Bordetella pertussis is the causative agent of whooping cough, a respiratory disease still considered as a major public health threat and for which recent re-emergence has been observed. Constant reshuffling of Bordetella pertussis genome organization was observed during evolution. These rearrangements are essentially mediated by Insertion Sequences (IS), a mobile genetic elements present in more than 230 copies in the genome, which are supposed to be one of the driving forces enabling the pathogen to escape from vaccine-induced immunity. Here we use high-throughput sequencing approaches (RNA-seq and differential RNA-seq), to decipher Bordetella pertussis transcriptome characteristics and to evaluate the impact of IS elements on transcriptome architecture. Transcriptional organization was determined by identification of transcription start sites and revealed also a large variety of non-coding RNAs including sRNAs, leaderless mRNAs or long 3' and 5'UTR including seven riboswitches. Unusual topological organizations, such as overlapping 5'- or 3'-extremities between oppositely orientated mRNA were also unveiled. The pivotal role of IS elements in the transcriptome architecture and their effect on the transcription of neighboring genes was examined. This effect is mediated by the introduction of IS harbored promoters or by emergence of hybrid promoters. This study revealed that in addition to their impact on genome rearrangements, most of the IS also impact on the expression of their flanking genes. Furthermore, the transcripts produced by IS are strain-specific due to the strain to strain variation in IS copy number and genomic context.

• MeSH
• 3' nepřekládaná oblast MeSH
• 5' nepřekládaná oblast MeSH
• bakteriální RNA genetika   MeSH
• Bordetella pertussis genetika   MeSH
• genetická transkripce * MeSH
• genom bakteriální genetika   MeSH
• messenger RNA genetika   MeSH
• nekódující RNA genetika   MeSH
• počátek transkripce MeSH
• stanovení celkové genové exprese * MeSH
• transpozibilní elementy DNA genetika   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Bordetella pertussis, the causative agent of human whooping cough (pertussis) produces a complex array of virulence factors in order to establish efficient infection in the host. The RNA chaperone Hfq and small regulatory RNAs are key players in posttranscriptional regulation in bacteria and have been shown to play an essential role in virulence of a broad spectrum of bacterial pathogens. This study represents the first attempt to characterize the Hfq regulon of the human pathogen B. pertussis under laboratory conditions as well as upon passage in the host and indicates that loss of Hfq has a profound effect on gene expression in B. pertussis. Comparative transcriptional profiling revealed that Hfq is required for expression of several virulence factors in B. pertussis cells including the Type III secretion system (T3SS). In striking contrast to the wt strain, T3SS did not become operational in the hfq mutant passaged either through mice or macrophages thereby proving that Hfq is required for the functionality of the B. pertussis T3SS. Likewise, expression of virulence factors vag8 and tcfA encoding autotransporter and tracheal colonization factor, respectively, was strongly reduced in the hfq mutant. Importantly, for the first time we demonstrate that B. pertussis T3SS can be activated upon contact with macrophage cells in vitro.

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• bakteriální RNA genetika   metabolismus   MeSH
• Bordetella pertussis genetika   metabolismus   patogenita   MeSH
• buněčné linie MeSH
• faktory virulence rodu Bordetella genetika   metabolismus   MeSH
• infekce bakteriemi rodu Bordetella mikrobiologie   MeSH
• interakce hostitele a patogenu MeSH
• makrofágy metabolismus   mikrobiologie   MeSH
• myši MeSH
• protein hostitelského faktoru 1 nedostatek   genetika   MeSH
• regulace genové exprese u bakterií * MeSH
• regulon MeSH
• sekreční systém typu III genetika   metabolismus   MeSH
• sekreční systém typu V genetika   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH