Increased Production Of Interleukin Research Articles

The Effect of Hexabromocyclododecane on the Production of Interleukin‐6 by Human Immune Cells

Hexabromocyclododecane (HBCD) is a compound that is used as an additive flame retardant for thermal insulation in buildings, but it can also be used in this manner for furniture fabrics and electrical apparatuses. Due to its hydrophobic properties it can leach from products such as treated fabrics and insulating materials and is found in dust particles, soil, and sewage sludge. This environmental contamination has led to its presence and in a number of foods especially fatty seafood, but also nuts and nut butters. HBCD has been detected in human serum samples. Possible routes for this exposure and accumulation of HBCD in human tissue could be due to exposure to HBCD treated products, dust particles, and ingestion of contaminated foods. Interleukin- 6 (IL-6) is produced by a number of different cell types, including human immune cells. It is involved in cell proliferation, differentiation, apoptosis, and bone remodeling. When IL-6 is overproduced it can lead to chronic inflammation. Diseases such as Castleman disease, Crohn's disease, rheumatoid arthritis, juvenile idiopathic arthritis, bone loss, and cardiovascular disease are associated with overproduction of IL-6. HBCD has been shown to increase the secretion of other pro-inflammatory cytokines. We hypothesize that HBCD may also increase production of IL-6. In this study peripheral blood mononuclear cells (PBMCs) were isolated from leukocyte filters and then exposed to HBCD for 24 hours at different concentrations (5-0.05 μM). Production of IL-6 (combination of secreted and intracellular levels) was determined by measuring secreted levels via enzyme linked immunosorbent assay (ELISA) and intracellular levels via Western blot. Increases in production of IL-6 were seen at five or more of the HBCD exposure levels in cells from 5 different donors. The average increase in IL-6 production seen at the 1 µM exposure was 2.4 fold (ranging from 1.2-3.6 fold) while that at 0.1 µM was 2.2 fold (ranging from 1.2-2.8 fold). These results show thatHBCD can induce increases in production of IL-6. Thus, HBCD may have the potential to contribute to inflammation in exposed individuals.

Uridine Diphosphate Promotes Rheumatoid Arthritis Through P2Y6 Activation.

BACKGROUND: Uridine diphosphate (UDP) is an extracellular nucleotide signaling molecule implicated in diverse biological processes via specific activation of pyrimidinergic receptor P2Y, G Protein-Coupled, 6 (P2Y6). There is very little knowledge about the function and mechanism of UDP in rheumatoid arthritis (RA). METHODS: This study used a quasi-targeted liquid chromatography-mass spectrometry (LC-MS) approach to investigate the unique expression of metabolites in RA synovial fluids (SF) (n = 10) with samples from osteoarthritis (OA) as controls (n = 10). RA fibroblast-like synoviocytes (FLSs) were collected from synovial tissues (n = 5) and cultured with UDP or MRS2578, a P2Y6 antagonist, and FLSs from OA were used as controls (n = 5). Rats with collagen-induced arthritis (CIA) were injected with UDP, MRS2578 or both (n = 9 for each group). P2Y6 expression was examined using real-time PCR, Western blotting and immunohistochemistry. Cell proliferation, apoptosis and migration of RA FLSs were measured using CCK-8 assay, real-time cell analysis, flow cytometry, wound healing assay and Transwell assay, respectively. The UDP levels in the culture medium, synovial fluid (n = 36) and peripheral blood (n = 36) of RA and CIA rats were measured using a Transcreener UDP Assay. Levels of proinflammatory cytokines were measured using a flow assay. Interleukin-6 (IL-6) levels were measured using ELISA and flow. RESULTS: LC-MS analysis detected significantly increased UDP levels in RA SF compared with OA SF, and the level was positively correlated with anticyclic citrullinated peptide (anti-CCP) and rheumatoid factor (RF)levels in RA. The increased UDP concentration was verified in the blood and synovial fluids of RA patients compared with samples from OA patients and healthy volunteers, respectively. UDP stimulated cell proliferation, migration and IL-6 secretion in RA FLSs and inhibited their apoptosis in culture, and MRS2578 inhibited these effects of UDP. UDP injection accelerated CIA and stimulated IL-6 production rather than other proinflammatory cytokines in the rat model, but simultaneous injection of MRS2578 suppressed these effects and alleviated CIA. P2Y6 expression was increased in RA and CIA synovial tissues. CONCLUSION: These results suggest that UDP is highly expressed in RA and stimulates RA pathogenesis by promoting P2Y6 activities to increase IL-6 production.

Evaluation of the Effectiveness of Post-Stroke Metformin Treatment Using Permanent Middle Cerebral Artery Occlusion in Rats.

Stroke is the second leading cause of death worldwide. Treatment options for ischemic stroke are limited, and the development of new therapeutic agents or combined therapies is imperative. Growing evidence suggests that metformin treatment, due to its anti-inflammatory action, exerts a neuroprotective effect against ischemia/reperfusion-induced brain damage. Experimental assessment has typically been performed in models of cerebral transient ischemia followed by long-term reperfusion. The aim of this study was to evaluate the neuroprotective effect of metformin treatment after permanent middle cerebral artery occlusion (pMCAO) without reperfusion in rats. Neurological deficits were assessed using the Longa scale, which offers a graded scale on body movement following pMCAO. Both infarct size and brain oedema area were measured by staining with 2,3,5-triphenyltetrazolium chloride. The number of neurons and total and activated microglia, as well as interleukin 10 (IL-10) production, in brain sections were evaluated by immunohistochemical staining. Our results show that metformin treatment improves the neurological state and reduces infarct size after 120 h of pMCAO. Metformin also prevents neuronal loss in the ischemic cortex but not in the striatum after 48 h of pMCAO. Moreover, post-stroke treatment with metformin significantly decreases the number of total and activated microglia at 48 h. The anti-inflammatory effect of metformin is associated with increased IL-10 production at 48 h after pMCAO. The results of the present study suggest that post-stroke treatment with metformin exerts anti-inflammatory and neuroprotective effects in a pMCAO model.

Oxidative stress promotes cellular damages in the cervix: implications for normal and pathologic cervical function in human pregnancy†.

A physiologic increase in reactive oxygen species throughout pregnancy is required to remodel the cervix. Oxidative stress can cause cellular damage that contributes to dysfunctional tissue. This study determined the oxidative stress-induced cell fate of human cervical epithelial and cervical stromal cells. We treated the ectocervical and endocervical epithelial cells and cervical stromal cells with cigarette smoke extract, an oxidative stress inducer, for 48 h. Cell viability (crystal violet assay); cell cycle, apoptosis, and necrosis (flow cytometry); senescence (senescence-associated β-galactosidase staining); autophagy (staining for autophagosome protein, microtubule-associated protein 1 light chain 3B); stress signaler p38 mitogen-activated protein kinases pathway activation (western blot analyses); and inflammation by measuring interleukin-6 (enzyme-linked immunosorbent assay) were conducted after 48 h of cigarette smoke extract treatment. Oxidative stress induced reactive oxygen species production in cervical cells, which was inhibited by N-acetylcysteine. Oxidative stress promoted cell cycle arrest and induced necrosis in cervical cells. High senescence and low autophagy were observed in cervical stromal cells under oxidative stress. Conversely, senescence was low and autophagy was high in endocervical epithelial cells. Oxidative stress induced p38 mitogen-activated protein kinases (p38MAPK) activation in all cervical cells but only increased interleukin-6 production by the ectocervical epithelial cells. Inhibition of interleukin-6 production by a p38 mitogen-activated protein kinases inhibitor confirmed the activation of an oxidative stress-induced pathway. In conclusion, oxidative stress can promote cell death and sterile inflammation that is mediated by p38 mitogen-activated protein kinases activation in the cellular components of the cervix. These cellular damages may contribute to the normal and premature cervical ripening, which can promote preterm birth.

Characterization of Circulating IL-10-Producing Cells in Septic Shock Patients: A Proof of Concept Study.

Sepsis is a worldwide health priority characterized by the occurrence of severe immunosuppression associated with increased risk of death and secondary infections. Interleukin 10 (IL-10) is a potent immunosuppressive cytokine which plasma concentration is increased in septic patients in association with deleterious outcomes. Despite studies evaluating IL-10 production in specific subpopulations of purified cells, the concomitant description of IL-10 production in monocytes and lymphocytes in septic patients’ whole blood has never been performed. In this pilot study, we characterized IL-10 producing leukocytes in septic shock patients through whole blood intracellular staining by flow cytometry. Twelve adult septic shock patients and 9 healthy volunteers were included. Intracellular tumor necrosis factor-α (TNFα) and IL-10 productions after lipopolysaccharide stimulation by monocytes and IL-10 production after PMA/Ionomycine stimulation by lymphocytes were evaluated. Standard immunomonitoring (HLA-DR expression on monocytes, CD4+ T lymphocyte count) of patients was also performed. TNFα expression by stimulated monocytes was reduced in patients compared with controls while IL-10 production was increased. This was correlated with a reduced monocyte HLA-DR expression. B cells, CD4+, and CD4- T lymphocytes were the three circulating IL-10 producing lymphocyte subsets in both patients and controls. No difference in IL-10 production between patients and controls was observed for B and CD4- T cells. However, IL-10 production by CD4+ T lymphocytes significantly increased in patients in parallel with reduced CD4+ T cells number. Parameters reflecting altered monocyte (increased IL-10 production, decreased HLA-DR expression and decreased TNFα synthesis) and CD4+ T lymphocyte (increased IL-10 production, decreased circulating number) responses were correlated. Using a novel technique for intracellular cytokine measurement in whole blood, our results identify monocytes and CD4+ T cells as the main IL-10 producers in septic patients’ whole blood and illustrate the development of a global immunosuppressive profile in septic shock. Overall, these preliminary results add to our understanding of the global increase in IL-10 production induced by septic shock. Further research is mandatory to determine the pathophysiological mechanisms leading to such increased IL-10 production in monocytes and CD4+ T cells.

Different iron-handling in inflamed small and large cholangiocytes and in small and large-duct type intrahepatic cholangiocarcinoma.

Cholangiocarcinoma (CCA) represents the second most common primary hepatic malignancy and originates from the neoplastic transformation of the biliary cells. The intrahepatic subtype includes two morpho-molecular forms: large-duct type intrahepatic CCA (iCCA) and small-duct type iCCA. Iron is fundamental for the cellular processes, contributing in tumor development and progression. The aim of this study was to evaluate iron uptake, storage, and efflux proteins in both lipopolysaccharide-inflamed small and large cholangiocytes as well as in different iCCA subtypes. Our results show that, despite an increase in interleukin-6 production by both small and large cholangiocytes, ferroportin (Fpn) was decreased only in small cholangiocytes, whereas transferrin receptor-1 (TfR1) and ferritin (Ftn) did not show any change. Differently from in vitro models, Fpn expression was increased in malignant cholangiocytes of small-duct type iCCA in comparison to large-duct type iCCA and peritumoral tissues. TfR1, Ftn and hepcidin were enhanced, even if at different extent, in both malignant cholangiocytes in comparison to the surrounding samples. Lactoferrin was higher in large-duct type iCCA in respect to small-duct type iCCA and peritumoral tissues. These findings show a different iron handling by inflamed small and large cholangiocytes, and small and large-duct type iCCA. The difference in iron homeostasis by the iCCA subtypes may have implications for the tumor management.

Effects of Tocilizumab, an Interleukin-6 Receptor Antagonist, on Cytokine Expression and Animal Survival in a Model of Fatal Acute Respiratory Distress Syndrome

This study aims to investigate effects of tocilizumab, a monoclonal antibody to interleukin-6 (IL-6) receptors, on cytokine expression and animal survival in a model of fatal acute respiratory distress syndrome (ARDS) characterized by high mortality rates and increased IL-6 production in the lungs. The expression of interleukin-1β (IL-1β), interleukin-6 (IL-6), tumour necrosis factor (TNF-α) and interferons α (IFN-α) and β (IFN-β) in the lungs was assessed by real-time PCR. Cytokine production was assessed by enzyme immunoassay. Although tocilizumab did not affect the expression of the studied cytokines in the lungs of animals with ARDS, it changed the profiles of their release. An acute multifold increase in the levels of IL-6 in the lungs was observed in the first two hours after the administration of tocilizumab, followed by a decrease of IL-6 to lower values similar to those observed in intact animals. Tocilizumab did not reduce mortality in treated animals with ARDS compared to those without treatment. Thus, the inhibition of the IL-6 receptor signaling pathway alone does not provide an effective solution to the problem of reducing mortality from ARDS associated with the development of a “cytokine storm”.

PM2.5 facilitates IL-6 production in human osteoarthritis synovial fibroblasts via ASK1 activation.

Osteoarthritis (OA) is a progressive degenerative joint disorder characterized by synovial inflammation. Interleukin-6 (IL-6) is a key proinflammatory cytokine in OA progression. Particulate matter 2.5 (PM2.5) exposure increases the risk of different diseases, including OA. Up until now, no studies have described any association between PM2.5 and IL-6 expression in human OA synovial fibroblasts (OASFs). Here, our data show that PM2.5 concentration- and time-dependently promoted IL-6 synthesis in human OASFs. We also found that reactive oxygen species (ROS) generation potentiated the effects of PM2.5 on IL-6 production. ASK1, ERK, p38, and JNK inhibitors reduced PM2.5-induced increases of IL-6 expression. Treatment of OASFs with PM2.5 promoted phosphorylation of these signaling cascades. We also found that PM2.5 enhanced c-Jun phosphorylation and its translocation into the nucleus. Thus, PM2.5 increases IL-6 production in human OASFs via the ROS, ASK1, ERK, p38, JNK, and AP-1 signaling pathways. Our evidence links PM2.5 with OA progression.

Pharmacological inhibition of carnitine palmitoyl transferase 1 inhibits and reverses experimental autoimmune encephalitis in rodents.

Multiple sclerosis (MS) is a neurodegenerative disease characterized by demyelination and inflammation. Dysregulated lipid metabolism and mitochondrial dysfunction are hypothesized to play a key role in MS. Carnitine Palmitoyl Transferase 1 (CPT1) is a rate-limiting enzyme for beta-oxidation of fatty acids in mitochondria. The therapeutic effect of pharmacological CPT1 inhibition with etomoxir was investigated in rodent models of myelin oligodendrocyte glycoprotein- and myelin basic protein-induced experimental autoimmune encephalitis (EAE). Mice receiving etomoxir showed lower clinical score compared to placebo, however this was not significant. Rats receiving etomoxir revealed significantly lower clinical score and lower body weight compared to placebo group. When comparing etomoxir with interferon-β (IFN-β), IFN-β had no significant therapeutic effects, whereas etomoxir treatment starting at day 1 and 5 significantly improved the clinical scores compared to the IFN-β and the placebo group. Immunohistochemistry and image assessments of brain sections from rats with EAE showed higher myelination intensity and decreased expression of CPT1A in etomoxir-treated rats compared to placebo group. Moreover, etomoxir mediated increased interleukin-4 production and decreased interleukin-17α production in activated T cells. In conclusion, CPT1 is a key protein in the pathogenesis of EAE and MS and a crucial therapeutic target for the treatment.

Hepatitis B e Antigen Induces NKG2A+ Natural Killer Cell Dysfunction via Regulatory T Cell-Derived Interleukin 10 in Chronic Hepatitis B Virus Infection.

Although persistent hepatitis B virus (HBV) infection is associated with natural killer (NK) cell dysfunction, it remains obscure whether HBV viral antigens are responsible for NK cell dysfunction in patients with chronic hepatitis B (CHB) infection. In this study, we found that the percentage of NK cells expressing the inhibitory receptor, NKG2A, was increased in CHB patients, and NKG2A blockade restored NK cell function. Furthermore, in CHB patients, the frequency of NK cells expressing NKG2A positively correlated with the number of regulatory T cells (Tregs) and production of interleukin-10 (IL-10) in these Tregs. Moreover, exposure of peripheral blood mononuclear cells (PBMCs) isolated from healthy controls to sera from CHB patients resulted in increased proportion of NKG2A+ NK cells; IL-10 blockade reduced the frequency of NKG2A+ NK cells while increasing the percentage of IFN-γ+ NK cells. In addition, stimulation of NK cells and Tregs from healthy controls with CHB sera together with anti-IL-10 antibody increased IFN-γ production in the culture supernatant. The frequencies of NKG2A+ NK cells and IL-10+ Tregs, along with serum levels of alanine transferase and HBV DNA, were significantly increased in CHB patients positive for the Hepatitis B e antigen (HBeAg, a marker of viral replication) when compared to HBeAg-negative CHB patients. Importantly, exposure of PBMCs from healthy controls to HBeAg resulted in increased IL-10 production but reduced levels of TNF and IFN-γ, and IL-10 blockade rescued the generation of TNF and IFN-γ in this assay. The reduced production of TNF and IFN-γ was also observed in NK cells and Tregs from healthy controls that were stimulated with HBeAg, while IL-10 blockade increased the secretion of these two cytokines. We conclude that HBeAg induces IL-10 production in Tregs, thereby leading to increased expression of NKG2A on NK cells, which contributes to NK cell dysfunction during CHB infection. These data suggest that HBeAg is associated with NK cell dysfunction in CHB.

Platelet Transforming Growth Factor-β1 Induces Liver Sinusoidal Endothelial Cells to Secrete Interleukin-6.

The roles and interactions of platelets and liver sinusoidal endothelial cells in liver regeneration are unclear, and the trigger that initiates hepatocyte proliferation is unknown. We aimed to identify the key factors released by activated platelets that induce liver sinusoidal endothelial cells to produce interleukin-6 (IL-6), a cytokine implicated in the early phase of liver regeneration. We characterized the releasate of activated platelets inducing the in vitro production of IL-6 by mouse liver sinusoidal endothelial cells and observed that the stimulating factor was a thermolabile protein. Following gel filtration, a single fraction of activated platelet releasate induced a maximal IL-6 secretion by liver sinusoidal endothelial cells (90.2 ± 13.9 versus control with buffer, 9.0 ± 0.8 pg/mL, p < 0.05). Mass spectroscopy analysis of this fraction, followed by in silico processing, resulted in a reduced list of 18 candidates. Several proteins from the list were tested, and only recombinant transforming growth factor β1 (TGF-β1) resulted in an increased IL-6 production up to 242.7 ± 30.5 pg/mL, which was comparable to non-fractionated platelet releasate effect. Using neutralizing anti-TGF-β1 antibody or a TGF-β1 receptor inhibitor, IL-6 production by liver sinusoidal endothelial cells was dramatically reduced. These results support a role of platelet TGF-β1 β1 in the priming phase of liver regeneration.

Particular paraclinical indices in newborn sepsis patients whose parents constantly lived in different environmental conditions

Xenobiotics can have a variety of effects on the human body, and especially on the course of intrauterine development. Numerous researchers point out that it is the nature of the environment that can negatively affect the course of certain diseases in both children and adults. Neonatal sepsis is one of the most serious diseases in neonatology practice. And, in our opinion, the topic of the influence of adverse environmental factors on the features of sepsis in newborns depending on the ecological situation of their parents' habitats is unclarified.The research aims at the particular paraclinical indices in children with neonatal sepsis whose parents constantly lived in different environmental conditions.Material and methods. To study the aim, a comprehensive survey of 260 newborns who suffered from neonatal sepsis in 2016-2018 was conducted. The groups have been formed based on the complex evaluation of the prolonged influence of the anthropogenic pollution of air, water and soil on the body of parents of newborns in the parts of the region. The ecological risk coefficient (ERC) has been proposed concerning the environmental situation in the regional centers. Thus, the first clinical group (the main group) included neonatal sepsis patients whose parents permanently lived in parts with an ERC of 2.0 or more and with unfavorable environmental characteristics of the regional center. The second group (comparison) was formed by newborns with sepsis, whose parents permanently lived in areas with a low risk of adverse effects of these environmental factors on their body (ERC&lt;2.0).Results and discussion. The content of interleukins-6, -8.-10, C-reactive protein, presepsin and procalcitonin in the blood serum of patients with neonatal sepsis showed the activity of the systemic inflammatory response of the body to an infectious agent. It should be noted that high serum levels of interleukin-10, which has an anti-inflammatory effect, was more often registered in patients of the I clinical group. Thus, the blood content of this interleukin 35.0 pg/ml occurred in the newborn of the main group in 23.7% of cases, and in children of the comparison group – in 18.1% of observations. Along with a clearer identification of high levels of anti-inflammatory interleukin-10 inpatients of the I group, a significant decrease in serum concentrations of immunoglobulins of classes A, G, M was observed in these newborns.Conclusions. The decrease in the level of the above serum immunoglobulins is probably due to the immunosuppressive effect of xenobiotics on the fetus, whose mother was under the conditions of long-term action of xenobiotics. This, in turn, reduces the resistance of the newborn body to infection and contributes to a more severe course of the infectious process. Probably, the more severe manifestations of neonatal sepsis in newborns of the I clinical group are partly due to a combination of decreased immunoglobulin synthesis and increased interleukin-10 production.

IL-6 During Influenza-Streptococcus pneumoniae Co-Infected Pneumonia—A Protector

Understanding of pathogenesis and protection mechanisms underlying influenza-Streptococcus pneumoniae co-infection may provide potential strategies for decreasing its high morbidity and mortality. Interleukin-6 (IL-6) is an important cytokine that acts to limit infection-related inflammation; however, its role in co-infected pneumonia remains unclear. Here we show that the clinically relevant co-infected mice displayed dramatically elevated IL-6 levels; which was also observed in patients with co-infected pneumonia. IL-6−/− mice presented with increased bacterial burden, early dissemination of bacteria to extrapulmonary sites accompanied by aggravated pulmonary lesions and high mortality when co-infection. This protective function of IL-6 is associated with cellular death and macrophage function. Importantly, therapeutic administration of recombinant IL-6 protein reduced cells death in BALF, and enhanced macrophage phagocytosis through increased MARCO expression. This protective immune mechanism furthers our understanding of the potential impact of immune components during infection and provides potential therapeutic avenues for influenza-Streptococcus pneumoniae co-infected pneumonia.

MiR-146a is over-expressed and controls IL-6 production in cystic fibrosis macrophages

Cystic fibrosis (CF) is an inherited disease that is characterised by susceptibility to bacterial infections and chronic lung inflammation. Recently, it was suggested that macrophages contribute to impaired host defence and excessive inflammatory responses in CF. Indeed, dysfunction attributed to CF macrophages includes decreased bacterial killing and exaggerated inflammatory responses. However, the mechanisms behind such defects have only been partially defined. MicroRNAs (miRNAs) have emerged as key regulators of several macrophage functions, including their activation, differentiation and polarisation. The goal of this study was to investigate whether miRNA dysregulation underlies the functional abnormalities of CF macrophages. MiRNA profiling of macrophages was performed, with 22 miRNAs identified as differentially expressed between CF and non-CF individuals. Among these, miR-146a was associated with significant enrichment of validated target genes involved in responses to microorganisms and inflammation. As miR-146a dysregulation has been reported in several human inflammatory diseases, we analysed the impact of increased miR-146a expression on inflammatory responses of CF macrophages. These data show that inhibition of miR-146a in lipopolysaccharide-stimulated CF macrophages results in increased interleukin-6 production, which suggests that miR-146a overexpression in CF is functional, to restrict inflammatory responses.

Effects of Brief Mood-Improving Interventions on Immunity: A Systematic Review and Meta-Analysis.

Positive mood has been associated with enhanced immune function. Interventions that improve mood could therefore provide a mechanism for optimizing immune-related health outcomes. Brief interventions that improve mood, also known as mood inductions, potentially offer a pragmatic approach to enhancing immune function for finite periods where this would be beneficial to health (e.g., in advance of vaccination or surgery). This review sought to systematically examine the evidence regarding the effects of brief, single-session positive mood interventions on immunity. Systematic searches of electronic databases were performed from earliest records to July 25, 2018. We identified 42 interventions suitable for inclusion, 6 of which were tested in multiple subpopulations. Random-effects meta-analyses were performed for pre-post experimental group immune outcomes measured in at least five intervention studies. Although interventions were heterogeneous, 81% resulted in a statistically significant change in at least one immune parameter after the positive mood intervention for one or more of the subpopulations examined. However, studies were, in general, of low-to-moderate quality with small sample sizes (median n = 32) and did not examine the persistence or clinical relevance of the immune changes observed. Random-effects meta-analyses showed a significant medium-sized effect of interventions on increasing secretory IgA concentration (g = 0.65), a small but statistically significant effect for increased Interleukin-6 production (g = 0.12), and nonsignificant effects on natural killer cell activity (g = 0.15). The current literature suggests that improvements in mood resulting from brief interventions can influence some immune parameters in ways indicative of enhanced immune function. However, there is a need for higher-quality research in this area that focuses on clinically relevant immune outcomes and mechanisms.

Heightened TLR7/9-Induced IL-10 and CXCL13 Production with Dysregulated NF-ҝB Activation in CD11chiCD11b+ Dendritic Cells in NZB/W F1 Mice.

Systemic lupus erythematosus (SLE) is a chronic, multifactorial autoimmune disease that predominantly affects young females. Dysregulation of different immune cell populations leads to self-tolerance breakdown and subsequent multiple organ damage as the disease develops. Plasmacytoid dendritic cells (pDCs) are potent producers of type I interferon (IFN), while myeloid dendritic cells (mDCs) are more specialized in antigen presentations. We have previously reported that bone-marrow (BM)-derived pDCs from the murine lupus model New Zealand black/white F1 (BWF1) possess abnormalities. Therefore, this study continues to investigate what aberrant properties peripheral pDCs and mDCs possess in BWF1 and how they mediate SLE progression, by comparing their properties in pre-symptomatic and symptomatic mice. Results showed that CD11chiCD11b+ myeloid DCs expanded during the disease state with down-regulation of co-stimulatory molecules and major histocompatibility complex class II molecules (MHC II), but their capacity to stimulate T cells was not hampered. During the disease state, this subset of mDCs displayed heightened toll-like receptors 7 and 9 (TLR 7/9) responses with increased interleukin 10 (IL-10) and C-X-C motif chemokine ligand 13 (CXCL13) expressions. Moreover, the expressions of myeloid differentiation primary response 88 (Myd88) and nuclear factor kappa B subunit 1 (Nfkb1) were higher in CD11chiCD11b+ DCs at the disease stage, leading to higher nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 phosphorylation activity. In summary, we reported aberrant phenotypic properties with enhanced TLR7/9 responses of CD11chiCD11b+ DCs in SLE mediated by aberrant NF-κB signaling pathway. Our findings add additional and novel information to our current understanding of the role of DCs in lupus immunopathogenesis. Lastly, molecular candidates in the NF-κB pathway should be exploited for developing therapeutic targets for SLE.

SPIONs enhances IL-10-producing macrophages to relieve sepsis via Cav1-Notch1/HES1-mediated autophagy.

BackgroundSepsis is a life-threatening condition caused by dysregulated host responses to infection. Macrophages, which recognize microbial infections through identification of bacterial markers such as lipopolysaccharide (LPS), are crucial to the pathogenesis of sepsis-associated liver injury. However, the understanding of the SPIONs-mediated modulation of macrophage responses in LPS-induced sepsis and liver injury is limited.Materials and methodsSuperparamagnetic iron oxide nanoparticles (SPIONs) of γ-Fe2O3 nanoparticles were prepared, and their morphology and magnetic properties were characterized.ResultsUsing a murine model of LPS-induced sepsis and liver injury, we found that SPIONs alleviated LPS-induced sepsis, preventing infiltration of inflammatory cells into the liver. SPIONs also increased the level of interleukin-10 (IL-10) in liver macrophages, while SPIONs’s effect on LPS-induced sepsis was abrogated in IL-10-/- mice, indicating that the protective effect of SPIONs is dependent on IL-10+ macrophages. Moreover, SPIONs activated macrophage autophagy to increase IL-10 production, which was markedly attenuated by autophagy inhibition. Furthermore, SPIONs upregulated the expression of Caveolin-1 (Cav1) in macrophages, which plays a role in cellular uptake of metallic nanoparticles. Interestingly, activation of Cav1 and Notch1/HES1 signaling was involved in SPIONs-induced autophagy in both RAW 264.7 cells and bone marrow-derived macrophages (BMDMs). Our data reveal a novel mechanism for SPIONs -induced autophagy in macrophages, which occurs through activation of the Cav1-Notch1/HES1 signaling pathway, which promotes the production of IL-10 in macrophages, leading to inhibition of inflammation in LPS-induced sepsis and liver injury.ConclusionOur results suggest that SPIONs may represent a potential therapeutic agent for the treatment of sepsis and sepsis-induced liver injury.

Abstract 4033: RAC1 genomic aberrations as predictive biomarkers for head and neck squamous cell carcinoma (HNSCC)

Abstract RAC1 is a small GTPase with known oncogenicity. Mutations of RAC1 are highly relevant to melanoma. Yet, little is known about RAC1 aberrations in other human cancers, including HNSCC. Pan-cancer analysis of 32 cancer types from the TCGA reveals that RAC1 mutations only affect 12/32 cancer types and HNSCC is the 2nd most frequently affected (2.64%; 14/510 cases), after melanoma (4.59%, 22/479 cases). 28/34 cancer types harbor RAC1 copy number alterations, including HNSCC (2.08% cases, all are amplifications). Among all 14 HNSCC-associated RAC1 mutations found in the TCGA cohort, RAC1 p.A159V mutation (residing in the highly conserved G5 Box of RAC1) appears to be particularly prevalent in HNSCC (6/14 cases), suggesting a likely mutant-specific role in HNSCC. HNSCC patients with somatic RAC1 aberrations [gene amplification/copy number gain/hotspot mutations (p.P29, p.K116 and p.A159)] have poorer overall survival (OS)(P=4.555e-5; median survival of 30.91 months vs 68.43 months) and disease-free survival (DFS) (P=5.49e-5; 27.89 months vs unreached median) vs. RAC1-unaltered HNSCC patients. RAC1-mutated tumors are also associated with a higher rate of TP53 mutation (P=2.07e-6), and a lower rate of HPV infection (P=7.397e-6; 7.7% vs. 87.2%; Fisher’s Exact test). Further, RAC1-altered patients are of more advanced T clinical staging (T3/4 vs T1/2; P=0.0312) and with more gross/microscopic extension (P=0.0111; 59/119 vs 54/201). These evidences strongly suggest that HNSCC with RAC1 aberrations are more aggressive and may serve as a prognostic biomarker for HNSCC. To further elucidate the biological function of RAC1 mutations in HNSCC, we analyzed the mutational profile of RAC1-mutated HNSCC tumors which showed enriched mutations of 3 tumor suppressor genes: FAT1, FAT4 and CSMD3 (P=0.0001, P=0.0038 and P=0.0467 respectively). Gene set enrichment analysis (GSEA) of RAC1-mutated HNSCC also demonstrates significant dysregulation of immune-related gene sets (vs. RAC1-WT tumors) including increased interleukin-6 (IL-6) production (P&amp;lt;0.0001), a pro-tumorigenic inflammatory cytokine known to be involved in HNSCC tumorigenesis and progression. A previous study showed that overexpression of RAC1 activating mutation (p.V12) could upregulate IL-6 production in a cervical cancer model, HeLa, which is supportive of a RAC1/IL-6 axis in HNSCC. This is further supported by our RNAseq finding that RAC1-mutated HNSCC tumors do have significant upregulation of MYD88 (P=0.0436), a gene that has been shown to induce IL-6 secretion in HNSCC cells. Subsequent Tumor Immune Estimation Resource (TIMER) analysis shows that RAC1-mutated HNSCC primary tumors have higher infiltrating neutrophil levels than RAC1-WT tumors (P=0.019). Our findings may uncover a novel tumorigenic mechanism by RAC1 mutations in HNSCC, first linking IL-6 dysregulation to an oncogene mutation in HNSCC. Citation Format: Hoi Lam Ngan, Yuchen Liu, Peony Hiu Yan Poon, Vivian Wai Yan Lui. RAC1 genomic aberrations as predictive biomarkers for head and neck squamous cell carcinoma (HNSCC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4033.

Upregulation of sphingosine-1-phosphate receptor 3 on fibroblast-like synoviocytes is associated with the development of collagen-induced arthritis via increased interleukin-6 production.

BackgroundSphingosine-1-phosphate receptor 3 (S1P3) is one of five receptors for sphingosine-1-phosphate (S1P). S1P/S1P3 signaling is involved in numerous physiological and pathological processes including bone metabolism, sepsis, cancer, and immunity. In rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLSs) are activated by several factors and promote abundant proinflammatory cytokine production and bone destruction. The aim of this study was to investigate whether S1P3 is associated with the development of autoimmune arthritis and the pathogenic function of FLSs.MethodsWild-type (WT) and S1P3 knockout (S1P3-KO) collagen-induced arthritis (CIA) mice were evaluated with respect to clinical and histological disease severity, along with the levels of anti-collagen antibodies and expression of tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6). S1P3 expression in the synovium was analyzed by real-time reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining. FLSs isolated from CIA mice were activated with TNFα and S1P3 expression was analyzed by real-time RT-PCR. The role of S1P/S1P3 signaling in activated and non-activated FLSs was investigated by measuring cell proliferation and cyto/chemokine production by real-time RT-PCR and/or enzyme-linked immunosorbent assay.ResultsClinical and histological scores, and synovial IL-6 expression were significantly lower in S1P3-KO mice with CIA than in WT mice. Arthritic synovia had higher S1P3 expression than intact synovia and FLSs in arthritic joints expressed S1P3 in vivo. Primary cultured FLSs produced IL-6 in a time-dependent manner in response to S1P stimulation and exhibited higher levels of S1P3 expression after activation with TNFα. S1P3-induced production of IL-6 and MMP-3 was increased in FLSs pre-activated with TNFα.ConclusionIn this study, we demonstrated that S1P3 expression is associated with the development of autoimmune arthritis via inflammation-induced increases in S1P/S1P3 signaling that increase production of IL-6 in FLSs. Inhibition of S1P/S1P3 signaling could open the door to the development of new therapies for RA.

IL-17A increases MHC class I expression and promotes T cell activation in papillary thyroid cancer patients with coexistent Hashimoto\u2019s thyroiditis

BackgroundThe incidence of coexisting papillary thyroid cancer (PTC) and Hashimoto’s thyroiditis (HT) is increasing. The impact of HT on PTC prognosis and its possible mechanism remains controversial. Interleukin-17A (IL-17A) has been reported to participate in the pathogenesis of multiple autoimmune diseases and cancers. The aim of this study is to investigate the role of IL-17A in PTC with coexistent HT and evaluate the changes in tumor antigenicity.MethodsExpression of IL-17A and major histocompatibility complex (MHC) class I molecules were compared on PTC tissue samples with or without HT. PTC cell lines K1 and TPC-1 were stimulated with IL-17A and analyzed for MHC class I expression afterwards. Cluster of differentiation (CD) 8+T cell activation, production of Interleukin-2 (IL-2) and Interferon-gamma (IFN-γ) as well as the programmed death-1 (PD-1) expression on lymphocytes were assessed by coculture of donor peripheral blood lymphocytes (PBLs) with IL-17A pretreated PTC cells.ResultsElevated IL-17A and MHC class I expression were observed in PTC tissue samples with coexistent HT. Stimulation of PTC cells with IL-17A effectively increased MHC class I expression in vitro. Coculture of PBLs with IL-17A pretreated PTC cells resulted in enhanced T cell activation (%CD25+ of CD3+T cells) and increased IL-2 production along with decreased IFN-γ secretion and PD-1 expression of the lymphocytes.ConclusionsPapillary thyroid cancer with coexisting Hashimoto’s thyroiditis presents elevated MHC class I expression, which may be the result of IL-17A secretion. T cell activation is enhanced in vitro by IL-17A and may provide future utility in PTC immunotherapy.