IL-1? mediates cellular cross-talk in the airway epithelial mesenchymal trophic unit.
ABSTRACT: The bronchial epithelium and underlying fibroblasts form an epithelial mesenchymal trophic unit (EMTU) which controls the airway microenvironment. We hypothesized that cell-cell communication within the EMTU propagates and amplifies the innate immune response to respiratory viral infections. EMTU co-culture models incorporating polarized (16HBE14o-) or differentiated primary human bronchial epithelial cells (HBECs) and fibroblasts were challenged with double-stranded RNA (dsRNA) or rhinovirus. In the polarized EMTU model, dsRNA affected ionic but not macromolecular permeability or cell viability. Compared with epithelial monocultures, dsRNA-stimulated pro-inflammatory mediator release was synergistically enhanced in the basolateral compartment of the EMTU model, with the exception of IL-1? which was unaffected by the presence of fibroblasts. Blockade of IL-1 signaling with IL-1 receptor antagonist (IL-1Ra) completely abrogated dsRNA-induced basolateral release of mediators except CXCL10. Fibroblasts were the main responders to epithelial-derived IL-1 since exogenous IL-1? induced pro-inflammatory mediator release from fibroblast but not epithelial monocultures. Our findings were confirmed in a differentiated EMTU model where rhinovirus infection of primary HBECs and fibroblasts resulted in synergistic induction of basolateral IL-6 that was significantly abrogated by IL-1Ra. This study provides the first direct evidence of integrated IL-1 signaling within the EMTU to propagate inflammatory responses to viral infection.
Project description:BACKGROUND:Interleukin-33 (IL-33) is a cytokine belonging to the IL-1 family, and its possible involvement in the pathophysiology of COPD and viral-induced exacerbations has been demonstrated. IL-33 has been shown to be increased in the airway epithelial cells from COPD patients, but the regulating mechanism of IL-33 expression in airway epithelial cells remains largely unknown. In the current study, we examined whether oxidative stress, which participates in the pathogenesis of COPD, affects the expression of IL-33 in airway epithelial cells and also evaluated the effect during viral infection. METHODS:The involvement of oxidative stress in the expression of IL-33, and its signal pathway was examined after stimulation with hydrogen peroxide (H2O2), with or without stimulation by polyinosinic-polycytidylic acid [poly (I:C)], a synthetic analogue of dsRNA that mimics viral infection, or rhinovirus infection in NCI-H292 cells and primary human bronchial epithelial cells (HBECs). In addition, the effect of antioxidant, N-acetylcysteine (NAC) in the expression of IL-33 was compared between HBECs from healthy subjects and those from COPD patients. RESULTS:Treatment with H2O2 significantly potentiated IL-33 expression in NCI-H292 cells, and the potentiation was reversed by NAC treatment. Mitogen-activated protein kinase (MAPK) inhibitors, but not nuclear factor-kappa B inhibitors, also significantly decreased the H2O2-potentiated IL-33 expression. In addition, H2O2 significantly potentiated the poly (I:C)- or rhinovirus-stimulated IL-33 expression. In HBECs from healthy subjects, H2O2-potentiated IL-33 expression and its reversal by NAC was also confirmed. Under the condition without H2O2-stimulation, treatment with NAC significantly decreased the expression of IL-33 in HBECs from COPD patients, but not in those from healthy subjects. CONCLUSIONS:These results demonstrate that oxidative stress involves in the expression of IL-33 in airway epithelial cells via MAPK signal pathway and it augments IL-33 expression during viral infection. This mechanism may participate in the regulation of IL-33 expression in airway epithelial cells in COPD and the viral-induced exacerbations. Modulation of this pathway could become a therapeutic target for viral-induced exacerbations of COPD.
Project description:Background:The role of miRNAs in the pathogenesis and determining the phenotypes of asthma is not fully elucidated. miR-146a has been previously shown to suppress inflammatory responses in different cells. In this study, we investigated the functions of miR-146a in human bronchial epithelial cells (HBECs) in association with neutrophilic, eosinophilic, and paucigranulocytic phenotypes of asthma. Methods:Bronchial brushing specimens and brochial mucosal biopsy samples were collected from adult patients with asthma and from age- and gender-matched non-asthmatic individuals. The expression of miR-146a in bronchial brushing specimens, bronchial biopsy tissue sections or cultured primary bronchial epithelial cells was analyzed by RT-qPCR or by in situ hybridization. The expression of direct and indirect miR-146a target genes was determined by RT-qPCR or ELISA. The migration of neutrophils was studied by neutrophil chemotaxis assay and flow cytometry. For statistical analysis, unpaired two-way Student's t test, one-way ANOVA or linear regression analysis were used. Results:Reduced expression of miR-146a was found in bronchial brushing specimens from asthma patients as compared to non-asthmatics and irrespective of the phenotype of asthma. In the same samples, the neutrophil attracting chemokines IL-8 and CXCL1 showed increased expression in patients with neutrophilic asthma and increased IL-33 expression was found in patients with eosinophilic asthma. Linear regression analysis revealed a significant negative association between the expression of miR-146a in bronchial brushings and neutrophil cell counts in bronchoalveolar lavage fluid of patients with asthma. In bronchial biopsy specimens, the level of miR-146a was highest in the epithelium as determined with in situ hybridization. In primary conventional HBEC culture, the expression of miR-146a was induced in response to the stimulation with IL-17A, TNF-?, and IL-4. The mRNA expression and secretion of IL-8 and CXCL1 was inhibited in both stimulated and unstimulated HBECs transfected with miR-146a mimics. Supernatants from HBECs transfected with miR-146a had reduced capability of supporting neutrophil migration in neutrophil chemotaxis assay. Conclusion:Our results suggest that decreased level of miR-146a in HBECs from patients with asthma may contribute to the development of neutrophilic phenotype of asthma.
Project description:While mouse models have contributed in our understanding of lung development, repair and regeneration, inherent differences between the murine and human airways requires the development of new models using human airway epithelial cells. In this study, we describe a three-dimensional model system using human bronchial epithelial cells (HBECs) cultured on reconstituted basement membrane. HBECs form complex budding and branching structures on reconstituted basement membrane when co-cultured with human lung fetal fibroblasts. These structures are reminiscent of the branching epithelia during lung development. The HBECs also retain markers indicative of epithelial cell types from both the central and distal airways suggesting their multipotent potential. In addition, we illustrate how the model can be utilized to understand respiratory diseases such as lung cancer. The 3D novel cell culture system recapitulates stromal-epithelial interactions in vitro that can be utilized to understand important aspects of lung development and diseases.
Project description:The IL-1 family of cytokines, which now includes 11 members, is well known to participate in inflammation. Although the most recently recognized IL-1 family cytokines (IL-1F5-11) have been shown to be expressed in airway epithelial cells, the regulation of their expression and function in the epithelium has not been extensively studied. We investigated the regulation of IL-1F5-11 in primary normal human bronchial epithelial cells. Messenger (m)RNAs for IL-1F6 and IL-1F9, but not IL-1F5, IL-1F8 or IL-1F10, were significantly up-regulated by TNF, IL-1?, IL-17 and the Toll-like receptor (TLR)3 ligand double-stranded (ds)RNA. mRNAs for IL-1F7 and IL-1F11 (IL-33) were weakly up-regulated by some of the cytokines tested. Notably, mRNAs for IL-1F6 and IL-1F9 were synergistically enhanced by the combination of TNF/IL-17 or dsRNA/IL-17. IL-1F9 protein was detected in the supernatant following stimulation with dsRNA or a combination of dsRNA and IL-17. IL-1F6 protein was detected in the cell lysate but was not detected in the supernatant. We screened for the receptor for IL-1F9 and found that lung fibroblasts expressed this receptor. We found that IL-1F9 activated mitogen-activated protein kinases and the transcription factor NF-?B in primary normal human lung fibroblasts. IL-1F9 also stimulated the expression of the neutrophil chemokines IL-8 and CXCL3 and the Th17 chemokine CCL20 in lung fibroblasts. These results suggest that epithelial activation by TLR3 (e.g., by respiratory viral infection) and exposure to cytokines from Th17 cells (IL-17) and inflammatory cells (TNF) may amplify neutrophilic inflammation in the airway via induction of IL-1F9 and activation of fibroblasts.
Project description:BACKGROUND:Some investigators find a deficiency in IFN production from airway epithelial cells infected with human rhinovirus in asthma, but whether this abnormality occurs with other respiratory viruses is uncertain. OBJECTIVE:To assess the effect of influenza A virus (IAV) and respiratory syncytial virus (RSV) infection on IFN production and viral level in human bronchial epithelial cells (hBECs) from subjects with and without asthma. METHODS:Primary-culture hBECs from subjects with mild to severe asthma (n = 11) and controls without asthma (hBECs; n = 7) were infected with live or ultraviolet-inactivated IAV (WS/33 strain), RSV (Long strain), or RSV (A/2001/2-20 strain) with multiplicity of infection 0.01 to 1. Levels of virus along with IFN-? and IFN-? and IFN-stimulated gene expression (tracked by 2'-5'-oligoadenylate synthetase 1 and myxovirus (influenza virus) resistance 1 mRNA) were determined up to 72 hours postinoculation. RESULTS:After IAV infection, viral levels were increased 2-fold in hBECs from asthmatic subjects compared with nonasthmatic control subjects (P < .05) and this increase occurred in concert with increased IFN-?1 levels and no significant difference in IFNB1, 2'-5'-oligoadenylate synthetase 1, or myxovirus (influenza virus) resistance 1mRNA levels. After RSV infections, viral levels were not significantly increased in hBECs from asthmatic versus nonasthmatic subjects and the only significant difference between groups was a decrease in IFN-? levels (P < .05) that correlated with a decrease in viral titer. All these differences were found only at isolated time points and were not sustained throughout the 72-hour infection period. CONCLUSIONS:The results indicate that IAV and RSV control and IFN response to these viruses in airway epithelial cells is remarkably similar between subjects with and without asthma.
Project description:BACKGROUND: Rhinovirus infections are the most common cause of asthma exacerbations. The complex responses by airway epithelium to rhinovirus can be captured by gene expression profiling. We hypothesized that: a) upper and lower airway epithelium exhibit differential responses to double-stranded RNA (dsRNA), and b) that this is modulated by the presence of asthma and allergic rhinitis. OBJECTIVES: Identification of dsRNA-induced gene expression profiles of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles. METHODS: This study had a cross-sectional design including 18 subjects: 6 patients with allergic asthma with concomitant rhinitis, 6 patients with allergic rhinitis, and 6 healthy controls. Comparing 6 subjects per group, the estimated false discovery rate was approximately 5%. RNA was extracted from isolated and cultured primary epithelial cells from nasal biopsies and bronchial brushings stimulated with dsRNA (poly(I:C)), and analyzed by microarray (Affymetrix U133+ PM Genechip Array). Data were analysed using R and the Bioconductor Limma package. Overrepresentation of gene ontology groups were captured by GeneSpring GX12. RESULTS: In total, 17 subjects completed the study successfully (6 allergic asthma with rhinitis, 5 allergic rhinitis, 6 healthy controls). dsRNA-stimulated upper and lower airway epithelium from asthma patients demonstrated significantly fewer induced genes, exhibiting reduced down-regulation of mitochondrial genes. The majority of genes related to viral responses appeared to be similarly induced in upper and lower airways in all groups. However, the induction of several interferon-related genes (IRF3, IFNAR1, IFNB1, IFNGR1, IL28B) was impaired in patients with asthma. CONCLUSIONS: dsRNA differentially changes transcriptional profiles of primary nasal and bronchial epithelial cells from patients with allergic rhinitis with or without asthma and controls. Our data suggest that respiratory viruses affect mitochondrial genes, and we identified disease-specific genes that provide potential targets for drug development.
Project description:We used bulk cell RNA-seq to investigate transcriptional effects of IFN-a, IL-17, and IL-13 in primary human bronchial epithelial cells (HBECs). Overall design: Bulk cell transcriptional effects of IFN-a, IL-17, and IL-13 in HBECs
Project description:Background:Obesity is associated with an elevated risk of respiratory infections and inflammatory lung diseases. The objective was to investigate (i) the effects of adipokines (adiponectin (APN), leptin, chemerin, and visfatin) on the production of cytokines by unstimulated and poly(I:C)- and TNF-?-activated human primary bronchial epithelial cells (hBECs), (ii) the cells' expression of the APN receptors (AdipoR1 and AdipoR2), and (iii) the cells' production of APN. Methods:The hBECs were isolated from patients undergoing surgery for lung carcinoma. The cells were then cultured with human recombinant adipokines in the absence or presence of TNF-? or poly(I:C) for 24 h. Supernatant levels of cytokines (IL-6, CCL2, CCL5, CCL20, CXCL1, CXCL8) and APN were measured using ELISAs. The mRNA levels of AdipoR1 and AdipoR2 in hBECs were determined using a real-time quantitative PCR. Results:Of the four adipokines tested, only APN significantly influenced the basal production and the TNF-? poly(I:C)-induced production of cytokines by hBECs. APN (3-30 µg.ml-1) was associated with greater basal production of IL-6, CCL20, and CXCL8, lower basal production of CCL2 and CXCL1 and no difference in CCL5 production. APN inhibited the poly(I:C)-induced production of these five cytokines and the TNF-?-induced production of CCL2 and CXCL1. AdipoR1 and AdipoR2 were both expressed in hBECs. In contrast to human bronchial explants, isolated hBECs did not produce APN. Conclusions:The APN concentrations are abnormally low in obese individuals, and this fall may contribute to the susceptibility to viral lung infections and the severity of these infections in obese individuals.
Project description:We have developed cdk4/hTERT-immortalized normal human bronchial epithelial cells (HBECs) to study lung cancer pathogenesis. By studying the oncogenic effect of common lung cancer alterations (p53, KRAS, and c-MYC) we demonstrate the ability of this model to characterize the stepwise transformation of bronchial epithelial cells to full malignancy. Using HBECs derived from multiple individuals we found: 1) the combination of five genetic alterations (p53, KRASV12, c-MYC, CDK4 and hTERT) is sufficient for full tumorigenic conversion of HBECs; 2) high levels of KRASV12 are required for full malignant transformation of HBECs, however these levels also stimulate oncogene-induced senescence; 3) RAS-induced senescence is largely bypassed with loss of p53 function; 4) over-expression of c-MYC greatly enhances malignancy but only in the context of sh-p53+KRASV12; 5) HBECs from different individuals vary in their sensitivity to transformation by these oncogenic manipulations; 6) serum-induced epithelial-to-mesenchymal transition (EMT) increases in vivo tumorigenicity; 7) genetically-identical clones of transformed HBECs exhibit pronounced differences in tumor growth, histology, and differentiation as well as sensitivity to standard platinum-based chemotherapies; and 8) an mRNA signature derived from tumorigenic and non-tumorigenic clones is predictive of outcome in lung cancer patients. Collectively, we demonstrate this HBEC model system can be used to study the effect of oncogenic mutations on malignant progression, oncogene-induced senescence, and EMT along with clinically translatable applications such as development of prognostic signatures and drug response phenotypes. Human bronchial epithelial cells (HBECs) immortalized with cdk4 and hTERT were transformed with p53 knockdown, KrasV12 and cMYC over-expression and profiled on Illumina HumanHT-12 V4.0 expression beadchips. Transformed HBECs were grown in two different growth media: KSFM (defined, serum-free medium) or R10 (RPMI with 10% FBS) as indicated. Clones were isolated from HBECs with sh-p53 + KrasV12 and sh-p53 + KrasV12 + cMYC.
Project description:We used scRNA-seq to investigate cell type-specific transcriptional effects of IFN-a, IL-17, and IL-13 in primary human bronchial epithelial cells (HBECs). Overall design: Cell type-specific transcriptional effects of IFN-a, IL-17, and IL-13 in HBECs