Bordetella pertussis, a strictly human re-emerging pathogen and the causative agent of whooping cough, exploits a broad variety of virulence factors to establish efficient infection. Here, we used RNA sequencing to analyse the changes in gene expression profiles of human THP-1 macrophages resulting from B. pertussis infection. In parallel, we attempted to determine the changes in intracellular B. pertussis-specific transcriptomic profiles resulting from interaction with macrophages. Our analysis revealed that global gene expression profiles in THP-1 macrophages are extensively rewired 6 h post-infection. Among the highly expressed genes, we identified those encoding cytokines, chemokines, and transcription regulators involved in the induction of the M1 and M2 macrophage polarization programmes. Notably, several host genes involved in the control of apoptosis and inflammation which are known to be hijacked by intracellular bacterial pathogens were overexpressed upon infection. Furthermore, in silico analyses identified large temporal changes in expression of specific gene subsets involved in signalling and metabolic pathways. Despite limited numbers of the bacterial reads, we observed reduced expression of majority of virulence factors and upregulation of several transcriptional regulators during infection suggesting that intracellular B. pertussis cells switch from virulent to avirulent phase and actively adapt to intracellular environment, respectively.

• Keywords
• Bordetella pertussis, host-pathogen interaction, infection, intracellular survival, macrophage,
• MeSH
• Bordetella pertussis physiology   MeSH
• Cell Line MeSH
• Gene Ontology MeSH
• Gene Regulatory Networks MeSH
• Host-Pathogen Interactions genetics   immunology   MeSH
• Cells, Cultured MeSH
• Real-Time Polymerase Chain Reaction MeSH
• Humans MeSH
• Macrophages immunology   metabolism   microbiology   MeSH
• Whooping Cough genetics   immunology   virology   MeSH
• Gene Expression Regulation MeSH
• Reproducibility of Results MeSH
• Gene Expression Profiling * methods   MeSH
• Transcriptome * MeSH
• Computational Biology methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

A series of 13 acyclic nucleoside phosphonates (ANPs) as bisamidate prodrugs was prepared. Five compounds were found to be non-cytotoxic and selective inhibitors of Bordetella pertussis adenylate cyclase toxin (ACT) in J774A.1 macrophage cell-based assays. The 8-aza-7-deazapurine derivative of adefovir (PMEA) was found to be the most potent ACT inhibitor in the series (IC50 =16 nm) with substantial selectivity over mammalian adenylate cyclases (mACs). AC inhibitory properties of the most potent analogues were confirmed by direct evaluation of the corresponding phosphonodiphosphates in cell-free assays and were found to be potent inhibitors of both ACT and edema factor (EF) from Bacillus anthracis (IC50 values ranging from 0.5 to 21 nm). Moreover, 7-halo-7-deazapurine analogues of PMEA were discovered to be potent and selective mammalian AC1 inhibitors (no inhibition of AC2 and AC5) with IC50 values ranging from 4.1 to 5.6 μm in HEK293 cell-based assays.

• Keywords
• Bacillus anthracis, Bordetella pertussis, adefovir, adenylate cyclase, inhibitors,
• MeSH
• Adenine analogs & derivatives   chemical synthesis   chemistry   pharmacology   MeSH
• Adenylyl Cyclases metabolism   MeSH
• Bacillus anthracis enzymology   MeSH
• Bordetella pertussis enzymology   MeSH
• Enzyme Inhibitors chemical synthesis   chemistry   pharmacology   MeSH
• Molecular Structure MeSH
• Organophosphonates chemical synthesis   chemistry   pharmacology   MeSH
• Dose-Response Relationship, Drug MeSH
• Structure-Activity Relationship MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, N.I.H., Extramural MeSH
• Names of Substances
• adefovir MeSH Browser
• Adenine MeSH
• Adenylyl Cyclases MeSH
• Enzyme Inhibitors MeSH
• Organophosphonates MeSH

Adenylate cyclase toxin (CyaA) is released in the course of B. pertussis infection in the host's respiratory tract in order to suppress its early innate and subsequent adaptive immune defense. CD11b-expressing dendritic cells (DC), macrophages and neutrophils are professional phagocytes and key players of the innate immune system that provide a first line of defense against invading pathogens. Recent findings revealed the capacity of B. pertussis CyaA to intoxicate DC with high concentrations of 3',5'-cyclic adenosine monophosphate (cAMP), which ultimately skews the host immune response towards the expansion of Th17 cells and regulatory T cells. CyaA-induced cAMP signaling swiftly incapacitates opsonophagocytosis, oxidative burst and NO-mediated killing of bacteria by neutrophils and macrophages. The subversion of host immune responses by CyaA after delivery into DC, macrophages and neutrophils is the subject of this review.

• Keywords
• T-helper cells, immune response, intracellular pathways, phagocytosis,
• MeSH
• Adenylate Cyclase Toxin immunology   MeSH
• Cyclic AMP chemistry   MeSH
• Bordetella pertussis MeSH
• Immunity, Cellular MeSH
• Dendritic Cells immunology   MeSH
• Respiratory System immunology   microbiology   MeSH
• Phagocytosis MeSH
• Host-Pathogen Interactions MeSH
• Humans MeSH
• Macrophages immunology   MeSH
• Neutrophils immunology   MeSH
• Whooping Cough immunology   MeSH
• T-Lymphocytes, Regulatory immunology   MeSH
• Signal Transduction MeSH
• Immunity, Mucosal MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Adenylate Cyclase Toxin MeSH
• Cyclic AMP MeSH

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.

• Keywords
• Bordetella pertussis, adenylate cyclase toxin-hemolysin, cAMP intoxication, lung colonization, pore-forming activity, virulence,
• MeSH
• Adenylate Cyclase Toxin metabolism   MeSH
• Cyclic AMP metabolism   MeSH
• CD11b Antigen metabolism   MeSH
• Bordetella pertussis pathogenicity   MeSH
• Cell Membrane metabolism   MeSH
• Dendritic Cells immunology   MeSH
• Phagocytes immunology   MeSH
• Hemolysin Proteins metabolism   MeSH
• Macrophage-1 Antigen metabolism   MeSH
• Mice, Inbred BALB C MeSH
• Mice, Inbred C57BL MeSH
• Mice MeSH
• Whooping Cough microbiology   MeSH
• Lung microbiology   pathology   MeSH
• T-Lymphocytes immunology   MeSH
• Virulence MeSH
• Animals MeSH
• Check Tag
• Mice MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Adenylate Cyclase Toxin MeSH
• Cyclic AMP MeSH
• CD11b Antigen MeSH
• Hemolysin Proteins MeSH
• Macrophage-1 Antigen MeSH

Integrins are heterodimeric cell surface adhesion and signaling receptors that are essential for metazoan existence. Some integrins contain an I-domain that is a major ligand binding site. The ligands preferentially engage the active forms of the integrins and trigger signaling cascades that alter numerous cell functions. Here we found that the adenylate cyclase toxin (CyaA), a key virulence factor of the whooping cough agent Bordetella pertussis, preferentially binds an inactive form of the integrin complement receptor 3 (CR3), using a site outside of its I-domain. CyaA binding did not trigger downstream signaling of CR3 in human monocytes and CyaA-catalyzed elevation of cAMP effectively blocked CR3 signaling initiated by a natural ligand. This unprecedented type of integrin-ligand interaction distinguishes CyaA from all other known ligands of the I-domain-containing integrins and provides a mechanistic insight into the previously observed central role of CyaA in the pathogenesis of B. pertussis.

• Keywords
• E. coli, adenylate cyclase toxin, biochemistry, cAMP signaling, complement receptor 3, infectious disease, microbiology,
• MeSH
• Adenylate Cyclase Toxin metabolism   MeSH
• Bordetella pertussis pathogenicity   MeSH
• Cell Line MeSH
• Host-Pathogen Interactions * MeSH
• Cricetinae MeSH
• Humans MeSH
• Macrophage-1 Antigen metabolism   MeSH
• Protein Binding MeSH
• Animals MeSH
• Check Tag
• Cricetinae MeSH
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adenylate Cyclase Toxin MeSH
• Macrophage-1 Antigen MeSH

Adenylate cyclase toxin (CyaA) is a key virulence factor of the whooping cough agent Bordetella pertussis. The toxin targets CD11b-expressing phagocytes and delivers into their cytosol an adenylyl cyclase (AC) enzyme that subverts cellular signaling by increasing cAMP levels. In the present study, we analyzed the modulatory effects of CyaA on adhesive, migratory and antigen presenting properties of Toll-like receptor (TLR)-activated murine and human dendritic cells (DCs). cAMP signaling of CyaA enhanced TLR-induced dissolution of cell adhesive contacts and migration of DCs towards the lymph node-homing chemokines CCL19 and CCL21 in vitro. Moreover, we examined in detail the capacity of toxin-treated DCs to induce CD4(+) and CD8(+) T cell responses. Exposure to CyaA decreased the capacity of LPS-stimulated DCs to present soluble protein antigen to CD4+ T cells independently of modulation of co-stimulatory molecules and cytokine production, and enhanced their capacity to promote CD4(+)CD25(+)Foxp3(+) T regulatory cells in vitro. In addition, CyaA decreased the capacity of LPS-stimulated DCs to induce CD8(+) T cell proliferation and limited the induction of IFN-γ producing CD8(+) T cells while enhancing IL-10 and IL-17-production. These results indicate that through activation of cAMP signaling, the CyaA may be mobilizing DCs impaired in T cell stimulatory capacity and arrival of such DCs into draining lymph nodes may than contribute to delay and subversion of host immune responses during B. pertussis infection.

• MeSH
• Adenylate Cyclase Toxin pharmacology   MeSH
• Lymphocyte Activation drug effects   MeSH
• Bordetella pertussis chemistry   MeSH
• Cell Adhesion drug effects   MeSH
• Cell Death drug effects   MeSH
• Antigens, CD metabolism   MeSH
• CD8-Positive T-Lymphocytes cytology   drug effects   immunology   MeSH
• Dendritic Cells cytology   drug effects   immunology   MeSH
• Humans MeSH
• Mice, Inbred C57BL MeSH
• Cell Movement drug effects   MeSH
• Cell Proliferation drug effects   MeSH
• T-Lymphocytes, Regulatory drug effects   MeSH
• Solubility MeSH
• Toll-Like Receptors metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Adenylate Cyclase Toxin MeSH
• Antigens, CD MeSH
• Toll-Like Receptors MeSH