood types is variable. This study investigates the effect of intraoperative blood transfusion on the number of Tregs and the expression of FOXP3 in the blood of patients with different ABO blood types and digestive tract malignancies.

Methods

Patients with digestive tract malignancies who underwent radical resection and received intraoperative blood transfusion were divided into four groups according to their blood types:blood group A, blood group B, blood group O and blood group AB (n = 20 for each group). Blood was collected from all patients before surgery, immediately after transfusion, 1 day after transfusion, and 5 days after transfusion. The number of Tregs was measured by flow cytometry. The expression of FOXP3 was detected by real time reverse transcription polymerase chain reaction (RT-PCR).

Results

There was no significant difference in the number of Tregs or expression of FOXP3 mRNA among patients with different blood types before surgery. However, the number of Tregs and the expression of FOXP3 increased after blood transfusion in all blood type groups. This increase was especially evident and statistically significant on the first day after blood transfusion when compared with measures obtained before the surgery. Measures returned to the preoperative level five days after surgery. There were significant differences in the increase of Tregs and expression of FOXP3 among patients with different blood types. The greatest increase was seen in patients with blood group B and the least in blood group A.

Conclusions

Intraoperative blood transfusion can lead to an increase in blood Tregs and FOXP3 expression in patients with digestive tract malignancies. Increases were greatest on the first day after surgery and differed among patients with different blood types. Increases were greatest in blood type B and least in blood type A.

Paeoniflorin ameliorates murine lupus nephritis by increasing CD4+Foxp3+ Treg cells via enhancing mTNFα-TNFR2 pathway

Treg cells are essential for re-establishing self-tolerance in lupus. However, given that direct Treg therapies may be inadequate to control autoimmunity and inflammation, a strategy of inducing or expanding endogenous Treg cells in vivo may be a good option. Macrophages are main tissue-infiltrating cells and play a role in promoting Treg differentiation while paeoniflorin (PF), a monoterpene glycoside, exhibits anti-inflammatory and immunoregulatory effects. Here, we studied the effects of PF on CD4⁺FoxP3⁺ Treg frequency and the potential mechanisms involving M2 macrophages. We demonstrated that PF ameliorated lupus nephritis in lupus-prone B6/gld mice by reducing urinary protein, serum creatinine and anti-dsDNA levels, diminishing renal cellular infiltration, improving renal immunopathology and downregulating renal gene and protein expressions of key cytokines, including IFN-γ, IL-6, IL-12 and IL-23. PF also lowered the percentage of CD44^highCD62L^low effector T cells while augmenting CD4⁺FoxP3⁺ Treg frequency in B6/gld mice. Importantly, PF increased TNFR2 expression on CD4⁺FoxP3⁺ Tregs, but not CD4⁺FoxP3^- T cells, in vivo and in vitro. Furthermore, we found that CD206⁺ subset of F4/80⁺CD11b⁺ macrophages expressed a higher level of mTNF-α than their CD206^- counterparts while PF increased mTNF-α expression on CD206⁺ macrophages in vitro and in vivo. In vitro studies showed that mTNF-α⁺ M2 macrophages were more potent in inducing Treg differentiation and proliferation than their mTNF-α^- counterparts, whereas the effects of mTNF-α⁺ M2 macrophages were largely reversed by separation of M2 macrophages using a transwell or TNFR2-blocking Ab in the culture. Finally, PF also promoted in vitro Treg generation induced by M2 macrophages. Thus, we demonstrated that mTNFα-TNFR2 interaction is a new mechanism responsible for Treg differentiation mediated by M2 macrophages. We provided the first evidence that PF may be used to treat lupus nephritis.

Protective Effect of the α7 Nicotinic Receptor Agonist PNU-282987 on Dopaminergic Neurons Against 6-Hydroxydopamine, Regulating Anti-neuroinflammatory and the Immune Balance Pathways in Rat

Neuroinflammation and inner immune dysfunction are increasingly accepted as important components of the etiopathogenesis of Parkinson’s disease (PD). According to emerging evidence, a7 nicotinic acetylcholine receptor (α7nAChR), a ligand-gated ion channel, plays an important role in inflammatory reactions and is also expressed on the surface of T cells. In particular, regulatory T cells (Tregs) are critical for the maintenance of immunological tolerance. In the present study, we investigated the roles of α7nAChR in inhibiting inflammation and maintaining the immune balance in rats with 6-hydroxydopamine (6-OHDA)-induced lesions and the possible mechanisms regulating the proportion of Tregs in vivo. Adult male Wistar rats (n = 90) were subjected to a unilateral injection of 6-OHDA into the left medial forebrain bundle, and PNU-282987, an α7nAChR agonist, was intraperitoneally injected 2 h prior to the induction of lesions by 6-OHDA and again at days 1, 7, and 13 postlesion. Behavioral tests and immunohistochemical staining to detect the expression of tyrosine hydroxylase (TH) in the bilateral substantial nigra (SN) were performed. Subsequently, CD4+ T lymphocytes and the expression of forkhead/winged helix transcription factor p3 (Foxp3, which is a marker of Treg cells) in the SN were also assessed using immunofluorescence staining. The expression of glial fibrillary acidic protein (GFAP) in the SN was determined by performing immunohistochemical staining. Additionally, the protein levels of α7nAChR, extracellular signal-regulated kinase (Erk) phosphorylated-Erk (p-Erk) and Foxp3 in the ventral midbrain were determined using Western blotting, and the relative expression of the TNF-α, IL-1β, and IL-10 mRNAs were detected using real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). We found that PNU-282987 significantly improved the motor deficits induced by 6-OHDA, reduced the loss of TH in the SN, suppressed the overactivation of GFAP+ cells and expression of related inflammatory cytokines, and increased the number of Foxp3+ cells. In addition, we also showed that PNU-282987 significantly increased the protein expression of the a7nAchR, p-Erk, and Foxp3 in 6-OHDA-lesioned rats (p < 0.05). These results indicated that α7nAChR activation could exert an anti-inflammatory effect and participate in the process of modulating the immune balance during 6-OHDA-induced injury, potentially through the α7nAChR/p-Erk/Foxp3 signaling pathway.

Regulatory B cells in cancer

Tumorigenesis proceeds through discrete steps where acquisition of genetic lesions and changes in the surrounding microenvironment combine to drive unrestricted neoplastic proliferation and metastasis. The ability of tumor-infiltrating immune cells to promote tumor growth via the provision of signals that enable tumor cell survival and proliferation as well as contribute to immune suppression is an active area of research. Recent efforts have provided us with mechanistic insights into how B cells can positively and negatively regulate immune responses. Negative regulation of immune responses in cancer can be mediated by regulatory B cells and is often a result of increased production of cytokines that can directly and indirectly affect anti-tumor immune function and cancer cell growth. Signals that lead to the expansion of regulatory B cells and the spectrum of their functional roles are not well understood and are the subject of active research by many groups. Here, we elaborate broadly on the history of regulatory B cells in cancer and summarize recent studies that have established genetic models for the study of regulatory B cell function and their potential for therapeutic intervention in the setting of solid cancers.

Vitamin D Insufficiency is Not Associated With Pediatric and Adolescent Immune Thrombocytopenia: A Study in Conjunction With its Receptor Genetic Polymorphisms

Idiopathic thrombocytopenic purpura (ITP) is a heterogeneous immunologic disorder. Vitamin D has immune-modulatory effects. The pleiotropic effects of vitamin D are exerted via vitamin D receptor (VDR) and its genetic alterations could influence its functions. In our study, we measured the serum 25-hydroxyvitamin D levels in 98 Pediatric and Adolescent ITP patients, in addition to 100 apparently healthy controls. Genetic polymorphisms of the VDR gene FokI, BsmI, ApaI, and TaqI were tested using specific restriction enzymes for each polymorphism. Vitamin D deficiency in the studied Pediatric age was a dominant factor, but it was found not to be associated with Pediatric ITP. However, patients carrying the FokI CC genotype had statistically higher vitamin D levels compared with those carrying other genotypes (P=0.036). Patients who were carriers of the BsmI G allele had a nearly 2-fold higher risk of ITP (odds ratio: 2.203; 95% confidence interval: 1.467-3.309). Therefore, the BsmI polymorphism of VDR could be considered a molecular risk factor for ITP.

T Lymphocytes and Testicular Immunity: A New Insight into Immune Regulation in Testes

The immune privilege of the testes is necessary to prevent immune attacks to gamete-specific antigens and paternal major histocompatibility complex (MHC) antigens, allowing for normal spermatogenesis. However, infection and inflammation of the male genital tract can break the immune tolerance and represent a significant cause of male infertility. Different T cell subsets have been identified in mammalian testes, which may be involved in the maintenance of immune tolerance and pathogenic immune responses in testicular infection and inflammation. We reviewed the evidence in the published literature on different T subtypes (regulatory T cells, helper T cells, cytotoxic T cells, γδ T cells, and natural killer T cells) in human and animal testes that support their regulatory roles in infertility and the orchitis pathology. While many in vitro studies have indicated the regulation potential of functional T cell subsets and their possible interaction with Sertoli cells, Leydig cells, and spermatogenesis, both under physiological and pathological processes, there have been no in situ studies to date. Nevertheless, the normal distribution and function of T cell subsets are essential for the immune privilege of the testes and intact spermatogenesis, and T cell-mediated immune response drives testicular inflammation. The distinct function of different T cell subsets in testicular homeostasis and the orchitis pathology suggests a considerable potential of targeting specific T cell subsets for therapies targeting chronic orchitis and immune infertility.

Menopausal factors and risk of seropositive rheumatoid arthritis in postmenopausal women: a nationwide cohort study of 1.36 million women

In previous literature regarding development of rheumatoid arthritis (RA), female reproductive factors have been described as protective factors, risk factors, or irrelevant, leading to inconsistent results. The aim of this study was to investigate the effect of female reproductive factors on the incidence of seropositive RA. A large population-based retrospective cohort of the National Health Insurance Service data in South Korea was used. Postmenopausal women who participated in both cardiovascular and breast cancer screening in 2009 were included and followed until date of seropositive RA diagnosis, death, or December 31, 2018. Multivariable-adjusted Cox proportional hazards model was used to assess the association between reproductive factors and incident seropositive RA. Of 1,357,736 postmenopausal women, 6056 women were diagnosed with seropositive RA, and the incidence rate was 54.16 cases/100,000 person-years. Reproductive factors other than hormone replacement therapy (HRT) were not significantly associated with seropositive RA incidence. Postmenopausal women who used HRT ≥ 5 years were associated with a higher aHR of incident seropositive RA than never-users (aHR 1.25; 95% CI 1.09–1.44). Alcohol consumption less than 30 g per day (aHR 0.80; 95% CI 0.74–0.87), regular physical activity (aHR 0.90; 95% CI 0.84–0.97), diabetes mellitus (aHR 0.85; 95% CI 0.78–0.93), and cancer (aHR 0.77; 95% CI 0.64–0.92) were associated with lower risk of seropositive RA. Most female reproductive factors did not significantly affect the development of seropositive RA in postmenopausal women. Only HRT is associated with a small but significant increase in risk of seropositive RA.

Vitamin D: does it help Tregs in active rheumatoid arthritis patients

Background Regulatory T cells (Tregs) play an important role in the maintenance of immunological tolerance. Tregs deficiency or suppressor functions reduction may be associated with autoimmune diseases development. Objectives To estimate the effect of vitamin D supplementation on Tregs level in the peripheral blood of active rheumatoid arthritis (RA) patients. Methods 40 active RA patients were randomly assigned into two groups. Group I received methotrexate (MTX) plus hydroxychloroquine, group II received MTX, hydroxychloroquine plus vitamin D supplementation for 3 months, and 30 healthy volunteers as control group. Peripheral blood Tregs were measured at baseline and after 3 months by Flow Cytometry. Results At baseline, Tregs percentage was significantly decreased (p<0.001) in both RA patient groups (13.52±1.95%, 13.65±2.98% respectively), compared to controls (28.44±7.37%) with no significant difference between the two patient groups (p=0.866). After 3 months, there was a significant elevation in Tregs percentage in group II compared to group I (p<0.001). Tregs elevation was associated with significant DAS-28 score reduction (p<0.001). Conclusion Vitamin D appears to have important immunomodulatory functions. Vitamin D supplementation can be combined safely with traditional DMARDs to regulate the immune system. Clinical trial registration Tanta University Protocol Record 33846, Vitamin D Effect in Rheumatoid Arthritis, http://www.clinicaltrials.gov, NCT04472481.

DNMT1-mediated Foxp3 gene promoter hypermethylation involved in immune dysfunction caused by arsenic in human lymphocytes

Growing evidence indicates that arsenic can cause long-lasting and irreversible damage to the function of the human immune system. It is known that forkhead box protein 3(Foxp3), which is specifically expressed in regulatory T cells (Tregs), plays a decisive role in immunoregulation and is regulated by DNA methylation. While evidence suggests that epigenetic regulated Foxp3 is involved in the immune disorders caused by arsenic exposure, the specific mechanism remains unclear. In this study, after primary human lymphocytes were treated with different doses of NaAsO₂, our results showed that arsenic induced the high expression of DNMT1 and Foxp3 gene promoter methylation level, thereby inhibiting the expression levels of Foxp3, followed by decreasing Tregs and reducing related anti-inflammatory cytokines, such as interleukin 10 (IL-10) and interleukin 10 (IL-35), and increasing the ratio of CD4⁺/CD8⁺ T cells in lymphocytes. Treatment with DNA methyltransferase inhibitor 5-Aza-CdR can notably inhibit the expression of DNMT1, effectively restoring the hypermethylation of the Foxp3 promoter region in primary human lymphocytes and upregulating the expression levels of Foxp3, balancing the ratio of CD4⁺/CD8⁺ T cells in lymphocytes. It also activates the secretion of anti-inflammatory cytokines and restores the immune regulatory functions of Tregs. In conclusion, our study provides limited evidence that DNMT1-mediated Foxp3 gene promoter hypermethylation is involved in immune dysfunction caused by arsenic in primary human lymphocytes. The study can provide a scientific basis for further understanding the arsenic-induced immune dysfunction in primary human lymphocytes.

Comprehensive flow cytometric reference intervals of leukocyte subsets from six study centers across Europe

A group of European FOCIS Centers of Excellence adapted panels of the Human Immunophenotyping Consortium (HIPC) for whole blood analysis. Using four core panels [T/regulatory T cell/B/natural killer (T/T_reg/B/NK) and myeloid cells] the main leukocyte populations were analyzed in a clinical–diagnostic setting in a harmonized manner across different platforms. As a first step, the consortium presents here the absolute and relative frequencies of the leukocyte subpopulations in the peripheral blood of more than 300 healthy volunteers across six different European centers.

The multifaceted functional role of DNA methylation in immune-mediated rheumatic diseases

Genomic predisposition cannot explain the onset of complex diseases, as well illustrated by the largely incomplete concordance among monozygotic twins. Epigenetic mechanisms, including DNA methylation, chromatin remodelling and non-coding RNA, are considered to be the link between environmental stimuli and disease onset on a permissive genetic background in autoimmune and chronic inflammatory diseases. The paradigmatic cases of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjogren's syndrome (SjS) and type-1 diabetes (T1D) share the loss of immunological tolerance to self-antigen influenced by several factors, with a largely incomplete role of individual genomic susceptibility. The most widely investigated epigenetic mechanism is DNA methylation which is associated with gene silencing and is due to the binding of methyl-CpG binding domain (MBD)-containing proteins, such as MECP2, to 5-methylcytosine (5mC). Indeed, a causal relationship occurs between DNA methylation and transcription factors occupancy and recruitment at specific genomic locus. In most cases, the results obtained in different studies are controversial in terms of DNA methylation comparison while fascinating evidence comes from the comparison of the epigenome in clinically discordant monozygotic twins. In this manuscript, we will review the mechanisms of epigenetics and DNA methylation changes in specific immune-mediated rheumatic diseases to highlight remaining unmet needs and to identify possible shared mechanisms beyond different tissue involvements with common therapeutic opportunities. Key Points • DNA methylation has a crucial role in regulating and tuning the immune system. • Evidences suggest that dysregulation of DNA methylation is pivotal in the context of immune-mediated rheumatic diseases. • DNA methylation dysregulation in FOXP3 and interferons-related genes is shared within several autoimmune diseases. • DNA methylation is an attractive marker for diagnosis and therapy.

microRNAs: key modulators of disease-modifying therapies in multiple sclerosis

There is a high level of heterogeneity in symptom manifestations and response to disease-modifying therapies (DMTs) in multiple sclerosis (MS), an immune-based neurodegenerative disease with ever-increasing prevalence in recent decades. Because of unknown aspects of the etiopathology of MS and mechanism of action of DMTs, the reason for this variability is undetermined, and much remains to be understood. Traditionally, physicians consider switching to other DMTs based on the exacerbation of symptoms and/or change in the results of magnetic resonance imaging and biochemical factors. Therefore, identifying biological treatment response markers that help us recognizing non-responders rapidly and subsequently choosing another DMTs is necessary. microRNAs (miRNAs) are micromanagers of gene expression which have been profiled in different samples of MS patients, highlighting their role in pathogenetic of MS. Recent studies have investigated expression profiling of miRNAs after treatment with DMTs to clarify possible DMTs-mediated mechanism and obtaining response to therapy biomarkers. In this review, we will discuss the modulation of miRNAs by DMTs in cells and pathways involved in MS.

Regulation of T Cell Activities in Rheumatoid Arthritis by the Novel Fusion Protein IgD-Fc-Ig

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and T cell hyper-activation. Emerging evidence has shown that the stimulation of immunoglobulin D (IgD) induces T cell activation and may contribute to disease pathogenesis. In this study, the sIgD concentrations were positively associated with disease activity score in 28 joints (DAS28) and anti-cyclic citrullinated peptide (anti-CCP) in RA. We demonstrated that IgD-Fc-Ig (composed of human IgD Fc domain and IgG₁ Fc domain, obtained through prokaryotic protein expression and chromatography purification) effectively inhibited the activation and proliferation of T cells in healthy controls and PBMCs in RA patients stimulated by IgD, recovered the Th17/Treg cell subset balance, and downregulated p-Lck and p-ZAP70 expression. Moreover, in vivo, IgD-Fc-Ig decreased the swollen joint counts and arthritis indices in mice with collagen-induced arthritis (CIA), and ameliorated histopathological changes in joint and spleen tissue. It also downregulated thymocyte proliferation and reduced the percentage of helper T cells (Th) and CD154⁺ T cells, reversed the imbalance of Th1/Th2 and Th17/Treg cell subsets, reduced cytokine and chemokine levels, and inhibited p-Lck and p-ZAP70 expression. Our data suggest that IgD-Fc-Ig fusion protein regulates T cell activity in RA. These findings have potential implications for IgD-targeted strategies to treat IgD-associated RA.

Blunted Expansion of Regulatory T Lymphocytes Is Associated With Increased Bacterial Translocation in Patients With Major Depressive Disorder

Background: Major Depressive Disorder (MDD) is associated with both proinflammatory and adaptive immune response abnormalities. Regulatory T lymphocytes (Tregs), a subtype of CD4+ T cells, are relevant for maintaining immune-inflammatory system homeostasis and control of inflammation such as the kind potentially induced by the interactions between the intestinal microbiome and gut mucosa. We investigated the Treg population and its distribution along their stages of differentiation/activation, as well as its function in MDD patients without concomitant diseases. We also studied the potential association between Treg alterations, intestinal barrier damage, and bacterial translocation. Methods: 30 MDD patients and 20 healthy controls were studied. The levels of circulating CD25FoxP3⁺ Tregs and their distribution on the naïve (T_N), effector (T_E), central (T_CM), and effector memory(T_EM) differentiation/activation stages were analyzed using polychromatic flow cytometry. Chemokine receptors (CCR) 2, 5, and 6, and the intracytoplasmic IL-10 expression by the Tregs were also analyzed. The serum IL-10 was measured using Luminex. The serum levels of zonulin and the intestinal fatty acid-binding protein (I-FABP), both markers of gut barrier function, and the LPS-binding protein (LBP), a marker of bacterial translocation, were measured using an enzyme-linked immunosorbent assay. Results: MDD patients had increased number of circulating Tregs cells with enhanced number of Tregs at the T_N, T_E, T_CM, and T_EM stages. The percentage of Tregs cells at T_N stage was significantly higher in MDD patients. The percentage of Tregs that expressed CCR2 and CCR6 was increased as well as those expressing IL-10. MDD patients had significantly increased levels of circulating I-FABP and LBP. MDD patients with high LBP levels had a significant reduction in the number of circulating Tregs compared to normal-LBP MDD patients. Conclusions: MDD patients showed an expansion of circulating Tregs and their CD25^highFoxP3⁺ and CD25^lowFoxP3⁺ subsets throughout the different stages of CD4+ T lymphocyte differentiation/activation. Tregs also showed an increased frequency of cells expressing CCR6 and CCR2. IL-10 Treg production was also enhanced in MDD patients that concurrently had increased serum IL-10 levels. However, this Treg expansion was blunted in MDD patients with gut barrier damage and increased bacterial translocation.

Getting to the Heart of the Matter: The Role of Regulatory T-Cells (Tregs) in Cardiovascular Disease (CVD) and Atherosclerosis

Cardiovascular diseases (CVD) are the leading cause of mortality worldwide. Atherosclerosis is directly associated with CVD and is characterized by slow progressing inflammation which results in the deposition and accumulation of lipids beneath the endothelial layer in conductance and resistance arteries. Both chronic inflammation and disease progression have been associated with several risk factors, including but not limited to smoking, obesity, diabetes, genetic predisposition, hyperlipidemia, and hypertension. Currently, despite increasing incidence and significant expense on the healthcare system in both western and developing countries, there is no curative therapy for atherosclerosis. Instead patients rely on surgical intervention to avoid or revert vessel occlusion, and pharmacological management of the aforementioned risk factors. However, neither of these approaches completely resolve the underlying inflammatory environment which perpetuates the disease, nor do they result in plaque regression. As such, immunomodulation could provide a novel therapeutic option for atherosclerosis; shifting the balance from proatherogenic to athero-protective. Indeed, regulatory T-cells (Tregs), which constitute 5-10% of all CD4⁺ T lymphocytes in the peripheral blood, have been shown to be athero-protective and could function as new targets in both CVD and atherosclerosis. This review aims to give a comprehensive overview about the roles of Tregs in CVD, focusing on atherosclerosis.