UNLABELLED: The adenylate cyclase toxin (ACT, AC-Hly, or CyaA) plays a key role in airway infections by Bordetella pertussis and ablates the oxidative burst and opsonophagocytic capacity of sentinel phagocytes. CyaA fragments eliciting toxin-neutralizing antibodies are considered prime antigen candidates for improved acellular pertussis (aP) vaccines but their contribution to aP-mediated protection against B. pertussis infection awaits demonstration. We explored whether hybrid antigens inducing simultaneously CyaA-neutralizing and anti-Prn opsonizing antibody responses can enhance aP-elicited protection of mouse airways from infection. Fusion to the N-terminus of an RTX908 antigen derived from CyaA enabled an accelerated folding of the pertactin passenger domain (rPrn) in function of calcium loading of the RTX908 moiety and conferred on the rPrn-RTX908 fusion antigen a superior capacity to induce functional anti-Prn IgG antibodies. The rPrn-RTX908 fusion antigen also elicited CyaA neutralizing anti-RTX antibodies that relieved the toxin-imposed inhibition of oxidative burst and opsonophagocytic uptake of B. pertussis bacteria by HL-60 cells exposed to physiological concentrations of the CyaA toxin. Intranasal immunization of mice with the rPrn-RTX908 antigen admixed into a PT and FHA-based aP vaccine elicited specific sIgA responses in mucosal secretions (saliva) and conferred a significantly enhanced protection of mouse lung and nose mucosa against B. pertussis infection, yielding a significantly accelerated clearance of bacteria from the infected lungs within a single day from infection. These results demonstrate the added value of anti-CyaA antibodies elicited by intranasal application of the rPrn-RTX908 fusion antigen in the protection of the airway against B. pertussis infection. IMPORTANCE: Despite high vaccine coverage, unexpectedly massive whooping cough outbreaks are currently resurging in the most developed countries using the acellular pertussis (aP) vaccine. Accelerated development of improved aP vaccines, conferring a more complete and longer-lasting protection of the airway from Bordetella pertussis infection, is sorely needed. The highly immunosuppressive RTX adenylate cyclase toxin (CyaA) was proposed as a prime antigen candidate for inclusion into improved aP vaccines. We show here that a soluble RTX-derived antigen fused to the major opsonizing antibody target pertactin (rPrn-RTX908 hybrid) elicits opsonizing and toxin-neutralizing antibody responses that relieve the CyaA-imposed block of bactericidal opsonophagocytic uptake capacities of sentinel phagocytes. Intranasal immunization with the rPrn-RTX908 hybrid antigen then enables a significantly accelerated clearance of B. pertussis bacteria from mouse lungs and superior protection of mouse nasal mucosa from bacterial infection. These results unravel the added value of RTX antigen inclusion into the next generation of aP vaccines.

• Klíčová slova
• Bordetella pertussis, adenylate cyclase toxin, pertactin, pertussis, protection, protein folding, whooping cough,
• MeSH
• adenylátcyklasový toxin * imunologie   genetika   aplikace a dávkování   MeSH
• antigeny bakteriální * imunologie   genetika   aplikace a dávkování   MeSH
• aplikace intranazální MeSH
• Bordetella pertussis * imunologie   genetika   MeSH
• faktory virulence rodu Bordetella * imunologie   genetika   aplikace a dávkování   MeSH
• lidé MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• neutralizující protilátky krev   imunologie   MeSH
• pertuse * prevence a kontrola   imunologie   mikrobiologie   MeSH
• pertusová vakcína * imunologie   aplikace a dávkování   genetika   MeSH
• proteiny vnější bakteriální membrány * imunologie   genetika   aplikace a dávkování   MeSH
• protilátky bakteriální krev   imunologie   MeSH
• rekombinantní fúzní proteiny imunologie   genetika   aplikace a dávkování   MeSH
• respirační sliznice * imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin * MeSH
• antigeny bakteriální * MeSH
• faktory virulence rodu Bordetella * MeSH
• neutralizující protilátky MeSH
• pertactin MeSH Prohlížeč
• pertusová vakcína * MeSH
• proteiny vnější bakteriální membrány * MeSH
• protilátky bakteriální MeSH
• rekombinantní fúzní proteiny MeSH

Bordetella pertussis infects human upper airways and deploys an array of immunosuppressive virulence factors, among which the adenylate cyclase toxin (CyaA) plays a prominent role in disarming host phagocytes. CyaA binds the complement receptor-3 (CR3 aka αMβ2 integrin CD11b/CD18 or Mac-1) of myeloid cells and delivers into their cytosol an adenylyl cyclase enzyme that hijacks cellular signaling through unregulated conversion of cytosolic ATP to cAMP. We found that the action of as little CyaA as 22 pM (4 ng/mL) blocks macrophage colony-stimulating factor (M-CSF)-driven transition of migratory human CD14+ monocytes into macrophages. Global transcriptional profiling (RNAseq) revealed that exposure of monocytes to 22 pM CyaA for 40 hours in culture with 20 ng/mL of M-CSF led to upregulation of genes that exert negative control of monocyte to macrophage differentiation (e.g., SERPINB2, DLL1, and CSNK1E). The sustained CyaA action yielded downregulation of numerous genes involved in processes crucial for host defense, such as myeloid cell differentiation, chemotaxis of inflammatory cells, antigen presentation, phagocytosis, and bactericidal activities. CyaA-elicited signaling also promoted deacetylation and trimethylation of lysines 9 and 27 of histone 3 (H3K9me3 and H3K27me3) and triggered the formation of transcriptionally repressive heterochromatin patches in the nuclei of CyaA-exposed monocytes. These effects were partly reversed by the G9a methyltransferase inhibitor UNC 0631 and by the pleiotropic HDAC inhibitor Trichostatin-A, revealing that CyaA-elicited epigenetic alterations mediate transcriptional reprogramming of monocytes and play a role in CyaA-triggered block of monocyte differentiation into bactericidal macrophage cells.IMPORTANCETo proliferate on host airway mucosa and evade elimination by patrolling sentinel cells, the whooping cough agent Bordetella pertussis produces a potently immunosubversive adenylate cyclase toxin (CyaA) that blocks opsonophagocytic killing of bacteria by phagocytes like neutrophils and macrophages. Indeed, chemotactic migration of CD14+ monocytes to the infection site and their transition into bactericidal macrophages, thus replenishing the exhausted mucosa-patrolling macrophages, represents one of the key mechanisms of innate immune defense to infection. We show that the cAMP signaling action of CyaA already at a very low toxin concentration triggers massive transcriptional reprogramming of monocytes that is accompanied by chromatin remodeling and epigenetic histone modifications, which block the transition of migratory monocytes into bactericidal macrophage cells. This reveals a novel layer of toxin action-mediated hijacking of functional differentiation of innate immune cells for the sake of mucosal pathogen proliferation and transmission to new hosts.

• Klíčová slova
• Bordetella pertussis, RTX toxins, cyclic AMP, differentiation, epigenetics, macrophages, monocytes,
• MeSH
• adenylátcyklasový toxin * metabolismus   MeSH
• Bordetella pertussis * patogenita   enzymologie   MeSH
• buněčná diferenciace * účinky léků   MeSH
• faktor stimulující kolonie makrofágů MeSH
• kultivované buňky MeSH
• lidé MeSH
• makrofágy * účinky léků   cytologie   MeSH
• monocyty * účinky léků   cytologie   fyziologie   MeSH
• přeprogramování buněk * MeSH
• restrukturace chromatinu * účinky léků   MeSH
• signální transdukce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin * MeSH
• faktor stimulující kolonie makrofágů MeSH

Bordetella pertussis infects the upper airways of humans and disarms host defense by the potent immuno-subversive activities of its pertussis (PT) and adenylate cyclase (CyaA) toxins. CyaA action near-instantly ablates the bactericidal activities of sentinel CR3-expressing myeloid phagocytes by hijacking cellular signaling pathways through the unregulated production of cAMP. Moreover, CyaA-elicited cAMP signaling also inhibits the macrophage colony-stimulating factor (M-CSF)-induced differentiation of incoming inflammatory monocytes into bactericidal macrophages. We show that CyaA/cAMP signaling via protein kinase A (PKA) downregulates the M-CSF-elicited expression of monocyte receptors for transferrin (CD71) and hemoglobin-haptoglobin (CD163), as well as the expression of heme oxygenase-1 (HO-1) involved in iron liberation from internalized heme. The impact of CyaA action on CD71 and CD163 levels in differentiating monocytes is largely alleviated by the histone deacetylase inhibitor trichostatin A (TSA), indicating that CyaA/cAMP signaling triggers epigenetic silencing of genes for micronutrient acquisition receptors. These results suggest a new mechanism by which B. pertussis evades host sentinel phagocytes to achieve proliferation on airway mucosa.IMPORTANCETo establish a productive infection of the nasopharyngeal mucosa and proliferate to sufficiently high numbers that trigger rhinitis and aerosol-mediated transmission, the pertussis agent Bordetella pertussis deploys several immunosuppressive protein toxins that compromise the sentinel functions of mucosa patrolling phagocytes. We show that cAMP signaling elicited by very low concentrations (22 pM) of Bordetella adenylate cyclase toxin downregulates the iron acquisition systems of CD14+ monocytes. The resulting iron deprivation of iron, a key micronutrient, then represents an additional aspect of CyaA toxin action involved in the inhibition of differentiation of monocytes into the enlarged bactericidal macrophage cells. This corroborates the newly discovered paradigm of host defense evasion mechanisms employed by bacterial pathogens, where manipulation of cellular cAMP levels blocks monocyte to macrophage transition and replenishment of exhausted phagocytes, thereby contributing to the formation of a safe niche for pathogen proliferation and dissemination.

• Klíčová slova
• Bordetella pertussis, adenylate cyclase toxin, cyclic AMP, differentiation, iron acquisition, macrophages, monocytes,
• MeSH
• adenylátcyklasový toxin * metabolismus   genetika   MeSH
• AMP cyklický * metabolismus   MeSH
• antigen CD163 MeSH
• antigeny diferenciační myelomonocytární MeSH
• Bordetella pertussis * MeSH
• buněčná diferenciace * MeSH
• CD antigeny metabolismus   genetika   MeSH
• lidé MeSH
• lipopolysacharidové receptory * metabolismus   MeSH
• monocyty * metabolismus   imunologie   mikrobiologie   MeSH
• proteinkinasy závislé na cyklickém AMP metabolismus   MeSH
• receptory buněčného povrchu metabolismus   genetika   MeSH
• signální transdukce * MeSH
• upregulace MeSH
• železo metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin * MeSH
• AMP cyklický * MeSH
• antigen CD163 MeSH
• antigeny diferenciační myelomonocytární MeSH
• CD antigeny MeSH
• CD14 protein, human MeSH Prohlížeč
• lipopolysacharidové receptory * MeSH
• proteinkinasy závislé na cyklickém AMP MeSH
• receptory buněčného povrchu MeSH
• železo MeSH

The adenylate cyclase (ACT) and the pertussis (PT) toxins of Bordetella pertussis exert potent immunomodulatory activities that synergize to suppress host defense in the course of whooping cough pathogenesis. We compared the mouse lung infection capacities of B. pertussis (Bp) mutants (Bp AC- or Bp PT-) producing enzymatically inactive toxoids and confirm that ACT action is required for maximal bacterial proliferation in the first days of infection, whereas PT action is crucial for persistence of B. pertussis in mouse lungs. Despite accelerated and near complete clearance from the lungs by day 14 of infection, the PT- bacteria accumulated within the lymphoid tissue of lung-draining mediastinal lymph nodes (mLNs). In contrast, the wild type or AC- bacteria colonized the lungs but did not enter into mLNs. Lung infection by the PT- mutant triggered an early arrival of migratory conventional dendritic cells with associated bacteria into mLNs, where the PT- bacteria entered the T cell-rich paracortex of mLNs by day 5 and proliferated in clusters within the B-cell zone (cortex) of mLNs by day 14, being eventually phagocytosed by infiltrating neutrophils. Finally, only infection by the PT- bacteria triggered an early production of anti-B. pertussis serum IgG antibodies already within 14 days of infection. These results reveal that action of the pertussis toxin blocks DC-mediated delivery of B. pertussis bacteria into mLNs and prevents bacterial colonization of mLNs, thus hampering early adaptive immune response to B. pertussis infection.

• MeSH
• Bordetella pertussis * MeSH
• dendritické buňky patologie   MeSH
• lymfatické uzliny patologie   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• pertuse * MeSH
• pertusový toxin MeSH
• plíce MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• pertusový toxin MeSH

Pulmonary infections caused by Bordetella pertussis used to be the prime cause of infant mortality in the pre-vaccine era and mouse models of pertussis pneumonia served in characterization of B. pertussis virulence mechanisms. However, the biologically most relevant catarrhal disease stage and B. pertussis transmission has not been adequately reproduced in adult mice due to limited proliferation of the human-adapted pathogen on murine nasopharyngeal mucosa. We used immunodeficient C57BL/6J MyD88 KO mice to achieve B. pertussis proliferation to human-like high counts of 108 viable bacteria per nasal cavity to elicit rhinosinusitis accompanied by robust shedding and transmission of B. pertussis bacteria to adult co-housed MyD88 KO mice. Experiments with a comprehensive set of B. pertussis mutants revealed that pertussis toxin, adenylate cyclase toxin-hemolysin, the T3SS effector BteA/BopC and several other known virulence factors were dispensable for nasal cavity infection and B. pertussis transmission in the immunocompromised MyD88 KO mice. In contrast, mutants lacking the filamentous hemagglutinin (FhaB) or fimbriae (Fim) adhesins infected the nasal cavity poorly, shed at low levels and failed to productively infect co-housed MyD88 KO or C57BL/6J mice. FhaB and fimbriae thus appear to play a critical role in B. pertussis transmission. The here-described novel murine model of B. pertussis-induced nasal catarrh opens the way to genetic dissection of host mechanisms involved in B. pertussis shedding and to validation of key bacterial transmission factors that ought to be targeted by future pertussis vaccines.

• MeSH
• adenylátcyklasový toxin MeSH
• bakteriální adheziny * metabolismus   MeSH
• Bordetella pertussis * genetika   MeSH
• faktory virulence rodu Bordetella genetika   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myeloidní diferenciační faktor 88 MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nosní dutina mikrobiologie   MeSH
• pertuse * přenos   MeSH
• pertusová vakcína MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• bakteriální adheziny * MeSH
• faktory virulence rodu Bordetella MeSH
• myeloidní diferenciační faktor 88 MeSH
• pertusová vakcína MeSH

The whooping cough agent, Bordetella pertussis, secretes an adenylate cyclase toxin-hemolysin (CyaA, ACT, or AC-Hly) that catalyzes the conversion of intracellular ATP to cAMP and through its signaling annihilates the bactericidal activities of host sentinel phagocytes. In parallel, CyaA permeabilizes host cells by the formation of cation-selective membrane pores that account for the hemolytic activity of CyaA. The pore-forming activity contributes to the overall cytotoxic effect of CyaA in vitro, and it has previously been proposed to synergize with the cAMP-elevating activity in conferring full virulence on B. pertussis in the mouse model of pneumonic infection. CyaA primarily targets myeloid phagocytes through binding of their complement receptor 3 (CR3, integrin αMβ2, or CD11b/CD18). However, with a reduced efficacy, the toxin can promiscuously penetrate and permeabilize the cell membrane of a variety of non-myeloid cells that lack CR3 on the cell surface, including airway epithelial cells or erythrocytes, and detectably intoxicates them by cAMP. Here, we used CyaA variants with strongly and selectively enhanced or reduced pore-forming activity that, at the same time, exhibited a full capacity to elevate cAMP concentrations in both CR3-expressing and CR3-non-expressing target cells. Using B. pertussis mutants secreting such CyaA variants, we show that a selective enhancement of the cell-permeabilizing activity of CyaA does not increase the overall virulence and lethality of pneumonic B. pertussis infection of mice any further. In turn, a reduction of the cell-permeabilizing activity of CyaA did not reduce B. pertussis virulence any importantly. These results suggest that the phagocyte-paralyzing cAMP-elevating capacity of CyaA prevails over the cell-permeabilizing activity of CyaA that appears to play an auxiliary role in the biological activity of the CyaA toxin in the course of B. pertussis infections in vivo.

• Klíčová slova
• Bordetella pertussis, RTX toxin, adenylate cyclase toxin, cAMP intoxication, lung colonization, lung inflammation, pore-forming activity, virulence,
• MeSH
• adenylátcyklasový toxin metabolismus   MeSH
• AMP cyklický metabolismus   MeSH
• Bordetella pertussis patogenita   fyziologie   MeSH
• fagocyty metabolismus   mikrobiologie   MeSH
• interakce hostitele a patogenu MeSH
• lidé MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• ovce MeSH
• permeabilita buněčné membrány MeSH
• pertuse metabolismus   mikrobiologie   patologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• AMP cyklický MeSH

The mucus layer protects airway epithelia from damage by noxious agents. Intriguingly, Bordetella pertussis bacteria provoke massive mucus production by nasopharyngeal epithelia during the initial coryza-like catarrhal stage of human pertussis and the pathogen transmits in mucus-containing aerosol droplets expelled by sneezing and post-nasal drip-triggered cough. We investigated the role of the cAMP-elevating adenylate cyclase (CyaA) and pertussis (PT) toxins in the upregulation of mucin production in B. pertussis-infected airway epithelia. Using human pseudostratified airway epithelial cell layers cultured at air-liquid interface (ALI), we show that purified CyaA and PT toxins (100 ng/mL) can trigger production of the major airway mucins Muc5AC and Muc5B. Upregulation of mucin secretion involved activation of the cAMP response element binding protein (CREB) and was blocked by the 666-15-Calbiochem inhibitor of CREB-mediated gene transcription. Intriguingly, a B. pertussis mutant strain secreting only active PT and producing the enzymatically inactive CyaA-AC- toxoid failed to trigger any important mucus production in infected epithelial cell layers in vitro or in vivo in the tracheal epithelia of intranasally infected mice. In contrast, the PT- toxoid-producing B. pertussis mutant secreting the active CyaA toxin elicited a comparable mucin production as infection of epithelial cell layers or tracheal epithelia of infected mice by the wild-type B. pertussis secreting both PT and CyaA toxins. Hence, the cAMP-elevating activity of B. pertussis-secreted CyaA was alone sufficient for activation of mucin production through a CREB-dependent mechanism in B. pertussis-infected airway epithelia in vivo.

• Klíčová slova
• Bordetella, CREB, adenylate cyclase toxin, cAMP, epithelium, mucin, pertussis toxin,
• MeSH
• adenylátcyklasový toxin toxicita   MeSH
• Bordetella pertussis metabolismus   patogenita   MeSH
• buněčné linie MeSH
• dýchací soustava metabolismus   mikrobiologie   MeSH
• epitelové buňky metabolismus   mikrobiologie   MeSH
• lidé MeSH
• mucin 5AC metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• pertuse metabolismus   mikrobiologie   MeSH
• protein vázající cAMP responzivní element metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• mucin 5AC MeSH
• protein vázající cAMP responzivní element MeSH

Bordetella pertussis whole-cell vaccines (wP) caused a spectacular drop of global pertussis incidence, but since the replacement of wP with acellular pertussis vaccines (aP), pertussis has resurged in developed countries within 7 to 12 years of the change from wP to aP. In the mouse infection model, we examined whether addition of further protective antigens into the aP vaccine, such as type 2 and type 3 fimbriae (FIM2/3) with outer membrane lipooligosaccharide (LOS) and/or of the adenylate cyclase toxoid (dACT), which elicits antibodies neutralizing the CyaA toxin, could enhance the capacity of the aP vaccine to prevent colonization of the nasal mucosa by B. pertussis. The addition of the toxoid and of the opsonizing antibody-inducing agglutinogens modestly enhanced the already high capacity of intraperitoneally-administered aP vaccine to elicit sterilizing immunity, protecting mouse lungs from B. pertussis infection. At the same time, irrespective of FIM2/3 with LOS and dACT addition, the aP vaccination ablated the natural capacity of BALB/c mice to clear B. pertussis infection from the nasal cavity. While wP or sham-vaccinated animals cleared the nasal infection with similar kinetics within 7 weeks, administration of the aP vaccine promoted persistent colonization of mouse nasal mucosa by B. pertussis.

• Klíčová slova
• Bordetella pertussis, nasal colonization, vaccines, whooping cough,
• Publikační typ
• časopisecké články MeSH

Circulating inflammatory monocytes are attracted to infected mucosa and differentiate into macrophage or dendritic cells endowed with enhanced bactericidal and antigen presenting capacities. In this brief Perspective we discuss the newly emerging insight into how the cAMP signaling capacity of Bordetella pertussis adenylate cyclase toxin manipulates the differentiation of monocytes and trigger dedifferentiation of the alveolar macrophages to facilitate bacterial colonization of human airways.

• Klíčová slova
• Bordetella pertussis, adenylate cyclase toxin, dedifferentiation, macrophages, monocytes,
• MeSH
• adenylátcyklasový toxin farmakologie   fyziologie   MeSH
• alveolární makrofágy cytologie   účinky léků   MeSH
• AMP cyklický fyziologie   MeSH
• biologické modely MeSH
• Bordetella pertussis fyziologie   MeSH
• buněčná diferenciace MeSH
• dediferenciace buněk účinky léků   MeSH
• dýchací soustava účinky léků   imunologie   mikrobiologie   MeSH
• fagocytóza MeSH
• interakce hostitele a patogenu imunologie   MeSH
• lidé MeSH
• monocyty cytologie   účinky léků   MeSH
• myši MeSH
• prezentace antigenu účinky léků   MeSH
• přirozená imunita účinky léků   MeSH
• slizniční imunita účinky léků   MeSH
• systémy druhého messengeru účinky léků   fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• AMP cyklický MeSH

The Bordetella adenylate cyclase toxin-hemolysin (CyaA) and the α-hemolysin (HlyA) of Escherichia coli belong to the family of cytolytic pore-forming Repeats in ToXin (RTX) cytotoxins. HlyA preferentially binds the αLβ2 integrin LFA-1 (CD11a/CD18) of leukocytes and can promiscuously bind and also permeabilize many other cells. CyaA bears an N-terminal adenylyl cyclase (AC) domain linked to a pore-forming RTX cytolysin (Hly) moiety, binds the complement receptor 3 (CR3, αMβ2, CD11b/CD18, or Mac-1) of myeloid phagocytes, penetrates their plasma membrane, and delivers the AC enzyme into the cytosol. We constructed a set of CyaA/HlyA chimeras and show that the CyaC-acylated segment and the CR3-binding RTX domain of CyaA can be functionally replaced by the HlyC-acylated segment and the much shorter RTX domain of HlyA. Instead of binding CR3, a CyaA1-710/HlyA411-1024 chimera bound the LFA-1 receptor and effectively delivered AC into Jurkat T cells. At high chimera concentrations (25 nm), the interaction with LFA-1 was not required for CyaA1-710/HlyA411-1024 binding to CHO cells. However, interaction with the LFA-1 receptor strongly enhanced the specific capacity of the bound CyaA1-710/HlyA411-1024 chimera to penetrate cells and deliver the AC enzyme into their cytosol. Hence, interaction of the acylated segment and/or the RTX domain of HlyA with LFA-1 promoted a productive membrane interaction of the chimera. These results help delimit residues 400-710 of CyaA as an "AC translocon" sufficient for translocation of the AC polypeptide across the plasma membrane of target cells.

• Klíčová slova
• AC domain translocation, AC translocon, Bordetella pertussis, CyaA, Escherichia coli (E. coli), HlyA, RTX toxin, acylation, acyltransferase, bacterial toxin, complement receptor 3 (CR3,), fatty acid, fatty acyl, integrin, protein acylation, protein translocation,
• MeSH
• adenylátcyklasový toxin metabolismus   MeSH
• antigen-1 spojený s lymfocytární funkcí metabolismus   MeSH
• Bordetella * MeSH
• CHO buňky MeSH
• Cricetulus MeSH
• cytosol metabolismus   MeSH
• Jurkat buňky MeSH
• lidé MeSH
• makrofágový antigen 1 metabolismus   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• THP-1 buňky MeSH
• transport proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenylátcyklasový toxin MeSH
• antigen-1 spojený s lymfocytární funkcí MeSH
• makrofágový antigen 1 MeSH