scholarly journals Cholesterol stimulates the lytic activity of Adenylate Cyclase Toxin on lipid membranes by promoting toxin oligomerization and formation of pores with a greater effective size

FEBS Journal ◽  
2021 ◽  
Author(s):  
David González Bullón ◽  
Kepa B. Uribe ◽  
Jone Amuategi ◽  
César Martín ◽  
Helena Ostolaza
Keyword(s):  
Adenylate Cyclase ◽  
Lipid Membranes ◽  
Lytic Activity ◽  
Effective Size ◽  
Adenylate Cyclase Toxin

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 Adenylate cyclase toxin of Bordetella pertussis: production, purification, and partial characterization.

1990 ◽  
Vol 58 (11) ◽  
pp. 3621-3626 ◽  
Author(s):  
M S Leusch ◽  
S Paulaitis ◽  
R L Friedman
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Partial Characterization ◽  
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.

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.

Oligomeric behavior of Bordetella pertussis adenylate cyclase toxin in solution

2005 ◽  
Vol 438 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Sang-Jin Lee ◽  
M.C. Gray ◽  
Kai Zu ◽  
E.L. Hewlett
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Adenylate Cyclase Toxin
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