In vivo monitoring of lung inflammation in CFTR-deficient mice

Abstract

BackgroundExperimentally, lung inflammation in laboratory animals is usually detected by the presence of inflammatory markers, such as immune cells and cytokines, in the bronchoalveolar lavage fluid (BALF) of sacrificed animals. This method, although extensively used, is time, money and animal life consuming, especially when applied to genetically modified animals. Thus a new and more convenient approach, based on in vivo imaging analysis, has been set up to evaluate the inflammatory response in the lung of CFTR-deficient (CF) mice, a murine model of cystic fibrosis.MethodsWild type (WT) and CF mice were stimulated with P. aeruginosa LPS, TNF-alpha and culture supernatant derived from P. aeruginosa (strain VR1). Lung inflammation was detected by measuring bioluminescence in vivo in mice transiently transgenized with a luciferase reporter gene under the control of a bovine IL-8 gene promoter.ResultsDifferences in bioluminescence (BLI) signal were revealed by comparing the two types of mice after intratracheal challenge with pro-inflammatory stimuli. BLI increased at 4 h after stimulation with TNF-alpha and at 24 h after administration of LPS and VR1 supernatant in CF mice with respect to untreated animals. The BLI signal was significantly more intense and lasted for longer times in CF animals when compared to WT mice. Analysis of BALF markers: leukocytes, cytokines and histology revealed no significant differences between CF and WT mice.ConclusionsIn vivo gene delivery technology and non-invasive bioluminescent imaging has been successfully adapted to CFTR-deficient mice. Activation of bIL-8 transgene promoter can be monitored by non-invasive BLI imaging in the lung of the same animal and compared longitudinally in both CF or WT mice, after challenge with pro-inflammatory stimuli. The combination of these technologies and the use of CF mice offer the unique opportunity of evaluating the impact of therapies aimed to control inflammation in a CF background.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0976-8) contains supplementary material, which is available to authorized users.

Inhibition of Pseudomonas aeruginosa secreted virulence factors reduces lung inflammation in CF mice

“…To evaluate in vivo the possible reduction of inflammation associated with inhibition of P. aeruginosa virulence exoproducts, we used a transgenic mouse model that was previously validated [15,37,38]. In presence of lung inflammatory response induced by non-invasive intratracheal challenge with culture supernatant, the exogenous IL-8 promoter is recognized by the mouse transcriptional apparatus and luciferase enzyme is produced.…”

ABCC7/CFTR Expression is Down-regulated in Patients with Active Ulcerative Colitis

“…It is well known that CFTR has been widely studied in cystic brosis (CF) and recently, it has grown interest in to study its role in other diseases or in ammatory conditions such as in the biliary epithelium and intestine 12,22−24 . In animal models and in vitro studies have demonstrated the role of CFTR in the intestinal in ammatory process characterized by histological in ltration of immune cells and increased of in ammatory fecal biomarkers [13][14][15][16] .…”

“…In patients with CF has been observed an increase of fecal calprotectin as same as happens in the in ammatory bowel disease (IBD) [13][14][15] . The ABCC7/CFTR knock-out mice model developed intestinal in ammation suggesting a role of this gene in the gut in ammation 12,16 . The levels of ABCC7/CFTR expression have been involved in modulating the NF-ĸB activity and the production of IL8 and IL6 production in lung cell lines [17][18][19] .…”

A CF IL-8 transgenic mouse model for the in vivo long-term monitoring of the anti-inflammatory role of metallo-protease inhibitors and antibiotics with mechanisms of action similar to that of azithromycin

“…In the past project we shown that the antibiotic azithromycin causes a significant decrease of the lung inflammation in that is capable of inhibiting the synthesis of bacterial virulence factors. Azithromycin is extensively used in cystic fibrosis as an anti-inflammatory molecule but several cases of azithromycin resistance have been reported [1][2], especially in patients using the drug for long times. It seems then important to identify other therapeutic agents to be used in nonresponding patients.…”

“…Background.The possibility of monitoring the inflammatory response in a IL-8 transgenic WT and CFTRknockout (CF), non invasive, animal model has been demonstrated in a previous project conducted by us [1,2].…”