title: Bordetella pertussis Adenylate Cyclase Toxin Blocks Induction of Bactericidal Nitric Oxide in Macrophages through cAMP-Dependent Activation of the SHP-1 Phosphatase.
abstract: The adenylate cyclase toxin-hemolysin (CyaA) plays a key role in the virulence of Bordetella pertussis. CyaA penetrates complement receptor 3-expressing phagocytes and catalyzes uncontrolled conversion of cytosolic ATP to the key second messenger molecule cAMP. This paralyzes the capacity of neutrophils and macrophages to kill bacteria by complement-dependent oxidative burst and opsonophagocytic mechanisms. We show that cAMP signaling through the protein kinase A (PKA) pathway activates Src homology domain 2 containing protein tyrosine phosphatase (SHP) 1 and suppresses production of bactericidal NO in macrophage cells. Selective activation of PKA by the cell-permeable analog N(6)-benzoyladenosine-3',5'-cyclic monophosphate interfered with LPS-induced inducible NO synthase (iNOS) expression in RAW264.7 macrophages, whereas inhibition of PKA by H-89 largely restored the production of iNOS in CyaA-treated murine macrophages. CyaA/cAMP signaling induced SHP phosphatase-dependent dephosphorylation of the c-Fos subunit of the transcription factor AP-1 and thereby inhibited TLR4-triggered induction of iNOS gene expression. Selective small interfering RNA knockdown of SHP-1, but not of the SHP-2 phosphatase, rescued production of TLR-inducible NO in toxin-treated cells. Finally, inhibition of SHP phosphatase activity by NSC87877 abrogated B. pertussis survival inside murine macrophages. These results reveal that an as yet unknown cAMP-activated signaling pathway controls SHP-1 phosphatase activity and may regulate numerous receptor signaling pathways in leukocytes. Hijacking of SHP-1 by CyaA action then enables B. pertussis to evade NO-mediated killing in sentinel cells of innate immunity.
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic.
authors: Ondrej
authors: O
authors: Cerny
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic.
authors: Jana
authors: J
authors: Kamanova
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic.
authors: Jiri
authors: J
authors: Masin
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic.
authors: Ilona
authors: I
authors: Bibova
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic.
authors: Karolina
authors: K
authors: Skopova
authors: Laboratory of Molecular Biology of Bacterial Pathogens, Institute of Microbiology of the ASCR, v.v.i., Czech Academy of Sciences, 142 20, Prague 4, Czech Republic sebo@biomed.cas.cz.
authors: Peter
authors: P
authors: Sebo
mesh_terms: D037361:Adenylate Cyclase Toxin / Q000276:immunology*; D000818:Animals; D001885:Bordetella Infections / Q000201:enzymology / Q000276:immunology*; D001886:Bordetella pertussis / Q000276:immunology; D002460:Cell Line; D000242:Cyclic AMP; D004789:Enzyme Activation / Q000276:immunology; D006801:Humans; D008264:Macrophages / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000096:biosynthesis; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000276:immunology* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000276:immunology
chemical_list: D037361:Adenylate Cyclase Toxin; D009569:Nitric Oxide; D000242:Cyclic AMP; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; C509248:Ptpn6 protein, mouse