Transcriptional profiling of FeHm effects on Haemophilus influenzae R2846
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ABSTRACT:
ORGANISM(S): Haemophilus influenzae
PROVIDER: GSE38638 | GEO | 2013/01/01
SECONDARY ACCESSION(S): PRJNA168314
REPOSITORIES: GEO
Similar Datasets
Project description:Recently described microarray studies have defined the genes that are regulated in response to iron and heme levels in three isolates of Haemophilus influenzae. Comparison of the data sets have allowed us to develop a putative core iron/heme modulon. Included in the core modulon are thirty seven genes that are preferentially expressed under iron/heme limitation. The majority of these genes are involved with iron and or heme acquisition such as hitA, tonB, exbD, exbB, hgpB, hgpC and the hxu and tbp operons. In addition, we identified several other loci with roles potentially related to iron and heme metabolism such as protection against oxidative stress, iron and heme storage and detoxification and biofilm formation. In this report, we describe the further definition of the core iron/heme modulon following transcriptomic analysis of H. influenzae strains 86028NP and R2846. With the defined core, we then test our original hypothesis that “iron and heme regulated genes are upregulated, and important, during clinical infection”. The in vivo expression profiles of the core genes were determined following inoculation of select isolates into the bullae of chinchillas. Isolates selected included 86028NP and a previously un-characterized isolate HI1722. To facilitate studies with the latter isolate, we sequenced the genome and annotated the identified CDS to ensure that oligonucleotides selected for Q-PCR would correctly target each gene of interest. The results from the in vitro studies show that the operons identified as core are actively upregulated in the chinchilla ear during otitis media. For isolate 86-028NP, 70% of the operons were significantly upregulated while isolate NTHI1722 had 100% of the operons upregulated.
2013-01-01 | GSE38637 | GEO
Project description:Recently described microarray studies have defined the genes that are regulated in response to iron and heme levels in three isolates of Haemophilus influenzae. Comparison of the data sets have allowed us to develop a putative core iron/heme modulon. Included in the core modulon are thirty seven genes that are preferentially expressed under iron/heme limitation. The majority of these genes are involved with iron and or heme acquisition such as hitA, tonB, exbD, exbB, hgpB, hgpC and the hxu and tbp operons. In addition, we identified several other loci with roles potentially related to iron and heme metabolism such as protection against oxidative stress, iron and heme storage and detoxification and biofilm formation. In this report, we describe the further definition of the core iron/heme modulon following transcriptomic analysis of H. influenzae strains 86028NP and R2846. With the defined core, we then test our original hypothesis that M-bM-^@M-^\iron and heme regulated genes are upregulated, and important, during clinical infectionM-bM-^@M-^]. The in vivo expression profiles of the core genes were determined following inoculation of select isolates into the bullae of chinchillas. Isolates selected included 86028NP and a previously un-characterized isolate HI1722. To facilitate studies with the latter isolate, we sequenced the genome and annotated the identified CDS to ensure that oligonucleotides selected for Q-PCR would correctly target each gene of interest. The results from the in vitro studies show that the operons identified as core are actively upregulated in the chinchilla ear during otitis media. For isolate 86-028NP, 70% of the operons were significantly upregulated while isolate NTHI1722 had 100% of the operons upregulated. Three replicate cultures were grown in iron and heme depleted media for 90 minutes and samples taken for expression analyses. Fe and heme were supplemented to the remaining cultures and the cultures allowed to incubate an additional 20 minutes. Microarray analyses were used to determine changes in gene expression resulting from transfer from FeHm-deplete to FeHm-replete conditions.
2013-01-01 | E-GEOD-38638 | biostudies-arrayexpress
Project description:Recently described microarray studies have defined the genes that are regulated in response to iron and heme levels in three isolates of Haemophilus influenzae. Comparison of the data sets have allowed us to develop a putative core iron/heme modulon. Included in the core modulon are thirty seven genes that are preferentially expressed under iron/heme limitation. The majority of these genes are involved with iron and or heme acquisition such as hitA, tonB, exbD, exbB, hgpB, hgpC and the hxu and tbp operons. In addition, we identified several other loci with roles potentially related to iron and heme metabolism such as protection against oxidative stress, iron and heme storage and detoxification and biofilm formation. In this report, we describe the further definition of the core iron/heme modulon following transcriptomic analysis of H. influenzae strains 86028NP and R2846. With the defined core, we then test our original hypothesis that M-bM-^@M-^\iron and heme regulated genes are upregulated, and important, during clinical infectionM-bM-^@M-^]. The in vivo expression profiles of the core genes were determined following inoculation of select isolates into the bullae of chinchillas. Isolates selected included 86028NP and a previously un-characterized isolate HI1722. To facilitate studies with the latter isolate, we sequenced the genome and annotated the identified CDS to ensure that oligonucleotides selected for Q-PCR would correctly target each gene of interest. The results from the in vitro studies show that the operons identified as core are actively upregulated in the chinchilla ear during otitis media. For isolate 86-028NP, 70% of the operons were significantly upregulated while isolate NTHI1722 had 100% of the operons upregulated. Three replicate cultures were grown in iron and heme depleted media for 90 minutes and samples taken for expression analyses. Fe and heme were supplemented to the remaining cultures and the cultures allowed to incubate an additional 20 minutes. Microarray analyses were used to determine changes in gene expression resulting from transfer from FeHm-deplete to FeHm-replete conditions.
2013-01-01 | E-GEOD-38637 | biostudies-arrayexpress
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. This SuperSeries is composed of the SubSeries listed below.
2009-01-21 | GSE11362 | GEO
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. Keywords: Transcription analyses
2009-01-21 | GSE11354 | GEO
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. Keywords: Transcription analyses
2009-01-21 | GSE11349 | GEO
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. This SuperSeries is composed of the following subset Series: GSE11349: Transcriptional profiling of FeHm effects on Haemophilus influenzae R2866 GSE11354: Transcriptional profiling of FeHm effects on Haemophilus influenzae 10810 Keywords: SuperSeries Refer to individual Series
2009-01-20 | E-GEOD-11362 | biostudies-arrayexpress
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. Keywords: Transcription analyses Three replicate cultures were grown in iron and heme depleted media for 90 minutes and samples taken for expression analyses. Fe and heme were supplemented to the remaining cultures and the cultures allowed to incubate an additional 20 minutes. Microarray analyses were used to determine changes in gene expression resulting from transfer from FeHm-deplete to FeHm-replete conditions.
2009-01-20 | E-GEOD-11349 | biostudies-arrayexpress
Project description:Background: Haemophilus influenzae has an absolute aerobic growth requirement for heme and has developed multiple complex mechanisms to obtain this essential nutrient. Although an understanding of the heme acquisition mechanisms of H. influenzae is emerging, significant gaps remain to be elucidated. In a previous study we utilized H. influenzae strain Rd KW20 to demonstrate the utility of transcriptional profiling in defining the genes exhibiting altered transcription in response to environmental iron and heme levels. The current study expands upon those initial observations by determining the iron/heme regulons of two additional H. influenzae clinical isolates, i.e. the type b isolate 10810 and the nontypeable isolate R2866, to characterize the core iron/heme regulon of the species. Results: A microarray chip was designed to incorporate probes for all of the genes of H. influenzae isolates 10810 and R2866, and microarray studies were performed to compare gene expression under iron/heme-replete and iron/heme-restricted conditions for each isolate. Of 1820 ORFs on the array corresponding to R2866 genes, 363 were significantly differentially expressed. Of these 363 genes, 233 were maximally transcribed under iron/heme-replete conditions and 130 were preferentially transcribed in iron/heme-restricted conditions. Of the 1883 ORFs representing genes of strain10810, 351 were significantly differentially transcribed, 150 of these were preferentially transcribed in iron/heme-replete conditions and 201 were preferentially transcribed in iron/heme-restricted conditions. Comparison of the data sets indicated that 163 genes were similarly regulated in both isolates and that 74 of these also exhibited similar patterns of regulation in strain Rd KW20. Conclusion: This study provides evidence for a core of H. influenzae genes that are regulated by the availability of iron and/or heme in the growth environment. Elucidation of this core regulon provides targets for investigation of genes with an unrecognized role in iron and heme homeostasis, as well as other potential virulence determinants. In addition, the set of core genes potentially provides targets for therapeutic and vaccine designs since these products of these genes are likely to be preferentially expressed during growth in iron/heme restricted sites of the human body. Keywords: Transcription analyses Three replicate cultures were grown in iron and heme depleted media for 90 minutes and samples taken for expression analyses. Fe and heme were supplemented to the remaining cultures and the cultures allowed to incubate an additional 20 minutes. Microarray analyses were used to determine changes in gene expression resulting from transfer from FeHm-deplete to FeHm-replete conditions.
2009-01-20 | E-GEOD-11354 | biostudies-arrayexpress
Project description:Haemophilus influenzae frequently causes human disease, and humans are it’s sole niche. This bacterium has an absolute requirement for both a porphyrin and an iron source for aerobic growth, and exogenous heme can satisfy both requirements. Heme and iron can be acquired by H. influenzae from free or human protein-bound sources. The ability to selectively regulate the acquisition of heme and iron from physiological sources is a major virulence determinant for this microorganism. We utilized whole genome arrays to identify the full set of H. influenzae Rd KW20 iron and heme regulated genes. Condition specific RNA was derived from cells starved for both heme and iron and cells from the same culture 20 mins after the addition of exogenous iron and heme. The results identified 162 genes with a change in transcription ≥ 1.5 fold. Eighty genes in 42 operons were preferentially expressed under iron/ heme starvation; 82 genes in 50 operons were preferentially expressed under iron/heme replete conditions. In each case, all genes contained within the operon were co-regulated. The former group included genes encoding proteins known to have a role in iron and heme uptake as well as several hypothetical ORFs. Enzymes involved in the gluconeogenesis pathway and glycogen biosynthesis were also upregulated. The genes showing increased transcription immediately after the addition of iron and heme primarily encode proteins involved with aerobic respiration and protein biosynthesis, consistent with a relaxation of starvation. Genomic transcriptional profiling provides a more complete understanding of the effects of iron and heme availability. Keywords: Transcription analyses
2006-07-28 | GSE5061 | GEO