Dataset Information

Gene expression in respiratory epithelial cells treated to induce resistance with synthetic TLR ligands

ABSTRACT: Among both healthy and immunocompromised patient populations, pneumonia is a leading cause of death worldwide. Yet, despite structural vulnerability resulting in recurrent exposure to pathogens, the lungs’ mucosal immunity successfully suppresses most infections. We recently reported that these innate defenses can be substantially augmented by inhalational exposure to a crude bacterial lysate, protecting broadly against respiratory pathogens, including lethal pneumonia caused by bacteria, fungi or viruses. The phenomenon of inducible resistance is associated with rapid pathogen killing in the lungs and persists in the absence of the typical leukocytes of innate immunity. Rather, the respiratory epithelium appears to be the predominant effector. Toll-like receptors (TLRs) are highly conserved pattern recognition receptors crucial to host defense through the sensing of pathogen associated molecular patterns. Given the importance of TLRs to mucosal immunity, the presence of numerous pathogen associated molecular patterns in the bacterial lysate, and the induction of many TLR-dependent genes following lysate treatment, we hypothesized that induced resistance follows simultaneous stimulation of multiple TLRs. To test this, we challenged mice deficient in TLR/IL1R adaptor proteins and found that resistance could not be induced in mice lacking MyD88. Having identified this phenomenon to be MyD88-dependent, we sought to determine whether the protective phenomenon could be recapitulated by treatment with synthetic TLR agonists. Mice were treated with aerosolized TLR ligands, alone and in combination, prior to infection with virulent pathogens. While limited protection against pneumonia was afforded by the individual TLR ligands, we discovered that the synergistic combination of diacylated lipopetide TLR2/6 agonist Pam2CSK4 and CpG oligodeoxynucleotide TLR9 agonist ODN2395 induced profound resistance against all tested pathogens. This combination also induced greater than additive pathogen killing in the lungs of challenged mice, and we found that the combination could effectively induce pathogen killing by respiratory epithelial cells in vitro. In order to better understand the mechanisms underlying the inducible pathogen killing by this unique combination of TLR agonists, we performed microarray analysis of murine MLE-15 respiratory epithelial cells following 4 h treatment with PBS (sham treatment), Pam2CSK4 alone, ODN2395 alone, or the combination of both agonists, using Illumina Sentrix MouseRef-8 v2 BeadChips. This allows for assessment of differential gene expression, not only between treated and untreated, but between single and combination treated. The intent of the experiment is to gain insight into the transcriptionally-regulated means by which TLR2/6 and TLR9 signaling pathways synergistically interact. Keywords: Differential expression, epithelium, in vitro

ORGANISM(S): Mus musculus

PROVIDER: GSE18725 | GEO | 2009/10/30

SECONDARY ACCESSION(S): PRJNA121625

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappaB, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: differential gene expression; time course; innate immunity; pneumonia; immunocompromised host; lung epithelium Gene expression patterns in mouse lung homogenates were analyzed 2h after exposure to aerosolized PBS (Sham treatment), 2h after exposure to aerosolized NTHi lysate or 4h after exposure to aerosolized NTHi lysate. Each group consisted of six mice.

Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappa-B, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: Differential expression, innate immunity, pneumonia, immunocompromised host; lung epithelium, in vitro, MLE-15 cells were treated with sham (PBS), NTHi lysate (100 ug/ml) or EF2505-III (40 ug/ml). 4 unique samples per group. Treated for 2 hours. Hybridized to Illumina Sentrix Mouse-6 v1.1 Beadhips.

Project description:This logical set encompases several 8hr timecourses (0,1,2,4,8 hrs) and their replicates. All correspond to treatments of bone marrow derived macrophages. Abstract: Innate and adaptive immunity depends critically on host recognition of pathogen-associated molecules. Toll-like receptors (TLRs) are key mediators of pathogen surveillance at the cell or phagocytic vacuole surface. However, mechanisms underlying recognition of pathogens in other cellular compartments remain unclear, and responses elicited by cytosolic challenge are poorly characterized. We therefore used mouse cDNA microarrays to investigate gene expression triggered by infection of bone marrow-derived macrophages with cytosol- and vacuole-localized Listeria monocytogenes (Lm), a model cytosolic pathogen. The resulting gene expression program included two basic categories of induced genes: an "early/persistent" cluster consistent with NF-kappaB-dependent responses downstream of TLRs, and a subsequent "late response" cluster largely composed of IFN-responsive genes (IRGs). The early/persistent cluster was observed upon infection with WT, heat-killed, or mutant Lm lacking listeriolysin O, the pore-forming hemolysin that promotes escape from phagocytic vacuoles. However, the IRG cluster depended on entry of WT Lm into the cytosol. Infection with listeriolysin O-expressing, cytosolic Bacillus subtilis (Bs) strikingly recapitulated the expression profile associated with WT Lm, including IRG induction. IRG up-regulation was associated with MyD88-independent induction of IFN-beta transcription and activity. Whereas Staphylococcus aureus (Sa) lipoteichoic acid treatment confirmed that many late-response genes could also be stimulated through TLRs, our study identified a cytosol-specific transcriptional program independent of TLR signaling through MyD88. Further characterization of cytosolic surveillance pathway(s) and their points of convergence with TLR- and IFN-dependent pathways will enhance our understanding of the means by which mammals detect and respond to pathogens. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Computed

Dataset Information

Gene expression in respiratory epithelial cells treated to induce resistance with synthetic TLR ligands

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets