Bordetella pertussis is a Gram-negative, strictly human re-emerging respiratory pathogen and the causative agent of whooping cough. The requirement of the RNA chaperone Hfq for the virulence of B. pertussis suggests that Hfq-dependent small regulatory RNAs (sRNAs) are involved in the virulence of this pathogen. To identify their potential mRNA targets, we applied a method combining experimental and computational approaches called RIL-seq. The majority of putative mRNA targets, including several virulence factors, interact with two sRNAs, CT_433 and CT_521, suggesting that these sRNAs may represent central riboregulatory nodes of B. pertussis. Furthermore, our data suggest that CT_532 sRNA can base pair with the 5'UTR region of ompA mRNA encoding outer membrane protein BP0943 (OmpA) and that CT_532, RNase III and Hfq are involved in the control of ompA expression. The CT_532 sRNA shares 60% identity with the E. coli sRNA MicA and its expression is also modulated by Hfq and stress conditions such as heat and cold shocks. Overall, these results suggest that CT_532 represents a MicA homolog. Importantly, the mutant lacking the first 22 nucleotides of CT_532 exhibits reduced cytotoxicity towards human macrophages and impaired biofilm production but increased resistance to complement compared to the wild type strain.

• MeSH
• 5' nepřekládaná oblast MeSH
• bakteriální RNA * metabolismus   genetika   MeSH
• biofilmy * růst a vývoj   MeSH
• Bordetella pertussis * genetika   patogenita   fyziologie   MeSH
• lidé MeSH
• malá nekódující RNA * metabolismus   genetika   MeSH
• messenger RNA metabolismus   MeSH
• protein hostitelského faktoru 1 * metabolismus   genetika   MeSH
• proteiny vnější bakteriální membrány genetika   metabolismus   MeSH
• regulace genové exprese u bakterií MeSH
• virulence genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 5' nepřekládaná oblast MeSH
• bakteriální RNA * MeSH
• malá nekódující RNA * MeSH
• messenger RNA MeSH
• OMPA outer membrane proteins MeSH Prohlížeč
• protein hostitelského faktoru 1 * MeSH
• proteiny vnější bakteriální membrány MeSH

Bordetella pertussis is a Gram-negative, strictly human re-emerging respiratory pathogen and the causative agent of whooping cough. Similar to other Gram-negative pathogens, B. pertussis produces the type III secretion system, but its role in the pathogenesis of B. pertussis is enigmatic and yet to be elucidated. Here, we combined RNA-seq, LC-MS/MS, and co-immunoprecipitation techniques to identify and characterize the novel CesT family T3SS chaperone BP2265. We show that this chaperone specifically interacts with the secreted T3SS regulator BtrA and represents the first non-flagellar chaperone required for the secretion of an anti-sigma factor. In its absence, secretion but not production of BtrA and most T3SS substrates is severely impaired. It appears that the role of BtrA in regulating T3SS extends beyond its activity as an antagonist of the sigma factor BtrS. Predictions made by artificial intelligence system AlphaFold support the chaperone function of BP2265 towards BtrA and outline the structural basis for the interaction of BtrA with its target BtrS. We propose to rename BP2265 to BtcB for the Bordetella type III chaperone of BtrA.In addition, the absence of the BtcB chaperone results in increased expression of numerous flagellar genes and several virulence genes. While increased production of flagellar proteins and intimin BipA translated into increased biofilm formation by the mutant, enhanced production of virulence factors resulted in increased cytotoxicity towards human macrophages. We hypothesize that these phenotypic traits result indirectly from impaired secretion of BtrA and altered activity of the BtrA/BtrS regulatory node.

• Klíčová slova
• Bordetella pertussis, CesT chaperone, T3SS, anti-sigma factor, biofilm,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• Bordetella pertussis * metabolismus   MeSH
• chromatografie kapalinová MeSH
• lidé MeSH
• pertuse * MeSH
• regulace genové exprese u bakterií MeSH
• sigma faktor genetika   MeSH
• tandemová hmotnostní spektrometrie MeSH
• umělá inteligence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• sigma faktor MeSH

Bacterial pathogens sense specific cues associated with different host niches and integrate these signals to appropriately adjust the global gene expression. Bordetella pertussis is a Gram-negative, strictly human pathogen of the respiratory tract and the etiological agent of whooping cough (pertussis). Though B. pertussis does not cause invasive infections, previous results indicated that this reemerging pathogen responds to blood exposure. Here, omics RNA-seq and LC-MS/MS techniques were applied to determine the blood-responsive regulon of B. pertussis. These analyses revealed that direct contact with blood rewired global gene expression profiles in B. pertussis as the expression of almost 20% of all genes was significantly modulated. However, upon loss of contact with blood, the majority of blood-specific effects vanished, with the exception of several genes encoding the T3SS-secreted substrates. For the first time, the T3SS regulator BtrA was identified in culture supernatants of B. pertussis. Furthermore, proteomic analysis identified BP2259 protein as a novel secreted T3SS substrate, which is required for T3SS functionality. Collectively, presented data indicate that contact with blood represents an important cue for B. pertussis cells.

• Klíčová slova
• Bordetella pertussis, T3SS, blood exposure, gene expression, omics analyses, protein secretion,
• MeSH
• anotace sekvence MeSH
• bakteriální proteiny metabolismus   MeSH
• Bordetella pertussis fyziologie   MeSH
• chromatografie kapalinová MeSH
• faktory virulence MeSH
• genomika * metody   MeSH
• lidé MeSH
• proteomika * metody   MeSH
• regulace genové exprese u bakterií MeSH
• sekreční systém typu III genetika   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• tandemová hmotnostní spektrometrie MeSH
• transkriptom MeSH
• virulence MeSH
• výpočetní biologie metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• sekreční systém typu III MeSH

Pertussis, also known as whooping cough, is a resurging acute respiratory disease of humans primarily caused by the Gram-negative coccobacilli Bordetella pertussis, and less commonly by the human-adapted lineage of B. parapertussisHU. The ovine-adapted lineage of B. parapertussisOV infects only sheep, while B. bronchiseptica causes chronic and often asymptomatic respiratory infections in a broad range of mammals but rarely in humans. A largely overlapping set of virulence factors inflicts the pathogenicity of these bordetellae. Their genomes also harbor a pathogenicity island, named bsc locus, that encodes components of the type III secretion injectosome, and adjacent btr locus with the type III regulatory proteins. The Bsc injectosome of bordetellae translocates the cytotoxic BteA effector protein, also referred to as BopC, into the cells of the mammalian hosts. While the role of type III secretion activity in the persistent colonization of the lower respiratory tract by B. bronchiseptica is well recognized, the functionality of the type III secretion injectosome in B. pertussis was overlooked for many years due to the adaptation of laboratory-passaged B. pertussis strains. This review highlights the current knowledge of the type III secretion system in the so-called classical Bordetella species, comprising B. pertussis, B. parapertussis, and B. bronchiseptica, and discusses its functional divergence. Comparison with other well-studied bacterial injectosomes, regulation of the type III secretion on the transcriptional and post-transcriptional level, and activities of BteA effector protein and BopN protein, homologous to the type III secretion gatekeepers, are addressed.

• Klíčová slova
• BopN, Bordetella, BteA/BopC, effector protein, pertussis, type III secretion system,
• MeSH
• bakteriální proteiny genetika   MeSH
• Bordetella bronchiseptica * MeSH
• Bordetella pertussis genetika   MeSH
• faktory virulence genetika   MeSH
• infekce bakteriemi rodu Bordetella * MeSH
• ovce MeSH
• sekreční systém typu III genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• bakteriální proteiny MeSH
• faktory virulence MeSH
• sekreční systém typu III MeSH