title: Transcriptional profiling of Bordetella pertussis reveals requirement of RNA chaperone Hfq for Type III secretion system functionality.
abstract: 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.
authors: a Institute of Microbiology of the ASCR ; Prague , Czech Republic.
authors: Ilona
authors: I
authors: Bibova
authors: David
authors: D
authors: Hot
authors: Kristina
authors: K
authors: Keidel
authors: Fabian
authors: F
authors: Amman
authors: Stephanie
authors: S
authors: Slupek
authors: Ondrej
authors: O
authors: Cerny
authors: Roy
authors: R
authors: Gross
authors: Branislav
authors: B
authors: Vecerek
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001885:Bordetella Infections / Q000382:microbiology; D001886:Bordetella pertussis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D002460:Cell Line; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D035001:Host Factor 1 Protein / Q000172:deficiency / Q000235:genetics*; D054884:Host-Pathogen Interactions; D008264:Macrophages / Q000378:metabolism / Q000382:microbiology; D051379:Mice; D012329:RNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D018085:Regulon; D059467:Transcriptome; D000069296:Type III Secretion Systems / Q000235:genetics* / Q000378:metabolism; D000069320:Type V Secretion Systems / Q000235:genetics / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D035001:Host Factor 1 Protein; D012329:RNA, Bacterial; D000069296:Type III Secretion Systems; D000069320:Type V Secretion Systems; D010566:Virulence Factors, Bordetella; C096309:tracheal colonization factor, Bordetella pertussis
keywords: ABC protein, ATP-binding cassette protein; Bsp22; CFU, colony forming unit; Hfq; OMP, outer membrane protein; P, P-value; RT-qPCR, quantitative reverse transcription polymerase chain reaction; SS medium, Steiner-Scholte medium; T3SS; T3SS, Type III secretion system; infection; transcriptomics; virulence; wt, wild-type