The impact of biological therapy on regulatory T cells in rheumatoid arthritis

Exploring the therapeutic potential of regulatory T cell in rheumatoid arthritis: Insights into subsets, markers, and signaling pathways

Rheumatoid arthritis (RA) is a complex autoimmune inflammatory rheumatic disease characterized by an imbalance between immunological reactivity and immune tolerance. Regulatory T cells (Tregs), which play a crucial role in controlling ongoing autoimmunity and maintaining peripheral tolerance, have shown great potential for the treatment of autoimmune inflammatory rheumatic diseases such as RA. This review aims to provide an updated summary of the latest insights into Treg-targeting techniques in RA. We focus on current therapeutic strategies for targeting Tregs based on discussing their subsets, surface markers, suppressive function, and signaling pathways in RA.

A novel Shiga toxin 2a neutralizing antibody therapeutic with low immunogenicity and high efficacy

Shiga toxin-producing Escherichia coli infections are difficult to treat due to the risk of antibiotic-induced stress upregulating the production of toxins, medical treatment is consequently limited to supportive care to prevent the development of hemolytic uremic syndrome (HUS). Here, we introduce a potentially therapeutic humanized mouse monoclonal antibody (Hu-mAb 2-5) targeting Stx2a, the most common Shiga toxin subtype identified from outbreaks. We demonstrate that Hu-mAb 2-5 has low immunogenicity in healthy adults ex vivo and high neutralizing efficacy in vivo, protecting mice from mortality and HUS-related tissue damage.

The clinical and experimental treatment of Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children and comprises of multiple subtypes. The most relevant disease subtypes, grouped upon current insight in disease mechanisms, are nonsystemic (oligo- and polyarticular) JIA and systemic JIA (sJIA). In this review, we summarize some of the main proposed mechanisms of disease in both nonsystemic and sJIA and discuss how current therapeutic modalities target some of the pathogenic immune pathways. Chronic inflammation in nonsystemic JIA is the result of a complex interplay between effector and regulatory immune cell subsets, with adaptive immune cells, specifically T-cell subsets and antigen-presenting cells, in a central role. There is, however, also innate immune cell contribution. SJIA is nowadays recognized as an acquired chronic inflammatory disorder with striking autoinflammatory features in the first phase of the disease. Some sJIA patients develop a refractory disease course, with indications for involvement of adaptive immune pathways as well. Currently, therapeutic strategies are directed at suppressing effector mechanisms in both non-systemic and sJIA. These strategies are often not yet optimally tuned nor timed to the known active mechanisms of disease in individual patients in both non-systemic and sJIA. We discuss current treatment strategies in JIA, specifically the 'Step-up' and 'Treat to Target approach' and explore how increased insight into the biology of disease may translate into future more targeted strategies for this chronic inflammatory disease at relevant time points: preclinical disease, active disease, and clinically inactive disease.

The Mechanisms and Efficacy of Photobiomodulation Therapy for Arthritis: A Comprehensive Review

Rheumatoid arthritis (RA) and osteoarthritis (OA) have a significant impact on the quality of life of patients around the world, causing significant pain and disability. Furthermore, the drugs used to treat these conditions frequently have side effects that add to the patient's burden. Photobiomodulation (PBM) has emerged as a promising treatment approach in recent years. PBM effectively reduces inflammation by utilizing near-infrared light emitted by lasers or LEDs. In contrast to photothermal effects, PBM causes a photobiological response in cells, which regulates their functional response to light and reduces inflammation. PBM's anti-inflammatory properties and beneficial effects in arthritis treatment have been reported in numerous studies, including animal experiments and clinical trials. PBM's effectiveness in arthritis treatment has been extensively researched in arthritis-specific cells. Despite the positive results of PBM treatment, questions about specific parameters such as wavelength, dose, power density, irradiation time, and treatment site remain. The goal of this comprehensive review is to systematically summarize the mechanisms of PBM in arthritis treatment, the development of animal arthritis models, and the anti-inflammatory and joint function recovery effects seen in these models. The review also goes over the evaluation methods used in clinical trials. Overall, this review provides valuable insights for researchers investigating PBM treatment for arthritis, providing important references for parameters, model techniques, and evaluation methods in future studies.

Intranasal administration of abatacept enhances IL-35+ and IL-10+ producing Bregs in lung tissues of ovalbumin-sensitized asthmatic mice model

Backgrounds

Treating asthmatic rheumatoid arthritis patients with abatacept has been shown to associate with better control of asthma symptoms. However, the mechanism behind that is not investigated.

Methods

Ovalbumin (OVA)- sensitized BALB/c female mice were treated intranasally (IN) or intraperitoneally (IP) with abatacept 4 hrs before the OVA challenge. The effects of abatacept IN or IP on the lungs and blood levels of Tregs and Bregs and their production of immunosuppressive cytokines, were determined using FACS analysis and ELISA assay.

Results

Treating OVA- sensitized asthmatic mice model with abatacept, IN or IP, reduced lung inflammation. IN treatment with abatacept increased the frequency of IL-35 and IL-10 producing Bregs in the lung tissues to a higher level compared to IP treatment. Moreover, the frequency of lungs LAG3⁺ Tregs was significantly increased following treatment. This was also associated with a reduction in lung tissue and serum IL-17 levels of treated mice.

Conclusions

These results suggest that abatacept by enhancing IL-35⁺IL-10⁺ Bregs and LAG3⁺ Tregs might reverse IL-17 induced lung inflammation during asthma.

Immunosuppressive effect of Columbianadin on maturation, migration, allogenic T cell stimulation and phagocytosis capacity of TNF-α induced dendritic cells

ETHNOPHARMACOLOGICAL RELEVANCE

Angelicae pubescentis radix (APR) has a long history in the treatment of rheumatoid arthritis (RA) in China. It has the effects of dispelling wind to eliminate dampness, removing arthralgia and stopping pain in the Chinese Pharmacopeia, but its mechanisms was unclear. Columbianadin (CBN) was one of the main bioactive compounds of APR, and has many pharmacological effects. But the immunosuppressive effect of CBN on DCs and the potential mechanism needed to be explored.

AIM OF THE STUDY

The study was aimed to clarify the immunosuppressive effect of CBN on maturation, migration, allogenic T cell stimulation and phagocytosis capacity of TNF-α induced DCs.

MATERIALS AND METHODS

Bone marrow-derived DCs were obtained and cultured from C57BL/6 mice in accordance with protocol. The phenotypic study (CD11c, CD40, CD80, CD86 and MHC Ⅱ) were measured by flow cytometry. FITC-dextran were uptaked by DCs and the change of endocytosis activity were mediated by acquired mannose receptor. Transwell chambers were used to detect the migration ability of DCs. Mixed leukocyte reaction (MLR) assay was used to detect the allostimulatory ability of CBN on TNF-α stimulated DCs. The secretion of cytokines and chemokines was measured by ELISA Kit. TLRs gene and MAPKs/NF-κB protein expression were checked by qRT-PCR and Western blot.

RESULTS

CBN inhibited the maturation of TNF-α-induced DCs while maintaining phagocytosis capabilities. Additionally, CBN inhibited the migration of TNF-α stimulated DCs, which related to reduce the production of chemokines (MCP-1, MIP-1α). Notably, CBN could suppress the proliferation of CD4⁺T cells by inhibiting DCs maturation, and decrease the proinflammatory cytokines IL-6 production. Furthermore, CBN inhibited mRNA expression of TLR2, TLR7 and TLR9 in TNF-α-activated DCs. Meanwhile, the phosphorylation of p38, JNK1/2 and NF-κB protein were significantly inhibited in CBN treated DCs.

CONCLUSIONS

These findings provided novel insights into the pharmacological activity of CBN. They also indicated that inhibition DCs maturation owning to the immunosuppressive effect of CBN. CBN was expected as a potential immunosuppressant and TLRs/MAPKs/NF-κB pathway may be an important mechanism for CBN's immunosuppressive activity.

Genetic variation in NDFIP1 modifies the metabolic patterns in immune cells of multiple sclerosis patients

One of the 233 polymorphisms associated with multiple sclerosis (MS) susceptibility lies within the NDFIP1 gene, and it was previously identified as eQTL in healthy controls. NDFIP1 shows interesting immune functions and is involved in the development of the central nervous system. We aimed at studying the NDFIP1 variant on activation and metabolism of immune cells. NDFIP1 mRNA and protein expression were assessed in PBMCs by qPCR and western blot in 87 MS patients and 84 healthy controls genotyped for rs4912622. Immune activation after PHA stimulation was evaluated by CD69 upregulation, and metabolic function of both basal and PHA-activated lymphocytes was studied by Seahorse Xfp-Analyzer. In minor-allele homozygous controls but not in patients, we found higher NDFIP1 expression, significantly reduced protein levels, and CD69 upregulation in B- and T-cells. PBMCs from minor-allele homozygous controls showed significantly higher basal mitochondrial respiration and ATP production compared to major-allele carriers, while minor-allele homozygous patients showed significantly lower metabolic activity than carriers of the major allele. In conclusion, we describe associations in minor-allele homozygous controls with lower levels of NDFIP1 protein, CD69 upregulation, and raised mitochondrial activity, which are not replicated in MS patients, suggesting a NDFIP1 differential effect in health and disease.

Favorable antibody responses to human coronaviruses in children and adolescents with autoimmune rheumatic diseases

BACKGROUND

Differences in humoral immunity to coronaviruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), between children and adults remain unexplained, and the effect of underlying immune dysfunction or suppression is unknown. Here, we sought to examine the antibody immune competence of children and adolescents with prevalent inflammatory rheumatic diseases, juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), and juvenile systemic lupus erythematosus (JSLE) against the seasonal human coronavirus (HCoV)-OC43 that frequently infects this age group.

METHODS

Sera were collected from JIA (n = 118), JDM (n = 49), and JSLE (n = 30) patients and from healthy control (n = 54) children and adolescents prior to the coronavirus disease 19 (COVID-19) pandemic. We used sensitive flow-cytometry-based assays to determine titers of antibodies that reacted with the spike and nucleoprotein of HCoV-OC43 and cross-reacted with the spike and nucleoprotein of SARS-CoV-2, and we compared them with respective titers in sera from patients with multisystem inflammatory syndrome in children and adolescents (MIS-C).

FINDINGS

Despite immune dysfunction and immunosuppressive treatment, JIA, JDM, and JSLE patients maintained comparable or stronger humoral responses than healthier peers, which was dominated by immunoglobulin G (IgG) antibodies to HCoV-OC43 spike, and harbored IgG antibodies that cross-reacted with SARS-CoV-2 spike. In contrast, responses to HCoV-OC43 and SARS-CoV-2 nucleoproteins exhibited delayed age-dependent class-switching and were not elevated in JIA, JDM, and JSLE patients, which argues against increased exposure.

CONCLUSIONS

Consequently, autoimmune rheumatic diseases and their treatment were associated with a favorable ratio of spike to nucleoprotein antibodies.

FUNDING

This work was supported by a Centre of Excellence Centre for Adolescent Rheumatology Versus Arthritis grant, 21593, UKRI funding reference MR/R013926/1, the Great Ormond Street Children's Charity, Cure JM Foundation, Myositis UK, Lupus UK, and the NIHR Biomedical Research Centres at GOSH and UCLH. This work was supported by the Francis Crick Institute, which receives its core funding from Cancer Research UK, the UK Medical Research Council, and the Wellcome Trust.

Insights into the biology and therapeutic implications of TNF and regulatory T cells

Treatments that block tumour necrosis factor (TNF) have major beneficial effects in several autoimmune and rheumatic diseases, including rheumatoid arthritis. However, some patients do not respond to TNF inhibitor treatment and rare occurrences of paradoxical disease exacerbation have been reported. These limitations on the clinical efficacy of TNF inhibitors can be explained by the differences between TNF receptor 1 (TNFR1) and TNFR2 signalling and by the diverse effects of TNF on multiple immune cells, including FOXP3⁺ regulatory T cells. This basic knowledge sheds light on the consequences of TNF inhibitor therapies on regulatory T cells in treated patients and on the limitations of such treatment in the control of diseases with an autoimmune component. Accordingly, the next generation of drugs targeting TNF is likely to be based on agents that selectively block the binding of TNF to TNFR1 and on TNFR2 agonists. These approaches could improve the treatment of rheumatic diseases in the future.

Low-dose IL-2 therapy limits the reduction in absolute numbers of circulating regulatory T cells in rheumatoid arthritis

Background:

Circulating regulatory T cells (Tregs) are responsible for mediating immune tolerance and maintaining immunological homeostasis. Decreases in Tregs may be involved in the onset of rheumatoid arthritis (RA). Low-dose interleukin-2 (IL-2) has been considered for the treatment of inflammatory diseases mediated by T cells. This study focused on the status of circulating CD4⁺T subsets and the clinical feasibility of IL-2 therapies in patients with RA.

Methods:

The subjects included 888 patients with RA and 100 healthy controls (HCs); 233 RA patients received IL-2 treatment with 0.5 million international units (MIU)/day from days 1 through 5. The demographic features, disease activity, and levels of CD4+T cells measured by modified flow cytometry were collected in all RA patients before and after treatment.

Results:

RA patients had lower absolute Treg counts (but not Th17) compared with HCs, which was associated with disease activity; previously treated RA patients had the fewest circulating Tregs (p < 0.05). Patients treated with low-dose IL-2 had a three-fold increase in absolute anti-inflammatory Treg counts, as well as a two-fold increase in the other CD4⁺T subsets. Moreover, post-treatment levels of markers of disease activity in RA patients treated with IL-2 were significantly lower than the baseline values (p < 0.001), with no apparent side effects.

Conclusion:

Decreased absolute counts of circulating CD4⁺T lymphocyte subsets were observed in patients with RA. Circulating Tregs, which mediate immune tolerance, may be involved in the pathogenesis and progression of RA; however, this was ameliorated by low-dose IL-2, without obvious side effects.

Plain language summary

Low-dose IL-2 treatment for rheumatoid arthritis

• Circulating Tregs may be involved in the pathogenesis and progression of RA.

• The absolute count of Tregs was significantly correlated with disease activity measures.

• Low-dose IL-2 was able to effectively expade Tregs and help for RA patients’ symptoms remission without evaluated side effects.

Abatacept enhances blood regulatory B cells of rheumatoid arthritis patients to a level that associates with disease remittance

Abatacept, an inhibitor of CD28 mediated T-cell activation, has been shown to be effective in controlling inflammation during rheumatoid arthritis (RA). However, its effects on immune regulatory B and T cells (Bregs and Tregs) has not been fully explored. Thirty-one RA patients treated with abatacept for ≥ 6 months along with 31 RA patients treated with other modalities as well as 30 healthy controls were recruited. Of these 62 RA patient, 49 (79%) were females with a mean age of 54 ± 12 years and disease duration of 10 ± 6 years. The blood levels of Tregs and Bregs and their production of immunosuppressive cytokines, were determined using FACS analysis and Luminex Multiplex assay. Treatment with abatacept significantly enhanced the blood level of IL-35⁺ IL-10⁺ Bregs (P = 0.0007). Their levels were higher in the blood of remitted patients (DAS28-CRP < 2.6) compared to the unremitted ones (P = 0.0173), 6 months following abatacept treatment initiation. Moreover, abatacept treatment significantly enhanced the blood levels of LAG3⁺ conventional and unconventional Tregs of RA patients. This increase in the blood levels of Bregs and Tregs was accompanied with an elevated serum level of IL-35 and IFN-β in abatacept-treated patients. Therefore, Abatacept efficiency to achieve remittance in RA could be attributed, in part, to its ability to enhance immune regulatory cells, especially IL-135⁺ IL-10⁺ Bregs.

Rheumatoid Arthritis Interstitial Lung Disease: Measuring and Predictive Factors Among Patients Treated in Rehabilitation Clinics at Royal Medical Services

Introduction

Autoimmune diseases have increasing importance in modern medicine and cover increasing areas of medicine including rheumatoid arthritis interstitial lung disease.

Aim

The main aims of this study are to evaluate the association of some autoimmune variables in patients with rheumatoid arthritis interstitial lung disease.

Methods

A retrospective study was conducted from files of patients with rheumatoid arthritis interstitial lung disease. A total of 210 files of intended patients were included in this study. The study was conducted in rehabilitation clinics at Royal Medical Services. Study variables include some demographic variables such as age, and gender; clinical variables such as disease related factors such as duration, diagnostic criteria; predictive factors such as rheumatoid factors, smoking, and MTX treatment. Data were collected and entered into excel spreadsheet to create raw data. The analysis of data was carried out using the software SPSS version 21. Descriptive statistical parameters were used to describe data including means and standard deviations for continuous variables. Frequency and percentages were used to describe categorized variables such as gender. The relationships between study variables were computed using independent T test, and One Way ANOVA test. Significance was determined if α≤ 0.05.

Results

The prevalence of RA-ILD was 3.70%. The study participants were subdivided into two groups according to MTX treatment, non-exposed group and exposed group. There were significant relationships between MTX treatment and study variables including gender, age of (rheumatoid arthritis) RA onset, smoking, and rheumatoid factor (RF). The progression of RA-ILD was impacted by gender, age of (rheumatoid arthritis) RA onset, smoking, rheumatoid factor (RF), and MTX treatment.

Conclusion

Patients with RA and RA-ILD follow similar clinical characteristics in other studies except MTX treatment, but this can't be generalized because of small number of RA-ILD patients.

Mesenchymal Stem Cells Enhance Therapeutic Effect and Prevent Adverse Gastrointestinal Reaction of Methotrexate Treatment in Collagen-Induced Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by articular destruction and functional loss. Methotrexate (MTX) is effective in RA treatment. However, MTX induces several adverse events and 20%-30% of patients do not respond to MTX. Thus, it is urgent to enhance the therapeutic effects and reduce the side effects of MTX. Recent studies showed that mesenchymal stem cells (MSCs) were participants in anti-inflammation, immunoregulation, and tissue regeneration. However, whether the combined application of MSCs and MTX promotes the therapeutic effects and reduces the side effects of MTX has not been studied. In this study, we used bovine type II collagen to induce rheumatoid arthritis in mice (collagen-induced arthritis, CIA). Then, CIA mice were subjected to MTX or MSC treatment, or both. The therapeutic effect and adverse events of different treatments on RA were evaluated with micro-CT, HE staining, and immunohistochemistry in vivo. Apoptosis and proliferation of MODE-K cells were measured after treated with MTX or/and cocultured with UCs. To test M2 polarization, Raw264.7 macrophages were stimulated by MTX with different concentrations or cocultured with UCs. We found that the combined application of MSCs and MTX increased the therapeutic effects on RA, as evidenced by decreased arthritis score, inflammatory responses, and mortality. Moreover, in this combination remedy, MTX prefers to suppress inflammation by facilitating macrophage polarization to M2 type while UCs prefer to eliminate gastrointestinal side effects of MTX via mitigating the apoptosis of intestinal epithelial cells. Thus, a combination of MTX and UCs is a promising strategy for RA treatment.

Th17/Treg-Related Transcriptional Factor Expression and Cytokine Profile in Patients With Rheumatoid Arthritis

Objectives

The aim of our study was to determine whether there is a correlation between transcription factors expression and Th17/Treg ratio, cytokine profile in the RA phenotype as well as to identify transcription factors that could be a potential biomarker for RA.

Methods

The study was conducted on 45 patients with RA, 27 patients with OA and 46 healthy controls (HCs). Th17 and Treg frequency was determined by flow cytometry (15 patients with RA/OA and 15 subjects of HC). Gene expression was estimated by qPCR, and the serum cytokine levels were determined by ELISA.

Results

The percentage of Treg (CD4+CD25highCD127-) cells in RA patients was lower than in OA patients or HCs. Proportions of Th17 (CD4+CCR6+CXCR3-) cells were higher in RA and OA in comparison to HCs. STAT5 showed a very high expression in the blood of RA patients compared to healthy subjects. The expression of STAT5 and HELIOS was not detected in Th17 cells. A positive correlation between SMAD3 and STAT3 in RA patients was observed. Negative correlations between HIF-1A and SMAD2 in RA Treg cells and DAS-28 score were observed. The range of serum of IL-17 and IL-21 were higher in RA patients than in OA patients. Concentrations of serum IL-2 and IFN-γ were higher in RA and OA patients than in healthy subjects. Based on the ROC analysis, the diagnostic potential of the combination of HIF1A, SMAD3 and STAT3, was determined at AUC 0.95 for distinguishing RA patients from HCs. For distinguishing RA patients from OA patients the diagnostic potential of the combination of SMAD2, SMAD3, SMAD4 and STAT3, was determined at AUC 0.95.

Conclusion

Based on our study, we conclude that SMAD3 and STAT3 could be potential diagnostic biomarkers for RA.

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

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

PRKCH polymorphism is associated with rheumatoid arthritis in a Chinese population

Genetic factors have been widely considered to have a substantial effect on the susceptibility to rheumatoid arthritis (RA). The purpose of this study was to determine whether the four newly discovered polymorphisms in a genome-wide association study (GWAS) meta-analysis confer susceptibility to RA in a Chinese Han population. We conducted a case-control study involving 359 RA cases and 873 age-and gender-matched controls and performed genotyping of four single nucleotide polymorphisms (SNPs), rs227163, rs726288, rs3783782 and rs2469434, using the dye terminator-based SNaPshot method. Consequently, we detected significant differences of genotype distribution of rs3783782 in PRKCH between RA and controls. The minor allele frequencies (MAFs) of rs3783782 were significantly higher in RA patients compared to control subjects. Moreover, the rs227163 in TNFRSF9 had higher MAFs in male RA compared with male controls. In addition, the polymorphism of rs3783782 in PRKCH was significantly associated with RA susceptibility (OR = 1.67, 95% CI = 1.32-2.11, p = 1.32 × 10^-5). After stratification by gender, the minor (A) allele was strongly associated with increased risk for RA in males (OR = 1.87, 95% CI = 1.34-2.60; p = 1.62 × 10^-4) and in females (OR = 1.51, 95% CI = 1.08-2.10; p = 0.014). For rs227163, the minor (C) allele was found to be associated with RA risk only in males (OR = 1.34, 95% CI = 1.02-1.75; p = 0.036). These findings for the first time confirmed that rs3783782 in PRKCH was associated with RA susceptibility in a Chinese population, and rs227163 in TNFRSF9 was associated with RA risk in Chinese males; these SNPs may serve as genetic markers for RA.

Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review

Rheumatoid arthritis (RA), a chronic inflammatory autoimmune disease, affects roughly 1% of the world's population. RA pathogenesis remains unclear, but genetic factors account for 50–60% of the risk while the remainder might be linked to modifiable factors, such as infectious diseases, tobacco smoking, gut bacteria, and nutrition. Dietary triggers may play an inciting role in the autoimmune process, and a compromised intestinal barrier may allow food components or microorganisms to enter the blood stream, triggering inflammation. In addition, excessive body weight may affect pharmacotherapy response and the likelihood of disease remission, as well as the risk of disease mortality. Evidence suggests that changes in diet might play an important role in RA management and remission. Several studies have shown improvements in RA symptoms with diets excluding animal products. Studies have also shown that dietary fiber found in these plant-based foods can improve gut bacteria composition and increase bacterial diversity in RA patients, thus reducing their inflammation and joint pain. Although some of the trigger foods in RA patients are individualized, a vegan diet helps improve symptoms by eliminating many of these foods. This review examines the potential role of a plant-based diet in mediating RA symptoms. Further research is needed to test the effectiveness of plant-based diets on joint pain, inflammation, and quality of life in patients with RA.

A Combined Transcriptomic and Genomic Analysis Identifies a Gene Signature Associated With the Response to Anti-TNF Therapy in Rheumatoid Arthritis

Background: Rheumatoid arthritis (RA) is the most frequent autoimmune disease involving the joints. Although anti-TNF therapies have proven effective in the management of RA, approximately one third of patients do not show a significant clinical response. The objective of this study was to identify new genetic variation associated with the clinical response to anti-TNF therapy in RA.

Methods: We performed a sequential multi-omic analysis integrating different sources of molecular information. First, we extracted the RNA from synovial biopsies of 11 RA patients starting anti-TNF therapy to identify gene coexpression modules (GCMs) in the RA synovium. Second, we analyzed the transcriptomic association between each GCM and the clinical response to anti-TNF therapy. The clinical response was determined at week 14 using the EULAR criteria. Third, we analyzed the association between the GCMs and anti-TNF response at the genetic level. For this objective, we used genome-wide data from a cohort of 348 anti-TNF treated patients from Spain. The GCMs that were significantly associated with the anti-TNF response were then tested for validation in an independent cohort of 2,706 anti-TNF treated patients. Finally, the functional implication of the validated GCMs was evaluated via pathway and cell type epigenetic enrichment analyses.

Results: A total of 149 GCMs were identified in the RA synovium. From these, 13 GCMs were found to be significantly associated with anti-TNF response (P < 0.05). At the genetic level, we detected two of the 13 GCMs to be significantly associated with the response to adalimumab (P = 0.0015) and infliximab (P = 0.021) in the Spain cohort. Using the independent cohort of RA patients, we replicated the association of the GCM associated with the response to adalimumab (P = 0.0019). The validated module was found to be significantly enriched for genes involved in the nucleotide metabolism (P = 2.41e-5) and epigenetic marks from immune cells, including CD4+ regulatory T cells (P = 0.041).

Conclusions: These findings show the existence of a drug-specific genetic basis for anti-TNF response, thereby supporting treatment stratification in the search for response biomarkers in RA.

Helios but not CD226, TIGIT and Foxp3 is a Potential Marker for CD4+ Treg Cells in Patients with Rheumatoid Arthritis

BACKGROUND/AIMS

Rheumatoid arthritis (RA) is a progressive, chronic, even disabling systemic autoimmune disease. Imbalance between pathogenic immune cells and immunosuppressive cells is associated with the pathogenesis and development of RA and other autoimmune diseases. As Foxp3 is also expressed on activated CD4⁺ cells in the presence of inflammation, the identification of Treg cells in patients with RA remains a challenge.

METHODS

Comprehensive analyses were carried out by Flow cytometry. Expression of Helios, CD226, T cell immunoreceptor with Ig and ITIM domains clinical samples and healthy controls.

RESULTS

We have systemically examined three potential markers, Helios, CD226 and TIGIT, that are possibly related to Treg identification, and found that Helios expression on CD4⁺Foxp3⁺cells was decreased and negatively correlated with the disease activity of RA patients, while CD226 and TIGIT both showed elevated expression levels in CD4⁺Foxp3⁺cells in RA patients and they were not associated with disease activity of RA patients.

CONCLUSION

Taken together, our findings indicate that CD4⁺CD25^hiCD127^low/-Foxp3⁺Helios⁺ may represent the real Treg cell population in patients with RA.

Counter-regulation of regulatory T cells by autoreactive CD8+ T cells in rheumatoid arthritis

The mechanisms whereby autoreactive T cells escape peripheral tolerance establishing thus autoimmune diseases in humans remain an unresolved question. Here, we demonstrate that autoreactive polyfunctional CD8⁺ T cells recognizing self-antigens (i.e., vimentin, actin cytoplasmic 1, or non-muscle myosin heavy chain 9 epitopes) with high avidity, counter-regulate Tregs by killing them, in a consistent percentage of rheumatoid arthritis (RA) patients. Indeed, these CD8⁺ T cells express a phenotype and gene profile of effector (eff) cells and, upon antigen-specific activation, kill Tregs indirectly in an NKG2D-dependent bystander fashion in vitro. This data provides a mechanistic basis for the finding showing that AE-specific (CD107a⁺) CD8⁺ T killer cells correlate, directly with the disease activity score, and inversely with the percentage of activated Tregs, in both steady state and follow-up studies in vivo. In addition, multiplex immunofluorescence imaging analyses of inflamed synovial tissues in vivo show that a remarkable number of CD8⁺ T cells express granzyme-B and selectively contact FOXP3⁺ Tregs, some of which are in an apoptotic state, validating hence the possibility that CD8⁺ Teff cells can counteract neighboring Tregs within inflamed tissues, by killing them. Alternatively, the disease activity score of a different subset of patients is correlated with the expansion of a peculiar subpopulation of autoreactive low avidity, partially-activated (pa)CD8⁺ T cells that, despite they conserve the conventional naïve (N) phenotype, produce high levels of tumor necrosis factor (TNF)-α and exhibit a gene expression signature of a progressive activation state. Tregs directly correlate with the expansion of this autoreactive (low avidity) paCD8⁺ TN cell subset in vivo, and efficiently control their differentiation rather their proliferation in vitro. Interestingly, autoreactive high avidity CD8⁺ Teff cells or low avidity paCD8⁺ TN cells are significantly expanded in RA patients who would become non-responders or patients who would become responders to TNF-α inhibitor therapy, respectively. These data provide evidence of a previously undescribed role of such mechanisms in the progression and therapy of RA.

Modulation of immune response to induced-arthritis by low-level laser therapy

As low-level laser therapy immune cells responses are not always clarified, this study aimed to evaluate cytokines and immune cells profile after low-level laser therapy (LLLT) on arthritis-induced model. Arthritis was induced in C57BL/6 mice divided into five groups: euthanized 5 hours after inflammation induction; untreated; dexamethasone treated; LLLT at 3 Jcm^-2 ; LLLT at 30 Jcm^-2 . Cytokine measurements by enzyme-linked immunosorbent assay and mRNA cytokine relative levels by real-time quantitative polymerase chain reaction were performed with arthritic ankle (IL-1β, IL-6, TNF-α, IL-10 and TGF-β). Macrophages, dendritic cells, natural killer cells, lymphocytes CD4⁺ , CD8⁺ , Treg and costimulatory proteins were quantified in proximal lymph node by flow cytometry. Data showed decrease in all cytokine levels after LLLT and alteration in mRNA relative levels, depending on the energy density used. LLLT was able to increase of immune cell populations analyzed in the lymph node as well as costimulatory proteins expression on macrophages and dendritic cells. Treg TCD4⁺ and TCD8⁺ population enrichment were observed in LLLT at 3 and 30 Jcm^-2 groups, respectively. Furthermore, Treg TCD8⁺ cells expressing higher levels of CD25 were observed at LLLT at 30 Jcm^-2 group. Our results indicate that LLLT could change the inflammatory course of arthritis, tending to accelerate its resolution through immune cells photobiostimulation.

Modulation of T-cell responses by anti-tumor necrosis factor treatments in rheumatoid arthritis: a review

Tumor necrosis factor (TNF) is a pleiotropic cytokine involved in many aspects of immune regulation. Anti-TNF biological therapy has been considered a breakthrough in the treatment of chronic autoimmune diseases, such as rheumatoid arthritis (RA). In this review, because of the major involvement of T cells in RA pathogenesis, we discuss the effects of anti-TNF biotherapy on T-cell responses in RA patients. We also outline the potential fields for future research in the area of anti-TNF therapy in RA.This could be useful to better understand the therapeutic efficiency and the side effects that are encountered in RA patients. Better targeting of T cells in RA could help set more specific anti-TNF strategies and develop prediction tools for response.

Dysregulated ICOS+ proinflammatory and suppressive regulatory T cells in patients with rheumatoid arthritis

Regulatory T cells (Tregs) serve an important role in the pathogenesis of rheumatoid arthritis (RA) by regulating autoimmunity and inflammation. Humans and mice contain inducible T-cell costimulator-positive (ICOS⁺) Tregs, although their role in RA is unclear. A total of 33 patients with RA and 17 normal control (NC) subjects were examined. The proportion of ICOS⁺ Tregs in the peripheral blood and intracellular cytokine levels in these cells were assessed using flow cytometry. The percentage of ICOS⁺ Tregs increased in the cohort of patients with RA compared with the NCs. Such increases were much larger in patients with inactive RA compared with patients with active RA. Additionally, ICOS⁺ Tregs expressed multiple suppressive cytokines, including interleukin (IL)-10, transforming growth factor-β and IL-35, but expressed low levels of IL-17. Importantly, the expression of suppressive cytokines in ICOS⁺ Tregs from patients with active RA decreased, but IL-17 expression noticeably increased compared with patients with inactive RA. The present findings suggested that ICOS⁺ Tregs may perform inflammatory and inhibitory functions, and abnormal ICOS⁺ Tregs numbers and functions may contribute to the pathogenesis of RA.

The Role of Nicotinamide Adenine Dinucleotide in the Pathogenesis of Rheumatoid Arthritis: Potential Implications for Treatment

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory, autoimmune disease characterised by small joint swelling, deformity, and dysfunction. Its exact aetiology is unclear. Current treatment approaches do not control harmful autoimmune attacks or prevent irreversible damage without considerable side effects. Nicotinamide adenine dinucleotide (NAD+), an important hydrogen carrier in mitochondrial respiration and oxidative phosphorylation, is the major determinant of redox state in the cell. NAD+ metabolites act as degradation substrates for a wide range of enzymes, such as sirtuins, poly-ADP-ribose polymerases, ADP-ribosyltransferases, and CD38. The roles of NAD+ have expanded beyond its role as a coenzyme, linking cellular metabolism to inflammation signalling and immune response. The aim of this review is to illustrate the role of NAD+-related enzymes in the pathogenesis of RA and highlight the potential therapeutic role of NAD+ in RA.

Intraperitoneal infusion of mesenchymal stem cell attenuates severity of collagen antibody induced arthritis

It is unclear how systemic administration of mesenchymal stem cells (MSCs) controls local inflammation. The aim of this study was to evaluate the therapeutic effects of human MSCs on inflammatory arthritis and to identify the underlying mechanisms. Mice with collagen antibody-induced arthritis (CAIA) received two intraperitoneal injections of human bone marrow-derived MSCs. The clinical and histological features of injected CAIA were then compared with those of non-injected mice. The effect of MSCs on induction of regulatory T cells was examined both in vitro and in vivo. We also examined multiple cytokines secreted by peritoneal mononuclear cells, along with migration of MSCs in the presence of stromal cell-derived factor-1 alpha (SDF-1α) and/or regulated on activation, normal T cell expressed and secreted (RANTES). Sections of CAIA mouse joints and spleen were stained for human anti-nuclear antibodies (ANAs) to confirm migration of injected human MSCs. The results showed that MSCs alleviated the clinical and histological signs of synovitis in CAIA mice. Peritoneal lavage cells from mice treated with MSCs expressed higher levels of SDF-1α and RANTES than those from mice not treated with MSCs. MSC migration was more prevalent in the presence of SDF-1α and/or RANTES. MSCs induced CD4+ T cells to differentiate into regulatory T cells in vitro, and expression of FOXP3 mRNA was upregulated in the forepaws of MSC-treated CAIA mice. Synovial and splenic tissues from CAIA mice receiving human MSCs were positive for human ANA, suggesting recruitment of MSCs. Taken together, these results suggest that MSCs migrate into inflamed tissues and directly induce the differentiation of CD4+ T cells into regulatory T cells, which then suppress inflammation. Thus, systemic administration of MSCs may be a therapeutic option for rheumatoid arthritis.

Clinical Remission of Sight-Threatening Non-Infectious Uveitis Is Characterized by an Upregulation of Peripheral T-Regulatory Cell Polarized Towards T-bet and TIGIT

Background

Non-infectious uveitis can cause chronic relapsing and remitting ocular inflammation, which may require high dose systemic immunosuppression to prevent severe sight loss. It has been classically described as an autoimmune disease, mediated by pro-inflammatory Th1 and Th17 T-cell subsets. Studies suggest that natural immunosuppressive CD4⁺CD25⁺FoxP3⁺ T-regulatory cells (Tregs) are involved in resolution of inflammation and may be involved in the maintenance of clinical remission.

Objective

To investigate whether there is a peripheral blood immunoregulatory phenotype associated with clinical remission of sight-threatening non-infectious uveitis by comparing peripheral blood levels of Treg, Th1, and Th17, and associated DNA methylation and cytokine levels in patients with active uveitic disease, control subjects and patients (with previously active disease) in clinical remission induced by immunosuppressive drugs.

Methods

Isolated peripheral blood mononuclear cells (PBMC) from peripheral blood samples from prospectively recruited subjects were analyzed by flow cytometry for CD3, CD4, FoxP3, TIGIT, T-bet, and related orphan receptor γt. Epigenetic DNA methylation levels of FOXP3 Treg-specific demethylated region (TSDR), FOXP3 promoter, TBX21, RORC2, and TIGIT loci were determined in cryopreserved PBMC using a next-generation sequencing approach. Related cytokines were measured in blood sera. Functional suppressive capacity of Treg was assessed using T-cell proliferation assays.

Results

Fifty patients with uveitis (intermediate, posterior, and panuveitis) and 10 control subjects were recruited. The frequency of CD4⁺CD25⁺FoxP3⁺ Treg, TIGIT⁺ Treg, and T-bet⁺ Treg and the ratio of Treg to Th1 were significantly higher in remission patients compared with patients with active uveitic disease; and TIGIT⁺ Tregs were a significant predictor of clinical remission. Treg from patients in clinical remission demonstrated a high level of in vitro suppressive function compared with Treg from control subjects and from patients with untreated active disease. PBMC from patients in clinical remission had significantly lower methylation levels at the FOXP3 TSDR, FOXP3 promoter, and TIGIT loci and higher levels at RORC loci than those with active disease. Clinical remission was also associated with significantly higher serum levels of transforming growth factor β and IL-10, which positively correlated with Treg levels, and lower serum levels of IFNγ, IL-17A, and IL-22 compared with patients with active disease.

Conclusion

Clinical remission of sight-threatening non-infectious uveitis has an immunoregulatory phenotype characterized by upregulation of peripheral Treg, polarized toward T-bet and TIGIT. These findings may assist with individualized therapy of uveitis, by informing whether drug therapy has induced phenotypically stable Treg associated with long-term clinical remission.

Microbiota Composition May Predict Anti-Tnf Alpha Response in Spondyloarthritis Patients: an Exploratory Study

Spondyloarthritis (SpA) pathophysiology remains largely unknown. While the association with genetic factors has been established for decades, the influence of gut microbiota is only an emerging direction of research. Despite the remarkable efficacy of anti-TNF-α treatments, non-responders are frequent and no predictive factors of patient outcome have been identified. Our objective was to investigate the modifications of intestinal microbiota composition in patients suffering from SpA three months after an anti-TNF-α treatment. We performed 16S rDNA sequencing of 38 stool samples from 19 spondyloarthritis patients before and three months after anti-TNF-α treatment onset. SpA activity was assessed at each time using ASDAS and BASDAI scores. Some modifications of the microbiota composition were observed after three months of anti-TNF-α treatment, but no specific taxon was modified, whatever the clinical response. We identified a particular taxonomic node before anti-TNF-α treatment that can predict the clinical response as a biomarker, with a higher proportion of Burkholderiales order in future responder patients. This study suggests a cross-influence between anti-TNF-α treatment and intestinal microbiota. If its results are confirmed on larger groups of patients, it may pave the way to the development of predictive tests suitable for clinical practices.

Immunology of idiopathic nephrotic syndrome

The pathogenesis of idiopathic nephrotic syndrome (INS) is as yet unknown, but several lines of evidence indicate that the immune system may play a crucial pathogenic role in non-genetic INS. The most important of these are, first, the effectiveness of therapy based on immunosuppression and, second, a vast body of data derived both from experimental models and from patient studies that implicate T cells and more recently B cells as major players in INS pathogenesis. However, recent findings also suggest a direct role of podocytes as drivers of the disease process, and the interplay between the glomerulus and the immune system is still being elucidated. In this review we provide an overview of current knowledge on the role of different components of the immune system in determining disease. Advances in our understanding of the pathogenesis of INS may help drive new, more tailored therapeutic approaches.

N-3 polyunsaturated fatty acids restore Th17 and Treg balance in collagen antibody-induced arthritis

N-3 polyunsaturated fatty acids (PUFA) have anti-inflammatory effects and were considered useful for the treatment of rheumatoid arthritis (RA). Recently, several studies suggested that n-3 PUFAs attenuated arthritis in animal model and human, however the mechanism is still unclear. Interleukin 17 (IL-17) is a pro-inflammatory cytokine mainly produced by T helper 17 (Th17) cells which cause tissue inflammation and bone erosion leading to joint destruction. In contrast, regulatory T (Treg) cells down-regulate various immune responses by suppression of naïve T cells. The imbalance between Th17 cells and Tregs cell is important for the pathogenesis of RA. Here, we investigated whether n-3 PUFAs attenuate arthritis in collagen antibody-induced arthritis (CAIA) model. We used fat-1 transgenic mice expressing the Caenorhabditis elegans fat-1 gene encoding an n-3 fatty acid desaturase that converts n-6 to n-3 fatty acids, leading to abundant n-3 fatty acids without the need of a dietary n-3 supply. Clinical arthritis score was significantly attenuated in fat-1 mice compared to wild type (WT) mice on day 7 (1.6±1.8, p = 0.012) and day 9 (1.5±1.6, p = 0.003). Ankle thickness also decreased significantly in fat-1 mice compared to WT mice (1.82±0.11, p = 0.008). The pathologic finding showed that inflammatory cell infiltration and bone destruction were reduced in fat-1 mice compared to WT. The expression levels of IL-17 and related cytokines including IL-6 and IL-23 decreased in the spleen and ankle joint tissue of fat-1 mice compared to WT mice. Furthermore, Treg cells were expanded in the spleen of fat-1 mice and Treg cell differentiation was significantly higher in fat-1 mice than in wild type (p = 0.038). These data suggest that n-3 PUFAs could attenuate arthritis through increasing the expression of FoxP3 and the differentiation of Treg, while reducing IL-17 production. Therefore, dietary supplementation of n-3 PUFAs could have a therapeutic potential for the treatment of RA.

Anti-inflammatory Mechanism of Geniposide: Inhibiting the Hyperpermeability of Fibroblast-Like Synoviocytes via the RhoA/p38MAPK/NF-κB/F-Actin Signal Pathway

Geniposide (GE) is the extraction and purification of iridoid glycosides from the Gardenia jasminoides Ellis, which is a promising anti-inflammatory drug, but its mechanism of actions on rheumatoid arthritis (RA) has not been clarified. This study investigated the molecular mechanism behind GE reduced the high permeability of fibroblast-like synoviocytes (FLSs) derived from SD rats with adjuvant arthritis (AA), with the aims of observing the action of GE in AA rats and exploring new therapeutic strategies for RA treatment. The CCK-8 method was used to detect FLSs proliferation. The pro-inflammatory cytokines levels and anti-inflammatory cytokines levels in FLSs were determined by ELISA kits. FLSs permeability assay was performed on Transwell. Immunofluorescence was used to assay the arrangement and morphology of F-actin. The expression of the key molecules related to FLSs permeability (RhoA, p-p38MAPK, NF-κB p-p65 and F-actin) was detected by western blotting. After treatment with lipopolysaccharide (LPS), the proliferation and the permeability of the cells increased significantly (all P < 0.05). The expression of RhoA, p-p38MAPK, NF-κB p-p65 and F-actin in FLSs was higher compared with the control group, and F-actin was redistributed, with the formation of additional stress fibers. But, these conditions were moderated after treatment with GE. We demonstrated that the treatment of different concentrations of GE (25, 50, and 100 μg/mL) had a significant inhibitory effect on the proliferation and permeability of FLSs in vitro. Furthermore, the levels of interleukin (IL)-1β and IL-17 secreted by FLSs were decreased in different doses of GE groups, and the levels of anti-inflammatory cytokines (IL-4, TGF-β1) were increased. Under treatment with GE, low expression of RhoA downregulated expression of p-p38MAPK, NF-κB p-p65, and F-actin while compared with control group, and restored the hyperpermeability of FLSs due to LPS treatment. Taken together, GE might play its anti-inflammatory and immunoregulatory effects via regulating the relative equilibrium of pro-inflammatory cytokines and anti-inflammatory cytokines. GE attenuated the hyperpermeability of FLSs. The down-regulation of the conduction of RhoA/p38MAPK/NF-κB/F-actin signal may play a critical role in the mechanisms of GE on RA. GE could be an effective therapeutic agent for the treatment of RA.

Inhibition of NF-κB pathway in fibroblast-like synoviocytes by α-mangostin implicated in protective effects on joints in rats suffering from adjuvant-induced arthritis

α-Mangostin (MG) is a bioactive compound isolated from mangosteen. This study was aimed to investigate effects of MG on adjuvant-induced arthritis (AA) in rats and decipher the underlying mechanisms. Clinical severity of AA was evaluated by paw oedema, arthritis score, and hematological parameters. Digital radiography (DR) and histological examinations were employed to assess joints destructions. Immune functions were evaluated by T cell subsets distribution. Effects on NF-κB pathway were investigated by immunohistochemical, western-blot and immunofluorescence methods both in vivo and vitro. It was found MG possessed superior anti-inflammatory effects in vivo, suggested by attenuated paw swelling, reduced inflammatory cells infiltration and decreased the secretion of TNF-α and IL-1β in serum. Meanwhile MG inhibited fibrous hyperplasia, synovial angiogenesis, cartilage and bone degradation in AA rats. Although MG exerted little effects on CD4⁺ population, it greatly decreased IFN-γ positive cells and promoted expression of FOXP3 in immune organs, indicating restoration of Th1/Treg cells ratio and recovery of immune homeostasis in vivo. Inhibition of NF-κB induced by MG was indicated by reduced the expression of p-p65 and VEGF in synovium. In vitro experiments found MG at 10 μg/ml significantly suppressed the expression and phosphorylation of key proteins implicated in NF-κB pathway and inhibited nucleus translocation of p65. These changes led to increased apoptosis and proliferation inhibition of HFLS-RA cells. The results demonstrated regulation of immune functions was deeply involved in the therapeutic actions of MG on AA, and it's inhibition on NF-κB in fibroblast-like synoviocytes was associated to the protective effects on joints.

Stimulation of TNF receptor type 2 expands regulatory T cells and ameliorates established collagen-induced arthritis in mice

Tumor necrosis factor (TNF) and its receptors TNF receptor type 1 (TNFR1) and type 2 (TNFR2) have a central role in chronic inflammatory diseases. While TNFR1 mainly confers inflammation, activation of TNFR2 elicits not only pro-inflammatory but also anti-inflammatory effects. In this study, we wanted to investigate the anti-inflammatory therapeutic potential of selective activation of TNFR2 in mice with established collagen-induced arthritis. Mice with established arthritis induced by immunization with bovine collagen type II were treated with six injections of the TNFR2-specific agonist TNCscTNF80, given every second day. Two days after treatment cessation, the cell compositions of bone marrow, spleen and lymph nodes were analyzed. Mice were visually scored until day 30 after the start of therapy and the degree of joint inflammation was determined by histology. Treatment with TNCscTNF80 increased arthritis-induced myelopoiesis. Little effect was seen on the infiltration rate of inflammatory immature myeloid cells and on the reduction of lymphoid cells in secondary lymphoid organs. Upon treatment, frequency of regulatory T (Treg) cells in the CD4⁺ T-cell population was increased in both spleen and inguinal lymph nodes. In addition, the expression of TNFR2 on Treg cells was enhanced. The clinical score started to improve 1 week after cessation treatment and remained lower 30 days after initiation of therapy. The histological score also revealed amelioration of joint inflammation in TNCscTNF80-treated versus control mice. Activation of TNFR2 might provide a suitable therapeutic strategy in autoimmune arthritis by increasing the numbers of regulatory cell types, in particular Treg cells, and by attenuation of arthritis.

Aging, Obesity, and Inflammatory Age-Related Diseases

The increase in the prevalence of obesity represents a worldwide phenomenon in all age groups and is pathologically and genetically correlated with several metabolic and cardiovascular diseases, representing the most frequent age-related diseases. Obesity superimposed on aging drastically increases chronic low-grade inflammation (inflammaging), which is an important link between obesity, insulin resistance, and age-associated diseases. Immune cells of both the innate and the adaptive immune systems infiltrate the adipose tissue (AT) and during obesity induce inflammatory responses associated with metabolic switches and changes in phenotypes and function of immune cell subsets. Obesity poses new health problems especially when it occurs in the context of other diseases, many of them frequently affect elderly subjects. An emerging problem is the decreased proportion of patients with obesity achieving clinical response to therapy. In this review, we will discuss the reciprocal influences of immune cell and AT inflammation in aging and age-associated diseases and the complex relationship of nutrient and energy-sensing homeostatic checkpoints, which contribute to shape the phenotype of the AT. We will specifically examine type-2 diabetes, rheumatoid arthritis, osteoarthritis, cognitive impairment, and dementia, where obesity plays a significant role, also in shaping some clinical aspects.

T-Cell Subsets in Rheumatoid Arthritis Patients on Long-Term Anti-TNF or IL-6 Receptor Blocker Therapy

Data on the impact of biological therapies on the T-cell phenotype in rheumatoid arthritis are limited. Here, we prospectively measured the percentages of 15 circulating T-cell subtypes using flow cytometry. We obtained transversal and longitudinal data in 30 anti-TNF responders, 19 secondary anti-TNF nonresponders, and 43 IL-6R antagonist responders, before, 8 weeks and at least 6 months after biological therapy. Untreated RA patients and healthy controls were also included. The important findings are the following: (1) the proportion of regulatory T-cells (Tregs) which are decreased in untreated RA patients becomes normal in all long-term-treated groups; (2) in anti-TNF responders as well as in nonresponders, the frequencies of naïve CD4+ and CD8+ cells are lower, whereas those of proinflammatory Th1, Th2, and Th17 cells and HLA-DR+-activated cells are higher than those in untreated RA or healthy controls; (3) in IL-6R responders, Th1 proportion is decreased, while that of Th2 and Th17 is increased as compared to that in anti-TNF-treated patients and controls; (4) pending confirmation, a CD4CD69 ratio < 2.43 at baseline, could be useful to predict a good therapeutic response to anti-TNF therapy. This study provides comprehensive information regarding the long-term impacts of those biological therapies on the ecotaxis of T-cells in RA. The ClinicalTrials.gov registration number of our study is NCT03266822.

Th17/Treg immunoregulation and implications in treatment of sulfur mustard gas-induced lung diseases

INTRODUCTION

Sulfur mustard (SM) is an extremely toxic gas used in chemical warfare to cause massive lung injury and death. Victims exposed to SM gas acutely present with inhalational lung injury, but among those who survive, some develop obstructive airway diseases referred to as SM-lung syndrome. Pathophysiologically, SM-lung shares many characteristics with smoking-induced chronic obstructive pulmonary disease (COPD), including airway remodeling, goblet cell metaplasia, and obstructive ventilation defect. Some of the hallmarks of COPD pathogenesis, which include dysregulated lung inflammation, neutrophilia, recruitment of interleukin 17A (IL -17A) expressing CD4⁺T cells (Th17), and the paucity of lung regulatory T cells (Tregs), have also been described in SM-lung. Areas covered: A literature search was performed using the MEDLINE, EMBASE, and Web of Science databases inclusive of all literature prior to and including May 2017. Expert commentary: Here we review some of the recent findings that suggest a role for Th17 cell-mediated inflammatory changes associated with pulmonary complications in SM-lung and suggest new therapeutic approaches that could potentially alter disease progression with immune modulating biologics that can restore the lung Th17/Treg balance.

Immunopathogenesis of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is the most common inflammatory arthropathy. The majority of evidence, derived from genetics, tissue analyses, models, and clinical studies, points to an immune-mediated etiology associated with stromal tissue dysregulation that together propogate chronic inflammation and articular destruction. A pre-RA phase lasting months to years may be characterized by the presence of circulating autoantibodies, increasing concentration and range of inflammatory cytokines and chemokines, and altered metabolism. Clinical disease onset comprises synovitis and systemic comorbidities affecting the vasculature, metabolism, and bone. Targeted immune therapeutics and aggressive treatment strategies have substantially improved clinical outcomes and informed pathogenetic understanding, but no cure as yet exists. Herein we review recent data that support intriguing models of disease pathogenesis. They allude to the possibility of restoration of immunologic homeostasis and thus a state of tolerance associated with drug-free remission. This target represents a bold vision for the future of RA therapeutics.

Interleukin-10-producing LAG3+ regulatory T cells are associated with disease activity and abatacept treatment in rheumatoid arthritis

BACKGROUND

Regulatory T cells (Tregs) play a role in the suppression of inflammation in autoimmune diseases, and lymphocyte activation gene 3 (LAG3) was reported as a marker of interleukin (IL)-10-producing Tregs. We aimed to clarify the function of human IL-10-producing CD4⁺CD25^-LAG3⁺ T cells (LAG3⁺ Tregs) and their association with rheumatoid arthritis (RA).

METHODS

LAG3⁺ Tregs of human peripheral blood mononuclear cells (PBMCs) were cultured with B cells and follicular helper T cells to examine antibody suppression effects. The frequency of LAG3⁺ Tregs was evaluated in peripheral blood samples from 101 healthy donors and 85 patients with RA. In patients treated with abatacept, PBMC samples were analyzed before and after treatment. Naive CD4⁺ T cells were sorted and cultured in the presence of abatacept, followed by flow cytometric analysis and function assays.

RESULTS

LAG3⁺ Tregs produced high amounts of IL-10 and interferon-γ, and they suppressed B-cell antibody production more strongly than CD25⁺ Tregs. Cell-to-cell contact was required for the suppressive function of LAG3⁺ Tregs. The frequency of LAG3⁺ Tregs was lower in patients with RA, especially those with higher Clinical Disease Activity Index scores. LAG3⁺ Tregs significantly increased after 6 months of abatacept treatment, whereas CD25⁺ Tregs generally decreased. Abatacept treatment in vitro conferred LAG3 and EGR2 expression on naive CD4⁺ T cells, and abatacept-treated CD4⁺ T cells exhibited suppressive activity.

CONCLUSIONS

IL-10-producing LAG3⁺ Tregs are associated with the immunopathology and therapeutic response in RA. LAG3⁺ Tregs may participate in a mechanism for the anti-inflammatory and immune-modulating effects of targeted therapy for costimulation.

FGF21 exerts comparable pharmacological efficacy with Adalimumab in ameliorating collagen-induced rheumatoid arthritis by regulating systematic inflammatory response

Previous studies have reported that Fibroblast growth factor 21 (FGF21) can regulate inflammation and may play an important role in inflammatory and immune-mediated diseases, such as autoimmune diseases. Adalimumab is one of the clinically effective anti-rheumatoid arthritis (RA) drugs. The aim of this study was to compare the therapeutic efficacy of FGF21 and Adalimumab on collagen-induced arthritis (CIA) model mice. Mice with CIA were subcutaneously treated with FGF21 or Adalimumab at dose of 1mgkg^-1d^-1, respectively. Our results showed that FGF21 significantly alleviated the severity of arthritis by reducing cellular immune responses and exerted the similar anti-inflammatory effects with Adalimumab in decreasing the mRNA and protein expression levels of IL-2, IL-6 and IL-17. However, the expression levels of IL-1β, RANKL and IL-10 in the mice treated with FGF21 were decreased 2.2-fold, 2.5-fold and increased 4.3-fold compared with Adalimumab, respectively. However, the levels of TNF-α in the mice treated with Adalimumab were lower than those in the mice treated with FGF21. Western blotting results demonstrated that FGF21 displayed equivalent effects with Adalimumab by inhibiting NF-κB/IκBα signaling pathway. However, FGF21 could also regulate systematic inflammatory response and the mechanism maybe related to other signal pathway. In summary, FGF21 exerts comparable pharmacological efficacy with Adalimumab by regulating systematic inflammatory response, providing that FGF21 may be a promising therapeutic agent for RA patients.

Foxp3 and Toll-like receptor signaling balance Treg cell anabolic metabolism for suppression

CD4⁺ effector T cells (T_eff cells) and regulatory T cells (T_reg cells) undergo metabolic reprogramming to support proliferation and immunological function. Although signaling via the lipid kinase PI(3)K (phosphatidylinositol-3-OH kinase), the serine-threonine kinase Akt and the metabolic checkpoint kinase complex mTORC1 induces both expression of the glucose transporter Glut1 and aerobic glycolysis for T_eff cell proliferation and inflammatory function, the mechanisms that regulate T_reg cell metabolism and function remain unclear. We found that Toll-like receptor (TLR) signals that promote T_reg cell proliferation increased PI(3)K-Akt-mTORC1 signaling, glycolysis and expression of Glut1. However, TLR-induced mTORC1 signaling also impaired T_reg cell suppressive capacity. Conversely, the transcription factor Foxp3 opposed PI(3)K-Akt-mTORC1 signaling to diminish glycolysis and anabolic metabolism while increasing oxidative and catabolic metabolism. Notably, Glut1 expression was sufficient to increase the number of T_reg cells, but it reduced their suppressive capacity and Foxp3 expression. Thus, inflammatory signals and Foxp3 balance mTORC1 signaling and glucose metabolism to control the proliferation and suppressive function of T_reg cells.

The role of progranulin in arthritis

Progranulin (PGRN) is a growth factor with a unique beads-on-a-string structure that is involved in multiple pathophysiological processes, including anti-inflammation, tissue repair, wound healing, neurodegenerative diseases, and tumorigenesis. This review presents up-to-date information concerning recent studies on the role of PGRN in inflammatory arthritis and osteoarthritis, with a special focus on the involvement of the interactions and interplay between PGRN and tumor necrosis factor receptor (TNFR) family members in regulating such musculoskeletal diseases. In addition, this paper highlights the applications of atsttrin, an engineered protein comprising three TNFR-binding fragments of PGRN, as a promising intervention in treating arthritis.

The balance between Foxp3 and Ror-γt expression in peripheral blood is altered by tocilizumab and abatacept in patients with rheumatoid arthritis

Background

The balance between Th17 cells and regulatory T (Treg) cells has been shown to play an important role in the development of rheumatoid arthritis (RA). Recent studies have shown that treatment with abatacept (ABT) or tocilizumab (TCZ) affects Th17 and Treg cell populations. Although not unanimously accepted, several reports have shown that Treg cells are decreased by ABT and increased by TCZ, and that Th17 cells are decreased by TCZ. To further investigate the effects of ABT and TCZ on the skewing of T cell populations, we analyzed the expression of master regulators genes of helper T cell lineages following ABT/TCZ treatment of RA patients.

Methods

Ten patients treated with ABT and 10 patients treated with TCZ were enrolled. Total RNA was extracted from peripheral blood cells at baseline, and after 12 and 24 weeks of therapy. The expression levels of T-bet, GATA3, Foxp3 and Ror-γt were semi-quantified using real-time PCR. The relative expression levels were expressed as the ratios of two genes (T-bet/GATA3, Foxp3/GATA3, Foxp3/T-bet, Foxp3/Ror-γt, Ror-γt/T-bet, Ror-γt/GATA3), and the changes in these ratios with treatment were determined.

Results

The Foxp3/Ror-γt ratio was decreased after ABT therapy (0.67 ± 0.16 at 24 weeks, P = 0.0034) but was increased after TCZ therapy (2.00 ± 1.03 at 24 weeks, P = 0.0013). In addition, the Ror-γt/GATA3 ratio was decreased after TCZ therapy (0.78 ± 0.37 at 24 weeks, P = 0.0008). Except for these ratios, no significant skewing in the expression of these factors was detected. No significant relationship between clinical response to the treatment and change in the ratios of these factors was determined.

Conclusion

Treatment with TCZ or ABT differently affected the balance between Foxp3 and Ror-γt expression in the peripheral blood of patients with RA.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1137-1) contains supplementary material, which is available to authorized users.

Infliximab therapy balances regulatory T cells, tumour necrosis factor receptor 2 (TNFR2) expression and soluble TNFR2 in sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown aetiology that most commonly affects the lungs. Although elevated levels of regulatory T cells (Tregs ) have been reported, the extent to which they play a role in sarcoidosis pathogenesis remains unclear. Tumour necrosis factor (TNF) is thought to be one of the driving forces behind granuloma formation, illustrated by the efficacy of infliximab in severe sarcoidosis. Tregs express TNF receptor 2 (TNFR2) highly. Here, we examined the influence of infliximab therapy on Tregs and (soluble) TNFR2 levels in sarcoidosis, and correlated these with response to therapy. We observed that relative frequencies of Tregs were significantly higher in patients (n = 54) compared to healthy controls (n = 26; median 6·73 versus 4·36%; P < 0·001) and decreased following therapy (4·95; P < 0·001). Baseline TNFR2 expression on Tregs was increased significantly in patients versus controls (99·4 versus 96·2%; P = 0·031), and also in responders to therapy versus non-responders (99·6 versus 97·3%; P = 0·012). Furthermore, baseline soluble TNFR2 (sTNFR2) was higher in responders than in non-responders (mean 174 versus 107 pg/ml; P = 0·015). After treatment, responders showed a significant reduction in sTNFR2 levels in peripheral blood (-44·7 pg/ml; P < 0·001), in contrast to non-responders (+3·59 pg/ml). Our results demonstrated that Treg frequencies and TNFR2 expression on Tregs are increased in sarcoidosis, followed by a decline during infliximab therapy, suggesting a pathophysiological role of this T cell subset. Interestingly, sTNFR2 levels at baseline differed significantly between responders and non-responders, making it a potential marker in predicting which patients might benefit from infliximab.