RESUMO
Bordetella pertussis persists inside host cells, and virulence factors are crucial for intracellular adaptation. The regulation of B. pertussis virulence factor transcription primarily occurs through the modulation of the two-component system (TCS) known as BvgAS. However, additional regulatory systems have emerged as potential contributors to virulence regulation. Here, we investigate the impact of BP1092, a putative TCS histidine kinase that shows increased levels after bacterial internalization by macrophages, on B. pertussis proteome adaptation under nonmodulating (Bvg+) and modulating (Bvg-) conditions. Using mass spectrometry, we compare B. pertussis wild-type (wt), a BP1092-deficient mutant (ΔBP1092), and a ΔBP1092 trans-complemented strain under both conditions. We find an altered abundance of 10 proteins, including five virulence factors. Specifically, under nonmodulating conditions, the mutant strain showed decreased levels of FhaB, FhaS, and Cya compared to the wt. Conversely, under modulating conditions, the mutant strain exhibited reduced levels of BvgA and BvgS compared to those of the wt. Functional assays further revealed that the deletion of BP1092 gene impaired B. pertussis ability to survive within human macrophage THP-1 cells. Taken together, our findings allow us to propose BP1092 as a novel player involved in the intricate regulation of B. pertussis virulence factors and thus in adaptation to the intracellular environment. The data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the data set identifier PXD041940.
Assuntos
Proteínas de Bactérias , Bordetella pertussis , Histidina Quinase , Bordetella pertussis/patogenicidade , Bordetella pertussis/genética , Histidina Quinase/metabolismo , Histidina Quinase/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Virulência/genética , Regulação Bacteriana da Expressão Gênica , Macrófagos/microbiologia , Humanos , Proteoma , Fatores de Virulência de Bordetella/genética , Fatores de Virulência de Bordetella/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Viabilidade MicrobianaRESUMO
PURPOSE OF REVIEW: An initial intracellular phase of usually extracellular bacterial pathogens displays an important strategy to hide from the host's immune system and antibiotics therapy. It helps the bacteria, including bacterial pathogens of airway diseases, to persist and eventually switch to a typical extracellular infection. Several infectious diseases of the lung are life-threatening and their control is impeded by intracellular persistence of pathogens. Thus, molecular adaptations of the pathogens to this niche but also the host's response and potential targets to interfere are of relevance. Here we discuss examples of historically considered extracellular pathogens of the respiratory airway where the intracellular survival and proliferation is well documented, including infections by Staphylococcus aureus, Bordetella pertussis, Haemophilus influenzae, Pseudomonas aeruginosa, and others. RECENT FINDINGS: Current studies focus on bacterial factors contributing to adhesion, iron acquisition, and intracellular survival as well as ways to target them for combatting the bacterial infections. SUMMARY: The investigation of common and specific mechanisms of pathogenesis and persistence of these bacteria in the host may contribute to future investigations and identifications of relevant factors and/or bacterial mechanisms to be blocked to treat or improve prevention strategies.
Assuntos
Bactérias/metabolismo , Infecções Bacterianas/microbiologia , Infecções Respiratórias/microbiologia , Interações Hospedeiro-Patógeno , Humanos , Ferro/metabolismoRESUMO
B. pertussis is the etiological agent of whooping cough, a highly contagious respiratory disease which remains uncontrolled worldwide. Understanding how this pathogen responds to the environmental changes and adapts to different niches found inside the host might contribute to gain insight into bacterial pathogenesis. Comparative analyses of previous transcriptomic and proteomic data suggested that post-transcriptional regulatory mechanisms modulate B. pertussis virulence in response to iron availability. Iron scarcity represents one of the major stresses faced by bacterial pathogens inside the host. In this study, we used gel-free nanoLC-MS/MS-based proteomics to investigate whether Hfq, a highly conserved post-transcriptional regulatory protein, is involved in B. pertussis adaptation to low iron environment. To this end, we compared the protein profiles of wild type B. pertussis and its isogenic hfq deletion mutant strain under iron-replete and iron-depleted conditions. Almost of 33% of the proteins identified under iron starvation was found to be Hfq-dependent. Among them, proteins involved in oxidative stress tolerance and virulence factors that play a key role in the early steps of host colonization and bacterial persistence inside the host cells. Altogether these results suggest that Hfq shapes the infective phenotype of B. pertussis. SIGNIFICANCE: In the last years, it became evident that post-transcriptional regulation of gene expression in ba cteria plays a central role in host-pathogen interactions. Hfq is a bacterial protein that regulates gene expression at post-transcriptional level found pivotal in the establishment of successful infections. In this study, we investigated the role of Hfq in Bordetella pertussis response to iron starvation, one of the main stresses imposed by the host. The data demonstrate that Hfq regulates the abundance of a significant number of B. pertussis proteins in response to iron starvation. Among them, virulence factors and proteins involved in oxidative stress tolerance, key players in host colonization and intracellular bacterial survival. Altogether, our results suggest a relevant role of Hfq in B. pertussis adaptation to the different niches found inside the host eventually granting bacterial pathogenesis.
Assuntos
Bordetella pertussis , Proteômica , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bordetella pertussis/metabolismo , Regulação Bacteriana da Expressão Gênica , Espectrometria de Massas em Tandem , Virulência , Fatores de VirulênciaRESUMO
Bordetella parapertussis is one of the pathogens that cause whooping cough. Even though its incidence has been rising in the last decades, this species remained poorly investigated. This study reports the first extensive proteome analysis of this bacterium. In an attempt to gain some insight into the infective phenotype, we evaluated the response of B. parapertussis to iron starvation, a critical stress the bacteria face during infection. Among other relevant findings, we observed that the adaptation to this condition involves significant changes in the abundance of two important virulence factors of this pathogen, namely, adenylate cyclase and the O-antigen. We further used the proteomic data to search for B. parapertussis proteins that are absent or classified as pseudogenes in the genome of Bordetella pertussis to unravel differences between both whooping cough causative agents. Among them, we identified proteins involved in stress resistance and virulence determinants that might help to explain the differences in the pathogenesis of these species and the lack of cross-protection of current acellular vaccines. Altogether, these results contribute to a better understanding of B. parapertussis biology and pathogenesis. SIGNIFICANCE: Whooping cough is a reemerging disease caused by both Bordetella pertussis and Bordetella parapertussis. Current vaccines fail to induce protection against B parapertussis and the incidence of this species has been rising over the years. The proteomic analysis of this study provided relevant insights into potential virulence determinants of this poorly-studied pathogen. It further identified proteins produced by B. parapertussis not present in B. pertussis, which might help to explain both the differences on their respective infectious process and the current vaccine failure. Altogether, the results of this study contribute to the better understanding of B. parapertussis pathogenesis and the eventual design of improved preventive strategies against whooping cough.
Assuntos
Bordetella parapertussis/metabolismo , Bordetella pertussis/metabolismo , Deficiências de Ferro , Proteômica/métodos , Fatores de Virulência/metabolismo , Proteínas de Bactérias/análise , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Bordetella parapertussis/efeitos dos fármacos , Bordetella parapertussis/patogenicidade , Bordetella pertussis/patogenicidade , Células Cultivadas , Meios de Cultura/química , Meios de Cultura/farmacologia , Humanos , Ferro/metabolismo , Ferro/farmacologia , Fenótipo , Proteoma/análise , Proteoma/metabolismo , Virulência/efeitos dos fármacosRESUMO
Bordetella pertussis, the causative agent of whooping cough, has the capability to survive inside the host cells. This process requires efficient adaptation of the pathogen to the intracellular environment and the associated stress. Among the proteins produced by the intracellular B. pertussis we identified a protein (BP0414) that shares homology with MgtC, a protein which was previously shown to be involved in the intracellular survival of other pathogens. To explore if BP0414 plays a role in B. pertussis intracellular survival a mutant strain defective in the production of this protein was constructed. Using standard in vitro growth conditions we found that BP0414 is required for B. pertussis growth under low magnesium availability or low pH, two environmental conditions that this pathogen might face within the host cell. Intracellular survival studies showed that MgtC is indeed involved in B. pertussis viability inside the macrophages. The use of bafilomycin A1, which inhibits phagosome acidification, abolished the survival defect of the mgtC deficient mutant strain suggesting that in intracellular B. pertussis the role of MgtC protein is mainly related to the bacterial adaptation to the acidic conditions found inside the of phagosomes. Overall, this work provides an insight into the importance of MgtC in B. pertussis pathogenesis and its contribution to bacterial survival within immune cells.
Assuntos
Proteínas de Bactérias/metabolismo , Bordetella pertussis/metabolismo , Proteínas de Bactérias/genética , Bordetella pertussis/efeitos dos fármacos , Bordetella pertussis/genética , Bordetella pertussis/crescimento & desenvolvimento , Cátions Bivalentes/metabolismo , Inibidores Enzimáticos/farmacologia , Escherichia coli , Humanos , Concentração de Íons de Hidrogênio , Macrolídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Macrófagos/patologia , Magnésio/metabolismo , Mutação , Homologia de Sequência de Aminoácidos , Células THP-1RESUMO
One of the mechanisms involved in host immunity is the limitation of iron accessibility to pathogens, which in turn provokes the corresponding physiological adaptation of pathogens. This study reports a gel-free nanoLC-MS/MS-based comparative proteome analysis of Bordetella pertussis grown under iron-excess and iron-depleted conditions. Out of the 926 proteins covered 98 displayed a shift in their abundance in response to low iron availability. Forty-seven of them were found to be increased in level while 58 were found with decreased protein levels under iron starvation. In addition to proteins previously reported to be influenced by iron in B. pertussis, we observed changes in metabolic proteins involved in fatty acid utilization and poly-hydroxybutyrate production. Additionally, many bacterial virulence factors regulated by the BvgAS two-component system were found at decreased levels in response to iron limitation. These results, together with the increased production of proteins potentially involved in oxidative stress resistance, seem to indicate that iron starvation provokes changes in B. pertussis phenotype that might shape host-pathogen interaction.