scholarly journals Cyclic AMP-Elevating Capacity of Adenylate Cyclase Toxin-Hemolysin Is Sufficient for Lung Infection but Not for Full Virulence of Bordetella pertussis

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Karolina Skopova ◽  
Barbora Tomalova ◽  
Ivan Kanchev ◽  
Pavel Rossmann ◽  
Martina Svedova ◽  
...  
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Whooping Cough ◽  
Lung Parenchyma ◽  
Lung Pathology ◽  
Phagocytic Cells ◽  
Content Type ◽  
Adenylate Cyclase Toxin

ABSTRACT The adenylate cyclase toxin-hemolysin (CyaA, ACT, or AC-Hly) of Bordetella pertussis targets phagocytic cells expressing the complement receptor 3 (CR3, Mac-1, αMβ2 integrin, or CD11b/CD18). CyaA delivers into cells an N-terminal adenylyl cyclase (AC) enzyme domain that is activated by cytosolic calmodulin and catalyzes unregulated conversion of cellular ATP into cyclic AMP (cAMP), a key second messenger subverting bactericidal activities of phagocytes. In parallel, the hemolysin (Hly) moiety of CyaA forms cation-selective hemolytic pores that permeabilize target cell membranes. We constructed the first B. pertussis mutant secreting a CyaA toxin having an intact capacity to deliver the AC enzyme into CD11b-expressing (CD11b+) host phagocytes but impaired in formation of cell-permeabilizing pores and defective in cAMP elevation in CD11b− cells. The nonhemolytic AC+ Hly− bacteria inhibited the antigen-presenting capacities of coincubated mouse dendritic cells in vitro and skewed their Toll-like receptor (TLR)-triggered maturation toward a tolerogenic phenotype. The AC+ Hly− mutant also infected mouse lungs as efficiently as the parental AC+ Hly+ strain. Hence, elevation of cAMP in CD11b− cells and/or the pore-forming capacity of CyaA were not required for infection of mouse airways. The latter activities were, however, involved in bacterial penetration across the epithelial layer, enhanced neutrophil influx into lung parenchyma during sublethal infections, and the exacerbated lung pathology and lethality of B. pertussis infections at higher inoculation doses (>107 CFU/mouse). The pore-forming activity of CyaA further synergized with the cAMP-elevating activity in downregulation of major histocompatibility complex class II (MHC-II) molecules on infiltrating myeloid cells, likely contributing to immune subversion of host defenses by the whooping cough agent.

scholarly journals BordetellaAdenylate Cyclase Toxin Inhibits Monocyte-to-Macrophage Transition and Dedifferentiates Human Alveolar Macrophages into Monocyte-like Cells

mBio ◽  
2019 ◽  
Vol 10 (5) ◽  
Author(s):  
Jawid Nazir Ahmad ◽  
Jana Holubova ◽  
Oldrich Benada ◽  
Olga Kofronova ◽  
Ludek Stehlik ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Immune Evasion ◽  
Bordetella Pertussis ◽  
Alveolar Macrophages ◽  
Human Monocyte ◽  
Content Type ◽  
Macrophage Cells ◽  
Human Alveolar Macrophages ◽  
Adenylate Cyclase Toxin

ABSTRACTMonocytes arriving at the site of infection differentiate into functional effector macrophages to replenish the resident sentinel cells.Bordetella pertussis, the pertussis agent, secretes an adenylate cyclase toxin-hemolysin (CyaA) that binds myeloid phagocytes through complement receptor 3 (CD11b/CD18) and swiftly delivers its adenylyl cyclase enzyme domain into phagocytes. This ablates the bactericidal capacities of phagocytes through massive and unregulated conversion of cytosolic ATP into the key signaling molecule cAMP. We show that exposure of primary human monocytes to as low a concentration as 22.5 pM CyaA, or a low (2:1) multiplicity of infection by CyaA-producingB. pertussisbacteria, blocks macrophage colony-stimulating factor (M-CSF)-driven differentiation of monocytes. CyaA-induced cAMP signaling mediated through the activity of protein kinase A (PKA) efficiently blocked expression of macrophage markers, and the monocytes exposed to 22.5 pM CyaA failed to acquire the characteristic intracellular complexity of mature macrophage cells. Neither M-CSF-induced endoplasmic reticulum (ER) expansion nor accumulation of Golgi bodies, mitochondria, or lysosomes was observed in toxin-exposed monocytes, which remained small and poorly phagocytic and lacked pseudopodia. Exposure to 22.5 pM CyaA toxin provoked loss of macrophage marker expression onin vitrodifferentiated macrophages, as well as on primary human alveolar macrophages, which appeared to dedifferentiate into monocyte-like cells with upregulated CD14 levels. This is the first report that terminally differentiated tissue-resident macrophage cells can be dedifferentiatedin vitro. The results suggest that blocking of monocyte-to-macrophage transition and/or dedifferentiation of the sentinel cells of innate immunity through cAMP-elevating toxin action may represent a novel immune evasion strategy of bacterial pathogens.IMPORTANCEMacrophages are key sentinel cells of the immune system, and, as such, they are targeted by the toxins produced by the pertussis agentBordetella pertussis. The adenylate cyclase toxin (CyaA) mediates immune evasion ofB. pertussisby suspending the bactericidal activities of myeloid phagocytes. We reveal a novel mechanism of potential subversion of host immunity, where CyaA at very low (22 pM) concentrations could inhibit maturation of human monocyte precursors into the more phagocytic macrophage cells. Furthermore, exposure to low CyaA amounts has been shown to trigger dedifferentiation of mature primary human alveolar macrophages back into monocyte-like cells. This unprecedented capacity is likely to promote survival of the pathogen in the airways, both by preventing maturation of monocytes attracted to the site of infection into phagocytic macrophages and by dedifferentiation of the already airway-resident sentinel cells.

scholarly journals Quantification of the Adenylate Cyclase Toxin of Bordetella pertussisIn Vitroand during Respiratory Infection

2013 ◽  
Vol 81 (5) ◽  
pp. 1390-1398 ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Jason M. Warfel ◽  
Christopher D. Paddock ◽  
Tara F. Jones ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Respiratory Tract ◽  
Whooping Cough ◽  
Extensive Study ◽  
Target Cells ◽  
Human Infants ◽  
Content Type ◽  
Adenylate Cyclase Toxin

ABSTRACTWhooping cough results from infection of the respiratory tract withBordetella pertussis, and the secreted adenylate cyclase toxin (ACT) is essential for the bacterium to establish infection. Despite extensive study of the mechanism of ACT cytotoxicity and its effects over a range of concentrationsin vitro, ACT has not been observed or quantifiedin vivo, and thus the concentration of ACT at the site of infection is unknown. The recently developed baboon model of infection mimics the prolonged cough and transmissibility of pertussis, and we hypothesized that measurement of ACT in nasopharyngeal washes (NPW) from baboons, combined with human andin vitrodata, would provide an estimate of the ACT concentration in the airway during infection. NPW contained up to ∼108CFU/mlB. pertussisand 1 to 5 ng/ml ACT at the peak of infection. Nasal aspirate specimens from two human infants with pertussis contained bacterial concentrations similar to those in the baboons, with 12 to 20 ng/ml ACT. When ∼108CFU/ml of a laboratory strain ofB. pertussiswas culturedin vitro, ACT production was detected in 60 min and reached a plateau of ∼60 ng/ml in 6 h. Furthermore, when bacteria were brought into close proximity to target cells by centrifugation, intoxication was increased 4-fold. Collectively, these data suggest that at the bacterium-target cell interface during infection of the respiratory tract, the concentration of ACT can exceed 100 ng/ml, providing a reference point for future studies of ACT and pertussis pathogenesis.

scholarly journals Cyclic AMP-Mediated Suppression of Neutrophil Extracellular Trap Formation and Apoptosis by the Bordetella pertussis Adenylate Cyclase Toxin

2014 ◽  
Vol 82 (12) ◽  
pp. 5256-5269 ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Erik L. Hewlett
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Neutrophil Function ◽  
Neutrophil Extracellular Trap ◽  
Target Cells ◽  
Content Type ◽  
Extracellular Traps ◽  
Adenylate Cyclase Toxin ◽  
Insight Into

ABSTRACTThe adenylate cyclase toxin (ACT) ofBordetella pertussisintoxicates target cells by generating supraphysiologic levels of intracellular cyclic AMP (cAMP). Since ACT kills macrophages rapidly and potently, we asked whether ACT would also kill neutrophils. In fact, ACT prolongs the neutrophil life span by inhibiting constitutive apoptosis and preventing apoptosis induced by exposure to liveB. pertussis. Imaging ofB. pertussis-exposed neutrophils revealed thatB. pertussislacking ACT induces formation of neutrophil extracellular traps (NETs), whereas wild-typeB. pertussisdoes not, suggesting that ACT suppresses NET formation. Indeed, ACT inhibits formation of NETs by generating cAMP and consequently inhibiting the oxidative burst. Convalescent-phase serum from humans following clinical pertussis blocks the ACT-mediated suppression of NET formation. These studies provide novel insight into the phagocyte impotence caused by ACT, which not only impairs neutrophil function but also inhibits death of neutrophils by apoptosis and NETosis.

scholarly journals Use of a Toxin Neutralization Assay To Characterize the Serologic Response to Adenylate Cyclase Toxin after Infection with Bordetella pertussis

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Jason M. Warfel ◽  
Tod J. Merkel ◽  
Erik L. Hewlett
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Neutralization Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunologic Response ◽  
Serum Samples ◽  
Content Type ◽  
Adenylate Cyclase Toxin ◽  
Strong Candidate ◽  
Candidate Antigen

ABSTRACT Adenylate cyclase toxin (ACT) is an essential virulence factor of Bordetella pertussis, and antibodies to ACT protect against B. pertussis infection in mice. The toxin is therefore a strong candidate antigen for addition to future acellular pertussis vaccines. In order to characterize the functionality of the immunologic response to ACT after infection, we developed an assay for testing the ability of serum samples from subjects infected with B. pertussis to neutralize ACT-induced cytotoxicity in J774 macrophage cells. Baboons develop neutralizing anti-ACT antibodies following infection with B. pertussis, and all sera from baboons with positive anti-ACT IgG enzyme-linked immunosorbent assay (ELISA) results neutralized ACT cytotoxicity. The toxin neutralization assay (TNA) was positive in some baboon sera in which ELISA remained negative. Of serum samples obtained from humans diagnosed with pertussis by PCR, anti-ACT IgG ELISA was positive in 72%, and TNA was positive in 83%. All samples positive for anti-ACT IgG ELISA were positive by TNA, and none of the samples from humans without pertussis neutralized toxin activity. These findings indicate that antibodies to ACT generated following infection with B. pertussis consistently neutralize toxin-induced cytotoxicity and that TNA can be used to improve understanding of the immunologic response to ACT after infection or vaccination.

scholarly journals The Adenylate Cyclase (CyaA) Toxin from Bordetella pertussis Has No Detectable Phospholipase A (PLA) Activity In Vitro

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 111 ◽  
Author(s):  
Alexis Voegele ◽  
Mirko Sadi ◽  
Dorothée Raoux-Barbot ◽  
Thibaut Douché ◽  
Mariette Matondo ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Whooping Cough ◽  
Adenyl Cyclase ◽  
Phospholipase A ◽  
Eukaryotic Cells ◽  
Experimental Conditions ◽  
Cyclase Domain ◽  
Charged Membranes

The adenylate cyclase (CyaA) toxin produced in Bordetella pertussis is the causative agent of whooping cough. CyaA exhibits the remarkable capacity to translocate its N-terminal adenyl cyclase domain (ACD) directly across the plasma membrane into the cytosol of eukaryotic cells. Once translocated, calmodulin binds and activates ACD, leading to a burst of cAMP that intoxicates the target cell. Previously, Gonzalez-Bullon et al. reported that CyaA exhibits a phospholipase A activity that could destabilize the membrane to facilitate ACD membrane translocation. However, Bumba and collaborators lately reported that they could not replicate these results. To clarify this controversy, we assayed the putative PLA activity of two CyaA samples purified in two different laboratories by using two distinct fluorescent probes reporting either PLA2 or both PLA1 and PLA2 activities, as well as in various experimental conditions (i.e., neutral or negatively charged membranes in different buffers.) However, we could not detect any PLA activity in these CyaA batches. Thus, our data independently confirm that CyaA does not possess any PLA activity.

scholarly journals The RNA Chaperone Hfq Is Required for Virulence of Bordetella pertussis

2013 ◽  
Vol 81 (11) ◽  
pp. 4081-4090 ◽  
Author(s):  
Ilona Bibova ◽  
Karolina Skopova ◽  
Jiri Masin ◽  
Ondrej Cerny ◽  
David Hot ◽  
...  
Keyword(s):  
Bordetella Pertussis ◽  
Posttranscriptional Regulation ◽  
Noncoding Rna ◽  
Whooping Cough ◽  
Lethal Dose ◽  
Rna Chaperone ◽  
Content Type ◽  
Small Noncoding Rna ◽  
Mrna Targets

ABSTRACTBordetella pertussisis a Gram-negative pathogen causing the human respiratory disease called pertussis or whooping cough. Here we examined the role of the RNA chaperone Hfq inB. pertussisvirulence. Hfq mediates interactions between small regulatory RNAs and their mRNA targets and thus plays an important role in posttranscriptional regulation of many cellular processes in bacteria, including production of virulence factors. We characterized anhfqdeletion mutant (Δhfq) ofB. pertussis18323 and show that the Δhfqstrain produces decreased amounts of the adenylate cyclase toxin that plays a central role inB. pertussisvirulence. Production of pertussis toxin and filamentous hemagglutinin was affected to a lesser extent.In vitro, the ability of the Δhfqstrain to survive within macrophages was significantly reduced compared to that of the wild-type (wt) strain. The virulence of the Δhfqstrain in the mouse respiratory model of infection was attenuated, with its capacity to colonize mouse lungs being strongly reduced and its 50% lethal dose value being increased by one order of magnitude over that of the wt strain. In mixed-infection experiments, the Δhfqstrain was then clearly outcompeted by the wt strain. This requirement for Hfq suggests involvement of small noncoding RNA regulation inB. pertussisvirulence.

scholarly journals Albumin, in the Presence of Calcium, Elicits a Massive Increase in Extracellular Bordetella Adenylate Cyclase Toxin

2017 ◽  
Vol 85 (6) ◽  
Author(s):  
Laura A. Gonyar ◽  
Mary C. Gray ◽  
Gregory J. Christianson ◽  
Borna Mehrad ◽  
Erik L. Hewlett
Keyword(s):  
Adenylate Cyclase ◽  
Whooping Cough ◽  
Critical Factor ◽  
The United States ◽  
Transcriptional Level ◽  
Content Type ◽  
Novel Host ◽  
Fetal Bovine ◽  
Adenylate Cyclase Toxin ◽  
Myeloid Leukocytes

ABSTRACT Pertussis (whooping cough), caused by Bordetella pertussis, is resurging in the United States and worldwide. Adenylate cyclase toxin (ACT) is a critical factor in establishing infection with B. pertussis and acts by specifically inhibiting the response of myeloid leukocytes to the pathogen. We report here that serum components, as discovered during growth in fetal bovine serum (FBS), elicit a robust increase in the amount of ACT, and ≥90% of this ACT is localized to the supernatant, unlike growth without FBS, in which ≥90% is associated with the bacterium. We have found that albumin, in the presence of physiological concentrations of calcium, acts specifically to enhance the amount of ACT and its localization to the supernatant. Respiratory secretions, which contain albumin, promote an increase in amount and localization of active ACT that is comparable to that elicited by serum and albumin. The response to albumin is not mediated through regulation of ACT at the transcriptional level or activation of the Bvg two-component system. As further illustration of the specificity of this phenomenon, serum collected from mice that lack albumin does not stimulate an increase in ACT. These data, demonstrating that albumin and calcium act synergistically in the host environment to increase production and release of ACT, strongly suggest that this phenomenon reflects a novel host-pathogen interaction that is central to infection with B. pertussis and other Bordetella species.

scholarly journals Adenylate Cyclase Toxin from Bordetella pertussis Synergizes with Lipopolysaccharide To Promote Innate Interleukin-10 Production and Enhances the Induction of Th2 and Regulatory T Cells

2004 ◽  
Vol 72 (3) ◽  
pp. 1568-1579 ◽  
Author(s):  
Pádraig J. Ross ◽  
Ed C. Lavelle ◽  
Kingston H. G. Mills ◽  
Aoife P. Boyd
Keyword(s):  
T Cell ◽  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Bacterial Colonization ◽  
Class Ii ◽  
Cell Surface Expression ◽  
Major Histocompatibility ◽  
Necrosis Factor Alpha ◽  
Adenylate Cyclase Toxin

ABSTRACT Adenylate cyclase toxin (CyaA) from Bordetella pertussis can subvert host immune responses allowing bacterial colonization. Here we have examined its adjuvant and immunomodulatory properties and the possible contribution of lipopolysaccharide (LPS), known to be present in purified CyaA preparations. CyaA enhanced antigen-specific interleukin-5 (IL-5) and IL-10 production and immunoglobulin G1 antibodies to coadministered antigen in vivo. Antigen-specific CD4+-T-cell clones generated from mice immunized with antigen and CyaA had cytokine profiles characteristic of Th2 or type 1 regulatory T (Tr1) cells. Since innate immune cells direct the induction of T-cell subtypes, we examined the influence of CyaA on activation of dendritic cells (DC) and macrophages. CyaA significantly augmented LPS-induced IL-6 and IL-10 and inhibited LPS-driven tumor necrosis factor alpha and IL-12p70 production from bone marrow-derived DC and macrophages. CyaA also enhanced cell surface expression of CD80, CD86, and major histocompatibility class II on immature DC. The stimulatory activity of our CyaA preparation for IL-10 production and CD80, CD86, and major histocompatibility complex class II expression was attenuated following the addition of polymyxin B or with the use of DC from Toll-like receptor (TLR) 4-defective mice. However, treatment of DC with LPS alone at the concentration present in the CyaA preparation (0.2 ng/ml) failed to activate DC in vitro. Our findings demonstrate that activation of innate cells in vitro by CyaA is dependent on a second signal through a TLR and that CyaA can promote Th2/Tr1-cell responses by inhibiting IL-12 and promoting IL-10 production by DC and macrophages.

scholarly journals Bordetella pertussis Inhibition of Interleukin-12 (IL-12) p70 in Human Monocyte-Derived Dendritic Cells Blocks IL-12 p35 through Adenylate Cyclase Toxin-Dependent Cyclic AMP Induction

2006 ◽  
Vol 74 (5) ◽  
pp. 2831-2838 ◽  
Author(s):  
Fabiana Spensieri ◽  
Giorgio Fedele ◽  
Cecilia Fazio ◽  
Maria Nasso ◽  
Paola Stefanelli ◽  
...  
Keyword(s):  
Immune Response ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Interleukin 12 ◽  
Protein Chain ◽  
Cell Functions ◽  
A Subunit ◽  
Adenylate Cyclase Toxin ◽  
The Impact

ABSTRACT Bordetella pertussis, the causative agent of whooping cough, possesses an array of virulence factors, including adenylate cyclase toxin (ACT), relevant in the establishment of infection. Here we better define the impact of cyclic AMP (cAMP) intoxication due to the action of ACT on dendritic cell (DC)-driven immune response, by infecting monocyte-derived DC (MDDC) with an ACT-deficient B. pertussis mutant (ACT−18HS19) or its parental strain (WT18323). Both strains induced MDDC maturation and antigen-presenting cell functions; however, only ACT−18HS19 infected MDDC-induced production of interleukin-12 (IL-12) p70. Gene expression analysis of the IL-12 cytokine family subunits revealed that both strains induced high levels of p40 (protein chain communal to IL-12 p70 and IL-23) as well as p19, a subunit of IL-23. Conversely only ACT−18HS19 infection induced consistent transcription of IL-12 p35, a subunit of IL-12 p70. Addition of the cAMP analogous d-butyril-cAMP (d-cAMP) abolished IL-12 p70 production and IL-12 p35 expression in ACT−18HS19-infected MDDC. ACT−18HS19 infection induced the expression of the transcription factors interferon regulatory factor 1 (IRF-1) and IRF-8 and of beta interferon, involved in IL-12 p35 regulation, and the expression of these genes was inhibited by d-cAMP addition and in WT18323-infected MDDC. The concomitant expression of IL-12 p70 and IL-23 allowed ACT−18HS19 to trigger a more pronounced T helper 1 polarization compared to WT18323. The present study suggests that ACT-dependent cAMP induction leads to the inhibition of pathways ultimately leading to IL-12 p35 production, thus representing a mechanism for B. pertussis to escape the host immune response.

scholarly journals Antibody-mediated inhibition of Bordetella pertussis adenylate cyclase–haemolysin-induced macrophage cytotoxicity is influenced by variations in the bacterial population

Microbiology ◽  
2014 ◽  
Vol 160 (5) ◽  
pp. 962-969 ◽  
Author(s):  
N. Hegerle ◽  
N. Guiso
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Bacterial Population ◽  
Whooping Cough ◽  
Cell Lysis ◽  
Macrophage Cytotoxicity ◽  
Different Types ◽  
Induced Immunity

Whooping cough is a vaccine-preventable disease presenting with epidemic cycles linked to natural and/or vaccine-driven evolution of the aetiological agent of the disease, Bordetella pertussis. Adenylate cyclase–haemolysin (AC-Hly) is a major toxin produced by this pathogen, which mediates macrophage apoptosis in vitro and in vivo. While current acellular pertussis vaccine (APV) formulations do not include AC-Hly, they all contain pertussis toxin and can comprise filamentous haemagglutinin (FHA), which interacts with AC-Hly, and pertactin (PRN), which has been hypothesized also to interact with AC-Hly. We aimed to study the capacity of specific antibodies to inhibit the in vitro B. pertussis AC-Hly-mediated cytotoxicity of J774A.1 murine macrophages in a background of a changing bacterial population. We demonstrate that: (i) clinical isolates of different types or PRN phenotype are all cytotoxic and lethal in the mouse model of respiratory infection; (ii) lack of PRN production does not impact AC-Hly-related phenotypes; (iii) anti-AC-Hly antibodies inhibit cell lysis whatever the phenotype of the isolate, while anti-PRN antibodies significantly inhibit cell lysis provided the isolate produces this antigen, which might be relevant in vivo for APV-induced immunity; and (iv) anti-FHA antibodies only inhibit lysis induced by isolates collected in 2012, maybe indicating specific characteristics of epidemic lineages of B. pertussis.

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