TNFα promotes Th17 cell differentiation through IL-6 and IL-1β produced by monocytes in rheumatoid arthritis

Immune System-Related Plasma Pathogenic Extracellular Vesicle Subpopulations Predict Osteoarthritis Progression

Certain molecules found on the surface or within the cargo of extracellular vesicles (EVs) are linked to osteoarthritis (OA) severity and progression. We aimed to identify plasma pathogenic EV subpopulations that can predict knee radiographic OA (rOA) progression. We analyzed the mass spectrometry-based proteomic data of plasma EVs and synovial fluid (SF) EVs from knee OA patients (n = 16, 50% female). The identified surface markers of interest were further evaluated in plasma EVs from an independent cohort of knee OA patients (n = 30, 47% female) using flow cytometry. A total of 199 peptides with significant correlation between plasma and SF EVs were identified. Of these, 41.7% were linked to immune system processes, 15.5% to inflammatory responses, and 16.7% to the complement system. Crucially, five previously identified knee rOA severity-indicating surface markers-FGA, FGB, FGG, TLN1, and AMBP-were confirmed on plasma EV subpopulations in an independent cohort. These markers' baseline frequencies on large plasma EVs predicted rOA progression with an AUC of 0.655-0.711. Notably, TLN1 was expressed in OA joint tissue, whereas FGA, FGB, FGG, and AMBP were predominantly liver derived. These surface markers define specific pathogenic EV subpopulations, offering potential OA prognostic biomarkers and novel therapeutic targets for disease modification.

IL-17A Levels and Progression of Kidney Disease Following Hospitalization with and without Acute Kidney Injury

Key Points

Background

AKI is associated with increased mortality and new or progressive CKD. Inflammatory cells play an important role in acute organ injury. We previously demonstrated that serum IL-17A levels were significantly elevated in critically ill patients with AKI and independently associated with hospital mortality. We hypothesize that IL-17A levels are elevated in hospitalized patients with AKI at diagnosis, and sustained elevation after discharge is associated with subsequent CKD incidence or progression.

Methods

This was an observational convenience sampling study of hospital survivors of stage 2 or 3 AKI and controls without AKI from the Assessment, Serial Evaluation, and Subsequent Sequelae of AKI study. Patients were classified as progression or nonprogression on the basis of a composite of CKD incidence, progression, or ESKD. IL-17A levels were evaluated with S-Plex assay (Meso Scale Discovery) at 0 (during hospitalization), 3, and 12 months postdischarge and analyzed along with clinical and biomarker data up to 84 months after discharge.

Results

Among 171 AKI and 175 non-AKI participants, IL-17A levels were elevated in AKI versus non-AKI patients at 0-, 3-, and 12-month time points (P < 0.05 for all comparisons). Furthermore, IL-17A levels were elevated in the progression versus nonprogression group at the 3- and 12-month time points for outcomes occurring at 3–6 and 12–84 months, respectively (P < 0.05 for both). In adjusted multivariable models, IL-17A levels were not independently associated with progression of kidney disease. IL-17A levels were positively correlated with kidney disease and immune activation biomarkers at all time points (P < 0.001).

Conclusions

IL-17A was higher in patients with AKI versus without AKI during hospitalization and up to 1-year postdischarge. IL-17A was higher in patients with progression of kidney disease after hospitalization, but not independently associated with subsequent progression of kidney disease in fully adjusted models.

Protein kinase D1 in myeloid lineage cells contributes to the accumulation of CXCR3+CCR6+ nonconventional Th1 cells in the lungs and potentiates hypersensitivity pneumonitis caused by S. rectivirgula

Introduction

Hypersensitivity pneumonitis (HP) is an extrinsic allergic alveolitis characterized by inflammation of the interstitium, bronchioles, and alveoli of the lung that leads to granuloma formation. We previously found that activation of protein kinase D1 (PKD1) in the lungs following exposures to Saccharopolyspora rectivirgula contributes to the acute pulmonary inflammation, IL-17A expression in the lungs, and development of HP. In the present study, we investigated whether PKD1 in myeloid-lineage cells affects the pathogenic course of the S. rectivirgula-induced HP.

Methods

Mice were exposed intranasally to S. rectivirgula once or 3 times/week for 3 weeks. The protein and mRNA expression levels of cytokines/chemokines were detected by enzyme-linked immunosorbent assay and quantitative real-time PCR, respectively. Flow cytometry was used to detect the different types of immune cells and the levels of surface proteins. Lung tissue sections were stained with hematoxylin and eosin, digital images were captured, and immune cells influx into the interstitial lung tissue were detected.

Results

Compared to control PKD1-sufficient mice, mice with PKD1 deficiency in myeloid-lineage cells (PKD1mKO) showed significantly suppressed expression of TNFα, IFNγ, IL-6, CCL2, CCL3, CCL4, CXCL1, CXCL2, and CXCL10 and neutrophilic alveolitis after single intranasal exposure to S. rectivirgula. Substantially reduced levels of alveolitis and granuloma formation were observed in the PKD1mKO mice repeatedly exposed to S. rectivirgula for 3 weeks. In addition, expression levels of the Th1/Th17 polarizing cytokines and chemokines such as IFNγ, IL-17A, CXCL9, CXCL10, CXCL11, and CCL20 in lungs were significantly reduced in the PKD1mKO mice repeatedly exposed to S. rectivirgula. Moreover, accumulation of CXCR3+CCR6+ nonconventional Th1 in the lungs were significantly reduced in PKD1mKO mice repeatedly exposed to S. rectivirgula.

Discussion

Our results demonstrate that PKD1 in myeloid-lineage cells plays an essential role in the development and progress of HP caused by repeated exposure to S. rectivirgula by contributing Th1/Th17 polarizing proinflammatory responses, alveolitis, and accumulation of pathogenic nonconventional Th1 cells in the lungs.

Immune-related events in individuals with solid tumors on immunotherapy associate with Th17 and Th2 signatures

BACKGROUNDImmune-related adverse events (irAEs) and their associated morbidity/mortality are a key concern for patients receiving immune checkpoint inhibitors (ICIs). Prospective evaluation of the drivers of irAEs in a diverse pan-tumor cohort is needed to identify patients at greatest risk and to develop rational treatment and interception strategies.METHODSIn an observational study, we prospectively collected blood samples and performed regular clinical evaluations for irAEs in patients receiving ICI therapy as standard of care for solid tumors. We performed in-parallel analysis of cytokines by Luminex immunoassay and circulating immune cells by cytometry by time-of-flight (CyTOF) at baseline and on treatment to investigate mechanisms of irAEs.RESULTSWe enrolled 111 patients, of whom 40.5% developed a symptomatic irAE (grade ≥ 2). Development of a grade ≥ 2 irAE was positively associated with the use of combination ICI and a history of an autoimmune disorder. Early changes in T helper 17 (Th17) (IL-6, IL-17f), type 2 (IL-5, IL-13, IL-25), and type 1 (TNF-α) cytokine signatures and congruent on-treatment expansions of Th17 and Th2 effector memory (Th2EM) T cell populations in peripheral blood were positively associated with the development of grade ≥2 irAEs. IL-6 levels were also associated with inferior cancer-specific survival and overall survival.CONCLUSIONSIn a diverse, prospective pan-tumor cohort, Th17 and Th2 skewing during early ICI treatment was associated with the development of clinically relevant irAEs but not antitumor responses, providing possible targets for monitoring and therapeutic interventions.FUNDINGJohns Hopkins Bloomberg-Kimmel Institute for Cancer Immunotherapy, the NCI SPORE in Gastrointestinal Cancers (P50 CA062924), NCI grant (R50CA243627 to LD), the NIH Center Core Grant (P30 CA006973), Swim Across America (to MY), NIAMS (K23AR075872 to LC), and imCORE-Genentech grant 137515 (to Johns Hopkins Medicine on behalf of MY).

Proton pump inhibitor alters Th17/Treg balance and induces gut dysbiosis suppressing contact hypersensitivity reaction in mice

Proton pump inhibitors (PPIs), such as omeprazole, are the most commonly prescribed drugs. Treatment with PPIs alters gut microbiota composition and reduces the production of reactive oxygen (ROS) and proinflammatory IL-1β, IL-6, and TNF-α cytokines. Here, using the T cell-dependent contact hypersensitivity (CHS) response, an animal model of allergic contact dermatitis (ACD) that affects up to 30% of the population, we demonstrated that a two-week omeprazole treatment suppresses the development of CHS. Omeprazole treatment before CHS induction, reduced inflammatory response in ears measured by ear swelling, ear biopsy weight, MPO activity, and proinflammatory cytokine production. These changes were associated with reduced frequency of TCRαβ+ CD4+ IL-17A+ and TCRαβ+ CD8+ IL-17A+ T cells and increased frequency of TCRαβ+ CD4+ CD25+ FoxP3+ Treg, and TCRαβ+ CD4+ IL-10+ Tr1 cells in peripheral lymphoid organs. Omeprazole treatment decreased the production of ROS, TNF-α, and IL-6, which supported Th17 cell induction, and increased the frequency of Clostridium cluster XIVab and Lactobacillus, implicated in Treg cell induction. The fecal microbiota transplantation (FMT) experiment confirmed the role of omeprazole-induced changes in gut microbiota profile in CHS suppression. Our data suggests that omeprazole ameliorates inflammatory response mediated by T-cells.

Bone Marrow Adipose Tissue as a Critical Regulator of Postmenopausal Osteoporosis - A Concise Review

Postmenopausal osteoporosis (PMOP) is a major health problem affecting millions of women worldwide. PMOP patients are often accompanied by abnormal accumulation of bone marrow adipose tissue (BMAT). BMAT is a critical regulator of bone homeostasis, and an increasing BMAT volume is negatively associated with bone mass reduction or fracture. BMAT regulates bone metabolism via adipokines, cytokines and the immune system, but the specific mechanisms are largely unknown. This review emphasizes the impact of estrogen deficiency on bone homeostasis and BMAT expansion, and the mechanism by which BMAT regulates PMOP, providing a promising strategy for targeting BMAT in preventing and treating PMOP.

Nrf2 Deficiency Accelerates IL-17-Dependent Neutrophilic Airway Inflammation in Asthmatic Mice

Asthma is a heterogeneous disease that can be broadly classified into type 2, which is primarily steroid-sensitive and eosinophilic, and non-type 2, which is primarily steroid-resistant and neutrophilic. While the mechanisms leading to the development of molecular-targeted therapies for type 2 asthma are being elucidated, much remains to be learned about non-type 2 asthma. To investigate the role of oxidative stress in refractory allergic airway inflammation, we compared asthma models generated by immunizing wild-type and nuclear factor erythroid-2-related factor 2 (Nrf2)-deficient mice with the house dust mite antigen. Both asthma models had similar levels of airway inflammation and hyperresponsiveness, but the Nrf2-deficient mice had increased oxidative stress and exacerbated neutrophilic airway inflammation compared with the wild-type mice. Type 2 cytokines and the expression of GATA3, a transcription factor that is important for Th2 cell differentiation, had decreased in Nrf2-deficient mice compared with the wild-type mice, whereas helper T (Th) 17 cytokines and the expression of RORγt, which is important for Th17 cell differentiation, had increased. Furthermore, the neutrophilic airway inflammation caused by Nrf2 deficiency was ameliorated by interleukin (IL)-17 neutralization. We have concluded that the disruption of the Nrf2-mediated antioxidant defense system contributed to the induction of Th17 differentiation and exacerbated allergic neutrophilic airway inflammation.

Role of Interleukin-17 family cytokines in disease severity of patients with knee osteoarthritis

BACKGROUND

Interleukin-17 (IL-17) family plays a role in the pathogenesis of knee osteoarthritis (KOA) by contributing to the inflammatory and destructive processes in the affected joint. This study aimed to measure levels of IL-17 A and IL-25 (IL-17E) in serum of KOA patients and determine their roles in the disease severity of patients.

METHODS

In this, 34 patients with KOA and 30 age and sex-matched healthy subjects (HS) were enrolled. Patients were categorized based on their Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Visual Analog Scale (VAS), and Body Mass Index (BMI) scores. The enzyme-linked immunosorbent assay (ELISA) technique was employed to measure serum levels of IL-17 A and IL-25.

RESULTS

Level of IL-25 was significantly higher (P < 0.0001) in the KOA subjects than HS. IL-17 A level was significantly higher in KOA cases with WOMAC < 40 (P < 0.0001) in comparison to HS. IL-25 level was significantly higher in the KOA cases with WOMAC < 40 (P < 0.0001) and with WOMAC ≥ 40 (P < 0.0001) compared to HS. IL-17 A concentration was significantly higher in the KOA cases with VAS < 5 (P < 0.0001) compared to HS. IL-25 level was significantly higher in the KOA cases with VAS < 5 (P < 0.0001) and with VAS ≥ 5 (P < 0.0001) in comparison to HS. KOA patients with BMI ≥ 30 had significantly higher IL-17 A and IL-25 concentration in comparison to HS.

CONCLUSIONS

The serum level of IL-25 in KOA patients is increased probably due to negative controlling feedback on inflammatory responses, which can be associated with obesity and disease activity.

Expression of Transcriptional Factors of T Helper Differentiation (T-bet, GATA-3, RORγt, and FOXP3), MIF Receptors (CD44, CD74, CXCR2, 4, 7), and Th1, Th2, and Th17 Cytokines in PBMC from Control Subjects and Rheumatoid Arthritis Patients

INTRODUCTION

The macrophage migration inhibitory factor (MIF) plays a pivotal role in the development of rheumatoid arthritis (RA). Previous research indicates that MIF can trigger the expression of cytokine profiles associated with Th1, Th2, and Th17 responses in peripheral blood mononuclear cells (PBMC) from both RA patients and control subjects (CS). Despite these, few studies to date precisely elucidate the molecular mechanisms involved. The present study aimed to associate the expression of Th differentiation TF (T-bet, GATA-3, RORγt) with MIF receptors (CD44, CD74, CXCR2, 4, 7) and Th1, Th2, and Th17 cytokines in PBMC from CS and RA patients.

METHOD

PBMC from both groups was cultured for 24 h. The expression of the canonical and non-canonical MIF receptors and the TF was determined by flow cytometry. Additionally, multiplex bead analysis was employed to assess the levels of cytokines in the culture supernatants. The findings revealed that T CD4+ lymphocytes in the CS group exhibited a heightened expression of CD74 (p<0.05), whereas RA patients displayed an elevated expression of CXCR7 (p<0.001). Furthermore, T CD4+ lymphocytes from RA patients exhibited greater expression of GATA3, RORγt, and FOXP3, along with elevated levels of pro-inflammatory cytokines compared to the CS group (p<0.001).

RESULT

These results indicate that CD74 is more prominently expressed in PBMC from the CS group, whereas CXCR7 is more expressed in PBMC from RA patients.

CONCLUSION

We also noted an increased secretion of Th17 profile cytokines in RA, potentially influenced by the activation of FOXP3 via CD74 and RORγt through CXCR7 using the endocytic pathway.

Chronic stress predisposes to the aggravation of inflammation in autoimmune diseases with focus on rheumatoid arthritis and psoriasis

The global incidence of autoimmune diseases is on the rise, and many healthcare professionals believe that chronic stress plays a prominent role in both the aggravation and remission of these conditions. It is believed that prolonged exposure to stress is associated with neuroimmune axis malfunction, which eventually dysregulates multiple immunological factors as well as deregulates autoimmune responses that play a central role in various autoimmune diseases, including rheumatoid arthritis and psoriasis. Herein, we performed validation of an 8-week long rat model of chronic unpredictable stress (CUS) which consisted of exposing groups of rats to random stressors daily for 8 weeks. Additionally, we developed a novel rat model combining 8-week long random stressor-induced CUS with CIA-triggered arthritis and IMQ-triggered psoriasis and have successfully used both these models to assess the role of chronic stress in the aggravation of arthritis and psoriasis, respectively. Notably, the 8-week CUS protocol extensively aggravated and prolonged both arthritis and psoriasis condition in the rat model by upregulating the release of different pro-inflammatory cytokines, dysregulation of immune cell responses and oxidative stress system, which were all related to severe inflammation. Further, CUS aggravated macroscopic features and the increase in destruction of joint tissue and epidermal thickness induced by CIA and IMQ, respectively, in rats. In conclusion, this study suggests that exposure to an 8-week long CUS paradigm aggravates the distinctive characteristics of rheumatoid arthritis and psoriasis in rats via amplifying the inflammatory circuits and immune cell responses linked to these autoimmune diseases.

Fixed-combination halobetasol propionate and tazarotene topical lotion decreases TNF-α and IL-17A levels in psoriatic lesions

OBJECTIVE

Fixed-combination halobetasol propionate (0.01%) and tazarotene (0.045%) lotion (HP/TAZ) is approved for the treatment of plaque psoriasis in adults, with a demonstrated efficacy and safety profile in phase 3 trials. This study examined the effect of HP/TAZ on the reduction of tumor necrosis factor alpha (TNF-α) and interleukin 17 A (IL-17A) and its correlation to psoriasis improvement.

MATERIALS AND METHODS

Ten adults with mild-to-moderate plaque psoriasis and 2 symmetrical plaques self-applied HP/TAZ (treated plaque) or vehicle lotion (untreated plaque) for 12 weeks. At baseline and each study visit (weeks 2, 4, 8, and 12), Investigator's Global Assessment (IGA) score and erythema, scaling, and induration were assessed. Additionally, D-squame tape strips were utilized to quantify TNF-α and IL-17A in target lesions by enzyme-linked immunosorbent assay.

RESULTS

Significant improvements in mean IGA score in HP/TAZ-treated compared with untreated plaques were evident at week 2 and maintained through week 12 (p < 0.003). HP/TAZ significantly reduced TNF-α levels at weeks 4 through 12 (p < 0.03) and IL-17A levels at weeks 2 through 8 (p < 0.05) in treated compared with untreated plaques.

CONCLUSIONS

HP/TAZ was highly effective in treating psoriasis plaques and, although HP/TAZ is not a biologic, effectively reduced cytokine-associated inflammatory markers that drive psoriatic disease.

The Effects and Potential Mechanisms of Moxibustion for Rheumatoid Arthritis-Related Pain: A Randomized, Controlled Trial

Purpose

To investigate the effects of moxibustion in relieving pain, and other clinical symptoms for patients with rheumatoid arthritis (RA), and explore the potential mechanism of moxibustion treatment for RA.

Patients and Methods

Seventy qualified RA patients were randomly assigned in a 1:1 ratio to the moxibustion group or the routine group. The routine group only took oral methotrexate tablets and folic acid tablets. The moxibustion group was treated with moxibustion based on oral pharmaceutical. Moxibustion was performed two times weekly for 8 weeks, a total of 16 sessions. Patients scored their pain on a visual analog scale (VAS). The American College of Rheumatology improvement criteria of 20%, 50% and 70% (ACR20, ACR50 and ACR70) after treatment were investigated. Clinical symptoms, a disease activity score using 28 joint counts (DAS28), simplified disease activity index (SDAI), clinical disease activity index (CDAI), health assessment questionnaire (HAQ), interleukin 1β (IL-1β), tumor necrosis factor-alpha (TNF-α), and vascular endothelial growth factor (VEGF) of RA patients were analyzed before and after treatment.

Results

After treatment, the VAS scores, tender and swollen joint counts, morning stiffness scores, disease activity scores (DAS28, SDAI, CDAI), HAQ scores in the two groups were both improved, and the effects of moxibustion group were more obvious (P < 0.05). The ACR20 and ACR50 of the moxibustion group were greater than that of the routine group (P < 0.05), no significant difference of the ACR70 existed between the two groups (P > 0.05). In addition, the decreases of IL-1β, TNF-α, VEGF of the moxibustion group were better than that of the routine group (P < 0.05).

Conclusion

Moxibustion could effectively relieve pain, ameliorate the clinical symptoms, and decrease the disease activity of RA. The potential mechanism may be the decrease in the level of serum inflammatory factors.

Immune predictors of hepatitis B surface antigen seroconversion in patients with hepatitis B reactivation

BACKGROUND

Hepatitis B surface antigen (HBsAg) seroconversion is sometimes observed in hepatitis B reactivation (rHBV), probably due to immune resetting and differentiation.

AIMS

To investigate sequential immune differentiation and abrogation of tolerance in patients with rHBV who achieved HBsAg seroconversion.

METHODS

We included 19 patients with chronic hepatitis B (CHBV; HBV DNA log10^3-8 ), 67 with rHBV (raised ALT [>5XULN], HBV DNAlog10^4-8 ) and 10 healthy controls. Immune differentiation, tolerance and functional status of CD4, CD8, T regulatory cells (Tregs), B cells and follicular T helper (Tfh) cells were assessed at baseline and 24 weeks.

RESULTS

At 24 weeks, 81% rHBV (n = 67) lost HBV DNA and HBeAg (41%), and 12 (19%) lost HBsAg and made anti-HBs titers >10 IU/ml. rHBV patients had higher Th1/17, T_EM , Tfh, Tfh1/17, plasma and ATM B cells, and lower Tregs, Th2, Th17 and TEMRA expression. rHBV showed lower PD1, TIM3, LAG3, SLAM and TOX compared to CHBV. There was a significant increase in CD8, CD8EM, Tfh, Tfh1/17 and plasma B cells in seroconverters than non-seroconverters. At 24 weeks, we also observed increased plasma B cell frequency in seroconverters. While non-seroconverters showed higher expression of PD1, TIM3, LAG3, SLAM and TOX on CD4/CD8 T cells, blockade of PD1, TIM3, LAG3 and CTLA4 significantly enhanced IFN-γ, TNF-α, IL-4 and IL-21 expression on CD4/CD8 and Tfh cells in non-seroconverters.

CONCLUSIONS

Non-seroconverters have increased inhibitory markers on CD4/CD8 T cells. There is a critical play of CD8, Tfh and B cells and subsets in seroclearance, along with checkpoint molecules as a potential therapy for non-seroconverters in HBV infection.

Perspectives from recent advances of Helicobacter pylori vaccines research

BACKGROUND

Helicobacter pylori (H. pylori) infection is the main factor leading to some gastric diseases. Currently, H. pylori infection is primarily treated with antibiotics. However, with the widespread application of antibiotics, H. pylori resistance to antibiotics has also gradually increased year by year. Vaccines may be an alternative solution to clear H. pylori.

AIMS

By reviewing the recent progress on H. pylori vaccines, we expected it to lead to more research efforts to accelerate breakthroughs in this field.

MATERIALS & METHODS

We searched the research on H. pylori vaccine in recent years through PubMed®, and then classified and summarized these studies.

RESULTS

The study of the pathogenic mechanism of H. pylori has led to the development of vaccines using some antigens, such as urease, catalase, and heat shock protein (Hsp). Based on these antigens, whole-cell, subunit, nucleic acid, vector, and H. pylori exosome vaccines have been tested.

DISCUSSION

At present, researchers have developed many types of vaccines, such as whole cell vaccines, subunit vaccines, vector vaccines, etc. However, although some of these vaccines induced protective immunity in mouse models, only a few were able to move into human trials. We propose that mRNA vaccine may play an important role in preventing or treating H. pylori infection. The current study shows that we have developed various types of vaccines based on the virulence factors of H. pylori. However, only a few vaccines have entered human clinical trials. In order to improve the efficacy of vaccines, it is necessary to enhance T-cell immunity.

CONCLUSION

We should fully understand the pathogenic mechanism of H. pylori and find its core antigen as a vaccine target.

The dual role of CD6 as a therapeutic target in cancer and autoimmune disease

Autoimmune disease involves loss of tolerance to self-antigen, while progression of cancer reflects insufficient recognition and response of the immune system to malignant cells. Patients with immune compromised conditions tend to be more susceptible to cancer development. On the other hand, cancer treatments, especially checkpoint inhibitor therapies, can induce severe autoimmune syndromes. There is recent evidence that autoimmunity and cancer share molecular targets and pathways that may be dysregulated in both types of diseases. Therefore, there has been an increased focus on understanding these biological pathways that link cancer and its treatment with the appearance of autoimmunity. In this review, we hope to consolidate our understanding of current and emerging molecular targets used to treat both cancer and autoimmunity, with a special focus on Cluster of Differentiation (CD) 6.

Dysregulation of immunity in COVID-19 and SLE

The immune response plays a crucial role in preventing diseases, such as infections. There are two types of immune responses, specific and innate immunity, each of which consists of two components: cellular immunity and humoral immunity. Dysfunction in any immune system component increases the risk of developing certain diseases. Systemic lupus erythematosus (SLE), an autoimmune disease in the human body, develops an immune response against its own components. In these patients, due to underlying immune system disorders and receipt of immunosuppressive drugs, the susceptibility to infections is higher than in the general population and is the single largest cause of mortality in this group. COVID-19 infection, which first appeared in late 2019, has caused several concerns in patients with SLE. However, there is no strong proof of additional risk of developing COVID-19 in patients with SLE, and in some cases, studies have shown less severity of the disease in these individuals. This review paper discusses the immune disorders in SLE and COVID-19.

CD4+ T-cell cooperation promoted pathogenic function of activated naïve B cells of patients with SLE

Objective

To explore cooperation between activated naïve (aNAV) B cells and CD4⁺ T cells in the pathogenesis of SLE through autoantibody production, T-cell differentiation and inflammatory cytokine secretion.

Methods

Peripheral blood mononuclear cell samples were obtained from 31 patients with SLE and used to characterise phenotype of aNAV B cells (n=14) and measured the phosphorylation of B-cell receptor (BCR) signalling molecules (n=5). Upregulation of T-cell costimulatory molecules after BCR and toll-like receptor (TLR)-7/TLR-8 stimulation was detected in cells from four subjects. To explore the role of these cells in SLE pathogenesis via T cell-dependent mechanisms, four subjects were analysed to detect the promotion of CD4⁺ T-cell activation and antibody-secreting cell (ASC) differentiation after CD4⁺ T-cell–B-cell cocultures. The aNAV B cells from four patients were used to assess cytokine secretion.

Results

The aNAV B cells of patients with SLE had increased expression of surface CD40, HLA-DR and interleukin-21 receptor (IL-21R) and FCRL5 molecules. With BCR stimulation, these cells greatly increased PLCγ2 phosphorylation. Integrated BCR and TLR-7/TLR-8 signals induced overexpression of CD40, CD86, IL-21R and HLA-DR on lupus aNAV B cells. In T-cell–B-cell cocultures, lupus aNAV B cells (with upregulated costimulatory molecules) promoted CD4⁺ T-cell proliferation and polarisation toward effector Th₂ and Th₁₇ cells. Importantly, in this coculture system, CD4⁺ T-cell signals enhanced aNAV B-cell differentiation into auto-ASCs and produced anti-DNA antibodies. The interaction between CD4⁺ T cell and aNAV B cell increased production of inflammatory cytokines (IL-6, IL-8 and IL-23).

Conclusion

Cooperation between aNAV B cells and CD4⁺ T cells contributed to SLE pathogenesis by promoting both differentiation of pathogenic T cells (Th₂ and Th₁₇) and autoantibody secretion.

Vaccination with Mycoplasma pneumoniae membrane lipoproteins induces IL-17A driven neutrophilia that mediates Vaccine-Enhanced Disease

Bacterial lipoproteins are an often-underappreciated class of microbe-associated molecular patterns with potent immunomodulatory activity. We previously reported that vaccination of BALB/c mice with Mycoplasma pneumoniae (Mp) lipid-associated membrane proteins (LAMPs) resulted in lipoprotein-dependent vaccine enhanced disease after challenge with virulent Mp, though the immune responses underpinning this phenomenon remain poorly understood. Herein, we report that lipoprotein-induced VED in a mouse model is associated with elevated inflammatory cytokines TNF-α, IL-1β, IL-6, IL-17A, and KC in lung lavage fluid and with suppurative pneumonia marked by exuberant neutrophilia in the pulmonary parenchyma. Whole-lung-digest flow cytometry and RNAScope analysis identified multiple cellular sources for IL-17A, and the numbers of IL-17A producing cells were increased in LAMPs-vaccinated/Mp-challenged animals compared to controls. Specific IL-17A or neutrophil depletion reduced disease severity in our VED model—indicating that Mp lipoproteins induce VED in an IL-17A-dependent manner and through exuberant neutrophil recruitment. IL-17A neutralization reduced levels of TNF-α, IL-1β, IL-6, and KC, indicating that IL-17A preceded other inflammatory cytokines. Surprisingly, we found that IL-17A neutralization impaired bacterial clearance, while neutrophil depletion improved it—indicating that, while IL-17A appears to confer both maladaptive and protective responses, neutrophils play an entirely maladaptive role in VED. Given that lipoproteins are found in virtually all bacteria, the potential for lipoprotein-mediated maladaptive inflammatory responses should be taken into consideration when developing vaccines against bacterial pathogens.

Effect of dietary sophorolipids on growth performance and gastrointestinal functionality of broiler chickens infected with Eimeria maxima

Two experiments were conducted to evaluate the effects of dietary sophorolipids (SLs) supplementation as antibiotic alternatives on growth performance and gut health of chickens infected with Eimeria maxima. In experiment 1, 336 (zero-day-old) male broilers were used. The chickens were weighed and randomly allocated to the following 6 treatments groups with 7 chickens/cage and 8 cages/treatment: control group that received a basal diet (NC), positive control group that received a basal diet and was challenged with E. maxima (PC), PC+C18:1 lactonic diacetyled SL (SL1), PC+C18:1 deacetyled SL (SL2), PC+C18:1 monoacetyled SL (SL3), and PC+C18:1 diacetyled SL (SL4). Each SL (200 mg/kg feed) was added to the corresponding treatment group. In experiment 2, 588 (zero-day-old) male broilers were used. The chickens were randomly allocated to the following experimental groups with 10 or 11 chickens/cage and 8 cages/treatment: NC, PC, PC+ monensin at 90 mg/kg feed (MO), PC+SL1 at 200 mg/kg feed (SL1 200), PC+SL1 at 500 mg/kg feed (SL1 500), PC+SL4 at 200 mg/kg feed (SL4 200), and PC+SL4 at 500 mg/kg of feed (SL4 500). The chickens and feed were weighed at 0, 7, 14, 20, and 22 d to determine growth performance. In both experiments, all chickens except the NC group were orally infected with E. maxima (10,000 oocysts/chicken) at d 14. One chicken per cage was euthanized at d 20 to sample jejunal tissue to measure lesion scores, cytokines, and tight junction (TJ) proteins. Excreta samples were collected daily between d 20 and 22 to measure oocyst numbers. Data were analyzed using Mixed Model (PROC MIXED) in SAS. In experiment 1, SLs did not affect the growth of broiler chickens, but SL4 decreased (P < 0.05) the lesion score and oocyst number compared to PC chickens. In terms of cytokines and TJ protein gene expression, SLs increased (P < 0.05) IL-1β, IL-6, IL-17F, IL-4, IL-13, occludin, and ZO1 levels compared to PC chickens. In experiment 2, monensin increased (P < 0.05) body weight, and decreased (P < 0.05) the lesion score and oocyst number compared to the PC group. SL4 500 increased (P < 0.05) average daily gain and feed conversion ratio but decreased (P < 0.05) lesion score and fecal oocyst number. SL4 decreased (P < 0.05) IL-6, IL-17F, TNFSF-15, IL-2, and IL-10 levels but increased (P < 0.05) occludin and ZO-1 levels. Overall, dietary SL supplementation, especially SL4, improved growth and gastrointestinal functionality of young broiler chickens, demonstrating significant potential as an antibiotic alternative.

The Importance of CXCL1 in Physiology and Noncancerous Diseases of Bone, Bone Marrow, Muscle and the Nervous System

This review describes the role of CXCL1, a chemokine crucial in inflammation as a chemoattractant for neutrophils, in physiology and in selected major non-cancer diseases. Due to the vast amount of available information, we focus on the role CXCL1 plays in the physiology of bones, bone marrow, muscle and the nervous system. For this reason, we describe its effects on hematopoietic stem cells, myoblasts, oligodendrocyte progenitors and osteoclast precursors. We also present the involvement of CXCL1 in diseases of selected tissues and organs including Alzheimer’s disease, epilepsy, herpes simplex virus type 1 (HSV-1) encephalitis, ischemic stroke, major depression, multiple sclerosis, neuromyelitis optica, neuropathic pain, osteoporosis, prion diseases, rheumatoid arthritis, tick-borne encephalitis (TBE), traumatic spinal cord injury and West Nile fever.

Plasma interleukin-23 and circulating IL-17A+IFNγ+ ex-Th17 cells predict opposing outcomes of anti-TNF therapy in rheumatoid arthritis

OBJECTIVES

TNF-α inhibitors are widely used in rheumatoid arthritis (RA) with varying success. Response to TNF-α inhibition may reflect the evolution of rheumatoid inflammation through fluctuating stages of TNF-α dependence. Our aim was to assess plasma concentrations of Th-17-related cytokines and the presence of circulating effector T-cells to identify predictors of response to TNF-α inhibitors.

METHODS

Ninety-three people with RA were seen prior to and 4-6 months after commencing etanercept or adalimumab. Plasma concentrations of Th17-related cytokines, circulating effector T-cells, their production of relevant transcription factors and intracellular cytokines were measured at baseline. EULAR response criteria were used to define poor (ΔDAS28 ≤ 1.2 and/or DAS28 > 3.2) and good (ΔDAS28 > 1.2 and DAS28 ≤ 3.2) responders. Multivariate logistic regression was used to identify predictors of response.

RESULTS

Participants with plasma IL-23 present at baseline were more likely to be poor responders [15/20 (75%) of IL-23⁺ versus 36/73 (49.3%) of IL-23^-; p = 0.041]. While frequencies of Th1, Th17, ex-Th17 and T_reg cell populations were similar between good and poor responders to anti-TNF therapy, IL-17A⁺IFNγ⁺ ex-Th17 cells were more prevalent in good responders (0.83% of ex-T_H17 cells) compared to poor responders (0.24% of ex-Th17 cells), p = 0.023. Both plasma IL-23 cytokine status (OR = 0.17 (95% CI 0.04-0.73)) and IL-17A⁺IFNγ⁺ ex-Th17 cell frequency (OR = 1.64 (95% CI 1.06 to 2.54)) were independently associated with a good response to anti-TNF therapy. Receiver operator characteristic (ROC) analysis, including both parameters, demonstrated an area under the ROC curve (AUC) of 0.70 (95% CI 0.60-0.82; p = 0.001).

CONCLUSIONS

Plasma IL-23 and circulating IL-17A⁺IFNγ⁺ ex-Th17 cells are independently associated with response to anti-TNF therapy. In combination, plasma IL-23 and circulating IL-17A⁺IFNγ⁺ ex-Th17 cells provide additive value to the prediction of response to anti-TNF therapy in RA.

Human Bone Marrow Mesenchymal Stromal/Stem Cells Regulate the Proinflammatory Response of Monocytes and Myeloid Dendritic Cells from Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a disabling autoimmune disease whose treatment is ineffective for one-third of patients. Thus, the immunomodulatory potential of mesenchymal stromal/stem cells (MSCs) makes MSC-based therapy a promising approach to RA. This study aimed to explore the immunomodulatory action of human bone marrow (BM)-MSCs on myeloid dendritic cells (mDCs) and monocytes, especially on cytokines/chemokines involved in RA physiopathology. For that, LPS plus IFNγ-stimulated peripheral blood mononuclear cells from RA patients (n = 12) and healthy individuals (n = 6) were co-cultured with allogeneic BM-MSCs. TNF-α, CD83, CCR7 and MIP-1β protein levels were assessed in mDCs, classical, intermediate, and non-classical monocytes. mRNA expression of other cytokines/chemokines was also evaluated. BM-MSCs effectively reduced TNF-α, CD83, CCR7 and MIP-1β protein levels in mDCs and all monocyte subsets, in RA patients. The inhibition of TNF-α production was mainly achieved by the reduction of the percentage of cellsproducing this cytokine. BM-MSCs exhibited a remarkable suppressive action over antigen-presenting cells from RA patients, potentially affecting their ability to stimulate the immune adaptive response at different levels, by hampering their migration to the lymph node and the production of proinflammatory cytokines and chemokines. Accordingly, MSC-based therapies can be a valuable approach for RA treatment, especially for non-responder patients.

Congenital iRHOM2 deficiency causes ADAM17 dysfunction and environmentally directed immunodysregulatory disease

We report a pleiotropic disease due to loss-of-function mutations in RHBDF2, the gene encoding iRHOM2, in two kindreds with recurrent infections in different organs. One patient had recurrent pneumonia but no colon involvement, another had recurrent infectious hemorrhagic colitis but no lung involvement and the other two experienced recurrent respiratory infections. Loss of iRHOM2, a rhomboid superfamily member that regulates the ADAM17 metalloproteinase, caused defective ADAM17-dependent cleavage and release of cytokines, including tumor-necrosis factor and amphiregulin. To understand the diverse clinical phenotypes, we challenged Rhbdf2-/- mice with Pseudomonas aeruginosa by nasal gavage and observed more severe pneumonia, whereas infection with Citrobacter rodentium caused worse inflammatory colitis than in wild-type mice. The fecal microbiota in the colitis patient had characteristic oral species that can predispose to colitis. Thus, a human immunodeficiency arising from iRHOM2 deficiency causes divergent disease phenotypes that can involve the local microbial environment.

Deacetylasperulosidic Acid Ameliorates Pruritus, Immune Imbalance, and Skin Barrier Dysfunction in 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis NC/Nga Mice

The prevalence of atopic dermatitis (AD), a disease characterized by severe pruritus, immune imbalance, and skin barrier dysfunction, is rapidly increasing worldwide. Deacetylasperulosidic acid (DAA) has anti-atopic activity in the three main cell types associated with AD: keratinocytes, mast cells, and eosinophils. Our study investigated the anti-atopic activity of DAA in 2,4-dinitrochlorobenzene-induced NC/Nga mice. DAA alleviated the symptoms of AD, including infiltration of inflammatory cells (mast cells and eosinophils), epidermal thickness, ear thickness, and scratching behavior. Furthermore, DAA reduced serum IgE, histamine, and IgG1/IgG2a ratio and modulated the levels of AD-related cytokines and chemokines, namely interleukin (IL)-1β, IL-4, IL-6, IL-9, IL-10, IL-12, tumor necrosis factor-α, interferon-γ, thymic stromal lymphopoietin, thymus and activation-regulated chemokine, macrophage-derived chemokine, and regulated on activation the normal T cell expressed and secreted in the serum. DAA restored immune balance by regulating gene expression and secretion of Th1-, Th2-, Th9-, Th17-, and Th22-mediated inflammatory factors in the dorsal skin and splenocytes and restored skin barrier function by increasing the expression of the pro-filaggrin gene and barrier-related proteins filaggrin, involucrin, and loricrin. These results suggest DAA as a potential therapeutic agent that can alleviate the symptoms of AD by reducing pruritus, modulating immune imbalance, and restoring skin barrier function.

Production of IL-6 and Phagocytosis Are the Most Resilient Immune Functions in Metabolically Compromised Human Monocytes

At sites of inflammation, monocytes carry out specific immune functions while facing challenging metabolic restrictions. Here, we investigated the potential of human monocytes to adapt to conditions of gradually inhibited oxidative phosphorylation (OXPHOS) under glucose free conditions. We used myxothiazol, an inhibitor of mitochondrial respiration, to adjust two different levels of decreased mitochondrial ATP production. At these levels, and compared to uninhibited OXPHOS, we assessed phagocytosis, production of reactive oxygen species (ROS) through NADPH oxidase (NOX), expression of surface activation markers CD16, CD80, CD11b, HLA-DR, and production of the inflammatory cytokines IL-1β, IL-6 and TNF-α in human monocytes. We found phagocytosis and the production of IL-6 to be least sensitive to metabolic restrictions while surface expression of CD11b, HLA-DR, production of TNF-α, IL-1β and production of ROS through NOX were most compromised by inhibition of OXPHOS in the absence of glucose. Our data demonstrate a short-term hierarchy of immune functions in human monocytes, which represents novel knowledge potentially leading to the development of new therapeutics in monocyte-mediated inflammatory diseases.

Integrated pharmacology reveals the mechanism of action of Bu-Shen-Tong-Du prescription against collagen-induced arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Bu-Shen-Tong-Du prescription (BSP) has traditionally been used in to treat RA but its underlying mechanisms remain unclear. In this study, we explored the potential mechanisms of BSP in collagen-induced arthritis (CIA) rats, a classic animal model of RA. We employed an integrated pharmacology approach in combination with network pharmacology, 1H-nuclear magnetic resonance (NMR) metabolomics, and biochemical analyses to determine the mechanisms of BSP for treating RA. We found that BSP can regulate immunity and inflammation by decreasing the spleen index; inhibiting hyperplasia of the white pulp; reducing the levels of IL-1β, IL-6, IL-17A, and IFN-γ; and increasing the levels of IL-10 in the serum. Network pharmacology was utilized to predict related signal transduction pathways of BSP in RA treatment. 1H NMR metabolomics of the serum confirmed that BSP regulated energy metabolism and amino acid metabolism. Finally, we validated the Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling pathway using immunohistochemical methods, which demonstrated that BSP controlled RA-induced inflammation by inhibiting the TLR4/NF-κB signaling pathway. These results confirm the therapeutic effect of BSP in a CIA rat model, which is exerted via the inhibition of the inflammation and the improvement of the immune function, balancing energy metabolism and amino acid metabolism, and inhibiting the TLR4/NF-κB signaling pathway. This study provides an experimental basis for using BSP as a combinatorial drug to inhibit inflammation and regulate immunity in the treatment of RA.

Lithospermum erythrorhizon Alleviates Atopic Dermatitis-like Skin Lesions by Restoring Immune Balance and Skin Barrier Function in 2.4-Dinitrochlorobenzene-Induced NC/Nga Mice

The incidence of atopic dermatitis (AD), a disease characterized by an abnormal immune balance and skin barrier function, has increased rapidly in developed countries. This study investigated the anti-atopic effect of Lithospermum erythrorhizon (LE) using NC/Nga mice induced by 2,4-dinitrochlorobenzene. LE reduced AD clinical symptoms, including inflammatory cell infiltration, epidermal thickness, ear thickness, and scratching behavior, in the mice. Additionally, LE reduced serum IgE and histamine levels, and restored the T helper (Th) 1/Th2 immune balance through regulation of the IgG1/IgG2a ratio. LE also reduced the levels of AD-related cytokines and chemokines, including interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor-α (TNF-α), thymic stromal lymphopoietin, thymus and activation-regulated chemokine, macrophage-derived chemokine, regulated on activation, normal T cell expressed and secreted, and monocyte chemoattractant protein-1 in the serum. Moreover, LE modulated AD-related cytokines and chemokines expressed and secreted by Th1, Th2, Th17, and Th22 cells in the dorsal skin and splenocytes. Furthermore, LE restored skin barrier function by increasing pro-filaggrin gene expression and levels of skin barrier-related proteins filaggrin, involucrin, loricrin, occludin, and zonula occludens-1. These results suggest that LE is a potential therapeutic agent that can alleviate AD by modulating Th1/Th2 immune balance and restoring skin barrier function.

Luteolin and apigenin derived glycosides from Alphonsea elliptica abrogate LPS-induced inflammatory responses in human plasma

ETHNOPHARMACOLOGICAL RELEVANCE

Numerous Alphonsea species including Alphonsea elliptica (mempisang) leaves and fruits are indigenously used in inflammatory conditions such as postpartum swelling and rheumatism in southeast Asian countries. In our previous in-vitro findings, A. elliptica methanol extract exhibited platelet-activating factor inhibition, suggesting the presence of phyto-constituents with anti-inflammatory potential.

AIM OF THE STUDY

However, so far there is no literature available on the anti-inflammatory activity of this species. Henceforth, based on the above background and our previous laboratory findings, we hypothesize that phytoconstituents of A. elliptica could possess anti-inflammatory potential against inflammatory mediators including prostaglandin-E₂ (PGE₂), cyclooxegenase-2 (COX-2) and cytokines (IL-1β and IL-6).

MATERIALS AND METHODS

Vacuum and column chromatography techniques were employed for the isolation of phytoconstituents. The structure elucidation was carried out using HRESI-MS, ¹H and ¹³C-NMR analysis and compared with the published literature. For cytotoxicity analysis, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed on peripheral blood mononuclear cells. In-vitro anti-inflammatory activities were evaluated against the levels of PGE₂, COX-2, IL-1β and IL-6 in lipopolysaccharide (LPS)-induced human plasma using enzyme-linked immunosorbent assay and radioimmunoassay.

RESULTS

Unprecedentedly, chromatographic purification of methanolic leaves extract afforded five flavones namely vitexin, isovitexin, orientin, isoorientin, schaftoside with three flavanols; kaempferol, myricetin and rutin from A elliptica. In cell viability analysis, isolates did not present cytotoxicity up to 50 μM. In anti-inflammatory evaluation, orientin and isoorientin exhibited strong (≥70%), while isovitexin and vitexin produced strong to moderate (50-69%) PGE₂, COX-2, IL-1β and IL-6 inhibition at 25 and 50 μM. Isoorientin, orientin, isovitexin, and vitexin showed significant (p < 0.05) and concentration-dependent PGE₂ inhibition with IC₅₀ values (μM) of 11.40, 14.71, 17.70 and 20.58 against indomethacin (8.80). Furthermore, isoorientin, orientin, isovitexin, and vitexin produced significant concentration-dependent inhibition with IC₅₀ values (μM) of COX-2: 7.13, 9.51, 12.81, 16.61; IL-1β 4.80, 6.20, 10.85, 14.51; IL-6: 4.01, 5.90, 11.51 and 14.88 as compared to dexamethasone: 5.29, 2.93, 3.72, respectively (p < 0.05).

CONCLUSION

Conclusively, isolated phytoconstituents are reported for the first time from the A. elliptica. Moreover, isovitexin, vitexin orientin and isoorientin abrogated LPS-induced inflammatory responses in human plasma at non-cytotoxic concentrations.

A Tale of Two Immune Cells in Rheumatoid Arthritis: The Crosstalk Between Macrophages and T Cells in the Synovium

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease. Joint inflammation of RA is closely related to infiltration of immune cells, synovium hyperplasia, and superfluous secretion of proinflammatory cytokines, which lead to cartilage degradation and bone erosion. The joint synovium of RA patients contains a variety of immune cellular types, among which monocytes/macrophages and T cells are two essential cellular components. Monocytes/macrophages can recruit and promote the differentiation of T cells into inflammatory phenotypes in RA synovium. Similarly, different subtypes of T cells can recruit monocytes/macrophages and promote osteoblast differentiation and production of inflammatory cytokines. In this review, we will discuss how T cell-monocyte/macrophage interactions promote the development of RA, which will provide new perspectives on RA pathogenesis and the development of targeted therapy.

The COVID-19 pandemic: an increased risk of rheumatoid arthritis

COVID-19 is a respiratory infection similar to viral pneumonia and is caused by SARS-CoV-2. Chloroquine and hydroxychloroquine make up the major part of the treatment regimen for the management of COVID-19 infections, which are also commonly used in treatment of patients with malaria as well as autoimmune diseases like rheumatoid arthritis (RA). In this review, we analyzed the scientific evidences pertaining to any possible association of SARS-CoV-2 infection with RA. We thus believe that people predisposed to RA carry a higher infection risk than the general population both due to the iatrogenic effects of the RA related drug therapy. Thus COVID-19 pandemic may bring a higher risk of health emergency in complex diseases such as RA.

Glaucocalyxin A suppresses inflammatory responses and induces apoptosis in TNF-a-induced human rheumatoid arthritis via modulation of the STAT3 pathway

The pathogenesis of rheumatoid arthritis (RA) is characterized by synoviocyte hyperplasia and proinflammatory cytokine secretion, as well as the destruction of cartilage and bone. Glaucocalyxin A (GLA) is an alkaloid derived from a Chinese medicinal plant that exhibits anti-inflammatory, anti-tumor and neuroprotective properties. We investigated the effects of GLA on RA-fibroblast-like synoviocytes (FLS cells), and collagen-induced arthritis (CIA), and further explored the underlying mechanisms. GLA inhibited TNF-a-induced RA-FLS proliferation, increased apoptotic ratios and upregulated levels of caspase-3, cleaved PARP, and Bax. GLA also inhibited the expression of IL-10, IL-1β, and IL-6 in vitro. Levels of p-STAT3 were downregulated in a dose-dependent manner. Over-expression of STAT3 partly neutralized the GLA-mediated elevation of caspase-3 and cleaved PARP levels as well as the downregulation of IL-10, IL-1B and IL-6 expression levels. This suggests that GLA inactivated the STAT3 pathway. Furthermore, the production of inflammatory cytokines in RA-FLS and a CIA rat model were inhibited effectively by GLA. Taken together, our data suggest that GLA is a potential long-term therapeutic agent for patients with RA.

Extracellular Vesicles and Immune System in Ageing and Immune Diseases

Immune system is essential for host homeostasis. Immune cells communicate with each other by binding to receptors or by releasing vesicles including chemokines and cytokines. Under healthy circumstances, immune cell-derived factors are critical for cellular growth, division and function, whereas under conditions such as ageing and inflammatory states, they can aggravate pathologies and cause disease. Cell-derived membranous extracellular vesicles mediate cell-to-cell communication and are implicated in various physiological and pathological processes involving ageing and age-related diseases. Extracellular vesicles are responsible for spreading detrimental factors to the surroundings and the propagation phase of inflammatory diseases. The regulation of extracellular vesicles is a putative target for treatment of inflammatory diseases. Moreover, their features are ideal for developing biomarkers and drug delivery systems modulated by bioengineering in inflammatory diseases. The present review summarizes the current understanding of extracellular vesicles in ageing and inflammatory diseases.

COVID-19, rheumatic diseases and immune dysregulation-a perspective

The COVID-19 pandemic has resulted in widespread hospitalisations and deaths around the world. As patients with rheumatic diseases generally have increased risk of infections and complications, understandably, there is significant concern of the impact of SARS-CoV-2 on these patients. However, there is a paucity of data in rheumatic patients. We review mechanisms through which SARS-CoV-2 results in infection, including ACE2 receptor, and complications (including immune dysregulation, thrombosis and complement activation). We assess these pathways in patients with rheumatic disease and those on immune modulating therapy. Although data thus far does not appear to show worse outcomes in rheumatic patients as a whole, given alterations in the underlying immune pathways in certain diseases (such as systemic lupus erythematosus), we posit that the risk is not equal in all rheumatic patients. We also discuss the benefit of underlying disease control with respect to COVID-19 risk reduction and potential increased risk of disease flares following viral infection from an immune standpoint.

Salidroside regulates imbalance of Th17/Treg and promotes ischemic tolerance by targeting STAT-3 in cerebral ischemia-reperfusion injury

INTRODUCTION

The balance between Th17 and Treg cells controls the immune response and is an important regulator of helper T cells acting on autoimmune diseases. Focal cerebral ischemia-reperfusion injury can induce imbalance of Th17/Treg cells in the brain and the peripheral immune system of rats. The aim of this study was to investigate the effect of salidroside (Sal) on the ratio of Th17 and Treg cells in an adult rat model of middle cerebral artery occlusion (MCAO).

MATERIAL AND METHODS

Forty rats were divided into 4 groups: normal group, sham group, surgery group, and Sal group. After treatment, the neurological deficits in rats were evaluated. Peripheral blood mononuclear cells were isolated and the count of Th17 and Treg cells was detected by flow cytometry. The infarct size and expression of RORγt and Foxp3 were detected in rat brain tissue. Rat spleen cells were isolated, CD4⁺ T cells were purified by immunomagnetic beads. Treg cells were induced by adding cytokine TGF-β. Th17 cells were induced by adding cytokine IL-6. The expression of STAT-3 was inhibited by SiRNA, and the effect of Sal on the differentiation of Th17/Treg cells was analyzed. The expression levels of IL-6, TNF-α, MCP-1, STAT-3 and NF-κ-B2 proteins were examined.

RESULTS

The results show that MCAO can induce an imbalance of Th17 and Treg cells in peripheral blood of rats. Sal treatment can significantly reduce the neurological deficit and infarct size of MCAO rats, reverse the oxidative stress of rat brain tissue, and inhibit the apoptosis of brain cells in MCAO rats. In the brain tissue of MCAO rats, Sal could significantly inhibit the expression of IL-6, TNF-α, MCP-1, STAT-3 and NF-κ-B2. Down-regulation of STAT-3 significantly reversed the therapeutic effects of Sal treatment.

CONCLUSIONS

Our results indicate that Sal can increase the tolerance of rat brain tissue to ischemia, inhibit cell apoptosis and reduce oxidative stress by targeting STAT-3.

Are losartan and imatinib effective against SARS-CoV2 pathogenesis? A pathophysiologic-based in silico study

Proposing a theory about the pathophysiology of cytokine storm in COVID19, we were to find the potential drugs to treat this disease and to find any effect of these drugs on the virus infectivity through an in silico study. COVID-19-induced ARDS is linked to a cytokine storm phenomenon not explainable solely by the virus infectivity. Knowing that ACE2, the hydrolyzing enzyme of AngII and SARS-CoV2 receptor, downregulates when the virus enters the host cells, we hypothesize that hyperacute AngII upregulation is the eliciting factor of this ARDS. We were to validate this theory through reviewing previous studies to figure out the role of overzealous activation of AT1R in ARDS. According to this theory losartan may attenuate ARDS in this disease. Imatinib, has previously been elucidated to be promising in modulating lung inflammatory reactions and virus infectivity in SARS and MERS. We did an in silico study to uncover any probable other unconsidered inhibitory effects of losartan and imatinib against SARS-CoV2 pathogenesis. Reviewing the literature, we could find that over-activation of AT1R could explain precisely the mechanism of cytokine storm in COVID19. Our in silico study revealed that losartan and imatinib could probably: (1) decline SARS-CoV2 affinity to ACE2. (2) inhibit the main protease and furin, (3) disturb papain-like protease and p38MAPK functions. Our reviewing on renin-angiotensin system showed that overzealous activation of AT1R by hyper-acute excess of AngII due to acute downregulation of ACE2 by SARS-CoV2 explains precisely the mechanism of cytokine storm in COVID-19. Besides, based on our in silico study we concluded that losartan and imatinib are promising in COVID19.

Aberrant expression of USF2 in refractory rheumatoid arthritis and its regulation of proinflammatory cytokines in Th17 cells

IL-17-producing Th17 cells are implicated in the pathogenesis of rheumatoid arthritis (RA) and TNF-α, a proinflammatory cytokine in the rheumatoid joint, facilitates Th17 differentiation. Anti-TNF therapy ameliorates disease in many patients with rheumatoid arthritis (RA). However, a significant proportion of patients do not respond to this therapy. The impact of anti-TNF therapy on Th17 responses in RA is not well understood. We conducted high-throughput gene expression analysis of Th17-enriched CCR6+CXCR3-CD45RA- CD4+ T (CCR6+ T) cells isolated from anti-TNF-treated RA patients classified as responders or nonresponders to therapy. CCR6+ T cells from responders and nonresponders had distinct gene expression profiles. Proinflammatory signaling was elevated in the CCR6+ T cells of nonresponders, and pathogenic Th17 signature genes were up-regulated in these cells. Gene set enrichment analysis on these signature genes identified transcription factor USF2 as their upstream regulator, which was also increased in nonresponders. Importantly, short hairpin RNA targeting USF2 in pathogenic Th17 cells led to reduced expression of proinflammatory cytokines IL-17A, IFN-γ, IL-22, and granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as transcription factor T-bet. Together, our results revealed inadequate suppression of Th17 responses by anti-TNF in nonresponders, and direct targeting of the USF2-signaling pathway may be a potential therapeutic approach in the anti-TNF refractory RA.

Er Miao San, a traditional Chinese herbal formula, attenuates complete Freund's adjuvant-induced arthritis in rats by regulating Th17/Treg cells

Context: Er Miao San (EMS) is a traditional Chinese medicine composed of Atractylodis Rhizoma and Phellodendri Cortex in a 1:1 weight ratio. EMS has been used to treat rheumatism in China for many years.Objective: To evaluate the anti-arthritic activity of EMS extract on adjuvant-induced arthritis (AA) in Sprague-Dawley rats and to clarify its mechanisms of action.Materials and methods: EMS (0.75, 1.5 and 3 g/kg, once daily) was orally administered from day 18 after immunization to day 31. The effects of EMS on AA rats were evaluated by histopathological examination, paw swelling and polyarthritis index. The proliferation of fibroblast-like synoviocyte (FLS) and T cells was detected by CCK-8. The percentages of Th17 cells and Treg cells in splenocytes were determined by flow cytometry. Levels of cytokines in serum were detected by ELISA.Results: EMS treatment significantly decreased the paw volume (from 1.20 to 0.81), polyarthritis index (from 9.56 to 4.46) and alleviated ankle joint histopathology in AA rats. EMS inhibited the proliferation of FLS and T cells. Furthermore, EMS treatment decreased Th17 cells (from 4.62 to 2.08%) and increased Treg cells (from 2.77 to 4.75%) in splenocytes. The levels of IL-17A, TNF-α and IL-6 were remarkably decreased in the serum of EMS-treated rats, whereas the levels of IL-10 and TGF-β1 were significantly increased.Conclusions: EMS exhibits anti-arthritic activity in the AA model by regulating the balance of cytokines and the ratio of Th17 and Treg cells. These insights may provide an experimental basis for the clinical treatment of RA.

Prevotella Induces the Production of Th17 Cells in the Colon of Mice

Th17-mediated mucosal inflammation is related to increased Prevotella bacterial abundance. The actual involvement of Prevotella in the development and accumulation of intestinal Th17 cells at a steady state, however, remains undefined. Herein, we investigated the role of Prevotella in inducing intestinal Th17 cells in mice. Mice were treated with a combination of broad-spectrum antibiotics (including ampicillin, neomycin sulfate, vancomycin hydrochloride, and metronidazole) in their drinking water for 4 weeks and then gavaged with Prevotella for 4 weeks. After inoculation, 16S rDNA sequencing was used to verify the colonization of Prevotella in the colon of mice. The IL-17A as well as IL-17A-expressing T cells was localized and quantified by an immunofluorescence assay (IFA) of colon sections. Th17 cells in the mesenteric lymph nodes of mice were counted by flow cytometry. Systemic immune response to Prevotella colonization was evaluated based on the serum levels of IL-6, TNF-α, IL-1β, IL-17A, IL-10, IL-4, IFN-γ, and IL-2. Th17-polarizing cytokines (IL-6, TNF-α, IL-1β, and IL-2) induced by Prevotella were evaluated by stimulation of bone marrow-derived dendritic cells (BMDCs). Results revealed that after inoculation, Prevotella successfully colonized the intestine of mice and induced the production and accumulation of colonic Th17 cells in the colon. Moreover, Prevotella elevated some of the Th17-related cytokines in the serum of mice. And Th17-polarizing cytokines (IL-6 and IL-1β) produced by BMDCs were mediated mainly through the interaction between Prevotella and Toll-like receptor 2 (TLR2). In conclusion, our data suggest that Prevotella induces the production of Th17 cells in the colon of mice, thus highlighting the potential role of Prevotella in training the intestinal immune system.

Intracytoplasmic Expression of IL-6 and IL-17A in Circulating CD4+ T Cells Are Strongly Associated with and Predict Disease Activity in Rheumatoid Arthritis: A Case-Control Study in Ghana

Background

T cell cytokines play important roles in the development and progression of rheumatoid arthritis (RA). Loss of Th1/Th2 and Th17/Treg balance has been reported in several inflammatory autoimmune diseases. However, their role in RA within hitherto rare Ghanaian context has not been explored. Here, we evaluated the intracytoplasmic CD4+ T cell cytokine patterns in rheumatoid arthritis patients in Ghana and determined their relationship with disease activity.

Methods

This case-control study included 48 newly diagnosed RA patients and 30 apparent healthy controls from two major hospitals in Ghana. Validated structured questionnaires were administered to obtain demographic data; blood samples were collected and processed for flow cytometric analysis.

Results

IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, IL-6/IL-4, and IL-17/IL-10 expressions were significantly higher in RA cases compared to the healthy controls. The expression of IL-6 (0.00 (0.00-0.98) vs. 0.82 (0.34-1.10) vs. 1.56 (1.39-1.68), p < 0.0001), IL-17A (0.00 (0.00-0.02) vs. 0.19 (0.09-0.30) vs. 0.99 (0.64-1.25), p < 0.0001), and IL-17A/IL-10 (0.00 (0.00-0.39) vs. 0.15 (0.09-0.26) vs. 0.88 (0.41-1.47), p < 0.0001) increased significantly from the healthy controls through RA patients with low DAS scores to RA patients with moderate DAS scores. IL-6 (β = 0.681, r² = 0.527, p < 0.0001), IL-17A (β = 0.770, r² = 0.593, p < 0.0001), and IL-17A/IL-10 (β = 0.677, r² = 0.452, p < 0.0001) expressions were significantly directly associated with DAS28 scores. IL-6 (cutoff = 1.32, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) and IL-17A (cutoff = 0.58, sensitivity = 100.0%, specificity = 100.0%, accuracy = 100.0%, and AUC = 1.000) presented with the best discriminatory power in predicting moderate DAS scores from low DAS scores.

Conclusion

Th1- and Th17-related cytokines predominate in the pathophysiology of RA, with IL-6 and IL-17 being principally and differentially expressed based on the severity of the disease. IL-6 and IL-17A could serve as useful prognostic and disease-monitoring markers in RA in the African context.

Induced, but not natural, regulatory T cells retain phenotype and function following exposure to inflamed synovial fibroblasts

Aberrant number and/or dysfunction of CD4⁺Foxp3⁺ Regulatory T cells (T_regs) are associated with the pathogenesis of rheumatoid arthritis (RA). A previous study has demonstrated that thymus-derived, natural T_regs (nT_regs) prefer to accumulate in inflamed joints and transdifferentiate to T_H17 cells under the stimulation of inflamed synovial fibroblasts (SFs). In this study, we made a head-to-head comparison of both T_reg subsets and demonstrated that induced T_regs (iT_regs), but not nT_regs, retained Foxp3 expression and regulatory function on T effector cells (T_effs) after being primed with inflamed SFs. In addition, iT_regs inhibited proliferation, inflammatory cytokine production, migration, and invasion ability of collagen-induced arthritis (CIA)-SFs in vitro and in vivo. Moreover, we noted that iT_regs directly targeted inflamed SFs to treat autoimmune arthritis, while nT_regs failed to do this. Thus, manipulation of the iT_reg subset may have a greater potential for prevention or treatment of patients with RA.

Vitamin D3 and K2 and their potential contribution to reducing the COVID-19 mortality rate

The world is desperately seeking for a sustainable solution to combat the coronavirus strain SARS-CoV-2 (COVID-19). Recent research indicated that optimizing Vitamin D blood levels could offer a solution approach that promises a heavily reduced fatality rate as well as solving the public health problem of counteracting the general vitamin D deficiency. This paper dived into the immunoregulatory effects of supplementing Vitamin D3 by elaborating a causal loop diagram. Together with D3, vitamin K2 and magnesium should be supplemented to prevent long-term health risks. Follow up clinical randomized trials are required to verify the current circumstantial evidence.

Inhibition of colitis by ring-modified analogues of 6-acetamido-2,4,5-trimethylpyridin-3-ol

6-Aminopyridin-3-ol scaffold has shown an excellent anti-inflammatory bowel disease activity. Various analogues with the scaffold were synthesized in pursuit of the diversity of side chains tethering on the C(6)-position. Structure-activity relationship among the analogues was investigated to understand the effects of the side chains and their linkers on their anti-inflammatory activities. In this study, structural modification moved beyond side chains on the C(6)-position and reached to pyridine ring itself. It expedited us to synthesize diverse ring-modified analogues of a representative pyridine-3-ol, 6-acetamido-2,4,5-trimethylpyridin-3-ol (9). In the evaluation of compounds on their inhibitory actions against TNF-α-induced adhesion of monocytic cells to colonic epithelial cells, an in vitro model mimicking colon inflammation, the effects of compounds 9, 17, and 19 were greater than tofacitinib, an orally available anti-colitis drug, and compound 17 showed the greatest activity. In addition, TNF-α-induced angiogenesis, which permits more inflammatory cell migration into inflamed tissues, was significantly blocked by compounds 17 and 19 in a concentration-dependent manner. In the comparison of in vivo therapeutic effects of compounds 9, 17, and 19 on dextran sulfate sodium (DSS)-induced colitis in mice, compound 17 was the most potent and efficacious, and compound 19 was better than compound 9 which showed a similar degree of inhibitory effect to tofacitinib. Taken together, it seems that either the trimethyl system or the hydroxyl group on the pyridinol ring is essential to the activity. This finding might become a new milestone in the development of pyridinol-based anti-inflammatory bowel disease agents.

Exosomes derived from synovial fibroblasts under hypoxia aggravate rheumatoid arthritis by regulating Treg/Th17 balance

IMPACT STATEMENT

A comparative study of osteoarthritis (OA) and RA mice was implemented to suggest that miR-424 expression was increased in RA, and exosome-miR-424 derived from synovial fibroblasts (SFs-exo) could significantly induce T cells differentiation in which Th17 cells increased and Treg cells decreased via targeting FOXP3. And thus, miR-424 may be a potential therapeutic target for RA.

The LFA-1 antagonist BIRT377 reverses neuropathic pain in prenatal alcohol-exposed female rats via actions on peripheral and central neuroimmune function in discrete pain-relevant tissue regions

Previous reports show that moderate prenatal alcohol exposure (PAE) poses a risk factor for developing neuropathic pain following adult-onset peripheral nerve injury in male rats. Recently, evidence suggests that immune-related mechanisms underlying neuropathic pain in females are different compared to males despite the fact that both sexes develop neuropathy of similar magnitude and duration following chronic constriction injury (CCI) of the sciatic nerve. Data suggest that the actions of peripheral T cells play a greater role in mediating neuropathy in females. The goal of the current study is to identify specificity of immune cell and cytokine changes between PAE and non-PAE neuropathic females by utilizing a well-characterized rodent model of sciatic nerve damage, in an effort to unmask unique signatures of immune-related factors underlying the risk of neuropathy from PAE. Cytokines typically associated with myeloid cell actions such as interleukin (IL)-1β, tumor necrosis factor (TNF), IL-6, IL-4 and IL-10 as well as the neutrophil chemoattractant CXCL1, are examined. In addition, transcription factors and cytokines associated with various differentiated T cell subtypes are examined (anti-inflammatory FOXP3, proinflammatory IL-17A, IL-21, ROR-γt, interferon (IFN)-γ and T-bet). Lymphocyte function associated antigen 1 (LFA-1) is an adhesion molecule expressed on peripheral immune cells including T cells, and regulates T cell activation and extravasation into inflamed tissue regions. A potential therapeutic approach was explored with the goal of controlling proinflammatory responses in neuroanatomical regions critical for CCI-induced allodynia by blocking LFA-1 actions using BIRT377. The data show profound development of hindpaw allodynia in adult non-PAE control females following standard CCI, but not following minor CCI, while minor CCI generated allodynia in PAE females. The data also show substantial increases in T cell-associated proinflammatory cytokine mRNA and proteins, along with evidence of augmented myeloid/glial activation (mRNA) and induction of myeloid/glial-related proinflammatory cytokines, CCL2, IL-1β and TNF in discrete regions along the pain pathway (damaged sciatic nerve, dorsal root ganglia; DRG, and spinal cord). Interestingly, the characteristic anti-inflammatory IL-10 protein response to nerve damage is blunted in neuropathic PAE females. Moreover, T cell profiles are predominantly proinflammatory in neuropathic Sac and PAE females, augmented levels of Th17-specific proinflammatory cytokines IL-17A and IL-21, as well as the Th1-specific factor, T-bet, are observed. Similarly, the expression of RORγt, a critical transcription factor for Th17 cells, is detected in the spinal cord of neuropathic females. Blocking peripheral LFA-1 actions with intravenous (i.v.) BIRT377 reverses allodynia in Sac and PAE rats, dampens myeloid (IL-1β, TNF, CXCL1)- and T cell-associated proinflammatory factors (IL-17A and RORγt) and spinal glial activation. Moreover, i.v. BIRT377 treatment reverses the blunted IL-10 response to CCI observed only in neuropathic PAE rats and elevates FOXP3 in pain-reversed Sac rats. Unexpectedly, intrathecal BIRT377 treatment is unable to alter allodynia in either Sac or PAE neuropathic females. Together, these data provide evidence that: 1) fully differentiated proinflammatory Th17 cells recruited at the sciatic nerve, DRGs and lumbar spinal cord may interact with the local environment to shape the immune responses underlying neuropathy in female rats, and, 2) PAE primes peripheral and spinal immune responses in adult females. PAE is a risk factor in females for developing peripheral neuropathy after minor nerve injury.

Network Pharmacology Approach to Uncover the Mechanism Governing the Effect of Radix Achyranthis Bidentatae on Osteoarthritis

BACKGROUND

This study used a network pharmacology approach to elucidate the molecular mechanism governing the effect of Radix Achyranthis Bidentatae (RAB) on osteoarthritis (OA).

METHODS

Based on oral bioavailability and drug-likeness, the main active components of RAB were screened via the Traditional Chinese Medicine Systems Pharmacology platform. The GeneCard, OMIM, PharmGkb, Therapeutic Targets database, and DrugBank database were used to establish a database of osteoarthritis targets. The interactive active network map of "ingredient-target" was constructed with Cytoscape software (Version 3.7.1). The protein-protein interaction network was constructed with the STRING database, and the related protein interaction relationship was analysed. GO biological function analysis and KEGG enrichment analysis for core targets were performed. Finally, docking of the active components with the core target was carried out.

RESULTS

Sixteen active components of RAB were obtained, and 63 potential targets for OA were identified. Network analysis results indicate that these targets are primarily involved in regulating biological processes, such as cell metabolism, apoptosis, and cell proliferation. Pathways involved in the treatment of osteoarthritis include virus-related signalling pathways, apoptosis signalling pathways, IL-17 signalling pathways, and PI3K/AKT signalling pathways.

CONCLUSION

RAB has the characteristics of being multi-system, multi-component and multi-target. Possible mechanisms of action for RAB include regulating the immune and inflammatory responses, reducing chondrocyte apoptosis, and protecting the joint synovial membrane and cartilage to control disease development. The active ingredients in RAB, such as sterols and flavonoids, exhibit strong potential as candidate drugs for the treatment of osteoarthritis.

PBT-6, a Novel PI3KC2γ Inhibitor in Rheumatoid Arthritis

Phosphoinositide 3-kinase (PI3K) is considered as a promising therapeutic target for rheumatoid arthritis (RA) because of its involvement in inflammatory processes. However, limited studies have reported the involvement of PI3KC2γ in RA, and the underlying mechanism remains largely unknown. Therefore, we investigated the role of PI3KC2γ as a novel therapeutic target for RA and the effect of its selective inhibitor, PBT-6. In this study, we observed that PI3KC2γ was markedly increased in the synovial fluid and tissue as well as the PBMCs of patients with RA. PBT-6, a novel PI3KC2γ inhibitor, decreased the cell growth of TNF-mediated synovial fibroblasts and LPS-mediated macrophages. Furthermore, PBT-6 inhibited the PI3KC2γ expression and PI3K/ AKT signaling pathway in both synovial fibroblasts and macrophages. In addition, PBT-6 suppressed macrophage migration via CCL2 and osteoclastogenesis. In CIA mice, it significantly inhibited the progression and development of RA by decreasing arthritis scores and paw swelling. Three-dimensional micro-computed tomography confirmed that PBT-6 enhanced the joint structures in CIA mice. Taken together, our findings suggest that PI3KC2γ is a therapeutic target for RA, and PBT-6 could be developed as a novel PI3KC2γ inhibitor to target inflammatory diseases including RA.

Monocyte chemoattractant protein‑1 promotes the proliferation, migration and differentiation potential of fibroblast‑like synoviocytes via the PI3K/P38 cellular signaling pathway

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the joints and joint destruction. Monocyte chemoattractant protein 1 (MCP‑1) is highly expressed in the joints of patients suffering from RA. The present study aimed to evaluate the effects of MCP‑1 on the phenotype of fibroblast‑like synoviocytes (FLSs) and their differentiation potential towards vascular endothelial cells. The expression of MCP‑1 in collagen‑induced arthritis (CIA) rats was investigated by PCR, ELISA and immunohistology. Cell proliferation induced by MCP‑1 was measured using a Cell Counting Kit‑8 (CCK‑8) and 5‑Bromo‑2‑deoxyuridine ELISA assay. In addition, the effects of MCP‑1 on the migration of FLSs was examined using a Transwell assay. Activation of PI3K and P38 were investigated by western blotting following MCP‑1 treatment. The vascular endothelial cell markers, tumor necrosis factor alpha (TNF‑α) and interleukin‑1 beta (IL‑β), were also examined by western blotting. LY294002 [PI3K inhibitor, (LY)] and SB203580 [P38 inhibitor, (SB)] were used to examine the proliferative and pro‑differentiation effect of PI3K and P38. The present findings showed that the expression level of MCP‑1 in the synovium of CIA rats was significantly higher compared with controls. The present in vitro study suggested that MCP‑1 increased the FLSs cell numbers with a maximal effect at 200 ng/ml, and induced the maximal phosphorylation of PI3K at 15 min and P38 at 30 min. In addition, MCP‑1 stimulation significantly increased the migration of FLSs. Furthermore, MCP‑1‑induced the expression of vascular endothelial growth factor and CD31 in FLSs. Suppression of PI3K and P38 was found to reduce MCP‑1 induced FLSs proliferation and migration, and decreased the expression levels of angiogenesis markers increased following MCP‑1 treatment. MCP‑1 was also found to increase the expression levels of both TNF‑α and IL‑β. Therefore, MCP‑1 could promote the proliferation and migration of FLSs, and was found to increase the expression levels of various angiogenesis markers via PI3K/P38, suggesting a role for this pathway in synovium hyperplasia in RA.

TNF-α in T lymphocytes attenuates renal injury and fibrosis during nephrotoxic nephritis

Nephrotoxic serum nephritis (NTN) models immune-mediated human glomerulonephritis and culminates in kidney inflammation and fibrosis, a process regulated by T lymphocytes. TNF-α is a key proinflammatory cytokine that contributes to diverse forms of renal injury. Therefore, we posited that TNF-α from T lymphocytes may contribute to NTN pathogenesis. Here, mice with T cell-specific deletion of TNF-α (TNF TKO) and wild-type (WT) control mice were subjected to the NTN model. At 14 days after NTN, kidney injury and fibrosis were increased in kidneys from TNF TKO mice compared with WT mice. PD1+CD4+ T cell numbers and mRNA levels of IL-17A were elevated in NTN kidneys of TNF TKO mice, suggesting that augmented local T helper 17 lymphocyte responses in the TNF TKO kidney may exaggerate renal injury and fibrosis. In turn, we found increased accumulation of neutrophils in TNF TKO kidneys during NTN. We conclude that TNF-α production in T lymphocytes mitigates NTN-induced kidney injury and fibrosis by inhibiting renal T helper 17 lymphocyte responses and infiltration of neutrophils.

Immunomodulatory effect of human bone marrow-derived mesenchymal stromal/stem cells on peripheral blood T cells from rheumatoid arthritis patients

Rheumatoid arthritis (RA) is a Th1/Th17-mediated autoimmune disease whose current treatment, consisting in the blockage of inflammatory cytokines by disease-modifying antirheumatic drugs, is not effective for all patients. The therapeutic potential of mesenchymal stromal/stem cells' (MSCs) immunomodulatory properties is being explored in RA. Here, we investigate the effect of human bone marrow (BM)-MSCs on the expression of cytokines involved in RA physiopathology by the distinct functional compartments of CD4⁺ and CD8⁺ T cells from RA patients. Peripheral blood mononuclear cells from healthy individuals (n = 6) and RA patients (n = 12) were stimulated with phorbol myristate acetate plus ionomycin and cultured in the presence/absence of BM-MSCs. The expression of (interleukin) IL-2, tumor necrosis factor alpha (TNF-α), and interferon-gamma (IFN-γ) was evaluated in naive, central memory, effector memory, and effector CD4⁺ and CD8⁺ T cells, whereas IL-6, IL-9, and IL-17 expression was measured in total CD4⁺ and CD8⁺ T cells. mRNA expression of IL-4, IL-10, transforming growth factor beta (TGF-β), cytotoxic T-lymphocyte-associated antigen 4, and/or forkhead box P3 was quantified in fluorescence-activated cell sorting-purified CD4⁺ T cells, CD8⁺ T cells, and CD4⁺ Treg. BM-MSCs inhibited the production of TNF-α, IL-17, IL-6, IL-2, IFN-γ, and IL-9 by T cells from RA patients, mainly by reducing the percentage of cells producing cytokines. This inhibitory effect was transversal to all T cell subsets analyzed. At mRNA level, BM-MSCs increased expression of IL-10 and TGF-β by CD4⁺ and CD8⁺ T cells. BM-MSCs displayed a striking inhibitory action over T cells from RA patients, reducing the expression of cytokines involved in RA physiopathology. Remarkably, BM-MSC-derived immunomodulation affected either naive, effector, and memory T cells.

Key role of organic cation transporter 2 for the nephrotoxicity effect of triptolide in rheumatoid arthritis

Tripterygium wilfordii Hook. F. (TwHF), a traditional Chinese Medicine, is effective in treating rheumatoid arthritis (RA), but its severe nephrotoxicity limits its extensive application. The nephrotoxic mechanism of Triptolide (TP), the main pharmacological and toxic component of TwHF, has not been fully revealed. This study was designed to explore the nephrotoxicity of TP in the RA state and the potential molecular mechanism. A rat collagen-induced arthritis (CIA) model was constructed and administered with TP for 28 days in vivo. Results showed that the kidney injury induced by TP was aggravated in the CIA state, the concentration of TP in the renal cortex was higher than that of the medulla after TP administration in the CIA rats, and the expression of organic cation transporter 2 (Oct2) in kidney was up-regulated under CIA condition. Besides, rat kidney slice study demonstrated that TP was transported by Oct2 and this was confirmed by transient silencing and overexpression of OCT2 in HEK-293T cells. Furthermore, cytoinflammatory models on HK-2 and HEK-293T cell lines were constructed by exposure of TNF-α or IL-1β to further explore the TP's renal toxicity. Results suggested that TNF-α exposure aggravated TP's toxicity and up-regulated the protein expression of OCT2 in both cell lines. TNF-α treatment also increased the function of OCT2 and finally OCT2 silencing confirmed OCT2 mediated nephrotoxicity of TP in HEK-293T cells. In summary, the exposure of TNF-α in RA state induced the expression of OCT2, which transported more TP into kidney cortex, subsequently exacerbated the kidney injury.