Epigenetically associated CCL20 upregulation correlates with esophageal cancer progression and immune disorder.

Chemokines have distinct effects on tumor progression by affecting cancer immunity and tumorigenesis. However, the characteristic chemokine profiles and their roles in immune cell recruitment and cancer cell biology are not entirely understood in esophageal cancer. Here, we scrutinized chemokine's expression profiles in independent esophageal cancer cohorts and identified the elevated CCL20 as a risk factor to predict patients' prognosis regardless of histology subtypes. Enhanced CCL20 expression was also associated with the acquisition of metastatic potential. Mechanistically, the upregulation of CCL20 in tumor cells was associated with promoter hypomethylation. Furthermore, by analyzing single-cell RNA sequencing data of a mouse model mimicking human ESCC development, we observed an imbalance among CD4+ T subtypes in the tumor microenvironment, namely Ccr6+ Th17 and Treg cells infiltration alongside the elevated Ccl20 expression in abnormal epithelial cells during the tumorigenic process. Together, these results reveal that hypomethylation-induced CCL20 promotes esophageal cancer progression and immune disorder. Targeting CCL20 might be a promising therapeutic approach in esophageal cancer.

Periodontitis is associated to increased systemic inflammation in postmyocardial infarction patients.

OBJECTIVE: Periodontitis has been independently associated to cardiovascular disease. However, the biological mechanisms underlying such association are still partially unknown. Thus, this study aimed to discover immunological clues accounting for the increased risk of myocardial infarction (MI) in patients having periodontitis. METHODS: We included 100 patients with a first MI, 50 with and 50 without severe periodontitis, and 100 age-matched, sex-matched and area-matched controls from the Periodontitis and Its Relation to Coronary Artery Disease Study. Participants underwent comprehensive clinical and laboratory examinations 6-10 weeks after the MI and plasma expression of 92 inflammation-related markers was assessed through proximity extension assay. RESULTS: Patients who had an MI displayed altered expression of CCL19, TNFRSF9 and LAP TGF-ß1 in comparison with controls. TNFRSF9 correlated significantly with the amount of alveolar bone loss. MI patients with deep periodontal pockets showed increased white cell count and higher expression of FGF-21, HGF, OSM, CCL20 and IL-18R1 than patients without. White cell count correlated significantly with four of these proteins. CONCLUSIONS: Collectively, our results indicate molecular markers that could be responsible for the increased systemic inflammatory activity in patients with MI with periodontitis.

EGFR/Ras-induced CCL20 production modulates the tumour microenvironment.

BACKGROUND: The activation of the EGFR/Ras-signalling pathway in tumour cells induces a distinct chemokine repertoire, which in turn modulates the tumour microenvironment. METHODS: The effects of EGFR/Ras on the expression and translation of CCL20 were analysed in a large set of epithelial cancer cell lines and tumour tissues by RT-qPCR and ELISA in vitro. CCL20 production was verified by immunohistochemistry in different tumour tissues and correlated with clinical data. The effects of CCL20 on endothelial cell migration and tumour-associated vascularisation were comprehensively analysed with chemotaxis assays in vitro and in CCR6-deficient mice in vivo. RESULTS: Tumours facilitate progression by the EGFR/Ras-induced production of CCL20. Expression of the chemokine CCL20 in tumours correlates with advanced tumour stage, increased lymph node metastasis and decreased survival in patients. Microvascular endothelial cells abundantly express the specific CCL20 receptor CCR6. CCR6 signalling in endothelial cells induces angiogenesis. CCR6-deficient mice show significantly decreased tumour growth and tumour-associated vascularisation. The observed phenotype is dependent on CCR6 deficiency in stromal cells but not within the immune system. CONCLUSION: We propose that the chemokine axis CCL20-CCR6 represents a novel and promising target to interfere with the tumour microenvironment, and opens an innovative multimodal strategy for cancer therapy.

Interleukin-17A affects extracellular vesicles release and cargo in human keratinocytes.

Psoriasis is a chronic inflammatory systemic disease caused by deregulation of the interleukin-23/-17 axis that allows the activation of Th17 lymphocytes and the reprogramming of keratinocytes proliferative response, thereby inducing the secretion of cyto-/chemokines and antimicrobial peptides. Beside cell-to-cell contacts and release of cytokines, hormones and second messengers, cells communicate each other through the release of extracellular vesicles containing DNA, RNA, microRNAs and proteins. It has been reported the alteration of extracellular vesicles trafficking in several diseases, but there is scarce evidence of the involvement of extracellular vesicles trafficking in the pathogenesis of psoriasis. The main goal of the study was to characterize the release, the cargo content and the capacity to transfer bioactive molecules of extracellular vesicles produced by keratinocytes following recombinant IL-17A treatment if compared to untreated keratinocytes. A combined approach of standard ultracentrifugation, RNA isolation and real-time RT-PCR techniques was used to characterize extracellular vesicles cargo. Flow cytometry was used to quantitatively and qualitatively analyse extracellular vesicles and to evaluate cell-to-cell extracellular vesicles transfer. We report that the treatment of human keratinocytes with IL-17A significantly modifies the extracellular vesicles cargo and release. Vesicles from IL-17A-treated cells display a specific pattern of mRNA which is undid by IL-17A neutralization. Extracellular vesicles are taken up by acceptor cells irrespective of their content but only those derived from IL-17A-treated cells enable recipient cells to express psoriasis-associated mRNA. The results imply a role of extracellular vesicles in amplifying the pro-inflammatory cascade induced in keratinocyte by pro-psoriatic cytokines.

Chemokine ligand 20 (CCL20) expression increases with NAFLD stage and hepatic stellate cell activation and is regulated by miR-590-5p.

CCL20 (CC chemokine ligand 20) is emerging as an important regulatory molecule in a pathway common to virus infection, alcoholic hepatitis, and non-alcoholic fatty liver disease (NAFLD) leading to the development of hepatic fibrosis. We previously observed upregulation of CCL20 in patients with NAFLD fibrosis and human hepatic stellate cells (LX-2 cells) in response to lipid loading. To date, the mechanisms mediating the relationship between CCL20 and hepatic fibrogenesis remain unknown. In this study, we sought to characterize the molecular mechanisms by which CCL20 may contribute to fibrogenesis in NAFLD. We observed that CCL20 levels increased with worsening severity of liver histology in NAFLD patients (normal < steatosis < inflammation < fibrosis) and during LX-2 cell activation in a time-dependent manner. We found that treatment of LX-2 cells with CCL20 corresponded with increased levels of CCL20 and ACTA2, and decreased levels of PLAU and SERPINE1, effects mitigated by CCL20 knockdown. We identified a putative binding site for miR-590-5p, which we previously reported to be downregulated in NAFLD fibrosis, in the CCL20 3' untranslated region (3'UTR), and found that exogenous miR-590-5p functionally interacted with the CCL20 3'UTR to downregulate its expression. Transfection of LX-2 hepatic stellate cells with miR-590-5p mimic or silencing RNA resulted in decreased or increased CCL20 levels, respectively. Our results indicate an association between CCL20 and hepatic stellate cell activation that includes modulation of key ECM components and functional interactions with a miRNA previously implicated in NAFLD fibrosis. Together, these findings support a novel mechanism by which CCL20 may promote fibrogenesis in NAFLD.

Identification of myeloid cells in the human enthesis as the main source of local IL-23 production.

OBJECTIVE: We investigated whether the normal human spinal enthesis contained resident myeloid cell populations, capable of producing pivotal proinflammatory cytokines including tumour necrosis factor (TNF) and interleukin (IL)-23 and determined whether these could be modified by PDE4 inhibition. METHODS: Normal human enthesis soft tissue (ST) and adjacent perientheseal bone (PEB) (n=15) were evaluated using immunohistochemistry (IHC), digested for myeloid cell phenotyping, sorted and stimulated with different adjuvants (lipopolysaccharide and mannan). Stimulated enthesis fractions were analysed for inducible production of spondyloarthropathy disease-relevant mediators (IL-23 full protein, TNF, IL-1ß and CCL20). Myeloid populations were also compared with matched blood populations for further mRNA analysis and the effect of PDE4 inhibition was assessed. RESULTS: A myeloid cell population (CD45+ HLADR+ CD14+ CD11c+) phenotype was isolated from both the ST and adjacent PEB and termed 'CD14+ myeloid cells' with tissue localisation confirmed by CD14+ IHC. The CD14- fraction contained a CD123+ HLADR+ CD11c- cell population (plasmacytoid dendritic cells). The CD14+ population was the dominant entheseal producer of IL-23, IL-1ß, TNF and CCL20. IL-23 and TNF from the CD14+ population could be downregulated by a PDE4I and other agents (histamine and 8-Bromo-cAMP) which elevate cAMP. Entheseal CD14+ cells had a broadly similar gene expression profile to the corresponding CD14+ population from matched blood but showed significantly lower CCR2 gene expression. CONCLUSIONS: The human enthesis contains a CD14+ myeloid population that produces most of the inducible IL-23, IL-1ß, TNF and CCL20. This population has similar gene expression profile to the matched blood CD14+ population.

Killed Whole-Cell Oral Cholera Vaccine Induces CCL20 Secretion by Human Intestinal Epithelial Cells in the Presence of the Short-Chain Fatty Acid, Butyrate.

Short-chain fatty acids (SCFAs), such as acetate, butyrate, and propionate, modulate immune responses in the gut. However, the effect of SCFAs on mucosal vaccine-induced immune cell migration is poorly understood. Here, we investigated whether SCFAs modulate chemokine expression induced by the killed whole-cell oral cholera vaccine, Shanchol™, in human intestinal epithelial cells. Shanchol™ induced expression of CCL2, CCL5, CCL20, and CXCL10 at the mRNA level, but not at the protein level. Interestingly, CCL20 secretion was substantially increased by co-stimulation with Shanchol™ and butyrate, while neither acetate nor propionate showed such effect. Enhanced CCL20 secretion was associated with GPR109A activation, and histone deacetylase (HDAC) inhibition. In addition, co-treatment with Shanchol™ and butyrate synergistically increased the secretion of adenosine triphosphate (ATP). Moreover, CCL20 secretion was decreased by inhibiting the extracellular ATP receptor P2X7. However, neither inflammasomes nor caspases were involved in CCL20 production. The culture supernatant of cells treated with Shanchol™ and butyrate augmented human immature dendritic cell migration. Collectively, these results suggest that butyrate enhances Shanchol™-induced CCL20 production in human intestinal epithelial cells via HDAC inhibition and ATP-P2X7 signaling by activating GPR109A. These effects potentially enhance the mucosal immune responses in the gut induced by this oral cholera vaccine.

Blockade of Store-Operated Calcium Entry Reduces IL-17/TNF Cytokine-Induced Inflammatory Response in Human Myoblasts.

Muscle inflammation as in idiopathic inflammatory myopathies (IIM) leads to muscle weakness, mononuclear cell infiltration, and myofiber dysfunction affecting calcium channels. The effects of interleukin-17A (IL-17) and tumor necrosis factor-α (TNFα) on inflammation and calcium changes were investigated in human myoblasts. Human myoblasts were exposed to IL-17 and/or TNFα with/without store-operated Ca2+ entry (SOCE) inhibitors (2-ABP or BTP2). For co-cultures, peripheral blood mononuclear cells (PBMC) from healthy donors activated or not with phytohemagglutinin (PHA) were added to myoblasts at a 5:1 ratio. IL-17 and TNFα induced in synergy CCL20 and IL-6 production by myoblasts (>14-fold). PBMC-myoblast co-cultures enhanced CCL20 and IL-6 production in the presence or not of PHA compared to PBMC or myoblast monocultures. Anti-IL-17 and/or anti-TNFα decreased the production of IL-6 in co-cultures (p < 0.05). Transwell system that prevents direct cell-cell contact reduced CCL20 (p < 0.01) but not IL-6 secretion. IL-17 and/or TNFα increased the level of the ER stress marker Grp78, mitochondrial ROS and promoted SOCE activation by 2-fold (p < 0.01) in isolated myoblasts. SOCE inhibitors reduced the IL-6 production induced by IL-17/TNFα. Therefore, muscle inflammation induced by IL-17 and/or TNFα may increase muscle cell dysfunction, which, in turn, increased inflammation. Such close interplay between immune and non-immune mechanisms may drive and increase muscle inflammation and weakness.

Bcl-3 induced by IL-22 via STAT3 activation acts as a potentiator of psoriasis-related gene expression in epidermal keratinocytes.

IL-22 induces STAT3 phosphorylation and mediates psoriasis-related gene expression. However, the signaling mechanism leading from pSTAT3 to the expression of these genes remains unclear. We focused on Bcl-3, which is induced by STAT3 activation and mediates gene expression. In cultured human epidermal keratinocytes, IL-22 increased Bcl-3, which was translocated to the nucleus with p50 via STAT3 activation. The increases in CXCL8, S100As and human ß-defensin 2 mRNA expression caused by IL-22 were abolished by siRNA against Bcl-3. Although CCL20 expression was also augmented by IL-22, the knockdown of Bcl-3 increased its level. Moreover, the combination of IL-22 and IL-17A enhanced Bcl-3 production, IL-22-induced gene expression, and the expression of other psoriasis-related genes, including those encoding IL-17C, IL-19, and IL-36γ. The expression of these genes (except for CCL20) was also suppressed by the knockdown of Bcl-3. Bcl-3 overexpression induced CXCL8 and HBD2 expression but not S100As expression. We also compared Bcl-3 expression between psoriatic skin lesions and normal skin. Immunostaining revealed strong signals for Bcl-3 and p50 in the nucleus of epidermal keratinocytes from psoriatic skin. The IL-22-STAT3-Bcl-3 pathway may be important in the pathogenesis of psoriasis.

Aire controls the recirculation of murine Foxp3+ regulatory T-cells back to the thymus.

In the thymus, medullary thymic epithelial cells (mTEC) determine the fate of newly selected CD4+ and CD8+ single positive (SP) thymocytes. For example, mTEC expression of Aire controls intrathymic self-antigen availability for negative selection. Interestingly, alterations in both Foxp3+ Regulatory T-cells (T-Reg) and conventional SP thymocytes in Aire-/- mice suggest additional, yet poorly understood, roles for Aire during intrathymic T-cell development. To examine this, we analysed thymocytes from Aire-/- mice using Rag2GFP and Foxp3 expression, and a recently described CD69/MHCI subset definition of post-selection CD4+ conventional thymocytes. We show that while Aire is dispensable for de novo generation of conventional αßT-cells, it plays a key role in controlling the intrathymic T-Reg pool. Surprisingly, a decline in intrathymic T-Reg in Aire-/- mice maps to a reduction in mature recirculating Rag2GFP- T-Reg that express CCR6 and re-enter the thymus from the periphery. Furthermore, we show mTEC expression of the CCR6 ligand CCL20 is reduced in Aire-/- mice, and that CCR6 is required for T-Reg recirculation back to the thymus. Collectively, our study re-defines requirements for late stage intrathymic αßT-cell development, and demonstrates that Aire controls a CCR6-CCL20 axis that determines the developmental makeup of the intrathymic T-Reg pool.

Rhinovirus-bacteria coexposure synergistically induces CCL20 production from human bronchial epithelial cells.

Exacerbations of chronic obstructive pulmonary disease are triggered by viral or bacterial pathogens, with human rhinovirus (HRV) and nontypeable Hemophilus influenzae (NTHI) among the most commonly detected pathogens. Patients who suffer from concomitant viral and bacterial infection have more severe exacerbations. The airway epithelial cell is the initial site of viral and bacterial interactions, and CCL20 is an epithelial chemokine that attracts immature dendritic cells to the airways and can act as an antimicrobial. As such, it contributes to innate and adaptive immune responses to infection. We used primary cultures of human bronchial epithelial cells and the BEAS-2B cell line to examine the effects of bacterial-viral coexposure, as well as each stimulus alone, on epithelial expression of CXCL8 and, in particular, CCL20. HRV-bacterial coexposure induced synergistic production of CXCL8 and CCL20 compared with the sum of each stimulus alone. Synergistic induction of CCL20 did not require viral replication and occurred with two different HRV serotypes that use different viral receptors. Synergy was also seen with either NTHI or Pseudomonas aeruginosa Synergistic induction of CCL20 was transcriptionally regulated. Although NF-κB was required for transcription, it did not regulate synergy, but NF-IL-6 did appear to contribute. Among MAPK inhibitors studied, neither SB203580 nor PD98059 had any effect on synergy, whereas U0126 prevented synergistic induction of CCL20 by HRV and bacteria, apparently via "off-target" effects. Thus bacterial-viral coexposure synergistically increases innate immune responses compared with individual infections. We speculate that this increased inflammatory response leads to worse clinical outcomes.

Shikonin Inhibits Inflammatory Cytokine Production in Human Periodontal Ligament Cells.

Shikonin, which is derived from Lithospermum erythrorhizon, a herb used in traditional medicine, has long been considered to be a useful treatment for various diseases in traditional oriental medicine. Shikonin has recently been reported to have several pharmacological properties, e.g., it has anti-microbial, anti-tumor, and anti-inflammatory effects. The aim of this study was to examine whether shikonin is able to influence the production of interleukin (IL)-6, IL-8, and/or chemokine C-C motif ligand (CCL)20, which contribute to the pathogenesis of periodontal disease, in human periodontal ligament cells (HPDLC). The production levels of IL-6, IL-8, and CCL20 in HPDLC were determined using an ELISA. Western blot analysis was used to detect nuclear factor kappa B (NF-κB) pathway activation in HPDLC. Shikonin prevented IL-1ß- or tumor necrosis factor (TNF)-α-mediated IL-6, IL-8, and CCL20 production in HPDLC. Moreover, we found that shikonin suppressed the phosphorylation and degradation of inhibitor of kappa B-alpha (IκB-α) in IL-1ß- or TNF-α-stimulated HPDLC. These findings suggest that shikonin could have direct beneficial effects against periodontal disease by reducing IL-6, IL-8, and CCL20 production in periodontal lesions.

Anti-bacterial and anti-inflammatory effects of ethanol extract from Houttuynia cordata poultice.

Houttuynia cordata (HC) has been commonly used as many traditional remedies in local areas of Japan. Although many pharmacological activities of HC have been reported, the mechanism underlying the effect of HC remains unknown. We conducted the interview survey in Japan to verify how HC was actually used. The interview survey revealed that HC poultice (HCP) prepared from smothering fresh leaves of HC was most frequently used for the treatment of purulent skin diseases including furuncle and carbuncle with high effectiveness. Ethanol extract of HCP (eHCP) showed anti-bacterial effects against methicillin-resistant Staphylococcus aureus (MRSA), and showed an anti-biofilm activity against MRSA. eHCP showed dose-dependent inhibition of S. aureus lipoteichoic acid (LTA)-induced interleukin-8 and CCL20 production in human keratinocyte without any cytotoxicity. These results suggest that HCP is effective for skin abscess and its underlying mechanism might be the complicated multiple activities for both bacteria and host cells.

Transcriptome profiling unveils the role of cholesterol in IL-17A signaling in psoriasis.

Psoriasis is a chronic inflammatory skin disease characterized by altered proliferation and differentiation of keratinocytes as well as infiltration of immune cells. Increased expression of Th17 cells and cytokines secreted by them provides evidence for its central role in the pathogenesis of psoriasis. IL-17A, signature cytokine of Th17 cells was found to be highly differentially expressed in psoriatic lesional skin. However, cellular and molecular mechanism by which IL-17A exerts its function on keratinocyte is incompletely understood. To understand IL-17A mediated signal transduction pathways, gene expression profiling was done and differentially expressed genes were analysed by IPA software. Here, we demonstrate that during IL-17A signaling total cholesterol levels were elevated, which in turn resulted in the suppression of genes of cholesterol and fatty acid biosynthesis. We found that accumulation of cholesterol was essential for IL-17A signaling as reduced total cholesterol levels by methyl ß cyclodextrin (MBCD), significantly decreased IL-17A induced secretion of CCL20, IL-8 and S100A7 from the keratinocytes. To our knowledge this study for the first time unveils that high level of intracellular cholesterol plays a crucial role in IL-17A signaling in keratinocytes and may explain the strong association between psoriasis and dyslipidemia.

CCL20 and Beta-Defensin 2 Production by Human Lung Epithelial Cells and Macrophages in Response to Brucella abortus Infection.

Both CCL20 and human ß-defensin 2 (hBD2) interact with the same membrane receptor and display chemotactic and antimicrobial activities. They are produced by airway epithelia in response to infectious agents and proinflammatory cytokines. Whereas Brucella spp. can infect humans through inhalation, their ability to induce CCL20 and hBD2 in lung cells is unknown. Here we show that B. abortus induces CCL20 expression in human alveolar (A549) or bronchial (Calu-6) epithelial cell lines, primary alveolar epithelial cells, primary human monocytes, monocyte-derived macrophages and the monocytic cell line THP-1. CCL20 expression was mainly mediated by JNK1/2 and NF-kB in both Calu-6 and THP-1 cells. CCL20 secretion was markedly induced in A549, Calu-6 and THP-1 cells by heat-killed B. abortus or a model Brucella lipoprotein (L-Omp19) but not by the B. abortus lipopolysaccharide (LPS). Accordingly, CCL20 production by B. abortus-infected cells was strongly TLR2-dependent. Whereas hBD2 expression was not induced by B. abortus infection, it was significantly induced in A549 cells by conditioned media from B. abortus-infected THP-1 monocytes (CMB). A similar inducing effect was observed on CCL20 secretion. Experiments using blocking agents revealed that IL-1ß, but not TNF-α, was involved in the induction of hBD2 and CCL20 secretion by CMB. In the in vitro antimicrobial assay, the lethal dose (LD) 50 of CCL20 for B. abortus (>50 µg/ml) was markedly higher than that against E. coli (1.5 µg/ml) or a B. abortus mutant lacking the O polysaccharide in its LPS (8.7 ug/ml). hBD2 did not kill any of the B. abortus strains at the tested concentrations. These results show that human lung epithelial cells secrete CCL20 and hBD2 in response to B. abortus and/or to cytokines produced by infected monocytes. Whereas these molecules do not seem to exert antimicrobial activity against this pathogen, they could recruit immune cells to the infection site.

Regulation of CD4⁺FOXP3⁺ T cells by CCL20/CCR6 axis in early unexplained recurrent miscarriage patients.

Expression and function of CCR6/CCL20 in CD4(+)FOXP3(+) regulatory T cells (Tregs) was investigated in unexplained recurrent miscarriage (URM) patients. Flow cytometry, reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, western blots, and Transwell migration assays were used to analyze the expression and function of regulatory T cells in peripheral blood (PB) and decidual samples of women with URM and of healthy controls. Proportions of CD4(+)FOXP3(+) T cells and CCR6(+)CD4(+)FOXP3(+) T cells were lower in URM patients than in healthy controls for both PB lymphocytes and decidual samples (P < 0.05). Expression levels of FOXP3 and CCR6 mRNA were lower in URM patients than in control subjects for PB and decidual samples (P < 0.05). CCL20 protein levels were lower in URM patients than in controls (P < 0.05). An effect of Treg migration was significantly blocked (by 89.13%) using a neutralizing anti-CCL20 antibody in vitro. Furthermore, CCL20-stimulated Tregs exhibited a 3.21-fold increase in migration and this was blocked using a neutralizing anti-CCL20 antibody. IL-10 concentration in culture supernatants of CD4(+)CD25(+)CD127(dim/-) Tregs of URM patients was significantly lower than that in controls. Anti-CCL20 antibody inhibited IL-10 and IL-4 expression but increased IFN-r and IL-17 levels when there was cell-cell contact between PB CD4(+)CD25(+) T cells and CD4(+)CD25(-) T cells. No difference was detected when cell-cell contact was prevented by a semi-permeable Transwell membrane. CCL20-CCR6 could drive immune activity of CD4(+)FOXP3(+) Tregs, followed by their migration to the feto-maternal microenvironment. These results elucidated the mechanism by which Tregs exert this suppressive effect.

Host Responses and Regulation by NFκB Signaling in the Liver and Liver Epithelial Cells Infected with A Novel Tick-borne Bunyavirus.

Infection in humans by severe fever with thrombocytopenia syndrome virus (SFTSV), a novel bunyavirus transmitted by ticks, is often associated with pronounced liver damage, especially in fatal cases. Little has been known, however, about how liver cells respond to SFTSV and how the response is regulated. In this study we report that proinflammatory cytokines were induced in liver tissues of C57/BL6 mice infected with SFTSV, which may cause tissue necrosis in mice. Human liver epithelial cells were susceptible to SFTSV and antiviral interferon (IFN) and IFN-inducible proteins were induced upon infection. We observed that infection of liver epithelial cells led to significant increases in proinflammatory cytokines and chemokines, including IL-6, RANTES, IP-10, and MIP-3a, which were regulated by NFκB signaling, and the activation of NFκB signaling during infection promoted viral replication in liver epithelial cells. Viral nonstructural protein NSs was inhibitory to the induction of IFN-ß, but interestingly, NFκB activation was enhanced in the presence of NSs. Therefore, NSs plays dual roles in the suppression of antiviral IFN-ß induction as well as the promotion of proinflammatory responses. Our findings provide the first evidence for elucidating host responses and regulation in liver epithelial cells infected by an emerging bunyavirus.

Dual oxidase 2 is essential for house dust mite-induced pro-inflammatory cytokine production in human keratinocytes.

House dust mites (HDMs) are known to trigger chronic inflammation through Toll-like receptors (TLRs) and their signalling cascades. In this study, we found that TLR2 ligation by HDMs induced the activation of dual oxidase 2 (Duox2) and nuclear factor-κB (NF-κB), leading to the production of pro-inflammatory cytokines in human keratinocytes. Stimulation of human keratinocytes with HDMs resulted in increases in interleukin-8 (IL-8) and chemokine (C-C motif) ligand 20 (CCL20) levels. However, pro-inflammatory cytokine production was abolished in keratinocytes transfected with TLR2 siRNA, indicating that HDM-induced cytokine production was mediated via TLR2 signalling. We also examined the function of Duox1/2 isozymes, which are primarily expressed in keratinocytes, in HDM-mediated pro-inflammatory cytokine production. Human keratinocytes transfected with control siRNA or Duox1 siRNA showed no inhibition of IL-8 or CCL20 production in response to HDMs, whereas the silencing of Duox2 expression resulted in a failure to induce cytokine production. Moreover, the phosphorylation and nuclear localization of RelA/p65, a component of NF-κB, were induced by HDMs in human keratinocytes. Transfection of human keratinocytes with TLR2 siRNA or Duox2 siRNA resulted in the complete abolishment of RelA/p65 nuclear localization in response to HDMs. Taken together, these results indicate that the HDM-dependent TLR2-Duox2 signalling axis indeed promotes NF-κB activation, which induces IL-8 and CCL20 production and mediates epidermal keratinocyte inflammation.

The key role of astrocyte elevated gene-1 in CCR6-induced EMT in cervical cancer.

In recent years, astrocyte elevated gene-1 (AEG-1) has been recommended as an important mediator that is involved in the epithelial-to-mesenchymal transition (EMT) process. However, the mechanisms underlying the chemokine (C-C motif) ligand 20 (CCL20)/chemokine (C-C motif) receptor 6 (CCR6)-AEG-1 pathway-mediated EMT in cervical cancer (CC) have not been well featured till now. We used immunohistochemistry and immunoblotting to assess the expression of AEG-1 in 94 cervical cancer tissues and cells. Subsequently, cervical cancer SiHa cells were treated with si-AEG-1 and then subjected to in vitro assays. We observed that AEG-1 proteins were highly expressed in cervical cancer tissues and closely correlated with International Federation of Gynecology and Obstetrics (FIGO) stage and metastasis. Importantly, we validated the expression of AEG-1, p-Erk1/2, p-Akt, vimentin, N-cadherin, and matrix metalloproteinase 2 (MMP2) increased in SiHa with CCL20 treatment in a concentration-dependent manner. When cells were treated with si-AEG-1, the expression of p-Erk1/2, p-Akt, vimentin, N-cadherin, and MMP2 was also downregulated. Using the cell cycle assay, the knockdown of AEG-1 inhibited the entry of G1 into S phase. In conclusion, AEG-1 mediates CCL20/CCR6-induced EMT development via both Erk1/2 and Akt signaling pathway in cervical cancer, which indicates that CCL20/CCR6-AEG-1-EMT pathway could be suggested as a useful target to affect the progression of cervical cancer.

TGF-ß-Dependent Dendritic Cell Chemokinesis in Murine Models of Airway Disease.

Small airway chronic inflammation is a major pathologic feature of chronic obstructive pulmonary disease (COPD) and is refractory to current treatments. Dendritic cells (DCs) accumulate around small airways in COPD. DCs are critical mediators of Ag surveillance and Ag presentation and amplify adaptive immune responses. How DCs accumulate around airways remains largely unknown. We use 2-photon DC imaging of living murine lung sections to directly visualize the dynamic movement of living DCs around airways in response to either soluble mediators (IL-1ß) or environmental stimuli (cigarette smoke or TLR3 ligands) implicated in COPD pathogenesis. We find that DCs accumulate around murine airways primarily by increasing velocity (chemokinesis) rather than directional migration (chemotaxis) in response to all three stimuli. DC accumulation maximally occurs in a specific zone located 26-50 µm from small airways, which overlaps with zones of maximal DC velocity. Our data suggest that increased accumulation of DCs around airways results from increased numbers of highly chemokinetic DCs entering the lung from the circulation with balanced rates of immigration and emigration. Increases in DC accumulation and chemokinesis are partially dependent on ccr6, a crucial DC chemokine receptor, and fibroblast expression of the integrin αvß8, a critical activator of TGF-ß. αvß8-Mediated TGF-ß activation is known to enhance IL-1ß-dependent fibroblast expression of the only known endogenous ccr6 chemokine ligand, ccl20. Taken together, these data suggest a mechanism by which αvß8, ccl20, and ccr6 interact to lead to DC accumulation around airways in response to COPD-relevant stimuli.