CD4+CD25+LAG3+ T Cells With a Feature of Th17 Cells Associated With Systemic Lupus Erythematosus Disease Activity

Type I interferon blockade with anifrolumab in patients with systemic lupus erythematosus modulates key immunopathological pathways in a gene expression and proteomic analysis of two phase 3 trials

INTRODUCTION

Anifrolumab is a type I interferon (IFN) receptor 1 (IFNAR1) blocking antibody approved for treating patients with systemic lupus erythematosus (SLE). Here, we investigated the immunomodulatory mechanisms of anifrolumab using longitudinal transcriptomic and proteomic analyses of the 52-week, randomised, phase 3 TULIP-1 and TULIP-2 trials.

METHODS

Patients with moderate to severe SLE were enrolled in TULIP-1 and TULIP-2 and received intravenous anifrolumab or placebo alongside standard therapy. Whole-blood expression of 18 017 genes using genome-wide RNA sequencing (RNA-seq) (pooled TULIP; anifrolumab, n=244; placebo, n=258) and 184 plasma proteins using Olink and Simoa panels (TULIP-1; anifrolumab, n=124; placebo, n=132) were analysed. We compared treatment groups via gene set enrichment analysis using MetaBase pathway analysis, blood transcriptome modules, in silico deconvolution of RNA-seq and longitudinal linear mixed effect models for gene counts and protein levels.

RESULTS

Compared with placebo, anifrolumab modulated >2000 genes by week 24, with overlapping results at week 52, and 41 proteins by week 52. IFNAR1 blockade with anifrolumab downregulated multiple type I and II IFN-induced gene modules/pathways and type III IFN-λ protein levels, and impacted apoptosis-associated and neutrophil extracellular traps-(NET)osis-associated transcriptional pathways, innate cell activating chemokines and receptors, proinflammatory cytokines and B-cell activating cytokines. In silico deconvolution of RNA-seq data indicated an increase from baseline of mucosal-associated invariant and γδT cells and a decrease of monocytes following anifrolumab treatment.

DISCUSSION

Type I IFN blockade with anifrolumab modulated multiple inflammatory pathways downstream of type I IFN signalling, including apoptotic, innate and adaptive mechanisms that play key roles in SLE immunopathogenesis.

Human umbilical cord mesenchymal stem cell-derived exosomes alleviate the severity of experimental autoimmune encephalomyelitis and enhance lag-3 expression on foxp3 + CD4 + T cells

BACKGROUND

Multiple sclerosis (MS) is a complex autoimmune disease that affects the central nervous system, causing inflammation, demyelination, and neurodegeneration. Understanding the dysregulation of Tregs, dynamic cells involved in autoimmunity, is crucial in comprehending diseases like MS. However, the role of lymphocyte-activation gene 3 (Lag-3) in MS remains unclear.

METHODS

In this study, we explore the potential of exosomes derived from human umbilical cord mesenchymal stem cells (hUMSCs-Exs) as an immune modulator in experimental autoimmune encephalomyelitis (EAE), a model for MS.

RESULTS

Using flow cytometry, our research findings indicate that groups receiving treatment with hUMSC-Exs revealed a significant increase in Lag-3 expression on Foxp3 + CD4 + T cells. Furthermore, cell proliferation conducted on spleen tissue samples from EAE mice using the CFSE method exposed to hUMSC-Exs yielded relevant results.

CONCLUSIONS

These results suggest that hUMSCs-Exs could be a promising anti-inflammatory agent to regulate T-cell responses in EAE and other autoimmune diseases. However, further research is necessary to fully understand the underlying mechanisms and Lag-3's precise role in these conditions.

Soybean Agglutinin Alters the Gut Microbiota and Promotes Inflammation in Lupus-Prone MRL/lpr Mice

BACKGROUND

Certain foods can trigger flares in patients with systemic lupus erythematosus. Lectins in edible plants have been reported to increase inflammation.

OBJECTIVE

This study aimed to determine the effects of 1-time intake of soybean agglutinin (SBA) on the gut microbiota and immune response in lupus-prone MRL/MpJ (MRL)/lpr mice.

METHODS

MRL/MpJ-Faslpr/J (MRL/lpr) and MRL mice were randomly assigned into 4 groups (8 mice/group): MRL mice + phosphate-buffered saline (PBS) (CON), MRL mice + SBA (CS), MRL/lpr mice + PBS (LPR), and MRL/lpr + SBA (LS). PBS and SBA were orally administered at 16 wk of age, and all mice were killed 24 h after oral challenge. The disease phenotype, levels of proinflammatory cytokines, and composition of the intestinal microbiota were determined.

RESULTS

Interferon-gamma (IFN-γ) in the serum was significantly higher, whereas the level of serum IL-10 was significantly lower in LS mice than in LPR mice [fold change (FC) = 1.31 and FC = 0.36, respectively]. The expression levels of IL-6 and TNF-α in the spleen of LS mice were significantly higher than those in LPR mice (FC = 1.66 and FC = 1.96, respectively). The expression levels of IL-6, TNF-α, and IL-1β in the kidney were also significantly higher in LS mice than in LPR mice (FC = 2.89, FC = 3.78, and FC = 2.02, respectively). The relative abundances of Erysipelotrichaceae and Turicibacter in LS mice were significantly higher than those in LPR mice (FC = 1.73 and FC = 1.74, respectively). The percentage of Breg cells in the mesenteric lymph nodes was significantly lower in LS mice than in LPR mice (FC = 0.53) (P < 0.05). No change was found between SBA treatment or not in the control (MRL) mice.

CONCLUSIONS

One-time intake of SBA can promote the secretion of proinflammatory cytokines, downregulate Breg cells, and alter the intestinal flora in MRL/lpr mice within 24 h of oral challenge, which may contribute to exacerbation of lupus.

Similarity and difference between systemic lupus erythematosus and NZB/W F1 mice by multi-omics analysis

OBJECTIVES

Several animal disease models have been used to understand the mechanisms of systemic lupus erythematosus (SLE); however, the translation of findings from animals to humans has not been sufficiently examined in drug development. To confirm the validity of New Zealand black x New Zealand white (NZB/W) F1 mice as an SLE model, we extensively characterized SLE patients and NZB/W F1 mice by omics analysis.

METHODS

Peripheral blood from patients and mice and spleen and lymph node tissue from mice were analysed using cell subset analysis, cytokine panel assays, and transcriptome analysis.

RESULTS

CD4+ effector memory T cells, plasmablasts, and plasma cells were increased in both SLE patients and NZB/W F1 mice. Levels of tumor necrosis factor-α, interferon gamma induced protein-10, and B cell activating factor in plasma were significantly higher in SLE patients and NZB/W F1 mice than in their corresponding controls. Transcriptome analysis revealed an upregulation of genes involved in the interferon signalling pathway and T-cell exhaustion signalling pathway in both SLE patients and the mouse model. In contrast, death receptor signalling genes showed changes in the opposite direction between patients and mice.

CONCLUSION

NZB/W F1 mice are a generally suitable model of SLE for analysing the pathophysiology and treatment response of T/B cells and monocytes/macrophages and their secreted cytokines.

A Case of Cerebral Large-Vessel Vasculitis Concomitant Fahr Syndrome in Systemic Lupus Erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is a heterogenous, devastating autoimmune inflammatory disease with multiorgan involvement. A variety of neurological and psychiatric symptoms may be caused by nervous system involvement, termed neuropsychiatric systemic lupus erythematosus.

CASE REPORT

We describe a young man newly diagnosed with SLE who had a stroke as an initial symptom and was found to have cerebral large-vessel vasculitis and Fahr syndrome.

CONCLUSIONS

The novelties of this report are the extensive cerebral calcification demonstrated on head computerized tomography in a patient with SLE, and the depiction of an underlying vasculitis on high-resolution magnetic resonance vessel wall imaging. It is our aim to describe this atypical form of neuropsychiatric systemic lupus erythematosus onset and to make known the usefulness of the new magnetic resonance imaging techniques for the diagnosis of cerebral large-vessel vasculitis.

CD4+LAG3+T cells are decreased in SSc-ILD and affect fibroblast mesenchymal transition by TGF-β3

Pulmonary fibrosis frequently occurs in rheumatic conditions, particularly systemic sclerosis-associated interstitial lung disease (SSc-ILD). The pathology involves cell transformation into interstitial structures and collagen accumulation. CD4+LAG3+T cells, known for immune inhibition, are relevant in autoimmunity. This study investigates CD4+LAG3+T cells in SSc-ILD. Clinical analysis revealed a correlation between CD4+LAG3+T cells and interleukin-6 (IL-6) and erythrocyte sedimentation rate (ESR). Using primary human lung fibroblasts (pHLFs) and murine bone marrow-derived macrophages (BMDMs), we showed that CD4+LAG3+T cells secreted TGF-β3 inhibits TGF-β1-induced mesenchymal transformation, modulates cellular function, and reduces collagen release. In mouse models, CD4+LAG3+T cells exhibited potential in alleviating bleomycin-induced pulmonary fibrosis. This study emphasizes CD4+LAG3+T cells' therapeutic promise against fibrosis and proposes their role as biomarkers.

Bioinformatic analysis of immune-related transcriptome affected by IFIT1 gene in childhood systemic lupus erythematosus

Background

The interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) gene is strongly associated with disease activity index of childhood systemic lupus erythematosus (SLE). However, whether IFIT1-regulated gene expression is the molecular basis of the pathogenesis of SLE has not been fully investigated.

Methods

Dataset GSE11909 was used to analyze the expression profiles of IFIT1 gene in 103 SLE cases and 12 healthy individuals. Differentially expressed genes (DEGs)-affected by IFIT1 gene were screened between the case group and control group, followed by gene function analysis. The clinical diagnostic potential of the least absolute shrinkage and selection operator (LASSO) model, established based on the expression profiles of IFIT1 and IFIFT1-affected DEGs, was evaluated. Analysis of association between IFIFT1-affected DEGs and immune infiltration was performed.

Results

IFIT1 was highly expressed in childhood SLE patients. IFIT1 and IFIT1-affected DEGs showed the potential to serve as a diagnostic marker for childhood SLE with area under the curve (AUC) value of 0.947. Childhood SLE patients showed 826 upregulated DEGs and 4,111 downregulated DEGs compared to the control group. Among them, 208 upregulated DEGs and 214 downregulated DEGs were identified in the IFIT1-high group compared to the IFIT1-low group. The LASSO model for the diagnosis of childhood SLE involved 7 marker genes that were related to immune checkpoint and tertiary lymphoid structure in SLE.

Conclusions

Our results confirmed the clinical diagnostic potential of IFIT1 and IFIT1-affected genes in childhood SLE. Moreover, this study elucidated that IFIT1-induced changes in the transcriptome are involved in immune checkpoint and tertiary lymphoid structure in childhood.

The emerging role of T cells in pemphigus vulgaris: a systematic review

Pemphigus vulgaris is a potential life-threatening autoimmune bullous disorder. The significant role of autoreactive B cells in the pathogenesis of PV has been explained extensively by producing autoantibodies. Recently, attention has been directed toward the role of T cells in the pathogenesis of PV; in other words, the underlying etiology of PV depends on the interaction between T cells and B cells resulting in antibody secretion. Herein, we systematically review the current literature on the emerging role of T cells in PV. To perform this systematic review, an extensive search through EMBASE, PubMed, Scopus, and ISI databases was performed from 1976 through 2021. Articles investigating the function of T cell subgroups in the pathogenesis or treatment of pemphigus vulgaris were included and reviewed. It is evidenced that T cells play a pivotal role in PV pathogenesis. Th1 and Th2 dichotomy including Th1 suppression and Th2 elevation may induce antibody production against desmoglein in keratinocytes. Furthermore, increased level of Th17 and decreased level of regulatory T cells have been detected in PV patients. However, further studies on the exact role of γδ-T cells in PV are required in order to clarify the pathogenesis of PV. T cells and their subtypes can be involved in the pathogenesis of PV. Thus, they can be considered as tentative targets of novel therapies for PV.

From bench to bedside: targeting lymphocyte activation gene 3 as a therapeutic strategy for autoimmune diseases

BACKGROUND

Immune checkpoints negatively regulate immune response, thereby playing an important role in maintaining immune homeostasis. Substantial studies have confirmed that blockade or deficiency of immune checkpoint pathways contributes to the deterioration of autoimmune diseases. In this context, focusing on immune checkpoints might provide alternative strategies for the treatment of autoimmunity. Lymphocyte activation gene 3 (LAG3), as a member of immune checkpoint, is critical in regulating immune responses as manifested in multiple preclinical studies and clinical trials. Recent success of dual-blockade of LAG3 and programmed death-1 in melanoma also supports the notion that LAG3 is a crucial regulator in immune tolerance.

METHODS

We wrote this review article by searching the PubMed, Web of Science and Google Scholar databases.

CONCLUSION

In this review, we summarize the molecular structure and the action mechanisms of LAG3. Additionally, we highlight its roles in diverse autoimmune diseases and discuss how the manipulation of the LAG3 pathway can serve as a promising therapeutic strategy as well as its specific mechanism with the aim of filling the gaps from bench to bedside.

The relationship between soluble lymphocyte activation gene-3 and coronary artery disease

Background

Soluble lymphocyte activation gene 3 (sLAG3) may be used for diagnosis or prognosis in various diseases. However, the relationship between sLAG3 and coronary artery disease (CAD) are still unclear. This study aimed to investigate the levels of sLAG3 in patients with CAD, and its potential clinical association with the disease.

Methods

A total of 66 subjects (49 patients with CAD and 17 control subjects without CAD) were enrolled. The sLAG3 level was measured using enzyme-linked immunosorbent assay (ELISA) kits. Clinical variables included demographics, biochemical markers, coronary angiography status, and ejection fraction of the heart (EF) were collected, and Gensini scores were calculated. LAG3 gene data was extracted from three datasets (GSE23561, GSE61144, GSE60993) in Gene Expression Omnibus (GEO) to compare differential expression between CAD and control subjects.

Results

The sLAG3 level was significantly lower in the CAD vs. the controls (P < 0.05), and negatively associated with CAD [odds ratio (OR): 0.212, 95% confidential interval (CI): 0.060–0.746, P < 0.05]. Furthermore, the area under the curve (AUC) of sLAG3 level was significant (P < 0.05). The sLAG3 level in subjects with body mass index (BMI) ≥ 24 kg/m² was lower compared to those with BMI < 24 kg/m² (P < 0.05). The sLAG3 level was also negatively associated with BMI and diabetes mellitus (P < 0.05), though not associated with the Gensini scores or EF (P > 0.05). Lastly, the LAG3 gene expression in peripheral whole blood of patients with CAD were down-regulated compared to healthy controls (P < 0.05).

Conclusion

The sLAG3 level was negatively associated with the occurrence but not severity of CAD. Meanwhile, the sLAG3 was negatively associated with BMI and diabetes mellitus, suggesting the reduced sLAG3 might be a novel risk factor for developing CAD.

Nanotechnology-enabled immunoengineering approaches to advance therapeutic applications

Immunotherapy has reached clinical success in the last decade, with the emergence of new and effective treatments such as checkpoint blockade therapy and CAR T-cell therapy that have drastically improved patient outcomes. Still, these therapies can be improved to limit off-target effects, mitigate systemic toxicities, and increase overall efficacies. Nanoscale engineering offers strategies that enable researchers to attain these goals through the manipulation of immune cell functions, such as enhancing immunity against cancers and pathogens, controlling the site of immune response, and promoting tolerance via the delivery of small molecule drugs or biologics. By tuning the properties of the nanomaterials, such as size, shape, charge, and surface chemistry, different types of immune cells can be targeted and engineered, such as dendritic cells for immunization, or T cells for promoting adaptive immunity. Researchers have come to better understand the critical role the immune system plays in the progression of pathologies besides cancer, and developing nanoengineering approaches that seek to harness the potential of immune cell activities can lead to favorable outcomes for the treatment of injuries and diseases.

Lymphocyte activation gene-3 (LAG-3) regulatory T cells: An evolving biomarker for treatment response in autoimmune diseases

Regulatory T cells (Tregs) comprise a CD4⁺CD25⁺Foxp3⁺ T cell subset for maintaining immune tolerance, and their deficits and/or dysfunction are observed in autoimmune diseases. The lymphocyte activation gene 3 (LAG-3, also known as CD223), which is an immunoglobulin superfamily member expressed on peripheral immune cells, is recognized as an inhibitory regulator of Tregs. LAG-3⁺ T cells represent a novel protective Tregs subset that produces interleukin-10. Alterations in LAG-3⁺ Tregs have been reported in several autoimmune diseases, suggesting their potential pathogenic role. Recent studies have indicated that LAG-3⁺ Tregs may be associated not only with immunopathology but also with response to therapy in several autoimmune and autoinflammatory diseases, such as rheumatoid arthritis, psoriasis, psoriatic arthritis and others. We present a review of Tregs phenotypes and functions, with a focus on LAG-3⁺ Tregs, and discuss their potential role as biomarkers for treatment response in autoimmune diseases.

Efficacy and Safety of Iguratimod Supplement to the Standard Immunosuppressive Regimen in Highly Mismatched Renal Transplant Recipients: A Pilot Study

Iguratimod (IGU) can mitigate the symptoms of rheumatoid arthritis through its anti-inflammatory effects. The objective of this study was to investigate the clinical efficacy and safety of IGU in highly HLA-mismatched renal transplant recipients, in combination with standard immunosuppressive regimen. This pilot study was designed as an open-label, blank-control, randomized clinical trial on patients recruited from a single transplant center in China. Patients who met the inclusion criteria were randomized to the IGU (n=27) and blank control (n=27) groups. IGU was administrated with the conventional triple immunosuppressive protocol for 52 weeks after kidney transplantation. The incidence of biopsy-proven acute rejection rate was 14.8% (4/27) in the IGU group and 29.6% (8/27) in the control group, P = 0.19. The clinical rejection rate was also substantially reduced in the IGU group (3.7% vs. 18.5%, P = 0.08). De novo donor-specific antibody also showed a decline trend in the IGU group after 52 weeks. The graft function and incidence of adverse events were similar between the two groups. In addition, IGU intervention significantly decreased the number of NK cells throughout the follow-up. In conclusion, our study has shown the possibility that IGU could reduce the allograft rejection rate and de novo DSA with appreciable safety in combination with conventional immunosuppressants. Formal clinical trials were warranted based on current findings.

Bayesian Networks to Support Decision-Making for Immune-Checkpoint Blockade in Recurrent/Metastatic (R/M) Head and Neck Squamous Cell Carcinoma (HNSCC)

Simple Summary

Tumor therapy in many human malignancies, including head and neck cancer, is increasingly demanding due to advances in diagnostics and individualized treatments. Multidisciplinary tumor boards, especially molecular tumor boards, consider a great amount of information to find the optimal treatment decision. Clinical decision support systems can help in optimizing this complex decision-making process. We designed a digital patient model based on conditional probability algorithms as Bayesian networks to support the decision-making process regarding treatment with approved immunotherapeutic agents (Nivolumab and Pembrolizumab). The model is able to process relevant clinical information to recommend a certain immunotherapeutic agent based on literature, approval, and guidelines.

Abstract

New diagnostic methods and novel therapeutic agents spawn additional and heterogeneous information, leading to an increasingly complex decision-making process for optimal treatment of cancer. A great amount of information is collected in organ-specific multidisciplinary tumor boards (MDTBs). By considering the patient’s tumor properties, molecular pathological test results, and comorbidities, the MDTB has to consent an evidence-based treatment decision. Immunotherapies are increasingly important in today’s cancer treatment, resulting in detailed information that influences the decision-making process. Clinical decision support systems can facilitate a better understanding via processing of multiple datasets of oncological cases and molecular genetic information, potentially fostering transparency and comprehensibility of available information, eventually leading to an optimum treatment decision for the individual patient. We constructed a digital patient model based on Bayesian networks to combine the relevant patient-specific and molecular data with depended probabilities derived from pertinent studies and clinical guidelines to calculate treatment decisions in head and neck squamous cell carcinoma (HNSCC). In a validation analysis, the model can provide guidance within the growing subject of immunotherapy in HNSCC and, based on its ability to calculate reliable probabilities, facilitates estimation of suitable therapy options. We compared actual treatment decisions of 25 patients with the calculated recommendations of our model and found significant concordance (Cohen’s κ = 0.505, p = 0.009) and 84% accuracy.

Mesenchymal stromal cell mitochondrial transfer to human induced T-regulatory cells mediates FOXP3 stability

The key obstacle to clinical application of human inducible regulatory T cells (iTreg) as an adoptive cell therapy in autoimmune disorders is loss of FOXP3 expression in an inflammatory milieu. Here we report human iTreg co-cultured with bone marrow-derived mesenchymal stromal cells (MSCs) during short-term ex vivo expansion enhances the stability of iTreg FOXP3 expression and suppressive function in vitro and in vivo, and further that a key mechanism of action is MSC mitochondrial (mt) transfer via tunneling nanotubules (TNT). MSC mt transfer is driven by mitochondrial metabolic function (CD39/CD73 signaling) in proliferating iTreg and promotes iTreg expression of FOXP3 stabilizing factors BACH2 and SENP3. These results elucidate cellular and molecular mechanisms underlying human MSC mt transfer to proliferating cells. MSC mt transfer stabilizes FOXP3 expression in iTregs, thereby enhancing and sustaining their suppressive function in inflammatory conditions in vitro and in vivo.

Update on the cellular pathogenesis of lupus

PURPOSE OF REVIEW

Aberrations in the innate and in the adaptive arms of the immune system play both important roles in the initiation and progression of systemic lupus erythematosus (SLE). The aim of this study was to provide an update on the most recent findings on the cellular pathogenesis of SLE. Our overview focused particularly on results obtained over the last 18 months.

RECENT FINDINGS

Recent observations have provided an improved understanding of the importance of low-density granulocytes, a highly proinflammatory subset of neutrophils. We also highlighted in this work recent descriptions of the various cellular sources associated with the interferon signature. In addition, novel contributions have also developed our understanding of the potential importance of extrafollicular T-B-cell interactions in SLE pathogenesis. Finally, the role of recently described B and T-cell subsets, that is, atypical memory B cells, T-peripheral helper cells, and Th10 T cells, were also reviewed.

SUMMARY

Recent findings in the cellular pathogenesis of SLE give a deeper comprehension of previously described mechanisms which drive SLE pathogenesis and shed light on novel players in immune dysregulation that could help to identify potential therapeutic targets.

The Confounders of Cancer Immunotherapy: Roles of Lifestyle, Metabolic Disorders and Sociological Factors

Checkpoint blockade immunotherapy (CPI) is an effective treatment option for many types of cancers. Irrespective of its wide clinical implications, the overall efficacy remains unpredictable and even poor in certain pathologies such as breast cancer. Thus, it is imperative to understand the role of factors affecting its responsiveness. In this review, we provide an overview on the involvement of sociological factors, lifestyles and metabolic disorders in modulating the CPI response in patients from multiple malignancies. Lifestyle habits including exercise, and diet promoted therapeutic responsiveness while alcohol consumption mitigated the CPI effect by decreasing mutational burden and hampering antigen presentation by dendritic cells. Metabolic disorder such as obesity was recognized to enhance the PD-1 expression while diabetes and hypertension were consequences of CPI therapy rather than causes. Among the sociologic factors, sex and race positively influenced the CPI effectiveness on account of increased effector T cell activity and increased PD-1 expression while ageing impaired CPI responsiveness by decreasing functional T cell and increased toxicity. The combined effect of these factors was observed for obesity and gender, in which obese males had the most significant effect of CPI. Therefore these variables should be carefully considered before treating patients with CPI for optimal treatment outcome.

Functional inhibition of regulatory CD4+CD25+T cells in peripheral blood of patients with pemphigus vulgaris

BACKGROUND

Pemphigus vulgaris (PV) is a potentially life-threatening autoimmune bullous disease affecting the skin and mucous membranes. Its pathogenic mechanism is still not fully understood. Regulatory T cells (Tregs) have been reported to play a significant role in regulating immune homeostasis in autoimmune disorders, such as PV.

AIM

To investigate the potential role of Tregs in the immunopathogenesis of PV.

METHODS

We enrolled 15 patients with PV and 15 healthy controls (HCs). Peripheral blood samples were collected from all participants before treatment. This was followed by flow cytometric, real-time reverse transcription PCR, and in vitro inhibition-based functional assays to explore the immunopathogenesis of Tregs in PV.

RESULTS

Our results showed no statistically significant differences in total CD4+CD25+ cells and CD4+CD25^high cells. In addition, expression levels of FOXP3 mRNA and the corresponding FOXP3 protein remained unchanged in the patients with PV and the HCs. However, the in vitro suppressive activity of CD4+CD25+ T cells was impaired in patients with PV compared with HCs.

CONCLUSIONS

Our observations suggest that inhibition of suppressive activity of Treg cells may be involved in the pathogenesis of PV.

Emerging patterns of regulatory T cell function in tuberculosis

Tuberculosis (TB) is one of the top 10 causes of mortality worldwide from a single infectious agent and has significant implications for global health. A major hurdle in the development of effective TB vaccines and therapies is the absence of defined immune‐correlates of protection. In this context, the role of regulatory T cells (T_reg), which are essential for maintaining immune homeostasis, is even less understood. This review aims to address this knowledge gap by providing an overview of the emerging patterns of T_reg function in TB. Increasing evidence from studies, both in animal models of infection and TB patients, points to the fact the role of T_regs in TB is dependent on disease stage. While T_regs might expand and delay the appearance of protective responses in the early stages of infection, their role in the chronic phase perhaps is to counter‐regulate excessive inflammation. New data highlight that this important homeostatic role of T_regs in the chronic phase of TB may be compromised by the expansion of activated human leucocyte antigen D‐related (HLA‐DR)⁺CD4⁺ suppression‐resistant effector T cells. This review provides a comprehensive and critical analysis of the key features of T_reg cells in TB; highlights the importance of a balanced immune response as being important in TB and discusses the importance of probing not just T_reg frequency but also qualitative aspects of T_reg function as part of a comprehensive search for novel TB treatments.

The Expression of P2X7 Receptor on Th1, Th17, and Regulatory T Cells in Patients with Systemic Lupus Erythematosus or Rheumatoid Arthritis and Its Correlations with Active Disease

P2X7 receptor (P2X7R) is highly expressed on immune cells, triggering the release of cytokines and regulating autoimmune responses. To investigate P2X7R surface expression on T helper (Th) 1, Th17, and regulatory T (Treg) cells in patients with systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) and correlations with disease activity, 29 SLE and 29 RA patients and 18 healthy controls (HCs) were enrolled. We showed that SLE and RA patients had significantly higher levels of plasma cytokines (IFN-γ, IL-1β, IL-6, IL-17A, and IL-23), frequencies of Th1 and Th17 cells, and expression of P2X7R on Th1 and Th17 than HCs, and the Th17/Treg ratio was significantly increased, whereas Treg cell levels were significantly decreased. The Ca²⁺ influx increase following BzATP stimulation was significantly higher in CD4⁺PBMCs from SLE and RA patients than in HCs. Blood levels of shed P2X7R were increased in SLE and RA patients. Furthermore, 28-joint Disease Activity Score and SLE Disease Activity Index score showed negative correlations with Treg cell levels and positive correlations with Th17/Treg ratio and Th17 cell P2X7R expression. Interestingly, Th17 cell P2X7R expression was closely correlated with IL-1β, C-reactive protein, the erythrocyte sedimentation rate, anticyclic citrullinated peptide Abs, albumin, and C4. These data indicate that increased Th17 cell P2X7R expression is functionally and positively related to disease activity and some inflammatory mediators in SLE and RA patients, and P2X7R could be critical in promoting the Th17 immune response and contributing to the complex pathogenesis of SLE and RA.