Possible roles of IL-12-family cytokines in rheumatoid arthritis

Repeated social defeat stress differently affects arthritis-associated hypersensitivity in male and female mice

Chronic stress enhances the risk of neuropsychiatric disorders and contributes to the aggravation and chronicity of pain. The development of stress-associated diseases, including pain, is affected by individual vulnerability or resilience to stress, although the mechanisms remain elusive. We used the repeated social defeat stress model promoting susceptible and resilient phenotypes in male and female mice and induced knee mono-arthritis to investigate the impact of stress vulnerability on pain and immune system regulation. We analyzed different pain-related behaviors, measured blood cytokine and immune cell levels, and performed histological analyses at the knee joints and pain/stress-related brain areas. Stress susceptible male and female mice showed prolonged arthritis-associated hypersensitivity. Interestingly, hypersensitivity was exacerbated in male but not female mice. In males, stress promoted transiently increased neutrophils and Ly6Chigh monocytes, lasting longer in susceptible than resilient mice. While resilient male mice displayed persistently increased levels of the anti-inflammatory interleukin (IL)-10, susceptible mice showed increased levels of the pro-inflammatory IL-6 at the early- and IL-12 at the late arthritis stage. Although joint inflammation levels were comparable among groups, macrophage and neutrophil infiltration was higher in the synovium of susceptible mice. Notably, only susceptible male mice, but not females, presented microgliosis and monocyte infiltration in the prefrontal cortex at the late arthritis stage. Blood Ly6Chigh monocyte depletion during the early inflammatory phase abrogated late-stage hypersensitivity and the associated histological alterations in susceptible male mice. Thus, recruitment of blood Ly6Chigh monocytes during the early arthritis phase might be a key factor mediating the persistence of arthritis pain in susceptible male mice. Alternative neuro-immune pathways that remain to be explored might be involved in females.

JAK/STAT signaling in rheumatoid arthritis leukocytes is uncoupled from serum cytokines in a subset of patients

OBJECTIVE

Rheumatoid Arthritis (RA) is a systemic autoimmune disease involving pro-inflammatory cytokines that can be therapeutically targeted by antibodies or kinase inhibitors. Nevertheless, these drugs fail in a subset of patients independent of the abundance of the targeted cytokines. We aim to explore the cellular basis of this phenomenon by analyzing the relation of cytokine abundance and activation of downstream signaling pathways in RA.

METHODS

The study included 62 RA patients and 9 healthy controls (HC). Phosphorylation of STAT 1-6 in various immune cell subsets was determined ex vivo using a novel robust flow cytometry-based protocol. Serum concentrations of IL-6, IL-10, IL-12p70, IL-17 A, interferon gamma, and TNFα in the same samples were measured using highly sensitive single molecule array (SIMOA).

RESULTS

We found an increase in circulating cytokines in RA patients, while STAT activity was lower in RA patients compared to HC. Based on STAT activity we determined three endotypes in active RA patients (cDAI>10, n = 28): 1) those with active STAT5a/b signaling in T cells (n = 7/28), 2) those with a low STAT activity in all assessed cell types (n = 14/28), and 3) those with active STAT1 and STAT3 signaling mainly in myeloid cells (n = 7/28). Integrating intracellular STAT activation and cytokine analysis revealed diminished JAK/STAT signaling in a subset of patients (n = 8/20) despite elevated serum cytokine concentrations.

CONCLUSION

Diminished JAK/STAT signaling in active RA may partly explain unresponsiveness to therapy targeting cytokine signaling. Analysis of JAK/STAT phosphorylation may identify patients at risk for non-response to these therapies.

IL-35 ameliorates lipopolysaccharide-induced endothelial dysfunction by inhibiting endothelial-to-mesenchymal transition

Sepsis is a systemic inflammatory response syndrome (SIRS) caused mainly by bacterial infection. The morbidity and mortality rates of sepsis are extremely high. About 18 million people worldwide suffer from severe sepsis each year, and about 14,000 people die from it every day. Previous studies have revealed that endothelial dysfunction plays a vital role in the pathological change of sepsis. Furthermore, endothelial-mesenchymal transition (EndMT, EndoMT) is capable of triggering endothelial dysfunction. And yet, it remains obscure whether interleukin-35 (IL-35) can alleviate endothelial dysfunction by attenuating LPS-induced EndMT. Here, through in vivo and in vitro experiments, we revealed that IL-35 has a previously unknown function to attenuate LPS-induced endothelial dysfunction by inhibiting LPS-induced EndMT. Mechanistically, IL-35 acts by regulating the NFκB signaling pathway.

Engineered mesenchymal stem cell-derived extracellular vesicles constitute a versatile platform for targeted drug delivery

Extracellular vesicles (EVs) are promising therapeutic carriers owing to their ideal size range and intrinsic biocompatibility. However, limited targeting ability has caused major setbacks in the clinical application of EV therapeutics. To overcome this, we genetically engineered natural free streptavidin (SA) on the cellular surface of bone marrow mesenchymal stem cells (BMSCs) and obtained typical EVs from these cells (BMSC-EVs). Biotin-coated gold nanoparticles confirmed the expression of SA on the membrane of EVs, which has a high affinity for biotinylated molecules. Using a squamous cell carcinoma model, we demonstrated that a pH-sensitive fusogenic peptide -modification of BMSC-EVs achieved targetability in the microenvironment of a hypoxic tumor to deliver anti-tumor drugs. Using EGFR+HER2- and EGFR-HER2+ breast cancer models, we demonstrated that anti-EGFR and anti-HER2 modifications of BMSC-EVs were able to specifically deliver drugs to EGFR+ and HER2+ tumors, respectively. Using a collagen-induced arthritis model, we confirmed that anti-IL12/IL23-modified BMSC-EVs specifically accumulated in the arthritic joint and alleviated inflammation. Administration of SA-overexpressing BMSC-EVs has limited immunogenicity and high safety in vivo, suggesting that BMSC-derived EVs are ideal drug delivery vehicle. These representative scenarios of targeting modification suggest that, using different biotinylated molecules, the SA-overexpressing BMSC-EVs could be endowed with different targetabilities, which allows BMSC-EVs to serve as a versatile platform for targeted drug delivery under various situations.

Vasculitis Activity-Predicting Ability of IL-12 Family Cytokines in Patients with Microscopic Polyangiitis and Granulomatosis with Polyangiitis

PURPOSE

The present study investigated and compared the antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) activity-predicting ability of the serum concentrations of the four interleukin (IL)-12 family cytokines including IL-23, IL-27, IL-35, and IL-39 in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA).

MATERIALS AND METHODS

The present study included 70 patients with MPA and GPA. Clinical and laboratory data, particularly Birmingham Vasculitis Activity Score (BVAS), at the time of blood collection were obtained. The serum concentrations of IL-23, IL-27, IL-35, and IL-37 were measured using sera stored at -80℃. Patients were divided into two groups: the upper half of BVAS (BVAS ≥12) and the lower half of BVAS (BVAS <12).

RESULTS

The serum concentrations of IL-23 and IL-27 reflected AAV activity. Patients with the upper half of BVAS exhibited significantly higher serum concentrations of IL-23 and IL-27 than those without. Patients with the serum concentrations of IL-23 ≥132.1 pg/mL or IL-27 ≥684.7 pg/mL exhibited higher frequency and risk for the upper half of BVAS than those without [relative risks (RR) 5.143 and RR 4.091, respectively]. The serum concentrations of IL-27 were associated with age ≥65 years and proteinase 3-ANCA (or C-ANCA) negativity, whereas, those of IL-23 were associated with MPA. However, the serum concentrations of IL-35 and IL-39 were not useful in predicting AAV activity in this study.

CONCLUSION

The present study is the first to demonstrate that among the various members of IL-12 family cytokines, the serum concentrations of IL-23 and IL-27 possess AAV activity-predicting ability.

Circulating interleukin-39 as a potential biomarker for rheumatoid arthritis diagnosis

BACKGROUND

Imbalances in cytokine networks have been shown to be a possible cause of rheumatoid arthritis (RA). The interleukin (IL)-12 family is involved in the pathogenesis of autoimmune diseases including RA, while IL-39 is a newly discovered member of the IL-12 family, although its role in RA remains unclear. The purpose of the present study was to detect the expression of IL-39 in the sera of patients with RA and its relationship with RA activity.

METHODS

We recruited 46 patients with RA and 35 healthy controls at Ningbo Sixth Hospital. Blood samples were collected for biochemical analysis, and disease activity scores of 28 joints based on C-reactive protein were monitored. Serum concentrations of IL-39 were determined using an enzyme-linked immunosorbent assay. The Pearson correlation test was used to analyze the association between serum IL-39 levels and clinical indicators.

RESULTS

Serum levels of IL-39 were significantly higher in patients with RA compared with healthy controls (p < 0.0001). IL-39 levels positively correlated with rheumatoid factor (RF), erythrocyte sedimentation rate (ESR), and IgM; RF positively correlated with ESR. Receiver operating characteristic curve analysis showed that IL-39 has diagnostic value for RA (p < 0.0001).

CONCLUSIONS

The significant increase of IL-39 levels in serum of patients with RA and its positive correlation with clinical indicators suggest that IL-39 may serve as biomarker for the diagnosis of RA.

Interleukin-12 induces IFN-γ secretion and STAT signaling implying its potential regulation of Th1 cell response in Nile tilapia

As a pleiotropic cytokine consisting of IL-12p35 and IL-12p40, Interleukin-12 (IL-12) features in inflammation regulation and anti-bacterial immunity. While IL-12 homologs have been identified in non-mammalian species, the precise mechanisms by which IL-12 contributes to early adaptive immune responses in vertebrates remain incompletely understood. Herein, an evolutionary conserved Oreochromis niloticus IL-12 (defined as OnIL-12) was identified by synteny characterization, structural comparisons and phylogenetic pattern of IL-12p35b and IL-12p40a. IL-12p35b and IL-12p40a exhibited widespread expression in lymphoid-related tissues of tilapia, while their mRNA expression in head-kidney demonstrated a significant increase after Edwardsiella piscicida infection. Compared with other lymphocytes, recombinant OnIL-12 (rOnIL-12) displayed stronger affinity binding to T cells. Although stimulation of lymphocytes with the p35b or p40a subunit resulted in a significant induction of IFN-γ expression, rOnIL-12 showed stronger potential to promote IFN-γ expression than these subunits. rOnIL-12 not only elevated the mRNA expression level Th1 cell-associated transcription factor T-bet in lymphocytes, but also increased the proportion of CD4-1+IFN-γ+ lymphocytes. Moreover, the mRNA and phosphorylation levels of STAT1, STAT3, STAT4 and STAT5 were enhanced by rOnIL-12. These findings will offer previous evidence for further exploration into the regulatory mechanisms of Th1 cellular immunity in early vertebrates.

Syringaldehyde ameliorates mouse arthritis by inhibiting dendritic cell maturation and proinflammatory cytokine secretion

Syringaldehyde (SD), a kind of flavonoid polyphenolic small molecule compound, has the antioxidant and anti-inflammatory properties. But it is unknown whether SD has properties on the treatment of rheumatoid arthritis (RA) by modulating dendritic cells (DCs). We explored the effect of SD on the maturation of DCs in vitro and in vivo. The results showed that SD significantly down-regulated the expression of CD86, CD40 and MHC II, decreased the secretion of TNF-α, IL-6, IL-12p40 and IL-23, and increased IL-10 secretion and antigen phagocytosis in vitro induced by lipopolysaccharides in a dose-dependent manner through reducing the activation of MAPK/NF-κB signaling pathways. SD also significantly inhibited the expression of CD86, CD40 and MHC II on DCs in vivo. Moreover, SD suppressed the expression of CCR7 and the in vivo migration of DCs. In arthritis mouse models induced by λ-carrageenan and complete Freund's adjuvant, SD significantly alleviated paw and joint oedema, reduced the levels of pro-inflammatory cytokines TNF-α and IL-6 and increased the level of IL-10 in serum. Interestingly, SD significantly decreased the numbers of type I helper T cells (Th1), Th2, Th17 and Th17/Th1-like (CD4⁺IFN-γ⁺IL-17A⁺), but increased the numbers of regulatory T cells (Tregs) in spleens of mice. Importantly, the numbers of CD11c⁺IL-23⁺ and CD11c⁺IL-6⁺ cells were negatively correlated with the numbers of Th17 and Th17/Th1-like. These results suggested that SD ameliorated mouse arthritis through inhibiting the differentiation of Th1, Th17 and Th17/Th1-like and promoting the generation of Tregs via regulation of DC maturation.

Transcriptomic signatures induced by the Ebola virus vaccine rVSVΔG-ZEBOV-GP in adult cohorts in Europe, Africa, and North America: a molecular biomarker study

BACKGROUND

A recombinant vesicular stomatitis virus vector expressing the Zaire Ebola virus glycoprotein (rVSVΔG-ZEBOV-GP) vaccine has been reported as safe, immunogenic, and highly protective in a ring vaccination trial. We aimed to identify transcriptomic immune response biomarker signatures induced by vaccination and associated signatures with its immunogenicity and reactogenicity to better understand the potential mechanisms of action of the vaccine.

METHODS

354 healthy adult volunteers were vaccinated in randomised, double-blind, placebo-controlled trials in Europe (Geneva, Switzerland [November, 2014, to January, 2015]) and North America (USA [Dec 5, 2014, to June 23, 2015]), and dose-escalation trials in Africa (Lambaréné, Gabon [November, 2014, to January, 2015], and Kilifi, Kenya [December, 2014, to January, 2015]) using different doses of the recombinant vesicular stomatitis virus vector expressing the Zaire Ebola virus glycoprotein (rVSVΔG-ZEBOV-GP; 3 × 10⁵ to 1 × 10⁸ plaque-forming units [pfu]). Longitudinal transcriptomic responses (days 0, 1, 2, 3, 7, 14, and 28) were measured in whole blood using a targeted gene expression profiling platform (dual-colour reverse-transcriptase multiplex ligation-dependent probe amplification) focusing on 144 immune-related genes. The effect of time and dose on transcriptomic response was also assessed. Logistic regression with lasso regularisation was applied to identify host signatures with optimal discriminatory capability of vaccination at day 1 or day 7 versus baseline, whereas random-effects models and recursive feature elimination combined with regularised logistic regression were used to associate signatures with immunogenicity and reactogenicity.

FINDINGS

Our results indicated that perturbation of gene expression peaked on day 1 and returned to baseline levels between day 7 and day 28. The magnitude of the response was dose-dependent, with vaccinees receiving a high dose (≥9 × 10⁶ pfu) of rVSVΔG-ZEBOV-GP exhibiting the largest amplitude. The most differentially expressed genes that were significantly upregulated following vaccination consisted of type I and II interferon-related genes and myeloid cell-associated markers, whereas T cell, natural killer cell, and cytotoxicity-associated genes were downregulated. A gene signature associated with immunogenicity (common to all four cohorts) was identified correlating gene expression profiles with ZEBOV-GP antibody titres and a gene signatures associated with reactogenicity (Geneva cohort) was identified correlating gene expression profiles with an adverse event (ie, arthritis).

INTERPRETATION

Collectively, our results identify and cross-validate immune-related transcriptomic signatures induced by rVSVΔG-ZEBOV-GP vaccination in four cohorts of adult participants from different genetic and geographical backgrounds. These signatures will aid in the rational development, testing, and evaluation of novel vaccines and will allow evaluation of the effect of host factors such as age, co-infection, and comorbidity on responses to vaccines.

FUNDING

Innovative Medicines Initiative 2 Joint Undertaking.

The Effect of IL-35 on the Expression of Nasal Epithelial-Derived Proinflammatory Cytokines

Background

Airway epithelium plays an important role during the development of allergic rhinitis (AR), which is characterized by production of thymic stromal lymphopoietin (TSLP), interleukin 33 (IL-33), and interleukin 25 (IL-25). IL-35, mainly expressed by Treg cells, have negative regulation in Th2, Th17, and ILC2 inflammation. However, the effect of IL-35 on human nasal epithelial cells (HNECs) especially the secretion of nasal epithelial-derived proinflammatory cytokines as well as the possible mechanism is still unclear.

Methods

HNECs were cultured and stimulated by various stimulators. The expression of IL-33, IL-25, TSLP, eotaxin-1, eotaxin-2, and eotaxin-3 from supernatant was measured using real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). AR mice were developed to verify the effect of IL-35 on nasal epithelial cells in vivo.

Results

After Poly I:C stimulation, IL-35 inhibited the production of IL-25, and TSLP from HNECs increased significantly compared with baseline levels (P < 0.05). After Dermatophagoides pteronyssinus or Aspergillus fumigatus stimulation, IL-35 inhibited the production of IL-25, IL-33, and TSLP from HNECs increased significantly compared with baseline levels (P < 0.05). After Dermatophagoides pteronyssinus, IL-35 inhibited the production of eotaxin-1, eotaxin-2, and eotaxin-3 released from HNECs increased significantly compared with baseline levels (P < 0.05). Similarly, IL-35-treated AR mice presented with decreased expression of IL-33, IL-25, TSLP, eotaxin-1, eotaxin-2, and eotaxin-3 in nasal lavage fluid.

Conclusion

IL-35 suppressed both type 2 inflammation-inducing cytokines and eosinophil chemotactic factor from HNECs, suggesting the important role of IL-35 during the development of AR.

The role of IL-18 in addition to Th17 cytokines in rheumatoid arthritis development and treatment in women

We aimed to analyze serum pro-inflammatory profiles of female rheumatoid arthritis (RA) patients and compare them with healthy women to establish the relative importance of pro-inflammatory cytokines in RA and their relation with different treatment regimens. Levels of six cytokines were determined by ELISA assays. A supervised dimensionality reducing approach (PLS-DA Analysis) was applied. All of the cytokines assayed were significantly elevated in the sera of RA female patients than healthy controls with fold change: 21-fold for IL-6; 6.1-fold for IL-17A; 2.5-fold for IL-23; 2.3-fold for IL-18; 1.94-fold for TNF-α; 1.7-fold for IL-12p40. According to the results of the PLS-DA analysis, IL-17A, IL-18, and TNF-α were of higher importance rank compared to IL-23 and IL-12p40. Women in the early stage of RA displayed significantly elevated IL-17A levels than those with longer disease duration: 8.04 pg/ml [8.04-175.3] vs 4.64 pg/ml [2.95-13.31], p = 0.007. IL-6 serum levels were related to higher disease activity. We have demonstrated altered cytokine production within female RA patients on different treatment regimens. Those on Tocilizumab therapy showed elevated IL-6 levels and decreased IL-17A versus the rest of the patients' subgroups. In conclusion, our data support the pivotal role of IL-18 in addition to IL-6, IL-17A, and TNF-α as the hierarchical cytokines in the pathogenesis of RA, particularly valid for women. Therapy with biological agents targeting IL-18 in addition to the Th17 axis may be an adequate approach in RA patients.

Interleukin-35 pathobiology in periodontal disease: a systematic scoping review

Background

Interleukin (IL)-35 is a novel anti-inflammatory cytokine that is produced by regulatory T cells. IL-35 mediates immunological functions and plays a protective role in several diseases such as asthma and rheumatoid arthritis. However, the role of IL-35 in gingivitis and periodontitis remains unclear. The aim of this study was to systematically review the literature and collecting the available evidence regarding the role of IL-35 in pathogenesis of periodontal disease.

Methods

A systematic search of electronic databases including MEDLINE, Google Scholar, Cochrane Library, Web of Science, and Scopus was conducted in November 2020 to identify studies addressing the Interleukin-35 pathobiology in periodontal disease. The identified studies were subjected to pre-identified inclusion criteria. The retrived papers were assessed by the authours independently and consensus was reached in cases where disagreement occurred. Articles written in languages other than English, case reports, letters to editors, conference abstracts, theses, and dissertations were excluded from the review.

Results

A total of 176 possibly relevant articles were identified through the search strategy. Finally, 15 papers which met the criteria of eligibility were included in this review by consensus. The included articles were classified based on their design and level of evidence.Three subclinical study, ten cross sectional investigation and two randomized clinical trials constituted the final set of studies in this review. At preclinical level, Il-35 showed inhibitory characteristics regarding alveolar bone resorption of animal periodontitis models. The results of observatory human studies confirmed the presence of high levels of IL-35 in saliva, GCF, serum, and gingival biopsies of patients suffering from inflammatory periodontal disease. Moreover, two included clinical trials showed that non-surgical periodontal therapy could downregulate IL-35 production in chronic periodontitis patients.

Conclusion

Interleukin-35 has an undeniable role in pathobiology of inflammatory periodontal disease. Further well-controlled studies are needed to better elucidate the functional pattern of IL-35 in pathogeneisis of gingival and periodontal disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01515-1.

Comparison of Host Cytokine Response in Piglets Infected With Toxigenic and Non-toxigenic Staphylococcus hyicus

Staphylococcus hyicus is the most common causative agent of exudative epidermitis (EE) in piglets. Staphylococcus hyicus can be grouped into toxigenic and non-toxigenic strains based on its ability to cause EE in pigs. However, the inflammatory response of piglets infected with toxigenic and non-toxigenic S. hyicus has not been elucidated. In this study, we evaluated the serum cytokine profile in piglets inoculated with toxigenic and non-toxigenic S. hyicus strains and recorded the clinical signs in piglets. Fifteen piglets were divided into three groups (n = 5) and inoculated with a toxigenic strain (ZC-4), a non-toxigenic strain (CF-1), and PBS (control), respectively. The changes in serum levels of cytokines (interleukin [IL]-1β, IL-4, IL-6, IL-8, IL-10, IL-12, granulocyte-macrophage colony-stimulating factor, interferon-γ, transforming growth factor-β1, and tumor necrosis factor-α) were evaluated using a cytokine array at 6, 24, 48, and 72 h post inoculation. The results showed that piglets infected with the toxigenic strain exhibited more severe clinical signs and higher mortality than those infected with the non-toxigenic strain. The serum levels of pro-inflammatory cytokine IL-1β were significantly increased in toxigenic-and non-toxigenic-strain-infected piglets compared to those in the control group (p < 0.05), while the anti-inflammatory cytokine IL-10 was significantly up-regulated only in toxigenic group than in control group (p < 0.05). These results indicated that piglets infected with toxigenic and non-toxigenic S. hyicus showed differential infection status and inflammatory responses. Both toxigenic- and non-toxigenic- S. hyicus infection could induce a pro-inflammatory reaction in piglets. In addition, the toxigenic strain induced a strong anti-inflammatory response in piglets as indicated by the increased serum level of IL-10, which may be associated with the severe clinical signs and increased mortality and may be the key cytokine response responsible for pathogenic mechanisms of S. hyicus.

Inhibited interleukin 35 expression and interleukin 35-induced regulatory T cells promote type II innate lymphoid cell response in allergic rhinitis

BACKGROUND

Interleukin (IL)-35 and IL-35-producing regulatory T cells (iTr35) have been reported to inhibit TH2 response in allergic rhinitis (AR). However, its effects on type II innate lymphoid cells (ILC2) are not well characterized.

OBJECTIVE

To investigate the effect of IL-35 on ILC2 in AR.

METHODS

A total of 25 patients with AR and 20 controls were recruited. The expression and regulation of IL-35 receptor in ILC2 were analyzed by real-time polymerase chain reaction. The effect of IL-35 on ILC2 differentiation and cytokine production was analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. In addition, iTr35 were cocultured with ILC2 to explore the effect of iTr35 on ILC2. The AR mice models were also established to confirm the role of IL-35 in vivo.

RESULTS

The patients with AR had decreased IL-35 expression and iTr35 proportion and increased ILC2 and type II cytokines compared with the controls. Notably, IL-35 inhibited ILC2 differentiation and type II cytokine production by regulating IL-12Rβ2 and gp130. IL-35 promoted the inducible costimulatory molecule expression by iTr35 and the inducible costimulatory molecule ligand expression by ILC2. IL-35-treated mice with AR presented decreased frequency and function of nasal ILC2.

CONCLUSION

IL-35 inhibited ILC2 responses directly or through mutual contact between iTr35 and ILC2 in AR, suggesting that IL-35 may be used as a potential treatment target in AR.

Can cinnamon spice down autoimmune diseases?

Autoimmune diseases are one of the dreadful group of human diseases that have always been of keen interest to researchers. Due to complex and broad-spectrum nature, scientists are not yet able to pinpoint the pathogenesis of and delineate effective therapy against this group of diseases. However, it is becoming clear that a decrease in number and function of T regulatory cells (Treg), an increase in autoreactive Th1/Th17 cells and associated immunomodulation and inflammation participate in the pathogenesis of many autoimmune diseases. Cinnamon (Cinnamonum verum or Cinnamonum cassia) is a widely used natural spice and flavoring ingredient and its metabolite sodium benzoate (NaB) is a food-additive and FDA-approved drug against nonketotic hyperglycinemia (NKH) and urea cycle disorders (UCD). Recent studies indicate that cinnamon either in powder or extract form and NaB are capable of modulating different autoimmune pathways as well as protecting animals from different autoimmune disorders. Here, we have made an honest attempt to delineate such pieces of evidence with available anti-autoimmune mechanisms and analyze whether cinnamon supplements could be used to control the fury of autoimmune disorders.

The Role of Chronic Inflammatory Bone and Joint Disorders in the Pathogenesis and Progression of Alzheimer's Disease

Late-onset Alzheimer's Disease (LOAD) is a devastating neurodegenerative disorder that causes significant cognitive debilitation in tens of millions of patients worldwide. Throughout disease progression, abnormal secretase activity results in the aberrant cleavage and subsequent aggregation of neurotoxic Aβ plaques in the cerebral extracellular space and hyperphosphorylation and destabilization of structural tau proteins surrounding neuronal microtubules. Both pathologies ultimately incite the propagation of a disease-associated subset of microglia-the principle immune cells of the brain-characterized by preferentially pro-inflammatory cytokine secretion and inhibited AD substrate uptake capacity, which further contribute to neuronal degeneration. For decades, chronic neuroinflammation has been identified as one of the cardinal pathophysiological driving features of AD; however, despite a number of works postulating the underlying mechanisms of inflammation-mediated neurodegeneration, its pathogenesis and relation to the inception of cognitive impairment remain obscure. Moreover, the limited clinical success of treatments targeting specific pathological features in the central nervous system (CNS) illustrates the need to investigate alternative, more holistic approaches for ameliorating AD outcomes. Accumulating evidence suggests significant interplay between peripheral immune activity and blood-brain barrier permeability, microglial activation and proliferation, and AD-related cognitive decline. In this work, we review a narrow but significant subset of chronic peripheral inflammatory conditions, describe how these pathologies are associated with the preponderance of neuroinflammation, and posit that we may exploit peripheral immune processes to design interventional, preventative therapies for LOAD. We then provide a comprehensive overview of notable treatment paradigms that have demonstrated considerable merit toward treating these disorders.

Role of signaling pathway in biological cause of Rheumatoid arthritis

Rheumatoid Arthritis is a chronic progressive inflammatory auto-immune disease in which the immune system of the body attacks its cartilage and joints lining. It not only affects synovial joints but also many other sites including heart, blood vessels, and skins. It is more common in females than in males. The exact cause of rheumatoid arthritis is not well established but the hypothesis reported in the literature is that in the development stage of the disease, both genetics and environmental factors can play an inciting role. Along with these factors alteration in the normal physiology of enzymatic action, acts as a trigger to develop this condition. Numerous signaling pathways involved in the pathogenesis of Rheumatoid Arthritis involves activation of mitogen-activated protein kinase, kinases Janus family, P-38 Mitogen-Activated Protein Kinase, Nuclear Factor-kappa B. Interleukin-1 to play a proinflammatory cytokine that plays an important role in inflammation in RA. These are also associated with an increase in neutrophil, macrophage and lymphocytic chemotaxis, mast cell degranulation, activation, maturation and survival of T-cells and B-cells activated. These signaling pathways also show that p38α downregulation in myeloid cells exacerbates the severity of symptoms of arthritis. Thus, present review carters about the detail of different signaling pathways and their role in rheumatoid arthritis.

IL-12-Induced Immune Suppressive Deficit During CD8+ T-Cell Differentiation

Autoimmune diseases are characterized by regulatory deficit in both the CD4+ and CD8+ T-cell compartments. We have shown that CD8+ T-cells associated with acute relapse of multiple sclerosis are significantly deficient in their immune suppressive ability. We hypothesized that distinct CD8+ cytotoxic T-cell (Tc) lineages, determined by cytokine milieu during naïve T-cell differentiation, may harbor differential ability to suppress effector CD4+ T-cells. We differentiated purified human naïve CD8+ T-cells in vitro toward Tc0 (media control), Tc1 and Tc17 lineages. Using in vitro flow cytometric suppression assays, we observed that Tc0 and Tc17 cells had similar suppressive ability. In contrast, Tc1 cells showed significant loss of suppressive ability against ex vivo CD4+ T-cells and in vitro-differentiated Th0, Th1 and Th17 cells. Of note, Tc1 cells were also suboptimal in suppressing CD4-induced acute xenogeneic graft versus host disease (xGVHD) in vivo. Tc subtypes derived under various cytokine combinations revealed that IL-12-containing conditions resulted in less suppressive cells exhibiting dysregulated cytotoxic degranulation. RNA sequencing transcriptome analyses indicated differential regulation of inflammatory genes and enrichment in GM-CSF-associated pathways. These studies provide insights into the role of T-cell differentiation in CD8 suppressive biology and may reveal therapeutically targetable pathways to reverse suppressive deficit during immune-mediated disease.

Cardiovascular diseases and metabolic abnormalities associated with obesity: What is the role of inflammatory responses? A systematic review

INTRODUCTION

Obesity is a chronic disease responsible for a high morbidity and mortality rate, with an increasing worldwide prevalence. Obesity is associated with immune responses characterized by chronic systemic inflammation. This article focuses on the mechanisms that explain the proposed link between obesity-associated diseases and inflammation. Also, it describes the role of inflammatory molecules in obesity-associated metabolic abnormalities.

METHODS

More than 200 articles were selected and consulted by an online English search using various electronic search databases. Predefined key-words for the pathogenesis of obesity-induced inflammation and associated diseases, as well as the role of various inflammatory molecules, were used.

RESULTS

We have summarized the data of the articles consulted in this research and we have found that obesity is associated with a low-grade inflammation resulting from the change of adipose tissue (AT). The AT produces a variety of inflammatory molecules called adipocytokines that are involved in the onset of systemic low-grade inflammation which is the link between obesity and associated-chronic abnormalities; such as insulin resistance, metabolic syndrome, cardiovascular disease (CVD), hypertension, diabetes, and some cancers. Also, we have searched all the inflammatory molecules involved in this pathogenesis and we have briefly described the role of 16 of them which are the most related to obesity-associated inflammation. The results have shown that there are inflammatory molecules that have a positive relationship with the pathogenesis of obesity-related diseases and others have a negative relationship with this pathogenesis.

CONCLUSION

Inflammation plays a crucial role in the development of various metabolic-abnormalities related to obesity. In this regard, the management of obesity may help reduce the risk of cardiovascular disease and other metabolic complications by inhibiting inflammatory mechanisms.

The effect of sex on immune responses to a homocitrullinated peptide in the DR4-transgenic mouse model of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is more common and severe in women compared to men. Both women and men with RA express autoantibodies to post-translationally modified antigens, including citrullinated and homocitrullinated proteins or peptides. These autoantibodies are strongly linked with the HLA-DR4 gene. The objective of this study was to determine sex differences in immune responses to homocitrullinated antigens. We used a humanized animal model of RA, DR4-transgenic mice and immunized them with a homocitrullinated peptide called HomoCitJED. Immune responses in these mice were measured for splenocyte proliferation by tritiated thymidine incorporation, serum autoantibody production by ELISA and cytokine levels by multiplex. We found that T cell and antibody responses to homocitrullinated antigens were similar in male and female mice. However, we found sex differences in serum cytokine profiles with female mice having higher ratio of IL-1α to IL-5, suggesting imbalances in immune regulation. This is the first study to report that immune responses to homocitrullinated antigens can be differentiated by sex.

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Splenocyte proliferation and antibody responses in DR4tg mice immunized with a homocitrullinated peptide were similar for females and males.

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The cytokine profile of homocitrullinated peptide-immunized DR4tg mice was differentiated by sex: females had a higher ratio of IL-1α to IL-5.

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Anti-homocitrullinated peptide splenocyte and antibody responses were more frequent in DR4tg than wild-type B6 mice.

IL-23, but not IL-12, plays a critical role in inflammation-mediated bone disorders

Interleukin-12 (IL-12) and IL-23 are thought to have central roles in inflammation and are critical to pathologies associated with inflammation-induced bone disorders. The deletion of IL-12p40 (a common subunit of IL-12 and IL-23) can improve bone regeneration. However, the relative roles of IL-12 and IL-23 in bone disorders are largely unknown. Methods: Ectopic bone formation and skull defect models were established to evaluate the relative roles of IL-12 and IL-23 in inflammatory bone disorders. Differences in bone mass among WT, IL-12p35^-/-, and IL-12p40^-/- mice (young and elderly) were detected by micro-CT. Osteogenic and osteoclastic activities were explored using ELISA, qRT-PCR, and histological analysis. Moreover, the mechanisms by which IL-12 and IL-23 regulated the differentiation of BMMSCs and RAW264.7 cells were explored using Alizarin Red and tartrate-resistant acid phosphatase staining in vitro. Apilimod was used to inhibit IL-12 and IL-23 production in vivo. Results: Mice deficient in IL-12p40 promoted bone formation and protected against aging-related bone loss. By contrast, bone loss was aggravated in IL-12^-/- mice, suggesting that IL-23 may play a dominant role in inflammation-related bone disorders. Mechanistically, IL-12 and IL-23 coupled osteogenesis and osteoclastic activities to regulate bone homeostasis and repair. IL-23 deficiency increased bone formation and inhibited bone resorption. Finally, apilimod treatment significantly improved bone regeneration and calvarial defect repair. Conclusion: These data collectively uncover a previously unrecognized role of IL-23 in skeletal tissue engineering. Thus, IL-23 can act as a biomarker to predict diseases and treatment efficacy, and apilimod can be used as an effective therapeutic drug to combat inflammatory bone disorders.

Drug delivery to macrophages: A review of targeting drugs and drug carriers to macrophages for inflammatory diseases

Macrophages play a key role in defending against foreign pathogens, healing wounds, and regulating tissue homeostasis. Driving this versatility is their phenotypic plasticity, which enables macrophages to respond to subtle cues in tightly coordinated ways. However, when this coordination is disrupted, macrophages can aid the progression of numerous diseases, including cancer, cardiovascular disease, and autoimmune disease. The central link between these disorders is aberrant macrophage polarization, which misguides their functional programs, secretory products, and regulation of the surrounding tissue microenvironment. As a result of their important and deterministic roles in both health and disease, macrophages have gained considerable attention as targets for drug delivery. Here, we discuss the role of macrophages in the initiation and progression of various inflammatory diseases, summarize the leading drugs used to regulate macrophages, and review drug delivery systems designed to target macrophages. We emphasize strategies that are approved for clinical use or are poised for clinical investigation. Finally, we provide a prospectus of the future of macrophage-targeted drug delivery systems.

Angiogenesis modulatory factors in subjects with chronic ocular complications of Sulfur Mustard exposure: A case-control study

BACKGROUND

Chronic ocular complications of Sulfur Mustard (SM) exposure leads to severe ocular morbidity during time. The aim of this study was to compare serum levels of Interleukin 17 (IL-17), IL-12, vascular endothelial growth factor (VEGF)-C, VEGF-D and nitric oxide (NO) in SM-exposed patients versus the control group and to measure tear concentration of VEGF-C only in the SM-exposed group.

METHODS

In this prospective case control, 128 SM-exposed patients and 31 healthy control subjects were included. In the case group ocular manifestations were classified to three subgroups of mild (19 cases), moderate (31 cases) and severe (78 cases) forms of disease. Serum levels of IL-17, IL-12, NO, VEGF-C and VEGF-D, in all subjects and tear concentration of VEGF-C in SM-exposed group was evaluated.

RESULTS

All subjects were male and mean ± standard deviation (SD) of age in the case and control groups were 44.9 ± 8.8 and 40.9 ± 10.1 years, respectively. Except for significantly lower serum level of IL-17 (p < 0.001) and NO (p = 0.003), other values were not significantly different. The tear concentration of VEGF-C and serum level of IL-12 were not different between subgroups in the SM-exposed group, yet were significantly lower among those with abnormally dilated and tortuous conjunctival vessels and corneal pannus, respectively (p = 0.01, p = 0.015).

CONCLUSIONS

Exposure to SM significantly reduced serum level of IL-17 and NO in the delayed phase, yet did not influence VEGF-C; VEGF-D or IL-12.

Interleukin-12 supports in vitro self-renewal of long-term hematopoietic stem cells

Hematopoietic stem cells (HSCs) self-renew or differentiate through division. Cytokines are essential for inducing HSC division, but the optimal cytokine combination to control self-renewal of HSC in vitro remains unclear. In this study, we compared the effects of interleukin-12 (IL-12) and thrombopoietin (TPO) in combination with stem cell factor (SCF) on in vitro self-renewal of HSCs. Single-cell assays were used to overcome the heterogeneity issue of HSCs, and serum-free conditions were newly established to permit reproduction of data. In single-cell cultures, CD150⁺CD48⁻CD41⁻CD34⁻c-Kit⁺Sca-1⁺lineage⁻ HSCs divided significantly more slowly in the presence of SCF+IL-12 compared with cells in the presence of SCF+TPO. Serial transplantation of cells from bulk and clonal cultures revealed that TPO was more effective than IL-12 at supporting in vitro self-renewal of short-term (<6 months) HSCs, resulting in a monophasic reconstitution wave formation, whereas IL-12 was more effective than TPO at supporting the in vitro self-renewal of long-term (>6 months) HSCs, resulting in a biphasic reconstitution wave formation. The control of division rate in HSCs appeared to be crucial for preventing the loss of self-renewal potential from their in vitro culture.

Effect of Chondroitin Sulfate on Blood Serum Cytokine Profile during Carrageenan-induced Edema and Monoiodoacetate-induced Osteoarthritis in Rats

BACKGROUND

Blood cytokines affect the development of inflammatory processes in both normal and pathological states. We have studied changes in the concentration of interleukins (ILs) - 1β, IL-4, IL-10, IL-12B p40, transforming growth factor β (TGF β), tumor necrosis factor (TNF-α) in acute carrageenan-induced inflammation and degenerative-dystrophic changes of knee joint caused by monoiodoacetate-induced Osteoarthritis (OA) in experimental models on rats. We also investigated the change in the cytokine profile during prophylactic and therapeutic administration of chondroitin sulfate to animals under experimental conditions.

METHODS

The concentration of the cytokines was measured in blood serum by enzyme-linked immunosorbent assay.

RESULTS

The manifestation of articular lesions was characterized by a disturbance in the balance between proinflammatory (IL-1β, IL-12B p40, TNF-α) and anti-inflammatory (IL-4, IL-10, TGF -β) cytokines.

CONCLUSION

A reduction in the concentration of proinflammatory cytokines in blood serum after prophylactic and therapeutic administration of chondroitin sulfate to the rat with experimental models of acute inflammation of the hind limb and degenerative-dystrophic changes in the knee joint with OA is associated with anti-inflammatory and regenerative properties of the drug.

Impact of IL12B Polymorphisms on Genetic Susceptibility and IL-12p40 and IL-23 Serum Levels in Rheumatoid Arthritis

The aim of this study was to evaluate the possible association of IL12B gene polymorphisms with serum levels of IL-12p40, IL-23 and genetic susceptibility to rheumatoid arthritis (RA) in the Bulgarian population. Genotyping for IL12Bpro (rs17860508) and IL12B A/C - 3' UTR (rs3212227) polymorphisms was performed by polymerase chain reaction (PCR)-based methods in 125 RA patients and 239 healthy controls. The IL-23 and IL-12p40 serum levels were measured by enzyme-linked immunosorbent assay (ELISA). An association was established between the rs17860508 polymorphism and RA susceptibility in Bulgarian population with an increased frequency of rs17860508 minor allele-2 and homozygous genotype-22 in RA patients. The rs17860508 risk RA genotype-22 was also significantly correlated to elevated serum IL-23 in RA patients. Although, there was no association between the rs3212227 and genetic predisposition to RA, significantly increased serum levels of both Il-12p40 and IL-23 were observed in RA patients with the rs3212227 AA genotype. Furthermore, the distribution of haplotypes and genotype combination in our cohort indicated increased RA risk in individuals carrying the rs17860508/rs3212227 2/A haplotype or 2.2/AC+CC combination, while 1/A haplotype or 1.1/AA combination may be protective for RA. In conclusion, our study demonstrates a functional effect of IL12B polymorphisms on IL-12p40 and IL-23 cytokine levels in RA patients and suggests a leading role for IL12B rs17860508 in the genetic predisposition to RA, while IL12B rs3212227 significantly modify the RA risk in Bulgarian population.

The Role of Monocytes and Macrophages in Autoimmune Diseases: A Comprehensive Review

Monocytes (Mo) and macrophages (Mϕ) are key components of the innate immune system and are involved in regulation of the initiation, development, and resolution of many inflammatory disorders. In addition, these cells also play important immunoregulatory and tissue-repairing roles to decrease immune reactions and promote tissue regeneration. Several lines of evidence have suggested a causal link between the presence or activation of these cells and the development of autoimmune diseases. In addition, Mo or Mϕ infiltration in diseased tissues is a hallmark of several autoimmune diseases. However, the detailed contributions of these cells, whether they actually initiate disease or perpetuate disease progression, and whether their phenotype and functional alteration are merely epiphenomena are still unclear in many autoimmune diseases. Additionally, little is known about their heterogeneous populations in different autoimmune diseases. Elucidating the relevance of Mo and Mϕ in autoimmune diseases and the associated mechanisms could lead to the identification of more effective therapeutic strategies in the future.

Early Peritoneal CC Chemokine Production Correlates with Divergent Inflammatory Phenotypes and Susceptibility to Experimental Arthritis in Mice

The inflammatory and autoimmune events preceding clinical symptoms in rheumatoid arthritis (RA) and other autoimmune diseases are difficult to study in human patients. Therefore, animal models that share immunologic and clinical features with human RA, such as pristane-induced arthritis (PIA), are valuable tools for assessing the primordial events related to arthritis susceptibility. PIA-resistant HIII and susceptible LIII mice were injected i.p. with pristane, and peritoneal lavage fluid was harvested in the early (7 days) and late (35 days) preclinical phases of PIA. Chemokine and cytokine levels were measured in lavage supernatant with ELISA, peritoneal inflammatory leukocytes were immunophenotyped by flow cytometry, and gene expression was determined by qRT-PCR. Leukocyte recruitment was quantitatively and qualitatively divergent in the peritoneum of HIII and LIII mice, with an early increase of CC chemokines (CCL2/CCL3/CCL5/CCL12/CCL22) in the susceptible LIII strain. Also, cytokines such as IL-12p40, IL-23, and IL-18 were elevated in LIII mice while IL-6 was increased in HIII animals. The results show that an early peritoneal CC chemokine response is an important feature of arthritis susceptibility and defines potential biomarkers in this model.

Decreased regulatory T-cell frequency and interleukin-35 levels in patients with rheumatoid arthritis

Interleukin-35 (IL-35) is a newly discovered anti-inflammatory cytokine predominantly released by regulatory T cells (Tregs) and may serve an important role in the pathogenesis of autoimmune diseases. The levels of IL-35 and corresponding Treg frequencies in patients with rheumatoid arthritis (RA) have scarcely been reported. The present study aimed to detect serum IL-35 levels and Treg frequencies in patients with RA, and analyze their association with each other and with indicators of RA. A total of 55 patients with RA, including 37 active-phase (AP) and 18 chronic-phase (CP) cases, as well as 20 healthy controls (HC), were recruited. Clinical parameters, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody and 28-joint disease activity score (DAS28) were assessed. The Treg frequency in peripheral blood (PB) was determined by flow cytometry. IL-35 mRNA in PB mononuclear cells of the patients with RA was measured by reverse transcription-quantitative polymerase chain reaction analysis, and IL-35 levels in the serum were detected by ELISA. The correlations between IL-35 levels and the abovementioned indexes were analyzed by determining Pearson's correlation coefficient. The results of the present study indicated that the Treg frequency was significantly decreased in patients with RA compared with that in HC. No significant difference in Treg frequency between the AP and CP groups of RA patients was identified. In addition, the serum IL-35 levels and mRNA expression in RA patients were obviously lower than those in the HC. Of note, the serum IL-35 levels were negatively correlated with the ESR and DAS28 of patients with RA, while no correlation with CRP, RF or anti-CCP antibodies was identified. In addition, a significant positive correlation was revealed between serum IL-35 levels and the Treg frequency. These results suggest that IL-35 and Tregs have a protective role regarding the development of RA.

In vitro and in vivo anti-inflammatory properties of imine resveratrol analogues

Resveratrol is a natural polyphenol found mainly on red grapes and in red wine, pointed as an important anti-inflammatory/immunomodulatory molecule. However, its bioavailability problems have limited its use encouraging the search for new alternatives agents. Thus, in this study, we synthetize 12 resveratrol analogues (6 imines, 1 thioimine and 5 hydrazones) and investigated its cytotoxicity, antioxidant activity and in vitro anti-inflammatory/immunomodulatory properties. The most promising compounds were also evaluated in vivo. The results showed that imines presented less cytotoxicity, were more effective than resveratrol on DPPH scavenger and exhibited an anti-inflammatory profile. Among them, the imines with a radical in the para position, on the ring B, not engaged in an intramolecular hydrogen-interaction, showed more prominent anti-inflammatory activity modulating, in vivo, the edema formation, the inflammatory infiltration and cytokine levels. An immunomodulatory activity also was observed in these molecules. Thus, our results suggest that imines with these characteristics presents potential to control inflammatory disorders.

Peptide-directed liposomal delivery improves the therapeutic index of an immunomodulatory cytokine in controlling autoimmune arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of the synovial tissue of the joints. Inadequately controlled disease may cause severe joint damage and deformity. Currently, the anti-arthritic drugs are given systemically, and therefore, they are widely distributed to other organs that are not the intended therapeutic targets. Accordingly, using a particular dose/regimen of a drug to achieve an effective local concentration of the drug in arthritic joints may lead to expected adverse effects involving other organs. Thus, improved methods of drug delivery are needed for arthritis therapy. One attractive approach is the targeting of a systemically administered drug to the inflamed joints. We describe here a prototypic drug delivery system using a novel peptide ligand denoted as ART-1. We previously reported ART-1 (=ADK) as a peptide that preferentially homes to the inflamed joints of arthritic rats and binds to synovial endothelial cells. We tested the ART-1-coated liposomes encapsulating a fluorescent compound for binding to activated endothelial cells in vitro and homing to arthritic joints in vivo, compared to control liposomes lacking the ART-1 coating. Similar liposomes but encapsulating an immunomodulatory cytokine interleukin-27 (ART-1-IL-27 liposomes) were tested for their anti-arthritic activity compared with control liposomes. ART-1-displaying liposomes showed better binding to endothelial cells as well as in vivo homing to arthritic joints compared to control liposomes. Furthermore, ART-1-IL-27 liposomes, when intravenously injected to arthritic rats after the onset of arthritis, were more effective in suppressing disease progression than control-IL-27 liposomes lacking ART-1 or free IL-27 at an equivalent dose of IL-27. In addition, ART-1-directed liposomal IL-27 had a better safety profile than undirected liposomal IL-27 or free IL-27, thereby offering an improved therapeutic index for IL-27 therapy. These results provide a proof-of concept for the use of a novel joint-homing peptide for targeted delivery of drugs including biologics or small molecule compounds to arthritic joints with enhanced efficacy and reduced systemic exposure. This targeted therapy platform may be suitable for use in RA patients.

Impact of obesity on autoimmune arthritis and its cardiovascular complications

Obesity can instigate and sustain a systemic low-grade inflammatory environment that can amplify autoimmune disorders and their associated comorbidities. Metabolic changes and inflammatory factors produced by the adipose tissue have been reported to aggravate autoimmunity and predispose the patient to cardiovascular disease (CVD) and metabolic comorbidities. Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are autoimmune arthritic diseases, often linked with altered body mass index (BMI). Severe joint inflammation and bone destruction have a debilitating impact on the patient's life; there is also a staggering risk of cardiovascular morbidity and mortality. Furthermore, these patients are at risk of developing metabolic symptoms, including insulin resistance resulting in type 2 diabetes mellitus (T2DM). In addition, arthritis severity, progression and response to therapy can be markedly affected by the patient's BMI. Hence, a complex integrative pathogenesis interconnects autoimmunity with metabolic and cardiovascular disorders. This review aims to shed light on the network that connects obesity with RA, PsA, systemic lupus erythematosus and Sjӧgren's syndrome. We have focused on clarifying the mechanism by which obesity affects different cell types, inflammatory factors and traditional therapies in these autoimmune disorders. We conclude that to further optimize arthritis therapy and to prevent CVD, it is imperative to uncover the intricate relation between obesity and arthritis pathology.

Inflammation and dementia: Using rheumatoid arthritis as a model to develop treatments?

Dementia is a major international public health problem which looks set to grow as the ageing population increases. Despite large amounts of investment there has been relatively little progress in developing new therapies to combat this. There is a growing body of evidence that both local and systemic inflammation are important in dementia; with cerebral inflammation occurring secondarily to beta-amyloid plaques, raised levels of serum inflammatory molecules and cytokines being present in Alzheimer's disease patients and systemic inflammation being associated with cerebral microvasculature disease in vascular dementia. Observational studies had suggested that non-steroidal anti-inflammatory drugs may reduce the risk of dementia, but subsequent interventional studies have been disappointing. More recently some observational studies have suggested a protective effect from conventional synthetic disease modifying anti-rheumatic drugs (csDMARDS) and tumour necrosis factor inhibiting (TNFi) biological therapies. Treatments for inflammatory rheumatic diseases have previously been repurposed and used successfully in other diseases, such as TNFi for inflammatory bowel disease. There are also studies looking at the use of csDMARDs such as methotrexate to improve outcomes after cardiovascular events. Ongoing interventional trials are currently looking at whether therapies designed to treat inflammatory and autoimmune diseases have the potential to be used to treat dementia.

The tolerogenic role of IFN-γ

Due to its extremely pleiotropic nature, the complex effects of IFN-γ exerted both on immune and non-immune cell types still remain only partially understood. The longstanding view of IFN-γ as being a predominantly inflammatory cytokine is constantly challenged by increasing demonstrations of its direct or indirect regulatory roles. Interferon-γ can exert tolerogenic effects on both innate and adaptive immune cell types, promoting tolerance of various antigen-presenting cells, and augmenting function and differentiation of regulatory T cells, respectively. Its capacity to induce IDO-competence is not limited to immune cells but extends to other cell types such as mesenchymal stem cells, epithelial cells, and tumors. The pro-inflammatory role of IFN-γ in tumor immune surveillance can backfire by directly inducing inhibitory molecule expression, such as PDL-1, on tumor cells. With increasing knowledge regarding the role of different helper T cell subsets in certain autoimmune diseases, the once contradictory observations of disease attenuation by IFN-γ can now be explained by its opposing interplay with other effector cytokines, particularly IL-17. The paradoxically immunosuppressive role of IFN-γ is also becoming evident in the transplantation setting, and graft-versus-host-disease. In the present review, we will discuss the latest findings that help to elucidate this dual role of IFN-γ at a cellular level, and in various pathophysiological states.

Protective effect of antirheumatic drugs on dementia in rheumatoid arthritis patients

Introduction

Rheumatoid arthritis is a systemic inflammatory disease, and classical disease-modifying antirheumatic drugs (cDMARDs) have proven efficacy. It is unknown what impact cDMARDs might have on dementia as an outcome.

Methods

Incident diagnoses of rheumatoid arthritis in persons over 18 years from 1995 to 2011 were identified from the UK Clinical Practice Research Datalink. There were 3876 cDMARD users and were propensity score matched to 1938 nonusers, on a wide range of confounders. Impact on dementia was assessed using survival models.

Results

cDMARD users were at reduced risk of dementia (hazard ratio: 0.60; 95% confidence interval: 0.42–0.85). The effect was strongest in methotrexate users (hazard ratio: 0.52; 95% confidence interval; 0.34–0.82).

Discussion

The strong effect of cDMARD use on halving of dementia risk requires replication in a trial and may provide an important therapeutic pharmacological treatment.

The Four-Way Stop Sign: Viruses, 12-Lipoxygenase, Islets, and Natural Killer Cells in Type 1 Diabetes Progression

Natural killer (NK) cells represent an important effector arm against viral infection, and mounting evidence suggests that viral infection plays a role in the development of type 1 diabetes (T1D) in at least a portion of patients. NK cells recognize their target cells through a delicate balance of inhibitory and stimulatory receptors on their surface. If unbalanced, NK cells have great potential to wreak havoc in the pancreas due to the beta cell expression of the as-yet-defined NKp46 ligand through interactions with the activating NKp46 receptor found on the surface of most NK cells. Blocking interactions between NKp46 and its ligand protects mice from STZ-induced diabetes, but differential expression non-diabetic and diabetic donor samples have not been tested. Additional studies have shown that peripheral blood NK cells from human T1D patients have altered phenotypes that reduce the lytic and functional ability of the NK cells. Investigations of humanT1D pancreas tissues have indicated that the presence of NK cells may be beneficial despite their infrequent detection. In non-obese diabetic (NOD) mice, we have noted that NK cells express high levels of the proinflammatory mediator 12/15-lipoxygenase (12/15-LO), and decreased levels of stimulatory receptors. Conversely, NK cells of 12/15-LO deficient NOD mice, which are protected from diabetes development, express significantly higher levels of stimulatory receptors. Furthermore, the human NK92 cell line expresses the ALOX12 protein [human 12-lipoxygenase (12-LO), related to mouse 12/15-LO] via Western blotting. Human 12-LO is upregulated in the pancreas of both T1D and T2D human donors with insulin-containing islets, showing a link between 12-LO expression and diabetes progression. Therefore, our hypothesis is that NK cells in those susceptible to developing T1D are unable to function properly during viral infections of pancreatic beta cells due to increased 12-LO expression and activation, which contributes to increased interferon-gamma production and an imbalance in activating and inhibitory NK cell receptors, and may contribute to downstream autoimmune T cell responses. The work presented here outlines evidence from our lab, as well as published literature, supporting our hypothesis, including novel data.

IL-17 Production of Neutrophils Enhances Antibacteria Ability but Promotes Arthritis Development During Mycobacterium tuberculosis Infection

To our knowledge, no studies have examined the role of IL-17 production by neutrophils in immune defense against Mycobacterium tuberculosis (MTB) infection and the pathogenesis of rheumatoid arthritis (RA) caused by MTB infection. Here, we determined that neutrophils express IL-17 in an autocrine IL-6- and IL-23-dependent manner during MTB infection. MTB H37Rv-induced IL-6 production was dependent on the NF-κB, p38, and JNK signaling pathways; however, IL-23 production was dependent on NF-κB and EKR in neutrophils. Furthermore, we found that Toll-like receptor 2 (TLR2) and TLR4 mediated the activation of the kinases NF-κB, p38, ERK, and JNK and the production of IL-6, IL-23, and IL-17 in neutrophils infected with MTB H37Rv. Autocrine IL-17 produced by neutrophils played a vital role in inhibiting MTB H37Rv growth by mediating reactive oxygen species production and the migration of neutrophils in the early stages of infection. However, IL-17 production by neutrophils contributed to collagen-induced arthritis development during MTB infection. Our findings identify a protective mechanism against mycobacteria and the pathogenic role of MTB in arthritis development.

Human Leukocyte Antigen Shared Epitope and Inflammation, Cardiovascular Disease, Cancer, and Mortality Among Postmenopausal Women in the Women's Health Initiative Rheumatoid Arthritis Study

Specific alleles of the human leukocyte antigen (HLA)-DRB1 gene (HLA-DRB1) encode a "shared epitope" (SE) associated with rheumatoid arthritis (RA), especially more severe cyclic-citrullinated peptide antibody-positive (anti-CCP+) RA. We evaluated associations of number of SE alleles (0, 1, or 2) with total and cardiovascular disease (CVD) mortality and incident coronary heart disease (CHD), CVD, and cancer over a mean 8.9 (standard deviation, 3.5) years of follow-up, stratifying by baseline anti-CCP status (positive (+) vs. negative (-)). A longitudinal study, the Women's Health Initiative RA Study (1993-2010), sampled postmenopausal women who reported RA at baseline (1993-1998) or follow-up in the Women's Health Initiative, classified as anti-CCP+ RA (n = 556) or anti-CCP- non-RA (n = 1,070). Among anti-CCP+ RA women, SE alleles were not related to age-adjusted risks of CHD, CVD, or cancer or to total or CVD mortality. Among anti-CCP- non-RA women, age-adjusted hazard ratios for 1 and 2 SE alleles versus 0 SE alleles were 0.41 (95% confidence interval (CI): 0.34, 0.50) and 0.44 (95% CI: 0.27, 0.72), respectively, for CVD; 0.43 (95% CI: 0.37, 0.53) and 0.30 (95% CI: 0.16, 0.64), respectively, for CHD; and 0.62 (95% CI: 0.53, 0.73) and 0.52 (95% CI: 0.33, 0.83), respectively, for cancer. Associations persisted after adjustment for CVD risk factors, joint pain, rheumatoid factor positivity, and inflammatory markers (white blood cell count or cytokine level). In future studies, investigators should evaluate SE associations among anti-CCP- adults without RA and potential mechanisms.

Significant reduction of peripheral blood interleukin-35 and CD4+EBI3+ T cells, which are negatively correlated with an increase in the plasma IL-17 and cTnI level, in viral myocarditis patients

Introduction

Viral myocarditis (VMC) has become an increasingly common heart disease that endangers human health. In the present study, the plasma interleukin-35 (IL-35) level and the percentage of CD4⁺EBI3⁺ T cells in VMC patients were detected to investigate the significance of changes in these parameters in the plasma of VMC patients and their association with the disease.

Material and methods

ELISA was performed to detect the plasma IL-35 level and the percentage of peripheral blood CD4⁺EBI3⁺ T cells in 40 VMC patients and in 20 healthy individuals. Moreover, the plasma IL-17 levels in the VMC patients and in the healthy individuals were detected using an ELISA, and the cardiac Troponin-I (cTnI) levels were detected using a chemiluminescent microparticle immunoassay to compare the differences in the groups.

Results

Plasma IL-35 level and the percentage of CD4⁺EBI3⁺ T cells in acute phase VMC patients was lower than that in the healthy control group and the convalescent phase VMC patients. Additionally, the plasma IL-35 level in the VMC patients exhibited a negative correlation with the levels of cTnI and IL-17. The percentage of CD4⁺EBI3⁺ T cells also showed a negative correlation with the levels of cTnI and IL-17.

Conclusions

The plasma IL-35 level and the percentage of CD4⁺EBI3⁺ T cells in VMC patients was reduced, and the amount of the decrease was associated with the severity of the disease. These results suggest that IL-35 and CD4⁺EBI3⁺ T might play important roles in the progression of VMC and could be used as indictors of the disease.

Interluekin-35 in Asthma and Its Potential as an Effective Therapeutic Agent

Interleukin- (IL-) 35 is a member of the IL-12 cytokine family and a heterodimeric protein formed by Epstein-Barr-induced gene 3 (EBI3) and IL-12p35. Emerging evidence shows that IL-35 is a key player in the regulation of cellular communication, differentiation, and inflammation. Altered IL-35 expression has been found in disease conditions such as cancer, rheumatoid arthritis, and, more recently, asthma. In cancer, IL-35 is involved in the regulation of tumorigenesis, cancer progression, and metastasis. In rheumatoid arthritis, IL-35 acts as a negative regulator of inflammation. Similarly, IL-35 also appears to suppress allergic inflammation in asthma. In an in vivo murine model of asthma, transfer of adenovirus-mediated IL-35 markedly reduced the degree of airway hyperresponsiveness (AHR) and inflammatory cell infiltration. Many studies have shown the involvement of IL-35 in a number of aspects of allergic inflammation, such as eosinophil and neutrophil recruitment as well as inhibition of inflammatory mediators of the Th2 subtype. However, the exact molecular mechanisms underlying the role of IL-35 in human asthma have yet to be fully elucidated. This review describes the current evidence regarding the role of IL-35 in the pathophysiology of asthma and evaluates the potential of IL-35 as a biomarker for airway inflammation and a therapeutic target for the treatment of asthma.

Combination of Interleukin-27 and MicroRNA for Enhancing Expression of Anti-Inflammatory and Proosteogenic Genes

Remission of inflammation has become an achievable goal in inflammatory or rheumatoid arthritis (RA); however, bone erosion continues in many patients. Interleukin- (IL-) 27 regulates immune and bone cell balance and also suppresses activities of several inflammatory cell types in RA. Despite its promise, challenges to clinical translation of IL-27 have been its partial effects in vivo. Due to their ability to modulate plasticity of bone and immune cell differentiation, we examined the potential for several microRNA (miR) candidates in enhancing the effects of IL-27. Using differentiation, luciferase, and real time quantitative PCR assays, we show that IL-27 promotes osteoblast differentiation, reduces expression of osteoblast inhibitory genes, and reduces osteoclast differentiation, and results suggest a potential coordination with TGFβ/BMP/SMAD and JAK/STAT pathways. We selected miRNA regulators of these and related pathways to examine whether the effects of IL-27 could be augmented for therapeutic applications. miR-29b and miR-21 augmented IL-27 proosteogenic while downregulating osteoclastogenic signals and also worked to reduce inflammatory signaling in activated macrophages, while miR-21 and miR-20b worked with IL-27 to reduce inflammatory gene expression in fibroblasts and T cells. It appears that several miRNAs can be utilized to enhance IL-27's impact on modulating osteogenesis and reducing proinflammatory signaling.

Cardiac Autoimmunity: Myocarditis

Myocarditis is the inflammation of the muscle tissues of the heart (myocardium). After a pathologic cardiac-specific inflammatory process, it may progress to chronic damage and dilated cardiomyopathy. The latter is characterized by systolic dysfunction, whose clinical correlate is heart failure. Nevertheless, other acute complications may arise as consequence of tissue damage and electrophysiologic disturbances. Different etiologies are involved in triggering myocarditis. In some cases, such as giant cell myocarditis or eosinophilic necrotizing myocarditis, it is an autoimmune process. Several factors predispose the development of autoimmune myocarditis such as systemic/local primary autoimmunity, viral infection, HLA and gender bias, exposure of cryptic antigens, mimicry, and deficient thymic training/Treg induction. Once the anti-myocardium autoimmune process is triggered, several components of the immune response orchestrate a sustained attack toward myocardial tissues with particular timing and immunopathogenic features. Innate response mediated by monocytes/macrophages, neutrophils, and eosinophils parallels the adaptive response, playing a final effector role and not only a priming function. Stromal cells like fibroblast are also involved in the process through specific cytokines. Furthermore, adaptive T cell responses have anti-paradigmatic features, as Th17 response is dispensable for acute myocarditis but is the main driver of the process leading to dilated cardiomyopathy. Humoral response, thought to be a bystander, is important in the appearance of late-stage hemodynamic complications. The complexity of that process, as well as the unspecific and variable clinical presentation, had generated difficulties for diagnosis and treatment, which remain suboptimal. In this chapter, we will discuss the most relevant immunopathogenic findings from a basic science and clinical perspective.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

Pretreatment of activated human CD8 T cells with IL-12 leads to enhanced TCR-induced signaling and cytokine production

During the immune response to pathogens and autoantigens, CD8T cells are exposed to numerous inflammatory agents including the cytokine IL-12. Previous studies have focused on how IL-12 regulates T cell functions when present during or after the activation of the T cell receptor (TCR). However, recent studies suggest that prior exposure to IL-12 also alters the TCR responsiveness of murine T cells. Whether similar phenomena occur in human activated CD8T cells and the mechanisms mediating these effects remain unexplored. In this study, we observed that pretreatment of human activated CD8T cells with IL-12 results in increased cytokine mRNA and protein production following subsequent TCR challenge. The potentiation of TCR-mediated cytokine release was transient and required low doses of IL-12 for at least 24h. Mechanistically, prior exposure to IL-12 increased the TCR induced activation of select MAPKs and AKT without altering the activation of more proximal TCR signaling molecules, suggesting that the IL-12 mediated changes in TCR signaling are responsible for the increased production of cytokines. Our data suggest that prior treatment with IL-12 potentiates human CD8T cell responses at sites of infection and inflammation, expanding our understanding of the function of this clinically important cytokine.

Exposure of Human CD4 T Cells to IL-12 Results in Enhanced TCR-Induced Cytokine Production, Altered TCR Signaling, and Increased Oxidative Metabolism

Human CD4 T cells are constantly exposed to IL-12 during infections and certain autoimmune disorders. The current paradigm is that IL-12 promotes the differentiation of naïve CD4 T cells into Th1 cells, but recent studies suggest IL-12 may play a more complex role in T cell biology. We examined if exposure to IL-12 alters human CD4 T cell responses to subsequent TCR stimulation. We found that IL-12 pretreatment increased TCR-induced IFN-γ, TNF-α, IL-13, IL-4 and IL-10 production. This suggests that prior exposure to IL-12 potentiates the TCR-induced release of a range of cytokines. We observed that IL-12 mediated its effects through both transcriptional and post-transcriptional mechanisms. IL-12 pretreatment increased the phosphorylation of AKT, p38 and LCK following TCR stimulation without altering other TCR signaling molecules, potentially mediating the increase in transcription of cytokines. In addition, the IL-12-mediated enhancement of cytokines that are not transcriptionally regulated was partially driven by increased oxidative metabolism. Our data uncover a novel function of IL-12 in human CD4 T cells; specifically, it enhances the release of a range of cytokines potentially by altering TCR signaling pathways and by enhancing oxidative metabolism.