title: Cyclic AMP-Elevating Capacity of Adenylate Cyclase Toxin-Hemolysin Is Sufficient for Lung Infection but Not for Full Virulence of Bordetella pertussis.
abstract: The adenylate cyclase toxin-hemolysin (CyaA, ACT, or AC-Hly) ofBordetella pertussistargets phagocytic cells expressing the complement receptor 3 (CR3, Mac-1, αMβ2integrin, 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 firstB. pertussismutant 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 cellsin vitroand 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 ofB. pertussisinfections at higher inoculation doses (>107CFU/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.
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Karolina
authors.initials: K
authors.lastname: Skopova
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Barbora
authors.initials: B
authors.lastname: Tomalova
authors.affiliation: Czech Centre for Phenogenomics, Division BIOCEV, Institute of Molecular Genetics of the CAS, v.v.i., Czech Academy of Sciences, Prague, Czech Republic.
authors.forename: Ivan
authors.initials: I
authors.lastname: Kanchev
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Rossmann
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Svedova
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Irena
authors.initials: I
authors.lastname: Adkins
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Ilona
authors.initials: I
authors.lastname: Bibova
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Tomala
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Masin
authors.affiliation: Institut Pasteur, Molecular Prevention and Therapy of Human Diseases Unit, Paris, France.|Centre National de la Recherche Scientifique (CNRS), URA3012, Paris, France.
authors.forename: Nicole
authors.initials: N
authors.lastname: Guiso
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Radim
authors.initials: R
authors.lastname: Osicka
authors.affiliation: Czech Centre for Phenogenomics, Division BIOCEV, Institute of Molecular Genetics of the CAS, v.v.i., Czech Academy of Sciences, Prague, Czech Republic.
authors.forename: Radislav
authors.initials: R
authors.lastname: Sedlacek
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic.
authors.forename: Marek
authors.initials: M
authors.lastname: Kovar
authors.affiliation: Institute of Microbiology of the CAS, v.v.i., Prague, Czech Republic sebo@biomed.cas.cz.
authors.forename: Peter
authors.initials: P
authors.lastname: Sebo
mesh_terms: D037361:Adenylate Cyclase Toxin / Q000378:metabolism*; D000818:Animals; D001886:Bordetella pertussis / Q000472:pathogenicity*; D039481:CD11b Antigen / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D003713:Dendritic Cells / Q000276:immunology; D005260:Female; D006460:Hemolysin Proteins / Q000378:metabolism*; D008168:Lung / Q000382:microbiology / Q000473:pathology; D016177:Macrophage-1 Antigen / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010586:Phagocytes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014774:Virulence; D014917:Whooping Cough / Q000382:microbiology*
chemical_list: D037361:Adenylate Cyclase Toxin; D039481:CD11b Antigen; D006460:Hemolysin Proteins; D016177:Macrophage-1 Antigen; D000242:Cyclic AMP
keywords: Bordetella pertussis; adenylate cyclase toxin-hemolysin; cAMP intoxication; lung colonization; pore-forming activity; virulence