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

Anti-inflammatory effects of infliximab and methotrexate on peripheral blood and synovial fluid mononuclear cells: ex vivo study

OBJECTIVE

To investigate the effects of methotrexate (MTX) and the tumour necrosis factor inhibitor infliximab (IFX) on immune cells derived from peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) of inflammatory arthritis patients.

METHOD

Phytohaemagglutinin (PHA)-induced proliferation of healthy donors' PBMCs and synovial intermediate monocytes (CD14+CD16+ cells) in SFMCs derived from psoriatic arthritis (PsA) and rheumatoid arthritis (RA) patients was determined by flow cytometry following co-culture with IFX and MTX. PHA-induced interferon-γ (IFN-γ) production in PBMCs was measured by enzyme-linked immunosorbent assay. The drugs' effect on mRNA expression in SFMCs was determined by quantitative polymerase chain reaction.

RESULTS

The combination of IFX 10 μg/mL + MTX 0.1 μg/mL had the strongest inhibitory effect on PBMC proliferation (91%), followed by MTX 0.1 μg/mL (86%) and IFX 10 μg/mL (49%). In PHA-stimulated PBMCs, IFN-γ production was reduced by IFX 10 μg/mL, MTX 0.1 μg/mL, and IFX 10 μg/mL + MTX 0.1 μg/mL by 68%, 90%, and 85%, respectively. In SFMCs, IFX 10 µg/mL significantly reduced CD14+CD16+ cells compared to medium (PsA 54%, p < 0.01; RA 46%, p < 0.05), while MTX had no effect on this population. IFX + MTX led to a similar suppression of CD14+CD16+ cells as achieved by IFX alone. The drugs had different impacts on SFMC gene expression.

CONCLUSION

Both IFX and MTX effectively inhibited PBMC proliferation and IFN-γ production, but only IFX reduced synovial monocytes and pro-inflammatory gene expression in SFMCs, suggesting a differential impact of IFX and MTX on critical inflammatory cell populations ex vivo.

A compendium of mitochondrial molecular characteristics provides novel perspectives on the treatment of rheumatoid arthritis patients

Rheumatoid arthritis (RA) is an autoimmune disease that exhibits a high degree of heterogeneity, marked by unpredictable disease flares and significant variations in the response to available treatments. The lack of optimal stratification for RA patients may be a contributing factor to the poor efficacy of current treatment options. The objective of this study is to elucidate the molecular characteristics of RA through the utilization of mitochondrial genes and subsequently construct and authenticate a diagnostic framework for RA. Mitochondrial proteins were obtained from the MitoCarta database, and the R package limma was employed to filter for differentially expressed mitochondrial genes (MDEGs). Metascape was utilized to perform enrichment analysis, followed by an unsupervised clustering algorithm using the ConsensuClusterPlus package to identify distinct subtypes based on MDEGs. The immune microenvironment, biological pathways, and drug response were further explored in these subtypes. Finally, a multi-biomarker-based diagnostic model was constructed using machine learning algorithms. Utilizing 88 MDEGs present in transcript profiles, it was possible to classify RA patients into three distinct subtypes, each characterized by unique molecular and cellular signatures. Subtype A exhibited a marked activation of inflammatory cells and pathways, while subtype C was characterized by the presence of specific innate lymphocytes. Inflammatory and immune cells in subtype B displayed a more modest level of activation (Wilcoxon test P < 0.05). Notably, subtype C demonstrated a stronger correlation with a superior response to biologics such as infliximab, anti-TNF, rituximab, and methotrexate/abatacept (P = 0.001) using the fisher test. Furthermore, the mitochondrial diagnosis SVM model demonstrated a high degree of discriminatory ability in distinguishing RA in both training (AUC = 100%) and validation sets (AUC = 80.1%). This study presents a pioneering analysis of mitochondrial modifications in RA, offering a novel framework for patient stratification and potentially enhancing therapeutic decision-making.

Efficacy of COVID-19 mRNA vaccination in patients with autoimmune disorders: humoral and cellular immune response

BACKGROUND

The impact of immunosuppressive therapies on the efficacy of vaccines to SARS-CoV-2 is not completely clarified. We analyzed humoral and T cell-mediated response after COVID-19 mRNA vaccine in immunosuppressed patients and patients with common variable immunodeficiency disease (CVID).

PATIENTS

We enrolled 38 patients and 11 healthy sex- and age-matched controls (HC). Four patients were affected by CVID and 34 by chronic rheumatic diseases (RDs). All patients with RDs were treated by corticosteroid therapy and/or immunosuppressive treatment and/or biological drugs: 14 patients were treated with abatacept, 10 with rituximab, and 10 with tocilizumab.

METHODS

Total antibody titer to SARS-CoV-2 spike protein was assessed by electrochemiluminescence immunoassay, CD4 and CD4-CD8 T cell-mediated immune response was analyzed by interferon-γ (IFN-γ) release assay, the production of IFN-γ-inducible (CXCL9 and CXCL10) and innate-immunity chemokines (MCP-1, CXCL8, and CCL5) by cytometric bead array after stimulation with different spike peptides. The expression of CD40L, CD137, IL-2, IFN-γ, and IL-17 on CD4 and CD8 T cells, evaluating their activation status, after SARS-CoV-2 spike peptides stimulation, was analyzed by intracellular flow cytometry staining. Cluster analysis identified cluster 1, namely the "high immunosuppression" cluster, and cluster 2, namely the "low immunosuppression" cluster.

RESULTS

After the second dose of vaccine, only abatacept-treated patients, compared to HC, showed a reduced anti-spike antibody response (mean: 432 IU/ml ± 562 vs mean: 1479 IU/ml ± 1051: p = 0.0034), and an impaired T cell response, compared with HC. In particular, we found a significantly reduced release of IFN-γ from CD4 and CD4-CD8 stimulated T cells, compared with HC (p = 0.0016 and p = 0.0078, respectively), reduced production of CXCL10 and CXCL9 from stimulated CD4 (p = 0.0048 and p = 0.001) and CD4-CD8 T cells (p = 0.0079 and p = 0.0006). Multivariable General Linear Model analysis confirmed a relationship between abatacept exposure and impaired production of CXCL9, CXCL10, and IFN-γ from stimulated T cells. Cluster analysis confirms that cluster 1 (including abatacept and half of rituximab treated cases) showed a reduced IFN-γ response, as well as reduced monocyte-derived chemokines All groups of patients demonstrated the ability to generate specific CD4 T activated cells after spike proteins stimulation. After the third dose of vaccine, abatacept-treated patients acquired the ability to produce a strong antibody response, showing an anti-S titer significantly higher compared to that obtained after the second dose (p = 0.0047), and comparable with the anti-S titer of the other groups.

CONCLUSIONS

Patients treated with abatacept showed an impaired humoral immune response to two doses of COVID-19 vaccine. The third vaccine dose has been demonstrated to be useful to induce a more robust antibody response to balance an impaired T cell-mediated one. All patients, exposed to different immunosuppressive drugs, were able to produce specific CD4-activated T cells, after spike proteins stimulation.

TRIAL REGISTRATION

Local Ethical Committee NP4187.

Red Cell Distribution Width and Absolute Lymphocyte Count Associate With Biomarkers of Inflammation and Subsequent Mortality in Rheumatoid Arthritis

OBJECTIVE

Morbidity and mortality in rheumatoid arthritis (RA) is partly mitigated by maintaining immune and hematologic homeostasis. Identification of those at risk is challenging. Red cell distribution width (RDW) and absolute lymphocyte count (ALC) associate with cardiovascular disease (CVD) and mortality in the general population, and with disease activity in RA. How these variables relate to inflammation and mortality in RA was investigated.

METHODS

In a retrospective single Veterans Affairs (VA) Rheumatology Clinic cohort of 327 patients with RA treated with methotrexate (MTX)+/- a tumor necrosis factor (TNF) inhibitor (TNFi), we evaluated RDW and ALC before and during therapy and in relation to subsequent mortality. Findings were validated in a national VA cohort (n = 13,914). In a subset of patients and controls, we evaluated inflammatory markers.

RESULTS

In the local cohort, high RDW and low ALC prior to MTX treatment was associated with subsequent mortality over 10 years (both P < 0.001). The highest mortality was observed in those with both high RDW and low ALC. This remained after adjusting for age and comorbidities and was validated in the national RA cohort. In the immunology cohort, soluble and cellular inflammatory markers were higher in patients with RA than in controls. ALC correlated with age, plasma TNF receptor II, natural killer HLA-DR mean fluorescence intensity, and CD4CM/CD8CM HLA-DR/CD38%, whereas RDW associated with age and ALC. MTX initiation was followed by an increase in RDW and a decrease in ALC. TNFi therapy added to MTX resulted in an increase in ALC.

CONCLUSION

RDW and ALC before disease-modifying antirheumatic drug therapy are associated with biomarkers of monocyte/macrophage inflammation and subsequent mortality. The mechanistic linkage between TNF signaling and lymphopenia found here warrants further investigation.

Comparison of Homologous and Heterologous Booster SARS-CoV-2 Vaccination in Autoimmune Rheumatic and Musculoskeletal Patients

Vaccination against SARS-CoV-2 to prevent COVID-19 is highly recommended for immunocompromised patients with autoimmune rheumatic and musculoskeletal diseases (aiRMDs). Little is known about the effect of booster vaccination or infection followed by previously completed two-dose vaccination in aiRMDs. We determined neutralizing anti-SARS-CoV-2 antibody levels and applied flow cytometric immunophenotyping to quantify the SARS-CoV-2 reactive B- and T-cell mediated immunity in aiRMDs receiving homologous or heterologous boosters or acquired infection following vaccination. Patients receiving a heterologous booster had a higher proportion of IgM+ SARS-CoV-2 S+ CD19+CD27+ peripheral memory B-cells in comparison to those who acquired infection. Biologic therapy decreased the number of S+CD19+; S+CD19+CD27+IgG+; and S+CD19+CD27+IgM+ B-cells. The response rate to a booster event in cellular immunity was the highest in the S-, M-, and N-reactive CD4+CD40L+ T-cell subset. Patients with a disease duration of more than 10 years had higher proportions of CD8+TNF-α+ and CD8+IFN-γ+ T-cells in comparison to patients who were diagnosed less than 10 years ago. We detected neutralizing antibodies, S+ reactive peripheral memory B-cells, and five S-, M-, and N-reactive T-cells subsets in our patient cohort showing the importance of booster events. Biologic therapy and <10 years disease duration may confound anti-SARS-CoV-2 specific immunity in aiRMDs.

A systematic literature review informing the consensus statement on efficacy and safety of pharmacological treatment with interleukin-6 pathway inhibition with biological DMARDs in immune-mediated inflammatory diseases

Objectives

Informing an international task force updating the consensus statement on efficacy and safety of biological disease-modifying antirheumatic drugs (bDMARDs) selectively targeting interleukin-6 (IL-6) pathway in the context of immune-mediated inflammatory diseases.

Methods

A systematic literature research of all publications on IL-6 axis inhibition with bDMARDs published between January 2012 and December 2020 was performed using MEDLINE, EMBASE and Cochrane CENTRAL databases. Efficacy and safety outcomes were assessed in clinical trials including their long-term extensions and observational studies. Meeting abstracts from ACR, EULAR conferences and results on clinicaltrials.gov were taken into consideration.

Results

187 articles fulfilled the inclusion criteria. Evidence for positive effect of IL-6 inhibition was available in various inflammatory diseases such as rheumatoid arthritis, juvenile idiopathic arthritis, giant cell arteritis, Takayasu arteritis, adult-onset Still’s disease, cytokine release syndrome due to chimeric antigen receptor T cell therapy and systemic sclerosis-associated interstitial lung disease. Newcomers like satralizumab and anti-IL-6 ligand antibody siltuximab have expanded therapeutic approaches for Castleman’s disease and neuromyelitis optica, respectively. IL-6 inhibition did not provide therapeutic benefits in psoriatic arthritis, ankylosing spondylitis and certain connective tissue diseases. In COVID-19, tocilizumab (TCZ) has proven to be therapeutic in advanced disease. Safety outcomes did not differ from other bDMARDs, except higher risks of diverticulitis and lower gastrointestinal perforations. Inconsistent results were observed in several studies investigating the risk for infections when comparing TCZ to TNF-inhibitors.

Conclusion

IL-6 inhibition is effective for treatment of several inflammatory diseases with a safety profile that is widely comparable to other bDMARDs.

Low-dose IL-2 therapy limits the reduction in absolute numbers of peripheral lymphocytes in systemic lupus erythematosus patients with infection

BACKGROUND

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disorder characterized by disturbed cellular and humoral immune responses. Dysregulations of immune system and immunosuppressive medications predispose SLE patients to infection. This study aims to investigate the alterations and absolute concentrations of lymphocyte subpopulations in SLE patients with different infection and their responses of low-dose IL-2 therapy.

METHODS

A total of 333 patients with SLE without recent infection, 162 patients suffering infection, and age and sex-matched 132 healthy controls (HCs) were recruited. Of them, 54 SLE patients (including 41 non-infected group and 13 infected group) received a 5-day course of low-dose IL-2 administration at a dose of 0.5 million IU per day. Lymphocyte subpopulations were analyzed by flow cytometry.

RESULTS

Patients with SLE had lower levels of lymphocyte subpopulations in peripheral blood such as T, B, NK, CD4 + T, CD8+ T, Th1, Th2, Th17, and Treg cells, and the reduction in these cells was more obvious in patients with infection (p <.05 to p <.01). Low-dose IL-2 effectively expanded T (p <.001), B (p <.001), CD4 + T (p <.01), CD8 + T (p <.001), Th1 (p <.01), Th17 (p <.1), and Treg cells (p <.01) of SLE patients, these cells were comparable to that of HCs after the IL-2 treatment.

CONCLUSIONS

Patients with SLE had insufficiency of circulating lymphocyte subsets. This phenomenon was more obverse in those accompanying infection, suggesting the low concentration of lymphocytes may be used as indicators of high infection risk in SLE patients. Low-dose IL-2 induced expansion of Treg cells and NK cells, which may contribute to the restoration of immune homeostasis in SLE patients.

Longitudinal analysis of blood DNA methylation identifies mechanisms of response to tumor necrosis factor inhibitor therapy in rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a chronic, immune-mediated inflammatory disease of the joints that has been associated with variation in the peripheral blood methylome. In this study, we aim to identify epigenetic variation that is associated with the response to tumor necrosis factor inhibitor (TNFi) therapy.

Methods

Peripheral blood genome-wide DNA methylation profiles were analyzed in a discovery cohort of 62 RA patients at baseline and at week 12 of TNFi therapy. DNA methylation of individual CpG sites and enrichment of biological pathways were evaluated for their association with drug response. Using a novel cell deconvolution approach, altered DNA methylation associated with TNFi response was also tested in the six main immune cell types in blood. Validation of the results was performed in an independent longitudinal cohort of 60 RA patients.

Findings

Treatment with TNFi was associated with significant longitudinal peripheral blood methylation changes in biological pathways related to RA (FDR<0.05). 139 biological functions were modified by therapy, with methylation levels changing systematically towards a signature similar to that of healthy controls. Differences in the methylation profile of T cell activation and differentiation, GTPase-mediated signaling, and actin filament organization pathways were associated with the clinical response to therapy. Cell type deconvolution analysis identified CpG sites in CD4+T, NK, neutrophils and monocytes that were significantly associated with the response to TNFi.

Interpretation

Our results show that treatment with TNFi restores homeostatic blood methylation in RA. The clinical response to TNFi is associated to methylation variation in specific biological pathways, and it involves cells from both the innate and adaptive immune systems.

Funding

The Instituto de Salud Carlos III.

Emerging therapeutic potential of regulatory T (Treg) cells for rheumatoid arthritis: New insights and challenges

Rheumatoid arthritis (RA) is an autoimmune-related disorder characterized by chronic inflammation. Although the etiopathogenesis of RA still remains to be clarified, it is supposed that the breakdown of immune self-tolerance may contribute to the development of RA. Thus, restoring of immune tolerance at the site of inflammation is the ultimate goal of RA treatment. Regulatory T cells (Treg cells) are the main suppressive cells that maintain tolerance and inhibit immunity against auto-antigen. Of note, recent studies demonstrated the efficacy of adoptive transfer of Treg cells in the modulation of the unwanted immune response, which makes them an ideal candidate to maintain immune homeostasis and restore antigen-specific tolerance in the case of RA and other autoimmune diseases. This review intends to submit recent finding of Treg cells-based therapies in RA with a focus on strategies applied to improve the therapeutic value of Treg cells to restore immune tolerance.

Instructive cartilage regeneration modalities with advanced therapeutic implantations under abnormal conditions

The development of interdisciplinary biomedical engineering brings significant breakthroughs to the field of cartilage regeneration. However, cartilage defects are considerably more complicated in clinical conditions, especially when injuries occur at specific sites (e.g., osteochondral tissue, growth plate, and weight-bearing area) or under inflammatory microenvironments (e.g., osteoarthritis and rheumatoid arthritis). Therapeutic implantations, including advanced scaffolds, developed growth factors, and various cells alone or in combination currently used to treat cartilage lesions, address cartilage regeneration under abnormal conditions. This review summarizes the strategies for cartilage regeneration at particular sites and pathological microenvironment regulation and discusses the challenges and opportunities for clinical transformation.

Peripheral distributions of IL-4-producing CD4 + T cells and CD4 + CD25 + FoxP3 + T cells (Tregs) in rheumatoid arthritis patients with poor response to therapy are associated with HLA shared epitope alleles and ACPA status

Specific profiling of CD4 + T cell subsets in the circulation and inflamed joints of rheumatoid arthritis (RA) patients may have therapeutic implications. This study aimed to evaluate the peripheral distributions of Th2 and Treg cells in relation to HLA-shared epitope (SE) alleles and anti-cyclic citrullinated peptide antibody (ACPAs) status in patients with good response (GR) and poor response (PR) to treatment. The frequencies of IL-4-producing CD4 + T cells (Th2) and CD4 + CD25 + Foxp3 + T cells (Tregs) were determined by flow cytometry in 167 RA patients including 114 GR and 53 PR cases. CD4 + T cell subsets were also analyzed based on HLA-SE and ACPAs statuses. One hundred nine of 167 patients were positives for HLA-SE, 63.4% for ACPAs, 43.7% for SE/ACPAs and 14.9% were negatives for SE/ACPAs. Higher frequencies of Th2 (P = 0.001) and Treg cells (P = 0.03) were found in the patients versus controls. Increased and decreased frequencies of Th2 and Tregs cells were observed in the PR versus GR patients respectively (P = 0.003 and P = 0.004). Higher proportions of Th2 cells were observed in the SE⁺RA versus SE^-RA (P = 0.001), in ACPA⁺RA versus ACPA^-RA (P = 0.005) and in the SE⁺ACPA⁺RA versus SE^-ACPA^-RA patients (P = 0.002). Treg cells frequencies decreased in the SE⁺RA versus SE^-RA (P = 0.03) and in SE⁺ACPA⁺RA versus SE^-ACPA^-RA (P = 0.02). ACPA⁺GR and SE⁺PR patients showed higher proportions of Th2 cells than ACPA^-GR and SE^-PR patients respectively (P = 0.02 and P = 0.01). Analysis of the CD4 + T cell subsets profiles in conjunction with genetic background and autoantibodies patterns can be useful for precise therapeutic response monitoring in the RA patients.

Humoral and Cellular Immunogenicity and Safety of Five Different SARS-CoV-2 Vaccines in Patients With Autoimmune Rheumatic and Musculoskeletal Diseases in Remission or With Low Disease Activity and in Healthy Controls: A Single Center Study

Background

Vaccine-induced immunity is essential for controlling the COVID-19 pandemic. Data on humoral and cellular immunogenicity and safety of different SARS-CoV-2 vaccines in patients with autoimmune rheumatic and musculoskeletal diseases (RMDs) are limited.

Methods

A single center observational study evaluated the immunogenicity and safety of the two-dose regimen of the BBIBP-CorV inactivated, Gam-COVID-Vac and AZD1222 adenovirus-based, and BNT162b2 and mRNA-1273 mRNA-based vaccines in patients with RMDs (n = 89) compared with healthy controls (n = 74). Neutralizing anti-RBD (receptor binding domain) specific antibodies and SARS-CoV-2 specific T-cell response were measured one and four months after the second vaccine dose in parallel with vaccination efficacy and safety.

Results

Disease-specific comparison showed that antibody response at four months was higher in spondylarthropathies compared to rheumatoid arthritis and autoimmune RMDs. Risk factors for reduced immunogenicity included longer disease duration, positive immunoserological profile and anti-CD20 therapy of patients. The rate of positive anti-RBD antibody response for healthy controls versus patients after 4 months post vaccination was 69% vs. 55% for the inactivated viral vaccine BBIBP-CorV, 97% vs. 53% for the pooled data of adenovirus vector-based vaccines Gam-COVID-Vac and AZD1222, or 100% vs. 81% for the pooled data of mRNA vaccines BNT162b2 and mRNA-1273, respectively. Patients who received the Gam-COVID-Vac or mRNA-1273 vaccines had a higher proportion of TNF-α producing CD4+ T-cells upon SARS-CoV-2 antigen stimulation compared to the inactivated viral vaccine.

Conclusion

All five investigated vaccines were immunogenic in the majority of patients and healthy controls with variable antibody and T-cell response and an acceptable safety profile.

Pharmacogenomics of Anti-TNF Treatment Response Marks a New Era of Tailored Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is the most commonly occurring chronic inflammatory arthritis, the exact mechanism of which is not fully understood. Tumor Necrosis Factor (TNF)-targeting drugs has been shown to exert high effectiveness for RA, which indicates the key importance of this cytokine in this disease. Nevertheless, the response to TNF inhibitors varies, and approximately one third of RA patients are non-responders, which is explained by the influence of genetic factors. Knowledge in the field of pharmacogenomics of anti-TNF drugs is growing, but has not been applied in the clinical practice so far. Different genome-wide association studies identified a few single nucleotide polymorphisms associated with anti-TNF treatment response, which largely map genes involved in T cell function. Studies of the gene expression profile of RA patients have also indicated specific gene signatures that may be useful to develop novel prognostic tools. In this article, we discuss the significance of TNF in RA and present the current knowledge in pharmacogenomics related to anti-TNF treatment response.

Polyene Phosphatidylcholine Interacting with TLR-2 Prevents the Synovial Inflammation via Inactivation of MAPK and NF-κB Pathways

Rheumatoid arthritis (RA) is a chronic autoimmune joint disease that causes cartilage and bone damage or even disability, seriously endangering human health. Chronic synovial inflammation has been shown to play a vital role in disease sustainability. Therefore, downregulation of synovial inflammation is considered to be an effective discipline for RA therapy. Polyene phosphatidylcholine (PPC) is a hepatoprotective agent, which was observed to inhibit inflammation in macrophages and prevent collagen-induced arthritis (CIA) of rats in our previous study. However, the underlying mechanism remains unclear. The present study further reported that PPC can inhibit synovial inflammation. In lipopolysaccharide (LPS)-stimulated primary synovial fibroblasts (SFs) of mice, PPC significantly decreased pro-inflammatory cytokines production while increasing anti-inflammatory cytokines level. In this process, PPC downregulated the expression of TLR-2 and their downstream signaling molecules such as MyD88, p-ERK1/2, p-JNK1/2, and p-P38 in MAPK pathway and p-IκBα and NF-κB-p65 in NF-κB pathway. Moreover, the inhibitory effect of PPC on the above molecules and cytokines was weakened after pre-treatment with TLR-2 agonist Pam3CSK4. In addition, PPC lost its anti-inflammatory effect and its suppressing capability on MAPK and NF-κB pathways in TLR-2^-/- primary SFs after exposure to LPS. Collectively, this study demonstrated that PPC can alleviate synovial inflammation through TLR-2-mediated MAPK and NF-κB pathways, which can be proposed to be a potential drug candidate for RA prevention.

Dysfunctions, Molecular Mechanisms, and Therapeutic Strategies of Regulatory T Cells in Rheumatoid Arthritis

Regulatory T cells (Tregs) represent a distinct subpopulation of CD4⁺ T lymphocytes that promote immune tolerance and maintain immune system homeostasis. The dysfunction of Tregs is tightly associated with rheumatoid arthritis (RA). Although the complex pathogenic processes of RA remain unclear, studies on Tregs in RA have achieved substantial progress not only in fundamental research but also in clinical application. This review discusses the current knowledge of the characterizations, functions, and molecular mechanisms of Tregs in the pathogenesis of RA, and potential therapies for these disorders are also involved.

Remission Induced by TNF Inhibitors Plus Methotrexate is Associated With Changes in Peripheral Naïve B Cells in Patients With Rheumatoid Arthritis

Biological therapies, such as TNF inhibitors (TNFi), are increasing remission (REM) rates in rheumatoid arthritis (RA) patients, although these are still limited. The aim of our study was to analyze changes in the profile of peripheral blood mononuclear cells (PBMC) in patients with RA treated with TNFi in relation to the clinical response. This is a prospective and observational study including 78 RA patients starting the first TNFi. PBMC were analyzed by flow cytometry both at baseline and at 6 months. Disease activity at the same time points was assessed by DAS28, establishing DAS28 ≤ 2.6 as the criteria for REM. Logistic regression models were employed to analyze the association between the changes in PBMC and REM. After 6 months of TNFi treatment, 37% patients achieved REM by DAS28. Patients who achieved REM showed a reduction in the percentage of naive B cells, but only when patients had received concomitant methotrexate (MTX) (OR: 0.59; 95% CI: 0.39–0.91). However, no association was found for patients who did not receive concomitant MTX (OR: 0.85; 95% CI: 0.63–1.16). In conclusion, PBMC, mainly the B-cell subsets, are modified in RA patients with TNFi who achieve clinical REM. A significant decrease in naive B-cell percentage is associated with achieving REM after 6 months of TNFi treatment in patients who received concomitant therapy with MTX.

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.

Combining Nivolumab and Ipilimumab with Infliximab or Certolizumab in Patients with Advanced Melanoma: First Results of a Phase Ib Clinical Trial

PURPOSE

TNF blockers can be used to manage gastrointestinal inflammatory side effects following nivolumab and/or ipilimumab treatment in patients with advanced melanoma. Our preclinical data showed that anti-TNF could promote the efficacy of immune checkpoint inhibitors.

PATIENTS AND METHODS

TICIMEL (NTC03293784) is an open-label, two-arm phase Ib clinical trial. Fourteen patients with advanced and/or metastatic melanoma (stage IIIc/IV) were enrolled. Patients were treated with nivolumab (1 mg/kg) and ipilimumab (3 mg/kg) combined to infliximab (5 mg/kg, N = 6) or certolizumab (400/200 mg, N = 8). The primary endpoint was safety and the secondary endpoint was antitumor activity. Adverse events (AEs) were graded according to the NCI Common Terminology Criteria for Adverse Events and response was assessed following RECIST 1.1.

RESULTS

Only one dose-limiting toxicity was observed in the infliximab cohort. The two different combinations were found to be safe. We observed lower treatment-related AEs with infliximab as compared with certolizumab. In the certolizumab cohort, one patient was not evaluable for response. In this cohort, four of eight patients exhibited hepatobiliary disorders and seven of seven evaluable patients achieved objective response including four complete responses (CRs) and three partial responses (PRs). In the infliximab cohort, we observed one CR, two PRs, and three progressive diseases. Signs of activation and maturation of systemic T-cell responses were seen in patients from both cohorts.

CONCLUSIONS

Our results show that both combinations are safe in human and provide clinical and biological activities. The high response rate in the certolizumab-treated patient cohort deserves further investigations.

Serum levels of 14-3-3η are associated with increased disease risk, activity and duration of rheumatoid arthritis in Chinese patients

The aim of the present study was to determine the association between serum 14-3-3η expression levels and disease risk, inflammation level and disease duration in Chinese patients with rheumatoid arthritis (RA). A total of 45 Chinese patients with RA, 45 patients with osteoarthritis (OA) and 44 age- and sex-matched (with the RA group) healthy control (HC) subjects were consecutively recruited for the present case-controlled study. In addition, the demographic and clinicopathological characteristics of the patients with RA were collected. Serum samples were obtained from patients with RA, patients with OA and the HCs, and the serum levels of 14-3-3η were determined by ELISA. Compared with that in the OA patients (P=0.006) and HCs (P<0.001), 14-3-3η expression was significantly increased in RA patients, and receiver operating characteristics (ROC) analysis indicated that it served as a potential predictive marker for the risk of RA. In patients with RA, serum levels of 14-3-3η were positively correlated with disease duration (P=0.003), erythrocyte sedimentation rate (P=0.006) and disease activity score in 28 joints (P=0.025). The proportion of rheumatoid factor (RF)-positive patients (P=0.023) and anti-citrullinated protein antibody (ACPA)-positive patients (P=0.002) with RA was increased (when 14-3-3η expression was increased) compared with RF-negative patients or ACPA-negative patients, respectively. Of note, 14-3-3η serum levels were able to distinguish patients with established RA (disease duration, >2 years) from patients with early RA (disease duration, ≤2 years) with an AUC of 0.759 (95% CI, 0.612-0.905), and the sensitivity and the specificity at the best cut-off point (14-3-3η=0.613 ng/ml) were 79.3 and 75.0%, respectively. Furthermore, 14-3-3η was able to differentiate between RF-positive RA patients and RF-negative patients or HCs. In conclusion, circulating 14-3-3η expression may serve as a novel biomarker for disease risk and activity of RA in Chinese patients.

Association of a Type 2-Polarized T Cell Phenotype With Methotrexate Nonresponse in Patients With Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease mediated through complex immunologic pathways. Among RA patients receiving low-dose methotrexate (MTX) monotherapy, approximately one-half exhibit a meaningful clinical response within the first 6 months of starting treatment. Whether baseline immune phenotypes differ between subsequent MTX responders and nonresponders is unknown. This study utilized comprehensive T cell immunophenotyping to identify specific immunologic pathways associated with MTX-nonresponsive joint inflammation in patients with RA.

METHODS

In total, 32 patients with recent-onset RA were treated with MTX therapy. After 6 months, 15 patients were categorized as responders and 17 as nonresponders. Comprehensive blood T cell immunophenotyping, using multiparameter immunofluorescence flow cytometry analyses, was performed at baseline and following 6 months of treatment.

RESULTS

Baseline measures of disease activity (Disease Activity Score in 28 joints [DAS28], C-reactive protein level, and erythrocyte sedimentation rate) did not differ between MTX responders and nonresponders following MTX treatment. Frequencies of CD4+ and CD8+ T cells were skewed to favor higher CD4:CD8 T cell ratios in MTX responders compared to nonresponders (P < 0.05). The proportion of inducible costimulator-expressing Treg cells was significantly greater among MTX nonresponders. Interleukin-13 (IL-13)-producing, but not interferon-γ- or IL-17-producing, CD4+ effector memory T (Tem) cells were significantly more frequent in MTX nonresponders (P < 0.05). The ratio of IL-13+:IL-17+ Tem cells among CD4+ Tem cells was 1.9-fold higher in MTX nonresponders compared to responders (P < 0.05). Both the CD4:CD8 T cell ratio and the frequency of IL-13+CD4+ Tem cells correlated with changes in the DAS28 score following MTX treatment, whereas T cell expression of immune checkpoint inhibitor markers (CTLA-4, programmed death 1, and T cell immunoglobulin and mucin domain-containing protein 3) did not differ between MTX responders and nonresponders.

CONCLUSION

We observed a bias toward type 2-polarized T cell inflammatory responses in the peripheral blood of MTX-nonresponsive RA patients. Targeting the IL-13+CD4+ T cell pathway could be a new therapeutic strategy in RA patients whose disease remains resistant to MTX.

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

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

Tofacitinib modulates the VZV-specific CD4+ T cell immune response in vitro in lymphocytes of patients with rheumatoid arthritis

OBJECTIVE

RA is a chronic inflammatory disease characterized by lymphocyte infiltration and release of inflammatory cytokines. Previous studies have shown that treatment with Janus kinase inhibitors, such as tofacitinib, increased the incidence rate of herpes zoster compared with conventional DMARDs. Therefore, this study aimed to investigate the effect of tofacitinib on the varicella-zoster-virus (VZV)-specific T cell immune response.

METHODS

The effect of tofacitinib on the VZV-specific T cell immune response was determined by evaluating the IFNγ production, the proliferative capacity, the VZV-induced differentiation into effector and memory T cells, the expression of activation marker CD69 and helper T cell type 1 (Th1)-characteristic chemokine receptors, such as CXCR3 and CCR5, as well as cytotoxic activity (perforin and granzyme B expression) of CD4+ T cells of patients with RA compared with healthy donors upon stimulation with VZV antigen in vitro.

RESULTS

Tofacitinib significantly reduced the IFNγ production, proliferation, activation, and CXCR3 expression of VZV-specific CD4+ T cells in a dose-dependent manner in short- and long-term lymphocyte culture. No effect on the distribution of naive, effectors or memory, or on the expression of perforin or granzyme B by VZV-specific CD4+ T cells was observed.

CONCLUSION

This study showed that tofacitinib significantly modulated the Th1 response to VZV. The poor VZV-specific cellular immune response in patients with RA may be considered in recommendations regarding appropriate vaccination strategies for enhancing the VZV-specific Th1 response.

PTEN negatively regulates the expression of pro-inflammatory cytokines and chemokines of fibroblast-like synoviocytes in adjuvant-induced arthritis

Rheumatoid arthritis (RA) is characterized by tumor-like expansion of the synovium and the subsequent destruction of adjacent articular cartilage and bone. The latest studies proved phosphatase and tension homolog deleted on chromosome 10 (PTEN) might contribute to the surviving, proliferation and pro-inflammatory cytokines in RA. The purpose of this study was to explore the function and underlying mechanisms of PTEN in RA pro-inflammatory cytokines and chemokines of fibroblast-like synoviocytes (FLSs). Increased level of PTEN was observed in adjuvant-induced arthritis (AIA) FLSs in comparison to normal rats. Increased concentrations of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), chemokines (CCL-2 and CCL-3), VCAM-1 and VEGF-α expression were observed in FLSs with PTEN inhibitor bpv or PTEN-RNAi. Moreover, co-incubation FLSs with overexpression vector with PTEN-GV141 reduced the expression of pro-inflammatory cytokines, chemokines, VCAM-1 and VEGF-α in AIA. Interestingly, we also found DNA methylation could regulate PTEN expression and activation of AKT signaling was with a change of PTEN. Altogether, our findings in the present study suggested that PTEN might play a pivotal role during pro-inflammatory cytokines and chemokines of FLSs through activation of AKT signaling pathway. In addition, PTEN expression may be regulated by DNA methylation in the pathogenesis of AIA.

Specific T-Cell Subsets Can Predict the Efficacy of Anti-TNF Treatment in Inflammatory Bowel Diseases

The effect of TNF-blockers on T-lymphocyte subsets is largely unknown in inflammatory bowel diseases (IBDs). The aim of the present study was to analyze the prevalence of T-cell subtypes and their correlation to therapeutic response. Sixty-eight patients with Crohn’s disease (CD), 46 with ulcerative colitis (UC) were enrolled. (1) The clinical course was followed after the initiation of TNF-blockers (prospective study). (2) The immunophenotype was also compared between long-term anti-TNF treated-responders and non-responders (cross-sectional study). The results were compared with those of therapy-naïve patients with active disease and those in remission with non-biological immunosuppressive therapy, and with healthy controls. Fourteen subtypes of peripheral blood T cells were measured with flow cytometry. The prevalence of Th2 and Th17 cells, of HLA-DR- and CD69-positive CD4 and CD8 cells, was higher, whereas the percentage of CD45RA-positive CD4 and CD8 cells was lower in both IBDs than in controls. CD8CD69 cell frequency was lower in remission, and decreased during anti-TNF therapy in CD responders. CD8CD45RO memory cells had higher prevalence in UC non-responders than in those starting anti-TNF. CD4CD45RO percentage < 49.05 at the initiation of TNF-blockers was predictive of a subsequent therapeutic response in CD, and Th2 and Th17 prevalence correlated with the duration of remission on TNF-blockers in UC. This study provided a detailed description of the T-cell composition in IBDs. CD8CD69 prevalence may be an activity marker in CD, and CD4CD45RO, Th2 and Th17 levels could be predictive for a therapeutic response to anti-TNF.

Role of Chemokines and Chemokine Receptors in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most prevalent autoimmune diseases and a prototypic inflammatory disease, affecting the small joints of the hands and feet. Chemokines and chemokine receptors play a critical role in RA pathogenesis via immune cells recruitment. Several chemokines and chemokine receptors are abundant in the peripheral blood and in the local inflamed joints of RA. Furthermore, synthetic and biologics disease modifying anti rheumatic drugs have been reported to affect chemokines expression. Thus, many studies have focused on targeting chemokines and chemokine receptors, where some have shown positive promising results. However, most of the chemokine blockers in human trials of RA treatment displayed some failures that can be attributed to several reasons in their structures and binding affinities. Nevertheless, targeting chemokines will continue to be under development, in order to improve their therapeutic potentials in RA and other autoimmune diseases. In this review we provide an up-to-date knowledge regarding the role of chemokines and chemokine receptors in RA with an emphasis on their activities on immune cells. We also discussed the effects of drugs targeting those molecules in RA. This knowledge might provide impetus for developing new therapeutic modalities to treat this chronic disease.

Therapeutic Effect of Exogenous Regulatory T Cells on Collagen-induced Arthritis and Rheumatoid Arthritis

Regulatory T (Treg) cells have anti-inflammatory functions and heighten immune tolerance. The proportion and functions of Treg cells are perturbed in rheumatoid arthritis (RA), contributing to the excessive immune activation associated with this disease. We therefore hypothesized that supplementation with foreign Treg cells could be used to treat RA. To investigate the therapeutic effects of exogenous Treg cells on RA and its mechanism, we used human Treg cells to treat collagen-induced arthritis (CIA) in a rat model to observe whether exogenous Treg cells can treat the disease across species. Successful treatment would indicate that Treg cell transplantation in humans is more likely to affect RA. In the present study, human Treg cells were collected from healthy human peripheral blood and culture-expanded in vitro. Induced human Treg cells were injected into CIA rats via the tail vein. The rats' lymphocyte subtypes, cytokines, and Th1/Th2 ratios were measured using flow cytometry. In the rats, following injection of the human Treg cells, the severity of CIA was significantly reduced (P < 0.01), the proportion of endogenous Treg cells increased in the peripheral blood and spleen (P = 0.007 and P < 0.01, respectively), and the proportion of B cells decreased (P = 0.031). The IL-5 level, IL-6 level, and Th1/Th2 ratio in the peripheral blood were decreased (P = 0.013, 0.009, and 0.012, respectively). The culture-expanded human Treg cells were also cultured with synovial fibroblast cells from RA patients (RASFs). After coculture with Treg cells, RASFs showed reduced proliferation (P < 0.01) and increased apoptosis (P = 0.037). These results suggest that exogenous and induced Treg cells can produce a therapeutic effect in RA and CIA by increasing endogenous Treg cells and RASF apoptosis and reducing B cells, the Th1/Th2 ratio, and secretion levels of IL-5 and IL-6. Treg cell transplantation could serve as a therapy for RA that does not cause immune rejection.

Anti-TNF treatment negatively regulates human CD4+ T-cell activation and maturation in vitro, but does not confer an anergic or suppressive phenotype

TNF‐blockade has shown clear therapeutic value in rheumatoid arthritis and other immune‐mediated inflammatory diseases, however its mechanism of action is not fully elucidated. We investigated the effects of TNF‐blockade on CD4⁺ T cell activation, maturation, and proliferation, and assessed whether TNF‐inhibitors confer regulatory potential to CD4⁺ T cells. CyTOF and flow cytometry analysis revealed that in vitro treatment of human CD4⁺ T cells with the anti‐TNF monoclonal antibody adalimumab promoted IL‐10 expression in CD4⁺ T cells, whilst decreasing cellular activation. In line with this, analysis of gene expression profiling datasets of anti‐TNF‐treated IL‐17 or IFN‐γ‐producing CD4⁺ T cells revealed changes in multiple pathways associated with cell cycle and proliferation. Kinetics experiments showed that anti‐TNF treatment led to delayed, rather than impaired T‐cell activation and maturation. Whilst anti‐TNF‐treated CD4⁺ T cells displayed some hyporesponsiveness upon restimulation, they did not acquire enhanced capacity to suppress T‐cell responses or modulate monocyte phenotype. These cells however displayed a reduced ability to induce IL‐6 and IL‐8 production by synovial fibroblasts. Together, these data indicate that anti‐TNF treatment delays human CD4⁺ T‐cell activation, maturation, and proliferation, and this reduced activation state may impair their ability to activate stromal cells.

Correlation between albumin to fibrinogen ratio, C-reactive protein to albumin ratio and Th17 cells in patients with rheumatoid arthritis

BACKGROUND

The albumin to fibrinogen ratio (AFR) and the C-reactive protein to albumin ratio (CAR) have been served as inflammatory markers. However, their roles in RA remain unclear. We investigated the association of AFR/CAR with the concentration of autoantibodies and Th17 cells in RA.

METHODS

A total of 196 RA patients, 200 patients with systemic lupus erythematosus (SLE), and 200 healthy donors (HD) who were admitted to the First Affiliated Hospital of Fujian Medical University were enrolled. The results of FIB, ALB, CRP, anti-cyclic citrullinated peptide antibodies (anti-CCP), rheumatoid factor (RF) and erythrocyte sedimentation rate (ESR) from RA patients and SLE patients were retrospectively analyzed. The percentage of Th17 cells in peripheral blood of RA patients was detected by flow cytometry, and the relative expression of TNF-α, IL-6 and IL-17A was detected by RT-qPCR. Correlation analysis of AFR/CAR and Th17 cells, CRP, ESR, TNF-α, IL-6 and IL-17A in RA was conducted.

RESULTS

Compared with SLE patients and healthy donors (HD), AFR concentration was significantly lower (P < 0.01) in RA patients, while CAR concentration was significantly increased (P < 0.01) in RA patients. AFR showed negative correlation with CRP (r = -0.7103), ESR (r = -0.6542), RF (-0.2219), Th17 cells (r = -0.5952) and IL-17A (r = -0.4681). CAR was positively correlated with CRP (r = 0.9899), ESR (r = 0.605), RF (0.1867), Th17 cells (r = 0.6818), TNF-α (r = 0.3388), and IL-17A (r = 0.2046).

CONCLUSIONS

The concentration of AFR in RA patients was reduced, while CAR concentration was increased. AFR and CAR are associated with CRP, ESR, RF, and Th17 cell ratios in RA patients, which can be used as potential indicators for determining RA inflammation.

A cross talk between dysbiosis and gut-associated immune system governs the development of inflammatory arthropathies

BACKGROUND

Emerging evidence suggests that dysbiosis, imbalanced gut microbial community, might be a key player in the development of various diseases, including inflammatory arthropathies, such as rheumatoid arthritis, spondyloarthritis (mainly, ankylosing spondylitis and psoriatic arthritis), and osteoarthritis. Yet, the underlying mechanisms and corresponding interactions remain poorly understood.

METHODS

We conducted a critical and extensive literature review to explore the association between dysbiosis and the development of inflammatory arthropathies. We also reviewed the literature to assess the perspectives that ameliorate inflammatory arthropathies by manipulating the microbiota with probiotics, prebiotics or fecal microbiota transplantation.

RESULTS

Some bacterial species (e.g. Prevotella, Citrobacter rodentium, Collinsella aerofaciens, Segmented filamentous bacteria) participate in the creation of the pro-inflammatory immune status, presumably via epitope mimicry, modification of self-antigens, enhanced cell apoptosis mechanisms, and destruction of tight junction proteins and intestinal barrier integrity, all leading to the development and maintainance of inflammatory arthropathies. Whether dysbiosis is an epiphenomenon or is an active driver of these disorders remains unclear, yet, recent observations clearly suggest that dysbiosis precedes and triggers their development implying a causative relationship between dysbiosis and inflammatory arthropathies. The underlying mechanisms include dysbiosis-mediated changes in the functional activity of the intestinal immune cell subsets, such as innate lymphoid cells, mucosa-associated invariant T cells, invariant natural killer T cells, T-follicular helper and T-regulatory cells. In turn, disturbed functionality of the gut-associated immune system is shown to promote the overgrowth of many bacteria, thus establishing a detrimental vicious circle of actively maintaining arthritis.

CONCLUSIONS

Analysis of the data described in the review supports the notion that a close, dynamic and tightly regulated cross talk between dysbiosis and the gut-associated immune system governs the development of inflammatory arthropathies.

Anti-TNF Therapy in Spondyloarthritis and Related Diseases, Impact on the Immune System and Prediction of Treatment Responses

Immune-mediated inflammatory diseases (IMIDs), such as spondyloarthritis (SpA), psoriasis, Crohn's disease (CD), and rheumatoid arthritis (RA) remain challenging illnesses. They often strike at a young age and cause lifelong morbidity, representing a considerable burden for the affected individuals and society. Pioneering studies have revealed the presence of a TNF-dependent proinflammatory cytokine cascade in several IMIDs, and the introduction of anti-TNF therapy 20 years ago has proven effective to reduce inflammation and clinical symptoms in RA, SpA, and other IMID, providing unprecedented clinical benefits and a valid alternative in case of failure or intolerable adverse effects of conventional disease-modifying antirheumatic drugs (DMARDs, for RA) or non-steroidal anti-inflammatory drugs (NSAIDs, for SpA). However, our understanding of how TNF inhibitors (TNFi) affect the immune system in patients is limited. This question is relevant because anti-TNF therapy has been associated with infectious complications. Furthermore, clinical efficacy of TNFi is limited by a high rate of non-responsiveness (30–40%) in RA, SpA, and other IMID, exposing a substantial fraction of patients to side-effects without clinical benefit. Despite the extensive use of TNFi, it is still not possible to determine which patients will respond to TNFi before treatment initiation. The recent introduction of antibodies blocking IL-17 has expanded the therapeutic options for SpA, as well as psoriasis and psoriatic arthritis. It is therefore essential to develop tools to guide treatment decisions for patients affected by SpA and other IMID, both to optimize clinical care and contain health care costs. After a brief overview of the biology of TNF, its receptors and currently used TNFi in the clinics, we summarize the progress that has been made to increase our understanding of the action of TNFi on the immune system in patients. We then summarize efforts dedicated to identify biomarkers that can predict treatment responses to TNFi and we conclude with a section dedicated to the recently introduced inhibitors of IL-17A and IL-23 in SpA and related diseases. The focus of this review is on SpA, however, we also refer to RA on topics for which only limited information is available on SpA in the literature.

Immunopathogenic Mechanisms and Novel Immune-Modulated Therapies in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, inflammatory autoimmune disease of unknown etiology. It is characterized by the presence of rheumatoid factor and anticitrullinated peptide antibodies. The orchestra of the inflammatory process among various immune cells, cytokines, chemokines, proteases, matrix metalloproteinases (MMPs), and reactive oxidative stress play critical immunopathologic roles in the inflammatory cascade of the joint environment, leading to clinical impairment and RA. With the growing understanding of the immunopathogenic mechanisms, increasingly novel marked and potential biologic agents have merged for the treatment of RA in recent years. In this review, we focus on the current understanding of pathogenic mechanisms, highlight novel biologic disease-modifying antirheumatic drugs (DMRADs), targeted synthetic DMRADs, and immune-modulating agents, and identify the applicable immune-mediated therapeutic strategies of the near future. In conclusion, new therapeutic approaches are emerging through a better understanding of the immunopathophysiology of RA, which is improving disease outcomes better than ever.

GANT61 alleviates arthritic symptoms by targeting fibroblast-like synoviocytes in CIA rats

BACKGROUND

Studies have identified that the fibroblast-like synoviocytes (FLS) exhibited tumor-like characteristics and was the key factor in the pathogenesis of Rheumatoid arthritis (RA). GANT61, an antagonist of the sonic hedgehog pathway, has been verified with inhibitory effect on many cancers. Here we investigated the effect of GANT61 on FLS and the development of collagen-induced arthritis (CIA).

METHODS

40 Sprague Dawley (SD) rats were randomly divided into four groups: normal, CIA, CIA+10 mg/kg GANT61 and CIA+20 mg/kg GANT61. CIA was induced in rat with collagen injecting. The GANT61 was administered by intraperitoneal injection every 2 days for 3 weeks. The CIA model was identified with the paw swelling, arthritis score and the pathologic changes in joint. The FLS of different group were primary cultured. The proliferative capacity of FLS was detecteded via Cell Counting Kit-8 (CCK-8) method, and the apoptosis was detecteded by flow cytometry. The Bcl-2, Bax, Caspases3 and cleaved Caspases3 in synovium and FLS were detecteded by Western Blot.

RESULTS

The 20 mg/kg GANT61 treatment reduced the incidence of CIA and relieved the arthritis symptoms in CIA rats. The Bcl-2 was upregulated and the Bax was downregulated in the CIA rats synovium. The 10 mg/kg and 20 mg/kg GANT61 diminished the Bcl-2 expression, 20 mg/kg GANT61 increased the Bax and activated the Caspases3 in the CIA synovium. The proliferation of CIA-FLS was significantly higher and the apoptosis of the CIA-FLS was lower than that of the control group. The 10 mg/kg and 20 mg/kg GANT61 treatment can reduce cell proliferation and induce apoptosis by diminishing Bcl-2 and increasing the Bax in CIA-FLS.

CONCLUSIONS

The GANT61 inhibit the proliferation of FLS and alleviated the arthritic symptoms in CIA rats, this implied the GANT61 may be recommended as a possible candidate for the therapy of RA.

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.

A Modified Compound From Paeoniflorin, CP-25, Suppressed Immune Responses and Synovium Inflammation in Collagen-Induced Arthritis Mice

Paeoniflorin-6’-O-benzene sulfonate (CP-25) is a modified paeoniflorin, which is the main bioactive component of total glucosides of peony. This study evaluated the anti-inflammatory and immunoregulatory effects of CP-25 in mice with collagen-induced arthritis (CIA) and the potential mechanisms underlying these effects. After the onset of CIA, mice were given CP-25 (17.5, 35, or 70 mg/kg) or methotrexate (MTX, 2.0 mg/kg). The arthritis index, swollen joint count, and joint and spleen histopathology were evaluated. T and B cell subsets were assayed using flow cytometry, while the proliferation of these cells and fibroblast-like synoviocytes (FLSs) were evaluated using the Cell Counting Kit-8. β2-adrenoceptor (β2-AR) expression was assayed using flow cytometry, immunohistochemistry, and western blotting. FLS migration and invasion were assayed using Transwells. CP-25 (35 or 70 mg/kg) attenuated the arthritis index and swollen joint count, alleviated joint and spleen histopathology, suppressed excessive T cell activation, and attenuated humoral immunity in CIA mice. CP-25 increased β2-AR expression on T cells, B cells, dendritic cells, and the synovium in CIA mice. CP-25 up-regulated the β2-AR agonist response and attenuated FLS activation; these effects may reflect CP-25-mediated reduction of β2-AR desensitization due to down-regulation of membrane G protein-coupled receptor kinase 2 expression. These results suggest that CP-25 suppressed immune responses and synovium inflammation in mice with CIA, effects that were associated with reduced β2-AR desensitization and the promotion of β2-AR signaling.

The Impact of Anti-TNF Therapy on CD4+ and CD8+ Cell Subsets in Ankylosing Spondylitis

OBJECTIVES

Ankylosing spondylitis (AS) is a chronic, progressive immune-mediated inflammatory disease, driven primarily by Th1 and Th17 cells. Anti-TNF therapies are successfully used in AS to achieve and maintain remission. However, their influence on the composition of T-cell subsets is not clear. We aimed to characterize the changes in the T-cell repertoire after a long-term anti-TNF treatment in AS patients.

METHODS

Twenty-two AS patients under long-term anti-TNF therapy were evaluated (15 anti-TNF responders and 7 nonresponders). A wide range of cell subtypes was analyzed with flow cytometry and compared with therapy-naïve and short-term data too.

RESULTS

Key findings include decreased proportions of naïve CD4 and CD8 cells, increased frequencies of Th1 and Th17 cells and higher Th1/Th2 ratios in the long-term anti-TNF-treated patients (responders, nonresponders and total), which was found to be significant not only when compared with healthy controls, but also with therapy-naïve and short-term anti-TNF-treated AS patients. We noted several alterations within the various activated T-cell subsets - increase in CD4HLADR cells in responders, in CD8HLADR cells in the whole AS group and in responders, and in CD4CD25 cells in responders, and decrease in CD4CD69 cell percentages in long-term treated patients - becoming evident only after long-term anti-TNF therapy.

CONCLUSIONS

This study provides a comprehensive assessment of the impact of anti-TNF therapy on the T-cell repertoire in AS. Changes in T-cell phenotype seem to develop progressively during therapy, even in inactive disease, and reflect an ongoing effector T-cell differentiation and activation, along with the parallel compensatory increase in regulatory T cells.