Abnormalities of T cells in systemic lupus erythematosus: new insights in pathogenesis and therapeutic strategies

Dysregulation of T Follicular Helper and Regulatory Cells in IRF5-SLE Homozygous Risk Carriers and Systemic Lupus Erythematosus Patients

T follicular helper (Tfh) and T follicular regulatory cells (Tfr) are required for antibody production and are dysregulated in SLE. Genetic variants within or near interferon regulatory factor 5 (IRF5) are associated with SLE risk. We previously reported higher plasma cells and autoantibodies in healthy IRF5-SLE homozygous risk carriers. Here, we report the dysregulation of circulating Tfh and Tfr in both SLE patients and presymptomatic IRF5-SLE homozygous risk carriers.

The Role of M6A Modification in Autoimmunity: Emerging Mechanisms and Therapeutic Implications

N6-methyladenosine (m6A), a prevalent and essential RNA modification, serves a key function in driving autoimmune disease pathogenesis. By modulating immune cell development, activation, migration, and polarization, as well as inflammatory pathways, m6A is crucial in forming innate defenses and adaptive immunity. This article provides a comprehensive overview of m6A modification features and reveals how its dysregulation affects the intensity and persistence of immune responses, disrupts immune tolerance, exacerbates tissue damage, and promotes the development of autoimmunity. Specific examples include its contributions to systemic autoimmune disorders like lupus and rheumatoid arthritis, as well as conditions that targeting specific organs like multiple sclerosis and type 1 diabetes. Furthermore, this review explores the therapeutic promise of target m6A-related enzymes ("writers," "erasers," and "readers") and summarizes recent advances in intervention strategies. By focusing on the mechanistic and therapeutic implications of m6A modification, this review sheds light on its role as a promising tool for both diagnosis and treatment in autoimmune disorders, laying the foundation for advancements in customized medicine.

Dysregulated Intestinal Host-Microbe Interactions in Systemic Lupus Erythematosus: Insights from Patients and Mouse Models

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by chronic inflammation that affects multiple organs, with its prevalence varying by ethnicity. Intestinal dysbiosis has been observed in both SLE patients and murine models. Additionally, intestinal barrier impairment is thought to contribute to the ability of pathobionts to evade and breach immune defenses, resulting in antigen cross-reactivity, microbial translocation, subsequent immune activation, and, ultimately, multiple organ failure. Since the detailed mechanisms underlying these processes are difficult to examine using human samples, murine models are crucial. Various SLE murine models, including genetically modified spontaneous and inducible murine models, offer insights into pathobionts and how they dysregulate systemic immune systems. Furthermore, since microbial metabolites modulate systemic immune responses, bacteria and their metabolites can be targeted for treatment. Based on human and mouse research insights, this review examines how lupus pathobionts trigger intestinal and systemic immune dysregulation. Therapeutic approaches, such as fecal microbiota transplantation and dietary adjustments, show potential as cost-effective and safe methods for preventing and treating SLE. Understanding the complex interactions between the microbiota, host factors, and immune dysregulation is essential for developing novel, personalized therapies to tackle this multifaceted disease.

Multi-centered clinical validation demonstrating superior precision in lupus diagnosis: T cell autoantibodies and TC4d outperform conventional lupus erythematosus biomarkers

Introduction

T Cell autoantibodies, TIgG and TIgM, as well as the T Cell-bound complement protein fragment C4d (TC4d) are novel diagnostic biomarkers that have demonstrated high specificity and sensitivity for SLE. The present study aims to characterize the clinical performance characteristics of the emergent T Cell biomarkers in a multi-center clinical validation cohort.

Methods

A cohort of 400 adult patients enrolled across 3 academic and 2 community-based autoimmune rheumatic centers, comprised of 105 SLE patients, 173 patients with autoimmune rheumatic diseases (ARD), 83 apparently healthy volunteers (AHV) and 39 other (non-autoimmune) disease (OD) controls were tested for TC4d, TIgG, TIgM and an extensive autoantibody profile. Diagnostic specificity was assessed against the ARD, AHV and OD groups, individually. Semi-quantitative flow cytometry analysis included TIgG and TIgM autoantibodies, cell-bound complement activation products (CB-CAPs), TC4d, erythrocyte-bound C4d (EC4d) and B lymphocyte-bound C4d (BC4d). Conventional autoantibodies and soluble complement proteins, C3 and C4, were assessed by ELISA and immunoturbidimetry, respectively.

Results

ROC analysis distinguishing ANA-positive (ANA+) SLE (N = 91) from ARD, TIgG, BC4d and TC4d demonstrated AUC values 0.81, 0.80 and 0.79, respectively, outperforming anti-dsDNA (0.72), C3 (0.69), TIgM (0.67), C4 (0.66) and anti-Smith (0.61). A similar ranking of discriminatory power was observed in ROC analysis distinguishing ANA+ SLE vs. OD as well as ANA+ SLE vs. AHV. At 95% diagnostic specificity for SLE vs. AHV, the sensitivity (95% CI) of TC4d, TIgG and TIgM for SLE was 58.1% (48.1 - 67.7%), 31.4% (22.7 - 41.2%) and 29.5% (21.0 - 39.2%), respectively. The T Cell SLE biomarkers uniquely identified 19% (20/105) of SLE patients who were otherwise negative (serologically inactive) for conventional SLE autoantibodies and had normal serum complement levels. Among the serologically inactive SLE subset, the T Cell SLE biomarkers collectively identified 53% of subjects.

Conclusions

The novel SLE biomarkers TC4d, TIgG and TIgM consistently outperform conventional markers across multiple cohorts. Their integration enhances diagnostic sensitivity, especially in SLE-specific autoantibody negative patients with normal complement levels. When coupled with conventional biomarkers, these novel tests may enable earlier and more accurate SLE detection, leading to more timely diagnosis and treatment.

Identification of Three Distinct Subgroups in Antiphospholipid Syndrome: Implication for Sex Differences and Prognostic Outcomes from a Multicenter Study

Antiphospholipid syndrome (APS) is a heterogeneous autoimmune disease with persistent antiphospholipid antibodies. This study aimed to identify unrecognized APS subgroups from multicenter cohorts (n = 760, training: n = 415; validation: n = 345). Patients are stratified through unsupervised K-means clustering analysis. Prognostic outcomes are evaluated using Kaplan-Meier survival analyses. Proteomic analysis is conducted on primary APS patients (n = 36) and healthy controls (n = 12). Key molecule insulin-like growth factor 1 is validated using ELISA. Three clusters are identified. Cluster 1 (n = 320, 42.1%) is completely consisted of females (100%), with predominant occurrence of pregnancy morbidity (88.8%) but low incidences of thrombocytopenia (18.4%) and thrombosis (15.0%), and a favorable prognosis. Cluster 2 (n = 309, 40.7%) is predominantly female (99.4%) and characterized by high thrombosis (85.8%) and thrombocytopenia (46.6%), low pregnancy morbidity (13.6%), and poor prognosis. Cluster 3 (n = 131, 17.2%) is predominantly male (99.2%), exhibiting highest thrombosis (96.2%) and moderate thrombocytopenia (32.8%), with worst prognosis. Immunological and proteomic analyses clearly differentiated three clusters. This study reveals a distinct difference between obstetric and thrombotic APS, and a sex-based distinction within thrombotic APS. Three APS subgroups display unique clinical and molecular characteristics, and marked difference in prognostic outcomes.

Primary cutaneous Mycobacteria avium complex infection in a systemic lupus erythematosus patient: A case report and review

RATIONALE

Nontuberculous mycobacteria infection is becoming more and more common in clinical practice, while skin and soft tissue infection is an important part. The evaluation of the immune status of patients has certain reference value for diagnosis and treatment.

PATIENT CONCERNS

A 48-year-old woman developed an erythematosus nodule with purulent discharge on the right hip for 4 months. She had a history of systemic lupus erythematosus for more than 20 years, in stable control with prednisone 10 mg/d, azathioprine 50 mg/12 h, and hydroxychloroquine 200 mg/12 h. There was no trauma prior to the lesion.

DIAGNOSES

After excluding other sites involved, the patient was diagnosed as Mycobacterium avium primary cutaneous infection based on laboratory culture, biopsy, and sequencing techniques.

INTERVENTIONS

After surgical resection, a combination of oral azithromycin, rifampicin, and ethambutol hydrochloride was given.

OUTCOMES

The lesion healed after 4 months with no relapse.

LESSONS

Primary cutaneous nontuberculous mycobacteria infection should raise more attention in immunocompromised and even immunocompetent populations.

The Changes of Lymphocytes and Immune Molecules in Irradiated Mice by Different Doses of Radiation

ABSTRACT

The effects of different radiation doses on T and B lymphocyte functional subsets and the changes of immune cells and immune molecules were observed in mice at different times post-irradiation to provide a theoretical basis for the changes of immune cells affected by radiation. In this study, the changes of T and B immune cells and immune-related molecules were observed at 1, 3, 7, 14, and 21 d after single irradiation of 2 Gy, 4 Gy, and 6 Gy. The results showed that white blood cells (WBC), lymphocytes (LYMPH), and lymphocyte percentage (LYMPH%) in peripheral blood of mice were significantly reduced and reached the lowest point 3 d after irradiation. Flow cytometry results showed that the percentages of CD3+T and CD8+/CD3+T lymphocytes in spleen and thymus were significantly decreased, and the percentages of CD19+B lymphocytes in spleen and CD4+/CD3+T lymphocytes in thymus were also decreased. However, the percentages of splenic NK cells, CD4+/CD3+T cells, and CD4+/CD8+ ratios in spleen and thymus were increased. Most of the indicators fell to the lowest or highest point 3 d after irradiation, indicating that immune function was suppressed at this time. From 7 to 21 d after irradiation, most immune cells gradually recovered. Single irradiation of 2 Gy, 4 Gy, and 6 Gy increased the contents of IL-1β, IL-2, IL-6, IL-17, TNF-α, TGF-β, and IFN-γ in serum of mice and decreased the contents of anti-inflammatory factors IL-4 and IL-10. The serum levels of immunoglobulin IgA, IgG, IgM and complement C3, C4 were significantly increased after irradiation. Our study showed that a single dose of 2 Gy, 4 Gy, and 6 Gy induced immunosuppression in mice, and maximum immunosuppression was achieved 3 d after irradiation. At this time, CD19+B lymphocytes were the most sensitive, followed by CD3+T lymphocytes, and NK cells were the most resistant. The radiosensitivity of CD8+/CD3+T lymphocytes was slightly higher than that of CD4+/CD3+T lymphocytes.

Jieduquyuziyin prescription alleviates lupus development via inhibiting neddylation pathway to promote Bim-induced apoptosis of double negative T cells

ETHNOPHARMACOLOGICAL RELEVANCE

Jieduquyuziyin prescription (JP) is an empirical prescription approved for application to treat systemic lupus erythematosus (SLE) in hospital within China. Despite the prominent treatment effect of JP clinically, further investigation is imperative to explore its underlying mechanisms.

AIM OF THE STUDY

We aim to investigate the impact of JP on DN T cell apoptosis in the treatment of SLE and the specific regulation mechanisms.

MATERIALS AND METHODS

Firstly, female MRL/lpr mice were treated with JP and the therapeutic efficacy of JP was evaluated via skin lesions, lymphoid organ enlargement, accumulation of autoantibodies and renal function. Then, flow cytometer analysis was performed to evaluate the proportions and the apoptosis of T cell subpopulations. Based on the above results, double-negative (DN) T cells were subjected to proteomic with subsequent differential screening. The expression of Ube2m and Bim was further validated using real-time PCR and Western blot. Subsequently, DN T cells were incubated with JP-contained serum in vitro, and cell apoptosis was quantified using flow cytometry. Additionally, the expression levels of Ube2m, Bim and other associated proteins were also assessed through western blotting. To further clarify whether Ube2m serves as the key target of JP in regulating DN T cell apoptosis, the mice that Ube2m was specific deleted in T cells with spontaneous lupus (Ube2m-/-lpr) were utilized. JP was administered to WTlpr or Ube2m-/-lpr mice, followed by assessment of the lupus condition and DN T cell apoptosis.

RESULTS

JP administration effectively ameliorated the lupus phenotype. Then flow cytometry assay showed that JP treatment enhanced DN T cell apoptosis to reduce their accumulation and restored the immune homeostasis. Proteomic analysis revealed a significant inhibition of Ube2m for JP treatment, which is essential for maintaining homeostasis of DN T cells. Further experiments confirmed that JP treatment effectively downregulated the expression of Ube2m and subsequently upregulated the level of pro-apoptotic protein Bim with decreased Bim degradation. In vitro experiments also confirmed that JP-contained serum significantly facilitated DN T cell apoptosis and reduced DN T cell accumulation by inhibiting Ube2m expression. Furthermore, Ube2m-/-lpr mice were utilized and the impact of JP treatment on the apoptosis of DN T cells was found to be minimal in the absence of Ube2m. Mechanistic investigation reveals that JP exerts its effects by suppressing the expression of Ube2m, subsequently inhibiting CRL-dependent degradation of Bim, and ultimately promoting Bim-induced apoptosis in DN T cells. Furthermore, the blockade of Ube2m in T cells effectively prevents JP-induced apoptosis in DN T cells, underscoring Ube2m as one crucial therapeutic target of JP in mediating DN T cell apoptosis and managing SLE.

CONCLUSIONS

Our findings indicate that JP treatment effectively restores the homeostasis of DN T cells in SLE by inhibiting Ube2m expression, thereby reducing Bim ubiquitination degradation. This ultimately enhanced DN T cell apoptosis and alleviated lupus phenotype.

Unravelling the TCRβ repertoire: a key to unlocking the immunopathogenesis and precision medicine in SLE

OBJECTIVES

SLE is a multifaceted autoimmune disorder with a complex pathogenesis involving genetic, environmental and hormonal factors, which converge on immune dysregulation. The T cell receptor (TCR) repertoire's role in SLE has garnered significant interest due to its potential in both diagnostics and therapeutics. Our study aimed to delineate the variances in the TCRβ repertoire between patients with SLE and healthy individuals, correlating these differences with the severity and subtypes of SLE.

METHODS

We conducted an analysis of blood samples from 50 treatment-naive patients with SLE and 50 healthy donors, employing RNA extraction, high-throughput sequencing and subsequent bioinformatics analysis.

RESULTS

Our findings revealed significant alterations in TRBV and TRBJ gene usage frequencies, indicative of a skewed TCR repertoire in patients with SLE. Notably, nine hub TRBV genes were identified as potential biomarkers for SLE with high diagnostic accuracy. Furthermore, we observed a reduction in TCR diversity, characterised by a lower diversity 50 value and increased clonal expansion, which correlated with disease severity.

CONCLUSIONS

The TCRβ repertoire is significantly altered in SLE, with potential implications for diagnostics and therapeutics. The identified hub genes may serve as novel biomarkers for SLE, and the findings contribute to the understanding of the immunopathogenesis of the disease.

Mitochondria dysfunction: A trigger for cardiovascular diseases in systemic lupus erythematosus

Cardiovascular disease (CVD), including pericarditis, myocarditis, sudden cardiac death, coronary heart disease, and stroke, are leading contributors to morbidity and mortality in systemic lupus erythematosus (SLE) patients. Emerging evidence highlights mitochondrial dysfunction as a key driver of cardiovascular pathology in SLE, with impaired oxidative phosphorylation, altered membrane potential, and disrupted metabolic processes promoting oxidative stress, inflammatory activation, and endothelial dysfunction. This review critically examines mitochondrial contributions to CVD in SLE, comparing these mechanisms with those in non-SLE CVD to highlight SLE-specific mitochondrial vulnerabilities. Furthermore, we discuss preclinical and clinical findings supporting mitochondrial pathways as potential therapeutic targets, aiming to bridge gaps in current understanding and outline future research directions. By synthesizing current knowledge of mitochondrial dysregulation, this review proposes therapeutic strategies to improve cardiovascular outcomes and advance patient care in SLE.

Safety Profile of SARS-CoV-2 Vaccination in Patients with Lupus Nephritis: A Retrospective Study

Objectives: Vaccination against SARS-CoV-2 has been vital in alleviating the spread of the recent pandemic. We aimed to estimate the frequency and type of adverse events related to SARS-CoV-2 vaccine in patients with lupus nephritis (LN), and assess its impact, if any, on the risk of subsequent reactivation of nephritis. Methods: This was a retrospective, multicenter study which included patients with biopsy-proven LN, who had received at least one vaccine dose. Patients who ended up with end-stage kidney disease (ESKD) prior to vaccination or were diagnosed with LN after vaccination were excluded. Adverse events, systemic or local, COVID-19 outcomes (full recovery, death, or long COVID-19), outcome of LN (remission, refractory disease, relapse, ESKD or death), demographics, laboratory measurements, and immunosuppressive regimens were recorded. Results: Sixty-seven patients were included. The median age was 33 (20-46) years. Induction therapy for LN was administered to 92.5% of patients and 74.6% received maintenance therapy. Of these, 94.02% were in remission at vaccination. The BNT162b2 mRNA vaccine was administered in 97.01% of cases, with mild systemic adverse symptoms in 28.35% (myalgias 17.91%, headache 13.43%, arthralgias 13.43%, and fever 10.44%) and local adverse effects in 35.82% (pain 25.37%, swelling 13.43%). Overall, among patients in remission upon vaccination, two (3.17%) experienced a LN relapse within 5.75 (±0.25) months, while 75% of those with active disease at vaccination achieved remission within 21 (±2) months. Conclusions: SARS-CoV-2 vaccination appears safe for LN patients without serious adverse events occurring, and there is no significant impact in the clinical course of the disease.

The Mechanism of Immune Intervention by Iguratimod in Oral Lichen Planus Patients: An In Vitro Experimental Study

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated immune disease. Iguratimod (IGU) is a novel immunomodulatory agent for rheumatoid arthritis. No studies have been reported on the mechanism of IGU in the treatment of OLP, which deserves investigation.

METHODS

Samples were collected from two batches of non-erosive OLP, erosive OLP (EOLP) patients and healthy control subjects. In the first batch, the effects of IGU or the same volume of dimethyl sulfoxide (DMSO) on proliferation, apoptosis and migration of peripheral blood T lymphocytes (PBL T) were examined by CCK-8, flow cytometry and transwell assay respectively. The levels of IL-6, IL-17, TNF-α, TGF-β and IL-10 were measured by enzyme-linked immunosorbent assay. In the second batch, the percentages of Th17 and Treg cells were determined by flow cytometry in peripheral blood mononuclear cells after IGU or DMSO stimulation.

RESULTS

Compared with the control, IGU promoted apoptosis and inhibited migration, but had no significant effect on the proliferation of PBL T in OLP. IL-6, IL-17 and TNF-α were decreased in OLP. TGF-β and IL-10 showed an upward trend in the IGU-treated EOLP. IGU decreased Th17 in OLP and reduced Th17/Treg ratio in EOLP. The percentage of Treg cells showed an upregulated trend but the difference was not statistically significant.

CONCLUSION

IGU may intervene in the immune response of OLP by affecting functions of PBL T, improving the balance of Th17/Treg and regulating related cytokines.

Fine-tuning SLE treatment: the potential of selective TYK2 inhibition

In systemic lupus erythematosus (SLE), adaptive immunity is activated by the stimulation of innate immunity, leading to the development of autoreactive T cells and activation and differentiation of B cells. Cytokine signalling plays an essential role in the pathogenesis and progression of this disease. In particular, the differentiation and function of CD4+ T cell subsets, which play a central role in SLE pathology, are significantly altered by cytokine stimulation. Many cytokines transmit signals via the Janus-activated kinase (JAK)-STAT pathway, but there is no one-to-one correspondence between cytokine receptors and JAK/TYK2. Multiple cytokines activate JAK/TYK2, and multiple JAK/TYK2 molecules are simultaneously activated by a single cytokine. Therefore, the modulation of the JAK-STAT pathway has the potential to control immune responses in SLE. Although several JAK/TYK2 inhibitors are currently undergoing clinical trials, more selective drugs that can target cytokine signals according to the specific pathology of the disease are required. TYK2 inhibitors, which are involved in the signal transduction of type I interferon and interleukin-12/23 pathways and are linked to disease susceptibility genes in SLE, may have the potential to fine-tune the differentiation and function of immune cells, particularly CD4+ T cells.

HMGA1 influence on iron-induced cell death in Tfh cells of SLE patients

The autoimmune disorder known as Systemic Lupus Erythematosus (SLE) exhibits intricate features with abnormal immune responses leading to tissue injury. The generation of antibodies and the disruption of immune regulation heavily depend on the pivotal function of T follicular helper (Tfh) cells. Iron dysregulation is significant in autoimmune diseases, impacting immune cell function and disease progression. Our study investigates the role of the HMGA1/EZH2/STAT3/GPX4 axis in modulating Tfh cells and iron homeostasis in SLE. Abnormal Tfh cell populations in SLE patients demonstrate reduced susceptibility to iron-induced cell death, with HMGA1 identified as a key player in Tfh cell proliferation and sensitivity to iron-induced death. Experimental interventions reveal the inhibitory role of the HMGA1 axis in Tfh cells' susceptibility to iron-induced death, suggesting therapeutic avenues for SLE and related autoimmune disorders. Our study underscores the importance of iron homeostasis in autoimmune conditions, providing novel insights and treatment strategies for further research in this field.

Single-Cell Transcriptome Reveals the Heterogeneity of T Cells in Mice with Systemic Lupus Erythematosus and Neuronal Inflammation

Introduction

Systemic lupus erythematosus is a heterogeneous autoimmune disease. A burst of autoimmune reactions in various systems can lead to severe clinical conditions closely associated with mortality. T cells serve as mediators that drive the occurrence and maintenance of inflammatory processes.

Methods

In this work, we employed single-cell transcriptome sequencing (scRNA-seq) involving 27704 cells from the brain and spleen tissues of MRL/lpr mice and 25355 healthy controls from BALB/c mice to explore the heterogeneity of T cells and their migration from the spleen to the brain.

Results

We identified a distinct group of double-negative T cells in systemic lupus erythematosus (SLE) mice that significantly expressed Eomes and other specific markers. We used the analysis of pseudotime trajectory and enrichment to show that double-negative T cells in SLE mice are strongly associated with cellular senescence and exhaustion. Additionally, we focused on the interactions among DNT, astrocytes, and microglia in the mice brain. We observed greater expression of MDK-related ligand‒receptor pairs between astrocytes and double-negative T cells, indicating that MDK may be a therapeutic target for treating neuroinflammation in SLE.

Discussion

This research sheds light on the intricate dynamics of immune responses in mice with SLE, specifically highlighting the role of double-negative T cells and their connection to cellular senescence. The exploration of interactions between T cells, astrocytes, and microglia in the mice brain unveils potential avenues for therapeutic intervention, particularly in addressing neuronal inflammation in SLE.

Reduced TRIM expression correlates with anomalous CD4 T cell activation in systemic lupus Erythematosus and its clinical diagnostic potential

OBJECTIVE

This study seeks to elucidate the expression, function, and clinical relevance of the T cell receptor interacting molecule (TRIM) within circulating CD4+T cell subsets in systemic lupus erythematosus (SLE) patients.

METHODS

We assessed TRIM expression across distinct subpopulations of human peripheral blood mononuclear cells (PBMCs) through the analysis of publicly available single-cell RNA sequencing data. In addition, TRIM expression was investigated within CD4+T cell subsets of peripheral blood and spleens in mice. PBMCs were isolated from both SLE patients, healthy controls (HCs) and rheumatoid arthritis (RA) patients with subsequent measurement and comparative analysis of TRIM expression and functional molecules using flow cytometry. To gauge the clinical relevance of TRIM in SLE, correlation and ROC curve analyses were performed.

RESULTS

In both healthy humans and mice, TRIM was higher expressed within CD4+T cell subsets, especially in naive CD4+T cells. TRIM+ Tregs exhibited lower Helios+ cells and CD45RA-FoxP3hi cells percentages compared to TRIM- Treg cells. TRIM+T cells demonstrated reduced granzyme B and perforin secretion and increased IFN-γ secretion in comparison to TRIM- T cells. Notably, the proportion of TRIM+CD4+T cells was diminished in SLE patients. The downregulation of TRIM+ in CD4+T cells positively correlated with diminished complement C3 and C1q levels and inversely correlated with CRP. The identification of TRIM-associated CD4 T cell subsets aids in distinguishing SLE patients from HCs and those with RA.

CONCLUSIONS

Reduced TRIM expression is linked to abnormal CD4+T cell activation in SLE. TRIM-associated CD4+T cells may be implicated in the pathogenesis of SLE and hold potential for clinical diagnostic purposes.

Double-Negative T Cells Promote Liver Fibrosis Progression by Regulating Treg/Th17

We investigated the mechanism whereby double-negative T cells (DNTs) regulate Treg/Th17 balance to promote the progression of liver fibrosis. Liver fibrosis was induced with carbon tetrachloride (CCl4) in mice. Mouse DNTs were isolated, amplified and injected. The proportions of iTreg (CDF4+CD25+Foxp3+) and Th17 (CD4+IL-17A+) in peripheral mononuclear cells, spleen and liver were analyzed by flow cytometry, and the cytokine levels were determined through enzyme-linked immunosorbent assay (ELISA). DNTs could promote the Th17 differentiation and inhibit the iTreg differentiation. The role of DNTs in promoting liver fibrosis progression and tissue inflammation was exerted through activation of IκBa. The use of IL-17A monoclonal antibody enabled suppression of the DNTs effects, reduction of the Th17 proportion and alleviation of liver fibrosis. Hal could suppress the Th17 differentiation and the effect of DNTs. DNTs can promote the Th17 differentiation through IL-17A and inhibit iTreg differentiation, thereby facilitating the liver fibrosis progression and microenvironmental inflammation. DNTs are a kind of important immunocytes that promote the liver fibrosis progression.

CMPK2 Promotes CD4+ T Cell Activation and Apoptosis through Modulation of Mitochondrial Dysfunction in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterized by abnormal autoantibodies, immune complex deposition, and tissue inflammation. Despite extensive research, the exact etiology and progression of SLE remain elusive. Cytidine/uridine monophosphate kinase 2 (CMPK2), a mitochondrial nucleoside monophosphate kinase, has garnered attention for its potential involvement in the development of various diseases, including SLE, where it has been observed to be dysregulated in affected individuals. However, the specific involvement of CMPK2 in the pathogenesis of SLE remains unclear. This study aims to clarify the expression level of CMPK2 in SLE CD4+ T cells and explore its impact on CD4+ T cells. The expression levels of the CMPK2 gene and the corresponding CMPK2 protein in CD4+ T cells of SLE patients were quantified using RT-qPCR and Western blot, respectively. Immunofluorescence and RT-qPCR were used to assess the mitochondrial function of SLE CD4+ T cells. Flow cytometry was used to assess CD4+ T cell activation and apoptosis levels. The impact of CMPK2 on CD4+ T cells was investigated by gene transfection experiment. We found that CMPK2 was significantly upregulated in SLE CD4+ T cells at both gene and protein levels. These cells demonstrated aberrant mitochondrial function, as evidenced by elevated mitochondrial reactive oxygen species (mtROS) levels, mitochondrial membrane potential, and mitochondrial DNA (mtDNA) copy number. Flow cytometry revealed a notable increase in both apoptosis and activation levels of CD4+ T cells in SLE patients. Gene transfection experiments showed that suppressing CMPK2 led to a significant improvement in these conditions. These findings suggest that CMPK2 may be involved in the pathogenesis of SLE by regulating mitochondrial dysfunction in CD4+ T cells and thus affecting CD4+ T cell activation and apoptosis. Our study may provide a new target for the treatment of SLE.

Semaphorin 5A promotes Th17 differentiation via PI3K-Akt-mTOR in systemic lupus erythematosus

BACKGROUND

Previously, we reported that serum Semaphorin 5 A (Sema5A) levels were increased in systemic lupus erythematosus (SLE) patients compared with healthy controls (HC), and elevated Sema5A correlated with disease activity and lupus nephritis in SLE patients. In this study, we aimed to further understand the role of Sema5A in promoting Th17 cells differentiation in SLE.

METHODS

Sema5A, interferon gamma (IFN-γ), interleukin 4 (IL-4), interleukin 17 A (IL-17 A) and interleukin 10 (IL-10) were measured by Enzyme Linked Immunosorbent Assay (ELISA). RNA and protein were isolated from peripheral blood mononuclear cells (PBMCs) in SLE patients and HC. Expression of PlexinA1 and PlexinB3 were measured by quantitative RT-PCR (qRT-PCR) and Western Blot. Th cell subsets were detected by flow cytometry. Treatment with recombinant human Sema5A (rhSema5A) and small interfering RNA (siRNA) were employed to examine the in vitro effect of Sema5A in CD4+T cell differentiation in SLE patients.

RESULTS

IL-17 A elevated in SLE patients and positively correlated with Sema5A. PlexinA1 was upregulated and mainly expressed in CD4+ T cells of SLE; Sema5A treatment induced the differentiation of Th17 cells, while did not affect the Th1 and Th2 skewing. These effects were associated with an upregulation of the transcription factor RORγt by Th17 cells, but not T-bet or GATA3 in Th1 and Th2 cells, respectively. Knock down PlexinA1 regulates IL-17 A production by CD4+T cells. Functional assays showed that Sema5A-PlexinA1 axis promoted Th17 cells differentiation via PI3K/Akt/mTOR signaling.

CONCLUSIONS

These findings demonstrated that Sema5A-PlexinA1 axis acts as a key mediator on Th17 differentiation, suggesting that Sema5A might be a novel therapeutic target in SLE.

2D4, a humanized monoclonal antibody targeting CD132, is a promising treatment for systemic lupus erythematosus

Current therapies for systemic lupus erythematosus that target a particular factor or cell type exhibit limited effectiveness. To address this limitation, our focus was on CD132, a subunit common to six inflammatory factor receptors implicated in SLE. Our study revealed heightened CD132 expression in SLE patients' lymphocytes, contributing to the production of pro-inflammatory cytokines and immunoglobulins. We developed a novel humanized anti-CD132 monoclonal antibody, named as 2D4. 2D4 efficiently blocked IL-21 and IL-15, with limited effectiveness against IL-2, thereby suppressing T and B cells without disrupting immune tolerance. In the mouse immunization model, 2D4 virtually inhibited T cell-dependent, antigen-specific B-cell response. In lupus murine models, 2D4 mitigated inflammation by suppressing multiple pro-inflammatory cytokines and anti-dsDNA antibody titers, also diminishing proteinuria and glomerulonephritis. Compared to Belimumab, 2D4 exhibited superior efficacy in ameliorating the inflammatory state and preserving renal function. Moreover, 2D4 exhibited the ability to inhibit the production of pro-inflammatory factors and autoantibodies in PBMCs from individuals with SLE, highlighting its therapeutic potential for SLE individuals. Potent, 2D4 has the potential to significantly improve clinical outcomes in SLE and other complex autoimmune disorders.

In vitro silencing of RIP2 in naive CD4+ T cells from lupus-prone mice promotes pathogenic Th17 cell differentiation

OBJECTIVE

This work aims to investigate whether RIP2 silencing in naive CD4+ T cells from lupus-prone mice impacts Th17 cell activity or differentiation in vitro.

METHODS

Naive CD4+ T cells isolation from MRL/lpr mice's spleens. Three RNA interference target sequences of RIP2 were packaged with lentivirus and transfected into naive CD4+ T cells. The shRIP2 with the highest interference efficiency was selected and transfected into naive CD4+ T cells. Naive CD4+ T cells were cultured under conventional (TGF-β1 and IL-6) and pathogenic (IL-6, IL-23, IL-1β) differentiation environments, respectively. Then, RT-qPCR, Western blot or Flow Cytometry were used for measuring the amounts of RIP2 and IL-17 and the differentiation of Th17 cells in two settings.

RESULTS

Under the conventional Th17 (cTh17) cell differentiation environment (TGF-β1 and IL-6), RIP2 deficiency is linked to decreased IL-17A levels (1.00 ± 0.03 vs 0.80 ± 0.03) and attenuated cTh17 cell (2.46 ± 0.08 vs 0.78 ± 0.03) differentiation (all, P < 0.05). Under the pathogenic Th17 (pTh17) cell environment (IL-1β, IL-23, IL-6), RIP2 deficiency is linked to elevated IL-17A levels (1.03 ± 0.05 vs 1.63 ± 0.07) and enhanced pTh17 cell (3.69 ± 0.19 vs 5.49 ± 0.10) differentiation (all, P < 0.05).

CONCLUSION

Our data suggest that RIP2 inhibition induces preferential differentiation of naive CD4+ T cells to pathogenic Th17 cells, while being able to upregulate IL-17A levels in the context of pTh17 cell differentiation. Our study opens up new research areas to reveal the underlying mechanisms and potential therapeutic targets for the prevention and treatment of SLE patients. Key Points • Silencing of RIP2 in naive CD4+ T cells from lupus-prone mice promotes pathogenic Th17 (pTh17) cell differentiation and IL-17A production under pTh17 cell (IL-1β, IL-23, and IL-6) conditions. • RIP2 deficiency in naive CD4+ T cells reduces conventional Th17 (cTh17) cell differentiation and IL-17A production under cTh17 cell (TGF-β1 and IL-6) conditions. • RIP2-deficient naive CD4+ T cells preferentially differentiate towards pTh17 cells rather than cTh17 cells in vitro. • Inhibition of RIP2 may be involved in the development of SLE via effects on Th17/IL-17.

Circ-CAMTA1 regulated by Ca2+ influx inhibited pyruvate carboxylase activity and modulate T cell function in patients with systemic lupus erythematosus

OBJECTIVES

To investigate the roles of Ca2+ influx-regulated circular RNAs (circRNAs) in T cells from patients with systemic lupus erythematosus (SLE).

METHODS

The expression profile of circRNAs in Jurkat cells, co-cultured with and without ionomycin, was analyzed by next-generation sequencing and validated using real-time polymerase chain reaction. The identified Ca2+ influx-regulated circRNAs were further examined in T cells from 42 patients with SLE and 23 healthy controls. The biological function of specific circRNA was investigated using transfection and RNA pull-down assay.

RESULTS

After validation, we confirmed that the expression levels of circ-ERCC4, circ-NFATC2, circ-MYH10, circ-CAMTA1, circ-ASH1L, circ-SOCS7, and circ-ASAP1 were consistently increased in Jurkat cells following Ca2+ influx. The expression levels of circ-CAMTA1, circ-ASH1L, and circ-ASAP1 were significantly lower in T cells from patients with SLE, with even lower levels observed in those with higher disease activity. Interferon (IFN)-α was found to suppress the expression of circ-CAMTA1. Circ-CAMTA1 bound to pyruvate carboxylase and inhibited its biological activity. Overexpression of circ-CAMTA1, but not its linear form, significantly decreased extracellular glucose levels. Furthermore, increased expression of circ-CAMTA1, but not its linear form, decreased miR-181c-5p expression, resulting increased IL-2 secretion.

CONCLUSION

Three Ca2+ influx-regulated circ-RNAs-circ-CAMTA1, circ-ASH1L, and circ-ASAP1 -were significantly reduced in T cells from patients with SLE and associated with disease activity. IFN-α suppressed the expression of circ-CAMTA1, which interacted with pyruvate carboxylase, inhibited its activity, affected glucose metabolism, and increased IL-2 secretion. These findings suggest that circ-CAMTA1 regulated by Ca²⁺ influx modulated T cell function in patients with SLE.

How Co-Stimulatory/Inhibitory Molecules Vary Across Immune Cell Subtypes in the Severity of Systemic Lupus Erythematosus Compared to Controls

BACKGROUND

Co-stimulatory and co-inhibitory molecules are critical to T cell responses and involved in the pathogenesis of systemic lupus erythematosus (SLE). This study aimed to comprehensively analyze the surface expression of these molecules in various phenotypic immune cells, comparing the differences between various levels of the severity in SLE and control groups.

METHODS

Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque from blood samples of severe SLE patients (treatment with immunosuppressants), mild SLE patients (excluding those with persistent proteinuria or thrombocytopenia), and healthy controls (n = 10 each). PBMCs were stimulated for 48 h. The cells were stained with anti-CD3, CD4, CD28, PD-1, and CTLA-4 antibodies and analyzed by flow cytometry. Differences between groups were assessed using the Kruskal-Wallis test and Mann-Whitney U-test, with median values and statistical significance (p < 0.05) reported.

RESULTS

The results showed that CD28 expression was significantly higher in SLE patients compared to controls, with the highest levels in mild SLE. However, CD3+ CD28+ and CD4+ CD28+ cells were more prevalent in controls (p = 0.032 and 0.017, respectively). Mild SLE patients exhibited the highest CTLA-4 expression, with significant differences from severe SLE and controls (p = 0.030 and 0.037, respectively). PD-1 expression was lowest in severe SLE but highest in mild SLE within CD3+ CD4+ cells (p = 0.001). After 48 h of activation, CD4+ CTLA4+ and CD3+ CTLA4+ expression levels were significantly higher in controls compared to SLE groups.

CONCLUSIONS

Our study highlighted that the expression of CD28, CTLA-4, and PD-1 in lymphocytes and specific T cell subsets was various according the severity of SLE in patients, underscoring their roles in disease pathogenesis.

Lymphocytes Change Their Phenotype and Function in Systemic Lupus Erythematosus and Lupus Nephritis

Systemic lupus erythematosus (SLE) is a complex autoimmune disease, characterized by considerable changes in peripheral lymphocyte structure and function, that plays a critical role in commencing and reviving the inflammatory and immune signaling pathways. In healthy individuals, B lymphocytes have a major role in guiding and directing defense mechanisms against pathogens. Certain changes in B lymphocyte phenotype, including alterations in surface and endosomal receptors, occur in the presence of SLE and lead to dysregulation of peripheral B lymphocyte subpopulations. Functional changes are characterized by loss of self-tolerance, intra- and extrafollicular activation, and increased cytokine and autoantibody production. T lymphocytes seem to have a supporting, rather than a leading, role in the disease pathogenesis. Substantial aberrations in peripheral T lymphocyte subsets are evident, and include a reduction of cytotoxic, regulatory, and advanced differentiated subtypes, together with an increase of activated and autoreactive forms and abnormalities in follicular T cells. Up-regulated subpopulations, such as central and effector memory T cells, produce pre-inflammatory cytokines, activate B lymphocytes, and stimulate cell signaling pathways. This review explores the pivotal roles of B and T lymphocytes in the pathogenesis of SLE and Lupus Nephritis, emphasizing the multifaceted mechanisms and interactions and their phenotypic and functional dysregulations.

Dynamics of CD4+ and CD8+ Lymphocytic Inflammatory Infiltrates in Lupus Nephritis

Lupus nephritis (LN) is a common clinical manifestation of systemic lupus erythematosus (SLE). Our study aims to quantitatively analyze CD4+ and CD8+ lymphocytes in different areas and LN classes and describe a specific distribution pattern that is correlated with the severity of LN-specific lesions. In total, 53 LN renal biopsies were immunohistochemically investigated using anti-CD4 and anti-CD8 antibodies. T lymphocytes were counted in 3 areas, including intraglomerular, periglomerular, and interstitial regions. The severity of glomerular and tubulo-interstitial lesions was assessed using an original semi-quantitative algorithm based on the renal corpuscle score (RC_S) and the tubulo-interstitial score (TI_S). The number of CD8+ T lymphocytes was higher than that of CD4+ T lymphocytes in each of the three areas and in each LN class, showing statistically significant differences. ANOVA analysis of all LN classes showed significant differences between periglomerular and interstitial CD4+ and CD8+ T lymphocytes, respectively. Irrespective of location, the number of CD8+ T lymphocytes statistically correlates with the RC_S and the TI_S; no significant correlations were found between the number of CD4+ T lymphocytes and the RC_S and the TI_S for all three considered areas. Our data provide strong evidence supporting the major role of CD8+ lymphocytes in LN lesion progression, with CD4+ lymphocytes playing a limited role.

Tissue Kallikrein-1 Suppresses Type I Interferon Responses and Reduces Depressive-Like Behavior in the MRL/lpr Lupus-Prone Mouse Model

Excessive production and response to Type I interferons (IFNs) is a hallmark of systemic lupus erythematosus (SLE). Neuropsychiatric lupus (NPSLE) is a common manifestation of human SLE, with major depression as the most common presentation. Clinical studies have demonstrated that IFNα can cause depressive symptoms. We have shown that the kallikrein-kinin system (KKS) [comprised of kallikreins (Klks) and bradykinins] and angiotensin-converting enzyme inhibitors suppressed Type I IFN responses in dendritic cells from lupus-prone mice and human peripheral blood mononuclear cells. Tissue Klk genes are decreased in patients with lupus, and giving exogenous Klk1 ameliorated kidney pathology in mice. We retro-orbitally administered mouse klk1 gene-carrying adenovirus in the Murphy Roths Large lymphoproliferative (MRL/lpr) lupus-prone mice at early disease onset and analyzed immune responses and depressive-like behavior. Klk1 improved depressive-like behavior, suppressed interferon-responsive genes and neuroinflammation, and reduced plasma IFNα levels and proinflammatory cytokines. Klk1 also reduced IFNAR1 and JAK1 protein expression, important upstream molecules in Type I IFN signaling. Klk1 reduced bradykinin B1 receptor expression, which is known to induce proinflammatory response. Together, these findings suggest that Klk1 may be a potential therapeutic candidate to control IFNα production/responses and other inflammatory responses in SLE and NPSLE.

Promising roles of combined therapy based on immune response and iron metabolism in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an intricate autoimmune disease with diverse manifestations. Immunometabolism reprogramming contributes to the progression of SLE by regulating the phenotype and function of immune cells. Dysregulated iron metabolism is implicated in SLE pathogenesis, affecting both systemic and immune cell-specific iron homeostasis. This review explores the systemic and cellular iron handling and regulation. Additionally, the advancements regarding iron metabolism in SLE with a focus on the distinct subsets of immune cells are highlighted. By gaining insight into the interplay between iron dysregulation and immune dysfunction, the potential therapeutic avenues may be unveiled. However, challenges remain in elucidating cell-specific iron metabolic reprogramming and its contribution to SLE pathogenesis needs further research for personalized therapeutic interventions and biomarker discovery. This review provides an in-depth understanding of immune cell-specific regulatory mechanisms of iron metabolism and new insights in current challenges as well as possible clinical applications.

Non-coding RNA and its network in the pathogenesis of Myasthenia Gravis

Myasthenia Gravis (MG) is a chronic autoimmune disease that primarily affects the neuromuscular junction, leading to muscle weakness in patients with this condition. Previous studies have identified several dysfunctions in thymus and peripheral blood mononuclear cells (PBMCs), such as the formation of ectopic germinal centers in the thymus and an imbalance of peripheral T helper cells and regulatory T cells, that contribute to the initiation and development of MG. Recent evidences suggest that noncoding RNA, including miRNA, lncRNA and circRNA may play a significant role in MG progression. Additionally, the network between these noncoding RNAs, such as the competing endogenous RNA regulatory network, has been found to be involved in MG progression. In this review, we summarized the roles of miRNA, lncRNA, and circRNA, highlighted their potential application as biomarkers in diagnosing MG, and discussed their potential regulatory networks in the abnormal thymus and PBMCs during MG development.

Telitacicept: A novel horizon in targeting autoimmunity and rheumatic diseases

BLyS and APRIL have the capability to bind to B cells within the body, allowing these cells to evade elimination when they should naturally be removed. While BLyS primarily plays a role in B cell development and maturation, APRIL is linked to B cell activation and the secretion of antibodies. Thus, in theory, inhibiting BLyS or APRIL could diminish the population of aberrant B cells that contribute to SLE and reduce disease activity in patients. Telitacicept functions by binding to and neutralizing the activities of both BLyS and APRIL, thus hindering the maturation and survival of plasma cells and fully developed B cells. The design of telitacicept is distinctive; it is not a monoclonal antibody but a TACI-Fc fusion protein generated through recombinant DNA technology. This fusion involves merging gene segments of the TACI protein, which can target BLyS/APRIL simultaneously, with the Fc gene segment of the human IgG protein. The TACI-Fc fusion protein exhibits the combined characteristics of both proteins. Currently utilized for autoimmune disease treatment, telitacicept is undergoing clinical investigations globally to assess its efficacy in managing various autoimmune conditions. This review consolidates information on the mechanistic actions, dosing regimens, pharmacokinetics, efficacy, and safety profile of telitacicept-a dual-targeted biological agent. It integrates findings from prior experiments and pharmacokinetic analyses in the treatment of RA and SLE, striving to offer a comprehensive overview of telitacicept's research advancements.

Reverse aging to treat lupus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with multifaceted pathogenetic processes, including abnormalities of T-cell subset distribution and function. Accumulation of senescent CD4+ T cells has been found to contribute to the development of the disease. In this issue, Jiang et al. provide compelling evidence that links an expanded pool of CD4+CD57+ senescent T cells in patients with SLE to disease activity favored by interleukin-15. Importantly, treatment of lupus-prone mice with a senolytic drug resulted in decreased autoimmune pathology. The findings of this study suggest possible novel therapeutics to treat patients with SLE.

Predicting autoimmune diseases: A comprehensive review of classic biomarkers and advances in artificial intelligence

Autoimmune diseases comprise a spectrum of disorders characterized by the dysregulation of immune tolerance, resulting in tissue or organ damage and inflammation. Their prevalence has been on the rise, significantly impacting patients' quality of life and escalating healthcare costs. Consequently, the prediction of autoimmune diseases has recently garnered substantial interest among researchers. Despite their wide heterogeneity, many autoimmune diseases exhibit a consistent pattern of paraclinical findings that hold predictive value. From serum biomarkers to various machine learning approaches, the array of available methods has been continuously expanding. The emergence of artificial intelligence (AI) presents an exciting new range of possibilities, with notable advancements already underway. The ultimate objective should revolve around disease prevention across all levels. This review provides a comprehensive summary of the most recent data pertaining to the prediction of diverse autoimmune diseases and encompasses both traditional biomarkers and the latest innovations in AI.

Mesenchymal stem cells in autoimmune disease: A systematic review and meta-analysis of pre-clinical studies

Mesenchymal Stem Cells (MSCs) are of interest in the clinic because of their immunomodulation capabilities, capacity to act upstream of inflammation, and ability to sense metabolic environments. In standard physiologic conditions, they play a role in maintaining the homeostasis of tissues and organs; however, there is evidence that they can contribute to some autoimmune diseases. Gaining a deeper understanding of the factors that transition MSCs from their physiological function to a pathological role in their native environment, and elucidating mechanisms that reduce their therapeutic relevance in regenerative medicine, is essential. We conducted a Systematic Review and Meta-Analysis of human MSCs in preclinical studies of autoimmune disease, evaluating 60 studies that included 845 patient samples and 571 control samples. MSCs from any tissue source were included, and the study was limited to four autoimmune diseases: multiple sclerosis, rheumatoid arthritis, systemic sclerosis, and lupus. We developed a novel Risk of Bias tool to determine study quality for in vitro studies. Using the International Society for Cell & Gene Therapy's criteria to define an MSC, most studies reported no difference in morphology, adhesion, cell surface markers, or differentiation into bone, fat, or cartilage when comparing control and autoimmune MSCs. However, there were reported differences in proliferation. Additionally, 308 biomolecules were differentially expressed, and the abilities to migrate, invade, and form capillaries were decreased. The findings from this study could help to explain the pathogenic mechanisms of autoimmune disease and potentially lead to improved MSC-based therapeutic applications.

SIT1 identifies circulating hypoactive T cells with elevated cytotoxic molecule secretion in systemic lupus erythematosus patients

This study aims to elucidate the expression and functionality of SIT1 in circulating CD8/CD4 + T cells in humans and to delineate its significance in systemic lupus erythematosus (SLE) patients. We employed multiparametric flow cytometry to investigate the expression of SIT1 in circulating CD8/CD4 + T cells and their respective subsets, comparing healthy controls (HCs) with SLE patients. Furthermore, we assessed the levels of granzyme B, perforin, IL-17, and IFN-γ in SIT1-related CD8/CD4 + T cells from both HCs and SLE patients, both before and after PMA stimulation. Clinically, we conducted receiver operating characteristic curve analysis and correlation analysis to evaluate the clinical relevance of SIT1-related CD8/CD4 + T cells in SLE patients. SIT1 exhibited higher expression in CD4 + T cells, with SIT1 - T cells demonstrating elevated levels of granzyme B, perforin, and IFN-γ compared to SIT1 + T cells. PMA-stimulated T cells exhibited reduced SIT1 expression compared to unstimulated T cells. SLE patients displayed increased SIT1 + proportions in CD8 + T cells and decreased SIT1 + CD4 + T cell numbers. Additionally, SIT1 + cells in SLE patients exhibited significantly higher levels of granzyme B and perforin compared to HCs. SIT1 + cells demonstrated significant associations with clinical indicators in SLE patients, with indicators related to SIT1 proving valuable in the diagnosis of SLE patients. SIT1 is inversely correlated with T cell activation. In SLE patients, SIT1 expression is altered in T cells concomitant with an augmented secretion of cytotoxic molecules. This upregulation may contribute to the pathogenesis of SLE and enhance its diagnostic potential.

Mesenchymal stem cell transplantation may be able to induce immunological tolerance in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a common, potentially fatal autoimmune disease involving a significant inflammatory response. SLE is characterised by failure of self-tolerance and activation of autoreactive lymphocytes, leading to persistent disease. Although current treatments achieve some improvement in patients, some SLE patients are refractory and others relapse after drug withdrawal. The toxicity of current drug regimens, with recurrent infections, together with ongoing inflammation, contribute significantly to the progressive decline in organ function. Therefore, the clinical management of SLE requires more effective and less toxic treatments, ideally inducing complete remission and self-tolerance. In this context, recently developed cell therapies based on mesenchymal stem cells (MSCs) represent a promising and safe strategy in SLE. MSCs inhibit the activation of B cells, prevent the differentiation of CD4⁺ T cells into autoreactive T cells, reprogram macrophages with anti-inflammatory effects and inhibit dendritic cells (DCs), limiting their activity as antigen-presenting cells. In addition, MSCs could induce antigen-specific tolerance by enhancing anergy processes in autoreactive cells - by inhibiting the maturation of antigen-presenting DCs, blocking the T cell receptor (TcR) pathway and secreting inhibitory molecules -, increasing apoptotic activity to eliminate them, and activating regulatory T cells (Tregs) to enhance their proliferation and induction of tolerogenic DCs. Thus, induction of self-tolerance leads to immune balance, keeping inflammation under control and reducing lupus flares.

Integrative, high-resolution analysis of single cells across experimental conditions with PARAFAC2

Effective tools for exploration and analysis are needed to extract insights from large-scale single-cell measurement data. However, current techniques for handling single-cell studies performed across experimental conditions (e.g., samples, perturbations, or patients) require restrictive assumptions, lack flexibility, or do not adequately deconvolute condition-to-condition variation from cell-to-cell variation. Here, we report that the tensor decomposition method PARAFAC2 (Pf2) enables the dimensionality reduction of single-cell data across conditions. We demonstrate these benefits across two distinct contexts of single-cell RNA-sequencing (scRNA-seq) experiments of peripheral immune cells: pharmacologic drug perturbations and systemic lupus erythematosus (SLE) patient samples. By isolating relevant gene modules across cells and conditions, Pf2 enables straightforward associations of gene variation patterns across specific patients or perturbations while connecting each coordinated change to certain cells without pre-defining cell types. The theoretical grounding of Pf2 suggests a unified framework for many modeling tasks associated with single-cell data. Thus, Pf2 provides an intuitive universal dimensionality reduction approach for multi-sample single-cell studies across diverse biological contexts.

Imbalance of Th17 cells, Treg cells and associated cytokines in patients with systemic lupus erythematosus: a meta-analysis

Objective

This article aims to investigate the changes of T helper 17 (Th17) cells, regulatory T (Treg) cells and their associated cytokines in patients with systemic lupus erythematosus (SLE).

Methods

Multiple databases were investigated to identify articles that explored Th17 cells, Treg cells and relevant cytokines in SLE patients. A random effects model was used for calculating pooled standardized mean differences. Stata version 15.0 was utilized to conduct the meta-analysis.

Results

The levels of Th17 cells, IL-17, IL-6, IL-21 and IL-10 were higher in SLE patients than in healthy controls (HCs), but the TGF-β levels were lower. The percentage of Treg cells was lower than HCs in SLE individuals older than 33. Among studies that had 93% or lower females, the percentage of Th17 cells was greater in patients than in HCs. However, the percentage of Treg cells was lower when the proportion of females was less than 90%. Patients with lupus nephritis or active SLE had an increased proportion of Th17 cells and a decreased proportion of Treg cells.

Conclusions

The increased level of Th17 cells and related cytokines could be the main reason for the elevated Th17/Treg ratio in SLE. The percentages of Th17 and Treg cells were associated with gender, age, disease activity and kidney function. Furthermore, the reduced proportions of Treg cells may primarily result in a rise in the Th17/Treg ratio in older or active SLE patients.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD42023454937.

Case report: Three cases of systemic lupus erythematosus presenting primarily with massive ascites and significantly elevated CA-125 levels and a review of pseudo-pseudo Meigs' syndrome in literature

This article presents three detailed case reports and a brief review of the literature on a rare manifestation of systemic lupus erythematosus (SLE) known as Pseudo-Pseudo Meigs' Syndrome (PPMS). The patients' condition was characterized by elevated CA-125 levels, massive ascites andpleural effusion which is typically associated with ovarian malignancies but can also present in various non-malignant conditions, including SLE. A thorough literature review was conducted, summarizing similar cases and their clinical outcomes to provide a broader understanding of this uncommon syndrome. The findings emphasize the need for heightened awareness and consideration of pseudo-pseudo Meigs' syndrome in patients with SLE presenting with unexplained ascites and pleural effusion.

Characterisation of choroid plexus-infiltrating T cells reveals novel therapeutic targets in murine neuropsychiatric lupus

OBJECTIVE

Diffuse central nervous system manifestations, referred to as neuropsychiatric lupus (NPSLE), are observed in 20-40% of lupus patients and involve complex mechanisms that have not yet been adequately elucidated. In murine NPSLE models, choroid plexus (ChP)-infiltrating T cells have not been fully evaluated as drivers of neuropsychiatric disease.

METHOD

Droplet-based single-cell transcriptomic analysis (single-cell RNA sequencing) and immune T-cell receptor profiling were performed on ChP tissue from MRL/lpr mice, an NPSLE mouse model, at an 'early' and 'late' disease state, to investigate the infiltrating immune cells that accumulate with NPSLE disease progression.

RESULTS

We found 19 unique clusters of stromal and infiltrating cells present in the ChP of NPSLE mice. Higher resolution of the T-cell clusters uncovered multiple T-cell subsets, with increased exhaustion and hypoxia expression profiles. Clonal analysis revealed that the clonal CD8+T cell CDR3 sequence, ASGDALGGYEQY, matched that of a published T-cell receptor sequence with specificity for myelin basic protein. Stromal fibroblasts are likely drivers of T-cell recruitment by upregulating the VCAM signalling pathway. Systemic blockade of VLA-4, the cognate ligand of VCAM, resulted in significant resolution of the ChP immune cell infiltration and attenuation of the depressive phenotype.

CONCLUSION

Our analysis details the dynamic transcriptomic changes associated with murine NPSLE disease progression, and highlights its potential use in identifying prospective lupus brain therapeutic targets.

Gut microbiota regulation of T lymphocyte subsets during systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by disturbance of pro-inflammatory and anti-inflammatory lymphocytes. Growing evidence shown that gut microbiota participated in the occurrence and development of SLE by affecting the differentiation and function of intestinal immune cells. The purpose of this study was to investigate the changes of gut microbiota in SLE and judge its associations with peripheral T lymphocytes.

METHODS

A total of 19 SLE patients and 16 HCs were enrolled in this study. Flow cytometry was used to detect the number of peripheral T lymphocyte subsets, and 16 s rRNA was used to detect the relative abundance of gut microbiota. Analyzed the correlation between gut microbiota with SLEDAI, ESR, ds-DNA and complement. SPSS26.0 software was used to analyze the experimental data. Mann-Whitney U test was applied to compare T lymphocyte subsets. Spearman analysis was used for calculating correlation.

RESULTS

Compared with HCs, the proportions of Tregs (P = 0.001), Tfh cells (P = 0.018) and Naïve CD4 + T cells (P = 0.004) significantly decreased in SLE patients, and proportions of Th17 cells (P = 0.020) and γδT cells (P = 0.018) increased in SLE. The diversity of SLE patients were significantly decreased. Addition, there were 11 species of flora were discovered to be distinctly different in SLE group (P < 0.05). In the correlation analysis of SLE, Tregs were positively correlated with Ruminococcus2 (P = 0.042), Th17 cells were positively correlated with Megamonas (P = 0.009), γδT cells were positively correlated with Megamonas (P = 0.003) and Streptococcus (P = 0.004), Tfh cells were positively correlated with Bacteroides (P = 0.040), and Th1 cells were negatively correlated with Bifidobacterium (P = 0.005). As for clinical indicators, the level of Tregs was negatively correlated with ESR (P = 0.031), but not with C3 and C4, and the remaining cells were not significantly correlated with ESR, C3 and C4.

CONCLUSION

Gut microbiota and T lymphocyte subsets of SLE changed and related to each other, which may break the immune balance and affect the occurrence and development of SLE. Therefore, it is necessary to pay attention to the changes of gut microbiota and provide new ideas for the treatment of SLE.

Soluble CD72, is a T-cell activator probably via binding to CD6 in homeostasis and autoimmunity

Background

CD72 is a highly required regulatory molecule in B cells. Its sufficient expression is crucial for maintaining self-tolerance. In contrast, soluble CD72 (sCD72) is reported to be increased in the serum of autoimmune diseases such as systemic lupus erythematosus and primary Sjogren's syndrome (pSS).

Objective

We wanted to assess the biological effect of sCD72 on CD4+T cells.

Methods

We performed mass spectrometry and co-immunoprecipitation experiments to look for a sCD72 receptor on activated CD4+T cells. Afterward, to explore the biological functions of sCD72, we used flow cytometry for the cytokine secretion profile, a phosphorylation assay for the signaling pathway, and a CFSE dye-based assay for cell proliferation.

Results

We found and validated the sCD72 and CD6 interaction as a possible ligand-receptor interaction. We also demonstrated that sCD72 significantly increases the expression of pro-inflammatory cytokines, namely IL-17A and IFN-γ, in activated CD4+T cells and increases the proliferation of CD4+T cells, possibly through its activation of the SLP-76-AKT-mTOR pathway.

Conclusion

The sCD72-CD6 axis on activated CD4+T cells is probably a new signaling pathway in the induction of immune-mediated diseases. Therefore, targeting sCD72 may become a valuable therapeutic tool in some autoimmune disorders.

Phosphatidic Acid Promoting the Generation of Interleukin-17A Producing Double-Negative T Cells by Enhancing mTORC1 Signaling in Lupus

OBJECTIVE

The goal was to investigate the role and intracellular regulatory mechanisms of double-negative T (DNT) cells in the pathogenesis of systemic lupus erythematosus (SLE).

METHODS

DNT cells were assessed in murine models, patients with SLE, and controls using flow cytometry (FCM). DNT cells from either resiquimod (R848) or vehicle-treated C57BL/6 (B6) mice were cultured with B cells from R848-treated mice to explore functions. Differential mechanistic target of rapamycin (mTOR) pathway signaling in DNT cells measured using FCM and quantitative polymerase chain reaction was validated by rapamycin inhibition. Candidate lipid metabolites detected using liquid chromatography with electrospray ionization mass spectrometry/mass spectrometry were functionally assessed in DNT cell cultures.

RESULTS

DNT cells were markedly increased in both spontaneous and induced mouse lupus models and in patients with SLE. Expanded DNT cells from R848-treated B6 mice produced elevated interleukin (IL)-17A and IgG with increased germinal center B (GCB) cells. Expansion of DNT cells associated with activation of mTORC1 pathway that both IL-17A levels and the number of DNT cells exhibited dose-dependent reduction with rapamycin treatment. Lipidomics studies revealed differential patterns of lipid metabolites in T cells of R848-treated mice. Among candidate metabolites, elevated phosphatidic acid (PA) that was partially controlled by phospholipase D2 increased the expression of the mTORC1 downstream target p-S6 and positively expanded IL-17A-producing DNT cells. Similarly, elevated proportions of circulating DNT cells in patients with SLE correlated with disease activity and proteinuria, and IL-17A secretion was elevated after in vitro PA stimulation.

CONCLUSION

The accumulation of PA in T cells could activate the mTORC1 pathway, promoting DNT cell expansion and IL-17A secretion, resulting in GCB cell abnormalities in lupus.

Metabolic dysregulation of lymphocytes in autoimmune diseases

Lymphocytes are crucial for protective immunity against infection and cancers; however, immune dysregulation can lead to autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Metabolic adaptation controls lymphocyte fate; thus, metabolic reprogramming can contribute to the pathogenesis of autoimmune diseases. Here, we summarize recent advances on how metabolic reprogramming determines the autoreactive and proinflammatory nature of lymphocytes in SLE and RA, unraveling molecular mechanisms and providing therapeutic targets for human autoimmune diseases.

Recent advances in pathogenesis, diagnosis, and therapeutic approaches for digestive system involvement in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by the presence of large amounts of autoantibodies and immune complex formation. Because of their atypical clinical symptoms, SLE patients with digestive system involvement may not be recognized or treated precisely and extensively. Clinicians should pay close attention to SLE with digestive system involvement, as these conditions can easily worsen the condition and possibly endanger the patient's life. In this review we summarized the pathogenesis, pathological characteristics, clinical manifestations, diagnosis, and therapies for digestive system involvement in SLE.

Research progress of SIRTs activator resveratrol and its derivatives in autoimmune diseases

Autoimmune diseases (AID) have emerged as prominent contributors to disability and mortality worldwide, characterized by intricate pathogenic mechanisms involving genetic, environmental, and autoimmune factors. In response to this challenge, a growing body of research in recent years has delved into genetic modifications, yielding valuable insights into AID prevention and treatment. Sirtuins (SIRTs) constitute a class of NAD-dependent histone deacetylases that orchestrate deacetylation processes, wielding significant regulatory influence over cellular metabolism, oxidative stress, immune response, apoptosis, and aging through epigenetic modifications. Resveratrol, the pioneering activator of the SIRTs family, and its derivatives have captured global scholarly interest. In the context of AID, these compounds hold promise for therapeutic intervention by modulating the SIRTs pathway, impacting immune cell functionality, suppressing the release of inflammatory mediators, and mitigating tissue damage. This review endeavors to explore the potential of resveratrol and its derivatives in AID treatment, elucidating their mechanisms of action and providing a comprehensive analysis of current research advancements and obstacles. Through a thorough examination of existing literature, our objective is to advocate for the utilization of resveratrol and its derivatives in AID treatment while offering crucial insights for the formulation of innovative therapeutic approaches.

UHRF1P contributes to IL-17A-mediated systemic lupus erythematosus via UHRF1-MAP4K3 axis

Inflammatory T cells contribute to the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE). Analysis of the T-cell transcriptomics data of two independent SLE patient cohorts by three machine learning models revealed the pseudogene UHRF1P as a novel SLE biomarker. The pseudogene-encoded UHRF1P protein was overexpressed in peripheral blood T cells of SLE patients. The UHRF1P protein lacks the amino-terminus of its parental UHRF1 protein, resulting in missing the proteasome-binding ubiquitin-like (Ubl) domain of UHRF1. T-cell-specific UHRF1P transgenic mice manifested the induction of IL-17A and autoimmune inflammation. Mechanistically, UHFR1P prevented UHRF1-induced Lys48-linked ubiquitination and degradation of MAP4K3 (GLK), which is a kinase known to induce IL-17A. Consistently, IL-17A induction and autoimmune phenotypes of UHRF1P transgenic mice were obliterated by MAP4K3 knockout. Collectively, UHRF1P overexpression in T cells inhibits the E3 ligase function of its parental UHRF1 and induces autoimmune diseases.

Animal models of studying the pathogenesis of multi-organ tissue damage in lupus

Moderate-to-severe systemic lupus erythematosus (SLE) is characterized by extensive autoantibody deposition and persistent autoinflammation. As the existing animal models are limited in accurately reproducing the pathological characteristics of human SLE, we introduced a novel animal model simulating multi-organ autoinflammation through intra-organ injections. The model closely mimicked key features of SLE, including IgG deposition, inflammation, and tissue damage. The model could be used to assess the roles of IgG, immune cells, cytokines, and Fc gamma receptor (FcγR) in the pathogenesis of autoinflammation. The results obtained from this model could be confirmed by lupus MRL/lpr mice. The review suggested that the diagnostic criteria should be reconsidered to incorporate IgG deposition in tissues and highlighted the limitations of current T-cell and B-cell-focused treatments. To summarize, the IgG deposition model can be used to investigate the pathogenesis and treatment of multi-organ tissue damage associated with SLE.

The causal association of specific gut microbiota on the risk of membranous nephropathy: a Mendelian randomization study

PURPOSE

Gut microbiota transplantation has been reported to improve the renal function of membranous nephropathy (MN). However, whether there is a causal effect of gut microbiota on MN remained unclear.

METHODS

We performed two-sample Mendelian randomization (MR) analysis. The inverse variance weighted (IVW) method was used as the main approach to evaluate the causal relationship between gut microbiota and MN. Additional methods including MR-Egger regression, weighted median, and MR-weighted mode were also conducted. Cochrane's Q test, MR-Egger regression, and MR-PRESSO were employed to detect heterogeneity and pleiotropy, respectively.

RESULTS

A total of 196 gut microbiota were examined. After IVW and sensitivity analysis, eight gut bacteria taxa were observed causal effects on the risk of MN. Specifically, Genus. Oscillibacter was a protective factor (OR: 0.57; 95% CI 0.328-0.979; P = 0.042), while Class. Melainabacteria (OR: 1.51; 95% CI 1.004-2.277; P = 0.048), Genus. Butyricicoccus (OR: 2.16; 95% CI 1.005-4.621; P = 0.048), Genus. Catenibacterium (OR: 1.49; 95% CI 1.043-2.134; P = 0.028), Genus.Ruminiclostridium5 (OR: 1.74; 95% CI 1.053-2.862; P = 0.030), Genus. Ruminococcaceae UCG-003 (OR: 1.73; 95% CI 1.110-2.692; P = 0.015), Order. Bacillales (OR: 1.52; 95% CI 1.135-2.025; P = 0.0048) and Order. Gastranaerophilales (OR: 1.45; 95% CI 1.010-2.085; P = 0.044) were risk factors. Heterogeneity was not significant for most single-nucleotide polymorphisms, and no statistical difference in pleiotropy.

CONCLUSIONS

This study first indicated the causal association between specific gut microbiota and MN, which would be of great significance to guide clinical prevention and treatment in MN.

Remodeling of T-cell mitochondrial metabolism to treat autoimmune diseases

T cells are key drivers of the pathogenesis of autoimmune diseases by producing cytokines, stimulating the generation of autoantibodies, and mediating tissue and cell damage. Distinct mitochondrial metabolic pathways govern the direction of T-cell differentiation and function and rely on specific nutrients and metabolic enzymes. Metabolic substrate uptake and mitochondrial metabolism form the foundational elements for T-cell activation, proliferation, differentiation, and effector function, contributing to the dynamic interplay between immunological signals and mitochondrial metabolism in coordinating adaptive immunity. Perturbations in substrate availability and enzyme activity may impair T-cell immunosuppressive function, fostering autoreactive responses and disrupting immune homeostasis, ultimately contributing to autoimmune disease pathogenesis. A growing body of studies has explored how metabolic processes regulate the function of diverse T-cell subsets in autoimmune diseases such as systemic lupus erythematosus (SLE), multiple sclerosis (MS), autoimmune hepatitis (AIH), inflammatory bowel disease (IBD), and psoriasis. This review describes the coordination of T-cell biology by mitochondrial metabolism, including the electron transport chain (ETC), oxidative phosphorylation, amino acid metabolism, fatty acid metabolism, and one‑carbon metabolism. This study elucidated the intricate crosstalk between mitochondrial metabolic programs, signal transduction pathways, and transcription factors. This review summarizes potential therapeutic targets for T-cell mitochondrial metabolism and signaling in autoimmune diseases, providing insights for future studies.

New and emerging therapies for systemic lupus erythematosus

Systemic Lupus Erythematosus (SLE) and lupus nephritis treatment is still based on non-specific immune suppression despite the first biological therapy for the disease having been approved more than a decade ago. Intense basic and translational research has uncovered a multitude of pathways that are actively being evaluated as treatment targets in SLE and lupus nephritis, with two new medications receiving FDA approval in the last 3 years. Herein we provide an overview of targeted therapies for SLE including medications targeting the B lymphocyte compartment, intracellular signaling, co-stimulation, and finally the interferons and other cytokines.

Dexamethasone-Integrated Mesenchymal Stem Cells for Systemic Lupus Erythematosus Treatment via Multiple Immunomodulatory Mechanisms

The therapeutic application of mesenchymal stem cells (MSCs) has good potential as a treatment strategy for systemic lupus erythematosus (SLE), but traditional MSC therapy still has limitations in effectively modulating immune cells. Herein, we present a promising strategy based on dexamethasone liposome-integrated MSCs (Dexlip-MSCs) for treating SLE via multiple immunomodulatory pathways. This therapeutic strategy prolonged the circulation time of dexamethasone liposomes in vivo, restrained CD4+T-cell proliferation, and inhibited the release of proinflammatory mediators (IFN-γ and TNF-α) by CD4+T cells. In addition, Dexlip-MSCs initiated cellular reprogramming by activating the glucocorticoid receptor (GR) signaling pathway to upregulate the expression of anti-inflammatory factors such as cysteine-rich secretory protein LCCL-containing domain 2 (CRISPLD2) and downregulate the expression of proinflammatory factors. In addition, Dexlip-MSCs synergistically increased the anti-inflammatory inhibitory effect of CD4+T cells through the release of dexamethasone liposomes or Dex-integrated MSC-derived exosomes (Dex-MSC-EXOs). Based on these synergistic biological effects, we demonstrated that Dexlip-MSCs alleviated disease progression in MRL/lpr mice more effectively than Dexlip or MSCs alone. These features indicate that our stem cell delivery strategy is a promising therapeutic approach for clinical SLE treatment.