Channel Formation in Model Membranes by the Adenylate Cyclase Toxin ofBordetella pertussis:  Effect of Calcium†

Biochemistry ◽  
2003 ◽  
Vol 42 (26) ◽  
pp. 8077-8084 ◽  
Author(s):  
Oliver Knapp ◽  
Elke Maier ◽  
Georg Polleichtner ◽  
Jirí Mašín ◽  
Peter Šebo ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Model Membranes ◽  
Channel Formation ◽  
Ofbordetella Pertussis ◽  
Adenylate Cyclase Toxin

Translocation and calmodulin-activation of the adenylate cyclase toxin (CyaA) ofBordetella pertussis

2018 ◽  
Vol 76 (8) ◽  
Author(s):  
Alexis Voegele ◽  
Darragh P O’Brien ◽  
Orso Subrini ◽  
Nicolas Sapay ◽  
Sara E Cannella ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Ofbordetella Pertussis ◽  
Adenylate Cyclase Toxin

scholarly journals Fluorescent Labels Influence Phagocytosis ofBordetella pertussis by Human Neutrophils

1999 ◽  
Vol 67 (8) ◽  
pp. 4264-4267 ◽  
Author(s):  
Christine L. Weingart ◽  
Gina Broitman-Maduro ◽  
Gary Dean ◽  
Simon Newman ◽  
Mark Peppler ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Virulence Factor ◽  
Fluorescent Protein ◽  
Fluorescein Isothiocyanate ◽  
Immune Serum ◽  
Human Neutrophils ◽  
Ofbordetella Pertussis ◽  
Adenylate Cyclase Toxin ◽  
Green Fluorescent

ABSTRACT To explore the role of neutrophil phagocytosis in host defense against Bordetella pertussis, bacteria were labeled extrinsically with fluorescein isothiocyanate (FITC) or genetically with green fluorescent protein (GFP) and incubated with adherent human neutrophils in the presence or absence of heat-inactivated human immune serum. In the absence of antibodies, FITC-labeled bacteria were located primarily on the surface of the neutrophils with few bacteria ingested. However, after opsonization, about seven times more bacteria were located intracellularly, indicating that antibodies promoted phagocytosis. In contrast, bacteria labeled intrinsically with GFP were not efficiently phagocytosed even in the presence of opsonizing antibodies, suggesting that FITC interfered with a bacterial defense. Because FITC covalently modifies proteins and could affect their function, we tested the effect of FITC on adenylate cyclase toxin activity, an important extracellular virulence factor. FITC-labeled bacteria had fivefold-less adenylate cyclase toxin activity than did unlabeled wild-type bacteria or GFP-expressing bacteria, suggesting that FITC compromised adenylate cyclase toxin activity. These data demonstrated that at least one extracellular virulence factor was affected by FITC labeling and that GFP is a more appropriate label forB. pertussis.

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 Hemolytic, but Not Cell-invasive Activity, of Adenylate Cyclase Toxin Is Selectively Affected by Differential Fatty-acylation inEscherichia coli

1995 ◽  
Vol 270 (35) ◽  
pp. 20250-20253 ◽  
Author(s):  
Murray Hackett ◽  
Carthene B. Walker ◽  
Lin Guo ◽  
Mary C. Gray ◽  
Sheila Van Cuyk ◽  
...  
Keyword(s):  
Adenylate Cyclase ◽  
Inescherichia Coli ◽  
Fatty Acylation ◽  
Adenylate Cyclase Toxin

scholarly journals Suppression of Platelet Aggregation byBordetella pertussis Adenylate Cyclase Toxin

1999 ◽  
Vol 67 (6) ◽  
pp. 2763-2768 ◽  
Author(s):  
Masaaki Iwaki ◽  
Kazunari Kamachi ◽  
Nikolaus Heveker ◽  
Toshifumi Konda
Keyword(s):  
Platelet Aggregation ◽  
Adenylate Cyclase ◽  
Suppressive Effect ◽  
Intracellular Camp ◽  
Platelet Dysfunction ◽  
Camp Content ◽  
Point Mutant ◽  
Rabbit Platelets ◽  
Adenylate Cyclase Toxin ◽  
Induced Aggregation

ABSTRACT The effect of Bordetella pertussis adenylate cyclase toxin (ACT) on platelet aggregation was investigated. This cell-invasive adenylate cyclase completely suppressed ADP (10 μM)-induced aggregation of rabbit platelets at 3 μg/ml and strongly suppressed thrombin (0.2 U/ml)-induced aggregation at 10 μg/ml. The suppression was accompanied by marked increase in platelet intracellular cyclic AMP (cAMP) content and was diminished by the anti-ACT monoclonal antibody B7E11. A catalytically inactive point mutant of ACT did not show the suppressive effect. Since an increase of cAMP content is a known cause of platelet dysfunction, these results indicate that the observed platelet inactivation was due to the catalytic activity of ACT through increase of intracellular cAMP.

Sign in / Sign up

Export Citation Format

Share Document