Transcript profiling in Actinobacillus pleuropneumoniae after adherence to, or planktonic growth over, SJPL cells.
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ABSTRACT:
ORGANISM(S): Actinobacillus pleuropneumoniae
PROVIDER: GSE12009 | GEO | 2008/07/09
SECONDARY ACCESSION(S): PRJNA113283
REPOSITORIES: GEO
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Project description:Host-pathogen interactions are of great importance in understanding the pathogenesis of infectious microorganisms. We developed in vitro models to study porcine respiratory tract pathogens using an immortalized epithelial cell line, the St. Jude Porcine Lung (SJPL) cell line. In conditions where cytotoxicity was absent or low, the transcriptomic profile of A. pleuropneumoniae after contact with the porcine lung epithelial cells was determined using DNA microarrays. Genes such as tadB, rcpA, members of a putative adhesion locus, and a gene with high homology to the Hsf autotransporter adhesin of Haemophilus influenzae were upregulated as well as genes pgaBC involved in biofilm biosynthesis, while capsular polysaccharide-associated genes were downregulated. Samples from A. pleuropneumoniae grown by either adhesion to SJPL cells or planktonic growth over SJPK cells were combined with samples from A. pleuropneumoniae grown in DMEM medium and co-hybridized on the microarray. Four hybridizations were conducted for each sample combination type. Microarray analysis was carried out using the TM4 Suite of softwares (TIGR) and the SAM algorithm, using a false discovery rate (FDR) value of 0%. For the planktonic and adhesion experiments, Cy5 signal (test) was compared to Cy3 signal (control) in order to obtain a list of significant differentially expressed genes. In order to obtain the list of differentially expressed genes between planktonic growth and adhesion, log2 ratios were compared in TM4 also using the SAM algorithm. Functional classification was performed using TIGR’s Comprehensive Microbial Resource.
2008-07-09 | E-GEOD-12009 | biostudies-arrayexpress
Project description:Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease which causes great economic losses worldwide. Many virulence factors are involved in the pathogenesis, namely capsular polysaccharides, RTX toxins, LPS and many iron acquisition systems. In order to identify genes that are expressed in vivo during a natural infection, we undertook transcript profiling experiments with an A. pleuropneumoniae DNA microarray, after recovery of bacterial mRNAs from serotype 5b-infected porcine lungs.
2009-09-15 | GSE15911 | GEO
Project description:Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease which causes great economic losses worldwide. Many virulence factors are involved in the pathogenesis, namely capsular polysaccharides, RTX toxins, LPS and many iron acquisition systems. In order to identify genes that are expressed in vivo during a natural infection, we undertook transcript profiling experiments with an A. pleuropneumoniae DNA microarray, after recovery of bacterial mRNAs from serotype 5b-infected porcine lungs. Comparative Genomic Hybridizations between Actinobacillus pleuropneumoniae serotype 5b strain L20 (ref) and serotype 5b fresh field isolate 896-07, recovered from infected pig lung tissues following natural acute infection. Two condition transcript profiling experiments : infectious 5b field strain isolated directly from lungs of naturally deceased pigs after acute infection vs infectious 5b field strain grown in BHI broth to an OD600 of 0.300.
2010-05-05 | E-GEOD-15911 | biostudies-arrayexpress
Project description:Actinobacillus pleuropneumoniae is the etiologic agent of contagious pleuropneumonia, an economically important disease of commercially reared swine throughout the world. To cause this disease, A. pleuropneumoniae must rapidly overcome porcine pulmonary innate immune defenses. Effects of koromycin, an antimicrobial agent that acts as an noncompetitive inhibitor of the interaction of NQR with its quinone substrate, on the transcriptome of A. pleuropneumoniae was investigated.
2009-01-06 | GSE13116 | GEO
Project description:Actinobacillus pleuropneumoniae is the etiologic agent of contagious pleuropneumonia, an economically important disease of commercially reared swine throughout the world. To cause this disease, A. pleuropneumoniae must rapidly overcome porcine pulmonary innate immune defenses. Since bronchoalveolar fluid (BALF) contains many of the innate immune components found in the lung, we examined the gene expression of a virulent serovar 1 strain of A. pleuropneumoniae after exposure to concentrated BALF. This experiment was also carried out with a malT mutant of the same strain.
2009-01-06 | GSE13006 | GEO
Project description:Porcine pleuropneumonia caused by Actinobacillus pleuropneumoniae affects pig health status and the swine industry worldwide. Despite of the extensive number of studies focused on A. pleuropneumoniae infection and vaccine development, its exoproteome is still rather unexplored. By combining high-throughput mass spectrometry and immunoproteomic approaches, with our current work we provide an in-depth characterisation of A. pleuropneumoniae serotype 2 exoproteome. Label-free liquid chromatography - tandem mass spectrometry (LC-MS/MS) combined with a comprehensive bioinformatics analysis revealed 484 secreted proteins, of which 84 were predicted to be virulence factors and 142 to be exported via different export mechanisms. The RTX toxins ApxIIA, ApxIIIA and ApxIVA were found to be the most abundant proteins in the A. pleuropneumoniae serotype 2 exoproteome, although ApxIVA is commonly assumed to be expressed exclusively in vivo. Immunoproteomic approaches coupled to LC-MS/MS analysis allowed to portray the immunogenic proteins within the bacterial exoproteome to identify potential vaccine candidates. Using serum pools from uninfected, acutely infected and chronically infected animals, we were able to monitor the seroconversion during disease progression. Overall, our work is expected to contribute to the understanding of the complex pathogenic mechanisms and to facilitate the discovery of potential antimicrobial agents for controlling porcine pleuropneumonia.
2022-10-13 | PXD029396 | Pride
Project description:Bacteria can use host hormones as environment cue to modulate their pathogenic processes, which was discovered to play essential role in disease development. Actinobacillus pleuropneumoniae is one of the most important porcine respiratory pathogens causing great economic losses in the pig industry worldwide. Stress factors were found to contribute to the outcome of A. pleuropneumoniae infection. To test whether A. pleuropneumoniae could respond to host stress hormone catecholamines, the gene expression profiles after epinephrine (Epi) and norepinephrine (NE) treatment were compared with the untreated bacteria using microarray. Although the bacterial growth was not affected in the conditions tested, 157 and 104 genes associated with various function categories including many virulence factors were differentially expressed by Epi and NE treatment. 18 common genes were regulated by the two hormones, these genes included genes encoding virulence factors and potential responsors of Epi and NE. Further investigations on virulence traits demonstrated that cytotoxic activity was enhanced by Epi but repressed by NE in accordance with the regulations on apxIA. Biofilm formation was not affected by the two hormones despite that the biofilm formation gene pgaB was affected. Adhesion to host cells was induced by NE but not by Epi, possibly involving other putative adhesins affected by the hormones in addition to the autotransporter adhesin (APL_0443). Our study demonstrated that A. pleuropneumoniae could actively respond to catecholamines to control its virulence traits. The different regulated genes and effects caused by Epi and NE suggested A. pleuropneumoniae may have multiple responsive systems to sense different type of catecholamine hormones.
2012-03-19 | GSE25516 | GEO
Project description:LuxS is an enzyme involved in the activated methyl cycle and the by-product autoinducer 2 (AI-2) was a quorum sensing signal in some species. In our previous study, the functional LuxS in AI-2 production was verified in the porcine respiratory pathogen Actinobacillus pleuropneumoniae. Enhanced biofilm formation and reduced virulence were observed in the luxS mutant. To comprehensively understand the luxS function, in this study, the transcriptional profiles were compared between the A. pleuropneumoniae luxS mutant and its parental strain in four different growth phases using microarray. Many genes associated with infection were differentially expressed. The biofilm formation genes pgaABC in the luxS mutant were up-regulated in early exponential phase, while 8 genes associated with adhesion were down-regulated in late exponential phase. A group of genes involved in iron acquisition and metabolism were regulated in four growth phases. Further investigations on these virulence traits demonstrated that the luxS mutant showed enhanced biofilm formation and reduced adhesion ability and these effects were not due to lack of AI-2. But AI-2 could increase biofilm formation and adhesion of A. pleuropneumoniae independent of LuxS. Growth under iron restricted condition could be controlled by LuxS through AI-2 production. These results revealed pleiotropic roles of LuxS and AI-2 on A. pleuropneumoniae virulence traits.
2011-11-09 | GSE19056 | GEO
Project description:Bacteria can use host hormones as environment cue to modulate their pathogenic processes, which was discovered to play essential role in disease development. Actinobacillus pleuropneumoniae is one of the most important porcine respiratory pathogens causing great economic losses in the pig industry worldwide. Stress factors were found to contribute to the outcome of A. pleuropneumoniae infection. To test whether A. pleuropneumoniae could respond to host stress hormone catecholamines, the gene expression profiles after epinephrine (Epi) and norepinephrine (NE) treatment were compared with the untreated bacteria using microarray. Although the bacterial growth was not affected in the conditions tested, 157 and 104 genes associated with various function categories including many virulence factors were differentially expressed by Epi and NE treatment. 18 common genes were regulated by the two hormones, these genes included genes encoding virulence factors and potential responsors of Epi and NE. Further investigations on virulence traits demonstrated that cytotoxic activity was enhanced by Epi but repressed by NE in accordance with the regulations on apxIA. Biofilm formation was not affected by the two hormones despite that the biofilm formation gene pgaB was affected. Adhesion to host cells was induced by NE but not by Epi, possibly involving other putative adhesins affected by the hormones in addition to the autotransporter adhesin (APL_0443). Our study demonstrated that A. pleuropneumoniae could actively respond to catecholamines to control its virulence traits. The different regulated genes and effects caused by Epi and NE suggested A. pleuropneumoniae may have multiple responsive systems to sense different type of catecholamine hormones. Transcriptional profiles were analyzed using microarray to compared the epinephrine (Epi) or norepinephrine(NE) treated and untreated A. pleuropneumoniae. All samples were harvested from middle exponential phase (4 hours after sub-culture) at the OD600=1.435M-BM-10.065 for control, OD600=1.461M-BM-10.019 for Epi treated strain and OD600=1.545M-BM-10.115 for NE treated strain. Three biological replicates were conducted for each treatment. The total RNA were extracted and hybridized with the whole genome microarray of A. pleuropneumoniae. The signal intensities were normalized and transformed into log2 values. The genes with fold change M-bM-^IM-% 1.5 and P < 0.05 were selected as differentially expressed.
2012-03-19 | E-GEOD-25516 | biostudies-arrayexpress
Project description:LuxS is an enzyme involved in the activated methyl cycle and the by-product autoinducer 2 (AI-2) was a quorum sensing signal in some species. In our previous study, the functional LuxS in AI-2 production was verified in the porcine respiratory pathogen Actinobacillus pleuropneumoniae. Enhanced biofilm formation and reduced virulence were observed in the luxS mutant. To comprehensively understand the luxS function, in this study, the transcriptional profiles were compared between the A. pleuropneumoniae luxS mutant and its parental strain in four different growth phases using microarray. Many genes associated with infection were differentially expressed. The biofilm formation genes pgaABC in the luxS mutant were up-regulated in early exponential phase, while 8 genes associated with adhesion were down-regulated in late exponential phase. A group of genes involved in iron acquisition and metabolism were regulated in four growth phases. Further investigations on these virulence traits demonstrated that the luxS mutant showed enhanced biofilm formation and reduced adhesion ability and these effects were not due to lack of AI-2. But AI-2 could increase biofilm formation and adhesion of A. pleuropneumoniae independent of LuxS. Growth under iron restricted condition could be controlled by LuxS through AI-2 production. These results revealed pleiotropic roles of LuxS and AI-2 on A. pleuropneumoniae virulence traits. A. pleuropneumoniae strains were cultured in TSB medium supplemented with 10 M-NM-<g/ml of nicotinamide adenine dinucleotide (NAD) and 10% (v/v)filtered cattle serum at 37M-BM-0C. The samples were collected from early exponential phase, middle exponential phase, late exponential phase and stationary phase respectively and the total RNA were extracted using RNA-Solv Reagent (Omega) according to the manufacturerM-bM-^@M-^Ys instructions. For each time point, four biological replicates were combined into two samples. The intensities were normalized and transformed into log2 value.The fold changes >=1.5 or <=-1.5 were selected as differentially expressed genes.
2011-11-09 | E-GEOD-19056 | biostudies-arrayexpress