Insertion sequences (IS) represent mobile genetic elements that have been shown to be associated with bacterial evolution and adaptation due to their effects on genome plasticity. In Bordetella pertussis, the causative agent of whooping cough, the numerous IS elements induce genomic rearrangements and contribute to the diversity of the global B. pertussis population. Previously, we have shown that the majority of IS-specific endogenous promoters induce the synthesis of alternative transcripts and thereby affect the transcriptional landscape of B. pertussis. Here, we describe the regulatory RNA Rfi2, which is transcribed from the Pout promoter of the IS481 gene BP1118 antisense to the adjacent fim2 gene encoding the major serotype 2 fimbrial subunit of B. pertussis. Among the classical bordetellae, Rfi2 is unique to B. pertussis, suggesting its specific role in virulence. We show that Rfi2 RNA attenuates fim2 transcription and, consequently, the production of the Fim2 protein. Interestingly, the mutant that does not produce Rfi2 displayed significantly increased cytotoxicity towards human macrophages compared to the parental strain. This observation suggests that the Rfi2-mediated reduction in cytotoxicity represents an evolutionary adaptation of B. pertussis that fine-tunes its interaction with the human host. Given the immunogenicity of Fim2, we further hypothesize that Rfi2-mediated modulation of Fim2 production contributes to immune evasion. To our knowledge, Rfi2 represents the first functionally characterized IS element-driven antisense RNA that modulates the expression of a virulence gene.

• Klíčová slova
• Bordetella pertussis, antisense RNA, cytotoxicity towards macrophages, fimbriae serotype 2, insertion sequence, modulation of virulence,
• MeSH
• antigeny bakteriální MeSH
• antisense RNA * genetika   metabolismus   MeSH
• bakteriální fimbrie * genetika   metabolismus   MeSH
• Bordetella pertussis * genetika   patogenita   metabolismus   MeSH
• faktory virulence rodu Bordetella genetika   MeSH
• lidé MeSH
• makrofágy mikrobiologie   MeSH
• pertuse mikrobiologie   MeSH
• promotorové oblasti (genetika) MeSH
• proteiny fimbrií * genetika   metabolismus   MeSH
• regulace genové exprese u bakterií * MeSH
• séroskupina MeSH
• transpozibilní elementy DNA * MeSH
• virulence MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny bakteriální MeSH
• antisense RNA * MeSH
• faktory virulence rodu Bordetella MeSH
• fim2 protein, Bordetella MeSH Prohlížeč
• proteiny fimbrií * MeSH
• transpozibilní elementy DNA * MeSH

BACKGROUND: Bordetella pertussis isolates which do not express some of acellular pertussis vaccine (aPv) antigens, e.g. pertactin (PRN), have been increasingly reported in countries using aPvs. In Finland, primary pertussis vaccination with whole-cell vaccine was replaced by aPv containing pertussis toxin (PT) and filamentous hemagglutinin (FHA) in 2005 and then by aPv containing PT, FHA, and PRN in 2009. We aimed to study alterations in the expression of FHA, PRN, and PT, three antigens included in aPvs and adenylate cyclase toxin (ACT) not included in current aPvs, among Finnish isolates collected during 1991-2020. METHODS: Of 904 isolates collected by the Finnish Reference Laboratory for Pertussis during 1991-2020, 302 were randomly included. An adapted, monoclonal antibody based, antigen expression ELISA, including the culture of B. pertussis in Stainer-Scholte medium, was performed to quantify the expression of ACT, FHA, PRN, and PT of each isolate. ACT activity was also measured for 16 isolates. Arbitrary units were used for comparing levels of each antigen expression of isolates grouped in every five years. FINDINGS: Following the implementation of aPv in 2005, B. pertussis isolates exhibited a 1.75-fold increase for FHA (p < 0.001) and a 1.5-fold increase for ACT (p < 0.0041) expression until 2020. No FHA or ACT deficient isolates were detected. As the number of PRN deficient isolates has significantly increased with the time, the amount of PRN produced by the positive isolates has also started to decrease, especially after the use of aPv containing PRN. During this period, fluctuations in PT expression were observed. INTERPRETATION: The study demonstrated that in response to aPv-induced selection pressure, different types of selection of B. pertussis has occurred. For FHA and ACT, a steady increase in their production is observed, whereas the frequency of PRN deficient isolates is increased with time.

• Klíčová slova
• Acellular pertussis vaccine, Antigen expression, Bordetella pertussis, Resurgence of pertussis,
• MeSH
• acelulární vakcíny imunologie   MeSH
• adenylátcyklasový toxin imunologie   MeSH
• antigeny bakteriální * imunologie   MeSH
• bakteriální adheziny MeSH
• Bordetella pertussis * imunologie   izolace a purifikace   MeSH
• ELISA MeSH
• faktory virulence rodu Bordetella imunologie   MeSH
• lidé MeSH
• pertuse * prevence a kontrola   imunologie   mikrobiologie   MeSH
• pertusová vakcína * imunologie   aplikace a dávkování   MeSH
• pertusový toxin imunologie   MeSH
• proteiny vnější bakteriální membrány imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Finsko MeSH
• Názvy látek
• acelulární vakcíny MeSH
• adenylátcyklasový toxin MeSH
• antigeny bakteriální * MeSH
• bakteriální adheziny MeSH
• faktory virulence rodu Bordetella MeSH
• filamentous hemagglutinin adhesin, Bordetella pertussis MeSH Prohlížeč
• pertactin MeSH Prohlížeč
• pertusová vakcína * MeSH
• pertusový toxin MeSH
• proteiny vnější bakteriální membrány MeSH

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

Pertussis resurged over the last decade in most countries that replaced the traditional whole-cell pertussis vaccines (wP) by the less reactogenic acellular pertussis vaccines (aP). The aP vaccines induce a Th2-polarized immune response and by a yet unknown mechanism hamper the clearance of Bordetella pertussis from infected nasopharyngeal mucosa. The aP-induced pertussis toxin-neutralizing antibodies effectively prevent the life-threatening pertussis pneumonia in infants, but aP-elicited immunity fails to prevent infection of nasopharyngeal mucosa and transmission of B. pertussis. In contrast, the more reactogenic traditional wP vaccines, alike natural infection, elicit a broad antibody response and trigger a Th1/Th17-polarized T cell immunity. We tackled here the reactogenicity of the conventional wP vaccines by genetic modification of the Fim2 and Fim3-producing B. pertussis strains used for wP vaccine manufacturing. Mutations were introduced into the genomes of vaccine strains (i) to reduce the TLR4 signaling potency of the lipid A of B. pertussis lipooligosaccharide (ΔlgmB), (ii) eliminate the enzymatic (immunosuppressive) activity of the pertussis toxin (PtxS1-R9K/E129G), and (iii) ablate the production of the dermonecrotic toxin (Δdnt). Experimental alum-adjuvanted wP vaccines prepared from such triply modified bacteria exhibited a reduced pyrogenicity in rabbits and a reduced systemic toxicity in mice, while conferring a comparable protection from B. pertussis infection as the unmodified wP vaccine.IMPORTANCEThe occasionally severe adverse reactions associated with some lots of the whole-cell pertussis vaccine (wP) led the industrialized nations to switch to the use of less reactogenic acellular pertussis vaccines that confer shorter-lasting protection. This yielded whooping cough resurgence and large whooping cough outbreaks are currently sweeping throughout European countries, calling for the replacement of the pertussis vaccine component of pediatric hexavaccines by an improved wP vaccine. We show that genetic detoxification of the Bordetella pertussis bacteria used for wP preparation yields a reduced reactogenicity wP vaccine that exhibits a reduced systemic toxicity in mice and reduced pyrogenicity in rabbits, while retaining high immunogenicity and protective potency in the mouse model of pneumonic infection by B. pertussis. This result has now been confirmed in a nonhuman primate model of B. pertussis infection of olive baboons, paving the way for the development of the next generation of pertussis vaccines.

• Klíčová slova
• Bordetella pertussis, dermonecrotic toxin, immunogenicity, lipooligosaccharide, pertussis toxin, protection, reactogenicity, whole-cell vaccine, whooping cough,
• MeSH
• antigeny bakteriální MeSH
• Bordetella pertussis * imunologie   genetika   MeSH
• faktory virulence rodu Bordetella genetika   imunologie   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• pertuse * prevence a kontrola   imunologie   MeSH
• pertusová vakcína * imunologie   genetika   aplikace a dávkování   MeSH
• proteiny fimbrií genetika   imunologie   MeSH
• protilátky bakteriální krev   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny bakteriální MeSH
• faktory virulence rodu Bordetella MeSH
• fim2 protein, Bordetella MeSH Prohlížeč
• fim3 protein, Bordetella MeSH Prohlížeč
• pertusová vakcína * MeSH
• proteiny fimbrií MeSH
• protilátky bakteriální 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 is the causative agent of whooping cough in humans, a disease that has recently experienced a resurgence. In contrast, Bordetella bronchiseptica infects the respiratory tract of various mammalian species, causing a range of symptoms from asymptomatic chronic carriage to acute illness. Both pathogens utilize type III secretion system (T3SS) to deliver the effector protein BteA into host cells. Once injected, BteA triggers a cascade of events leading to caspase 1-independent necrosis through a mechanism that remains incompletely understood. We demonstrate that BteA-induced cell death is characterized by the fragmentation of the cellular endoplasmic reticulum and mitochondria, the formation of necrotic balloon-like protrusions, and plasma membrane permeabilization. Importantly, genome-wide CRISPR-Cas9 screen targeting 19,050 genes failed to identify any host factors required for BteA cytotoxicity, suggesting that BteA does not require a single nonessential host factor for its cytotoxicity. We further reveal that BteA triggers a rapid and sustained influx of calcium ions, which is associated with organelle fragmentation and plasma membrane permeabilization. The sustained elevation of cytosolic Ca2+ levels results in mitochondrial calcium overload, mitochondrial swelling, cristolysis, and loss of mitochondrial membrane potential. Inhibition of calcium channels with 2-APB delays both the Ca2+ influx and BteA-induced cell death. Our findings indicate that BteA exploits essential host processes and/or redundant pathways to disrupt calcium homeostasis and mitochondrial function, ultimately leading to host cell death.IMPORTANCEThe respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica exhibit cytotoxicity toward a variety of mammalian cells, which depends on the type III secretion effector BteA. Moreover, the increased virulence of B. bronchiseptica is associated with enhanced expression of T3SS and BteA. However, the molecular mechanism underlying BteA cytotoxicity is elusive. In this study, we performed a CRISPR-Cas9 screen, revealing that BteA-induced cell death depends on essential or redundant host processes. Additionally, we demonstrate that BteA disrupts calcium homeostasis, which leads to mitochondrial dysfunction and cell death. These findings contribute to closing the gap in our understanding of the signaling cascades targeted by BteA.

• Klíčová slova
• Bordetella, calcium homeostasis, effector protein BteA, host cell death mechanism, type III secretion system (T3SS),
• MeSH
• bakteriální proteiny * metabolismus   genetika   MeSH
• Bordetella bronchiseptica genetika   metabolismus   účinky léků   MeSH
• Bordetella pertussis genetika   patogenita   metabolismus   účinky léků   MeSH
• buněčná smrt * účinky léků   MeSH
• endoplazmatické retikulum metabolismus   účinky léků   MeSH
• homeostáza * MeSH
• interakce hostitele a patogenu MeSH
• lidé MeSH
• mitochondrie metabolismus   účinky léků   MeSH
• sekreční systém typu III metabolismus   genetika   MeSH
• vápník * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny * MeSH
• sekreční systém typu III MeSH
• vápník * MeSH

Whole-cell pertussis (wP) vaccines introduced in the 1940s led to a dramatic reduction of pertussis incidence and are still widely used in low- and middle-income countries (LMICs) worldwide. The reactogenicity of wP vaccines resulted in reduced public acceptance, which drove the development and introduction of acellular pertussis (aP) vaccines in high-income countries in the 1990s. Increased incidence of pertussis disease has been observed in high-income countries following the introduction of aP vaccines despite near universal rates of pediatric vaccination. These increases are attributed to the reduced protection against colonization, carriage, and transmission as well as reduced duration of immunity conferred by aP vaccines relative to the wP vaccines they replaced. A reduced reactogenicity whole-cell pertussis (RRwP) vaccine was recently developed with the goal of achieving the same protection as conferred by wP vaccination but with an improved safety profile, which may benefit countries in which wP vaccines are still in routine use. In this study, we tested the RRwP vaccine in a baboon model of pertussis infection. We found that the RRwP vaccine induced comparable cellular and humoral immune responses and comparable protection following challenge relative to the wP vaccine, while significantly reducing injection-site reactogenicity.IMPORTANCEThe World Health Organization (WHO) recommended in 2015 that countries administering wP vaccines in their national vaccine programs should continue to do so, and that switching to aP vaccines for primary infant immunization should only be considered if periodic booster vaccinations and/or maternal immunization could be assured and sustained in their national immunization schedules (WHO, Vaccine 34:1423-1425, 2016, https://doi.org/10.1016/j.vaccine.2015.10.136). Due to the considerably higher cost of aP vaccines and the larger number of doses required, most LMICs continue to use wP vaccines. The development and introduction of a wP vaccine that induces fewer adverse events without sacrificing protection would significantly benefit countries in which wP vaccines are still in routine use. The results of this study indicate this desirable goal may be achievable.

• Klíčová slova
• baboon model, pertussis, whole cell vaccines,
• MeSH
• Bordetella pertussis imunologie   MeSH
• modely nemocí na zvířatech MeSH
• Papio * imunologie   MeSH
• pertuse * prevence a kontrola   imunologie   MeSH
• pertusová vakcína * imunologie   aplikace a dávkování   MeSH
• protilátky bakteriální krev   MeSH
• vakcinace MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• pertusová vakcína * MeSH
• protilátky bakteriální MeSH

BACKGROUND: Pertussis, also known as whooping cough, is an acute respiratory illness primarily caused by Bordetella pertussis. Highly contagious, it poses significant morbidity and mortality risks, especially in infants. Despite widespread vaccination efforts, pertussis cases have recently resurged globally. This case report details possible complication in a 48-year-old woman, involving a cough-induced rib fracture and recurrent pneumothorax, highlighting the need for considering pertussis in patients with severe cough and back pain. CASE PRESENTATION: A 48-year-old female non-smoker with hypertension, treated with ACE inhibitor (perindopril), presented with a runny nose, productive cough, and back pain. Initial treatment for a common cold provided temporary relief. However, her symptoms worsened, and further examination revealed a fractured rib, pneumothorax, and subcutaneous emphysema. Laboratory tests confirmed elevated Bordetella pertussis toxin antibodies. She was treated with antibiotics, and despite recurrent symptoms, a conservative management approach was successful. Follow-up indicated resolution of symptoms, but significant anxiety related to her condition. CONCLUSION: This case emphasises the importance of considering pertussis in adults, as early symptoms resembling a common cold can lead to misdiagnosis. It also highlights the potential for significant musculoskeletal and pulmonary injuries due to intense coughing associated with pertussis. Prompt diagnosis and comprehensive management, including antibiotics and supportive care, are essential for favorable outcomes.

• Klíčová slova
• Back pain, Cough, Pertussis, Pneumothorax, Rib fracture,
• MeSH
• antibakteriální látky terapeutické užití   MeSH
• Bordetella pertussis izolace a purifikace   MeSH
• fraktury žeber * komplikace   MeSH
• kašel etiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• pertuse * komplikace   farmakoterapie   MeSH
• pneumotorax * etiologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• antibakteriální látky MeSH

BACKGROUND: Bordetella pertussis continues to cause whooping cough globally even in countries with high immunisation coverage. Booster vaccinations with acellular pertussis vaccines are thus used in children, adolescents, and adults. T cell immunity is crucial for orchestrating the immune response after vaccination. However, T cell assays can be expensive and difficult to implement in large clinical trials. In this study, a whole blood (WB) stimulation assay was developed to identify secreted T cell associated cytokines in different age groups after acellular pertussis booster vaccination. MATERIAL AND METHODS: Longitudinal WB samples were collected from a small set of subjects (n = 38) aged 7-70 years participating in a larger ongoing clinical trial. For assay development, samples were diluted and incubated with purified inactivated pertussis toxin (PT), filamentous haemagglutinin (FHA), inactivated B. pertussis lysate, and complete medium (M) as stimulating conditions, with anti-CD28 and anti-CD49d as co-stimulants. Different timepoints around the vaccination (D0, D7, D14, D28), WB dilution factor (1:2, 1:4) and incubation time (24 h, 48 h, 72 h) were compared. Responses to 15 cytokines were tested with Luminex/multiplex immunoassay. RESULTS: The optimized assay consisted of WB incubation with M, PT, and FHA (including the two co-stimulants). After 48 h incubation, supernatants were collected for measurement of seven selected T cell associated cytokines (IL-2, IL-5, IL-10, IL-13, IL-17 A, IL-17F, and IFN-y) from samples before and 28 days after vaccination. PT stimulation showed a trend for upregulation of IL-2, IL-13, and IL-17 A/F for adult subjects, whereas the responses of all cytokines were downregulated for the paediatric subjects. Furthermore, PT and FHA-stimulated WB showed diverse cytokine producing profiles. CONCLUSIONS: The developed WB-based cytokine assay was shown to be less costly, easy to perform, and functional in differently aged individuals. Further, it requires only a small amount of fresh blood, which is beneficial especially for studies including infants. Our results support the use of this assay for other immunological studies in the future.

• Klíčová slova
• Bordetella pertussis, Cytokines, Filamentous hemagglutinin, Pertussis toxin, Vaccination, Whole blood,
• MeSH
• antigeny bakteriální * imunologie   MeSH
• Bordetella pertussis * imunologie   MeSH
• cytokiny * krev   imunologie   MeSH
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pertuse * imunologie   krev   prevence a kontrola   MeSH
• pertusová vakcína * imunologie   aplikace a dávkování   MeSH
• sekundární imunizace MeSH
• senioři MeSH
• T-lymfocyty * imunologie   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny bakteriální * MeSH
• cytokiny * MeSH
• pertusová vakcína * 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