The ability of M. abscessus to stimulate the innate immune response of cystic fibrosis CFBE41o- respiratory epithelial cells was measured as expression of HβD2 by RT PCR, and release of IL-8 by ELISA.
Here, we identify a novel signaling pathway contributing to IL-8 secretion in the CF bronchial epithelium with KL functioning as an endocrine and local anti-inflammatory mediator that antagonizes pro-inflammatory actions of FGF23 and TGF-β.
We investigated the TLR-4 expression and the inflammatory profile (IL-8 and IL-6 secretion) in CF bronchial epithelial cell line CFBE41o- and its CF transmembrane ion condcutance regulator (CFTR)-corrected counterpart grown under air-liquid interface conditions after stimulation with lipopolysaccharide (LPS) from gram-negative bacteria.
Primary airway epithelial cells derived from children with CF (<i>n</i> = 8, age range 0.2-5.5 years, 5 males) or healthy non-CF controls (<i>n</i> = 8, age range 2.5-4.0 years, 4 males) were then exposed to purified phage for 48 h. Levels of inflammatory IL-1β, IL-6, and IL-8 cytokine production were measured in culture supernatant by immunoassays and the extent of cellular apoptosis was measured using a ssDNA kit.
Chronic lung inflammation in cystic fibrosis (CF) is specifically characterized by predominant endobronchial neutrophil infiltrates, colonization by Pseudomonas aeruginosa, and elevated levels of cytokines and chemokines, first of all IL-8.
An equivalent establishment rate of CF nasal epithelium reported elsewhere, significant associations to CFTR mutation phenotype, elevated airway IL-8 and opportunistic pathogens all suggest this is likely related to the CF disease milieu.
We determined the relationship between surface-bound NE activity and severity of lung disease in CF.Surface-bound NE activity was measured on sputum neutrophils from 35 CF patients and eight healthy controls using novel lipidated Förster resonance energy transfer reporters and correlated with free NE activity, neutrophil counts, interleukin-8, myeloperoxidase and antiproteases in sputum supernatant, and with lung function parameters.Surface-bound NE activity was increased in CF compared to healthy controls (p<0.01) and correlated with free NE activity (p<0.05) and other inflammation markers (p<0.001).
In vitro regulation studies showed that CF airway fluid and the CF-characteristic chemokines CXCL8 and CXCL2 down-regulated IFRD1 expression in neutrophils, an effect that was mediated through CXCR2.
Inflammatory cytokines, particularly the neutrophil chemoattractant IL-8, are elevated in the cystic fibrosis (CF) airway, even in the absence of detectable infection.
The increased content of pro-inflammation cytokines such as interleukin-8 (IL-8) suggest that, before infection, airway inflammation occurs very early in CF.
Pro-inflammatory alleles of three cytokine genotypes, IL-8, IL-10 and IL-1β, appear to be associated with slightly more severe lung disease in patients with CF over a 13 year period.
Consistent with this notion, we observe a normalization of the increased levels of the cytokines IL-1β and KC/IL-8 in lungs of CF mice upon treatment with caspase 1 inhibitors.
The CXCL8-CXCR1/2 signaling axis is involved in the pathogenesis of several diseases including chronic obstructive pulmonary diseases (COPD), asthma, cystic fibrosis and cancer.
Examination of bronchoalveolar lavage fluid revealed positive culture results (7/10) but variable colony counts, neutrophil percentages, and concentrations of interleukin-8 and interleukin-1 beta equally in both CF genotype groups.
Infection with the P. aeruginosa strain PAO1 up-modulated the expression of 14 (27%) genes in IB3-1 cells and 15 (29%) genes in CF primary respiratory epithelia grown at an air-liquid interface, including chemokines (IL-8, growth-regulated Gro-α/β/γ proteins, and granulocyte chemotactic peptide-2 [GCP-2]), proinflammatory cytokines (IL-1α/β, IL-6, and TNF-α), and the intercellular adhesion molecule-1, nuclear factor kB1, toll like receptor 2, and human defensin B4 genes, confirming that bronchial epithelium is an important source of inflammatory mediators.
Thus, IL-8 mRNA expression was prolonged after P. aeruginosa stimulation in CF epithelial cells, and this sustained IL-8 expression may contribute to the excessive inflammatory response in CF.
<i>In vitro</i> studies demonstrated that exposure of the apical face of polarized intestinal cell lines to <i>Bacteroides</i> species supernatants significantly reduced production of interleukin 8 (IL-8), suggesting a mechanism whereby changes in the intestinal microbiota could impact inflammation in CF.
Top-ranked miRNAs that increased in response to CF plasma (adjusted <i>P</i> < 0.05) included miR-155 and miR-146a, which target many immune-related genes, such as IL-8.