In Glässer's disease outbreaks, Glaesserella (Haemophilus) parasuis has to overcome the non-specific immune system in the lower respiratory tract, the alveolar macrophages. Here we showed that porcine alveolar macrophages (PAMs) were able to recognize and phagocyte G. parasuis with strain-to-strain variability despite the presence of the capsule in virulent (serovar 1, 5, 12) as well in avirulent strains (serovar 6 and 9). The capsule, outer membrane proteins, virulence-associated autotransporters, cytolethal distending toxins and many other proteins have been identified as virulence factors of this bacterium. Therefore, we immunized pigs with the crude capsular extract (cCE) from the virulent G. parasuis CAPM 6475 strain (serovar 5) and evaluated the role of the anti-cCE/post-vaccinal IgG in the immune response of PAMs to in vitro infection with various G. parasuis strains. We demonstrated the specific binding of the antibodies to the cCE by Western-blotting assay and immunoprecipitation as well as the specific binding to the strain CAPM 6475 in transmission electron microscopy. In the cCE, we identified several virulence-associated proteins that were immunoreactive with IgG isolated from sera of immunized pigs. Opsonization of G. parasuis strains by post-vaccinal IgG led to enhanced phagocytosis of G. parasuis by PAMs at the first two hours of infection. Moreover, opsonization increased the oxidative burst and expression/production of both pro- and anti-inflammatory cytokines. The neutralizing effects of these antibodies on the antioxidant mechanisms of G. parasuis may lead to attenuation of its virulence and pathogenicity in vivo. Together with opsonization of bacteria by these antibodies, the host may eliminate G. parasuis in the infection site more efficiently. Based on these results, the crude capsular extract is a vaccine candidate with immunogenic properties.

• MeSH
• alveolární makrofágy imunologie   metabolismus   mikrobiologie   MeSH
• antigeny bakteriální imunologie   MeSH
• bakteriální pouzdra imunologie   MeSH
• fagocytóza MeSH
• Haemophilus parasuis imunologie   patogenita   MeSH
• hemofilové infekce imunologie   metabolismus   mikrobiologie   MeSH
• kinetika MeSH
• kultivované buňky MeSH
• neutralizující protilátky imunologie   metabolismus   MeSH
• protilátky bakteriální imunologie   metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• séroskupina MeSH
• specificita protilátek MeSH
• Sus scrofa MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In vitro three-dimensional (3D) lung cell models have been thoroughly investigated in recent years and provide a reliable tool to assess the hazard associated with nanomaterials (NMs) released into the air. In this study, a 3D lung co-culture model was optimized to assess the hazard potential of multiwalled carbon nanotubes (MWCNTs), which is known to provoke inflammation and fibrosis, critical adverse outcomes linked to acute and prolonged NM exposure. The lung co-cultures were exposed to MWCNTs at the air-liquid interface (ALI) using the VITROCELL® Cloud system while considering realistic occupational exposure doses. The co-culture model was composed of three human cell lines: alveolar epithelial cells (A549), fibroblasts (MRC-5), and macrophages (differentiated THP-1). The model was exposed to two types of MWCNTs (Mitsui-7 and Nanocyl) at different concentrations (2-10 μg/cm2) to assess the proinflammatory as well as the profibrotic responses after acute (24 h, one exposure) and prolonged (96 h, repeated exposures) exposure cycles. The results showed that acute or prolonged exposure to different concentrations of the tested MWCNTs did not induce cytotoxicity or apparent profibrotic response; however, suggested the onset of proinflammatory response.

• MeSH
• aerosoly MeSH
• alveolární makrofágy metabolismus   patologie   MeSH
• biologické modely * MeSH
• buňky A549 MeSH
• fibroblasty metabolismus   patologie   MeSH
• lidé MeSH
• nanotrubičky uhlíkové škodlivé účinky   MeSH
• pneumocyty metabolismus   patologie   MeSH
• THP-1 buňky MeSH
• zánět chemicky indukované   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Monocytes arriving at the site of infection differentiate into functional effector macrophages to replenish the resident sentinel cells. Bordetella pertussis, the pertussis agent, secretes an adenylate cyclase toxin-hemolysin (CyaA) that binds myeloid phagocytes through complement receptor 3 (CD11b/CD18) and swiftly delivers its adenylyl cyclase enzyme domain into phagocytes. This ablates the bactericidal capacities of phagocytes through massive and unregulated conversion of cytosolic ATP into the key signaling molecule cAMP. We show that exposure of primary human monocytes to as low a concentration as 22.5 pM CyaA, or a low (2:1) multiplicity of infection by CyaA-producing B. pertussis bacteria, blocks macrophage colony-stimulating factor (M-CSF)-driven differentiation of monocytes. CyaA-induced cAMP signaling mediated through the activity of protein kinase A (PKA) efficiently blocked expression of macrophage markers, and the monocytes exposed to 22.5 pM CyaA failed to acquire the characteristic intracellular complexity of mature macrophage cells. Neither M-CSF-induced endoplasmic reticulum (ER) expansion nor accumulation of Golgi bodies, mitochondria, or lysosomes was observed in toxin-exposed monocytes, which remained small and poorly phagocytic and lacked pseudopodia. Exposure to 22.5 pM CyaA toxin provoked loss of macrophage marker expression on in vitro differentiated macrophages, as well as on primary human alveolar macrophages, which appeared to dedifferentiate into monocyte-like cells with upregulated CD14 levels. This is the first report that terminally differentiated tissue-resident macrophage cells can be dedifferentiated in vitro The results suggest that blocking of monocyte-to-macrophage transition and/or dedifferentiation of the sentinel cells of innate immunity through cAMP-elevating toxin action may represent a novel immune evasion strategy of bacterial pathogens.IMPORTANCE Macrophages are key sentinel cells of the immune system, and, as such, they are targeted by the toxins produced by the pertussis agent Bordetella pertussis The adenylate cyclase toxin (CyaA) mediates immune evasion of B. pertussis by suspending the bactericidal activities of myeloid phagocytes. We reveal a novel mechanism of potential subversion of host immunity, where CyaA at very low (22 pM) concentrations could inhibit maturation of human monocyte precursors into the more phagocytic macrophage cells. Furthermore, exposure to low CyaA amounts has been shown to trigger dedifferentiation of mature primary human alveolar macrophages back into monocyte-like cells. This unprecedented capacity is likely to promote survival of the pathogen in the airways, both by preventing maturation of monocytes attracted to the site of infection into phagocytic macrophages and by dedifferentiation of the already airway-resident sentinel cells.

• MeSH
• adenylátcyklasový toxin škodlivé účinky   metabolismus   MeSH
• alveolární makrofágy účinky léků   metabolismus   MeSH
• Bordetella pertussis chemie   MeSH
• buněčná diferenciace účinky léků   MeSH
• interakce hostitele a patogenu MeSH
• lidé MeSH
• monocyty účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AIMS: To elucidate the role of alveolar macrophages (AM) in the pathogenesis of hypoxic pulmonary hypertension (HPH), we tested the effects of sustained hypoxia on AM polarization and on the formation of superoxide by AM in vivo and in vitro. MAIN METHODS: Rat AM were obtained by bronchoalveolar lavage. 4-day exposure to hypoxia (10% O2) was carried out in vivo (rats in isobaric hypoxic chamber, controls kept in air) or in vitro (control AM in 21% O2 and 5% CO2). Superoxide production was measured by luminol-orthovanadate chemiluminescence, AM polarization was detected immunocytochemically. To ascertain the effect of substances contained in the alveolar environment, we cultivated cells also in the presence of non-cellular components of the bronchoalveolar lavage fluid (BALF) either from controls or from rats exposed to 4 days of hypoxia. KEY FINDINGS: In vivo, but not in vitro, hypoxia increased AM superoxide production. Both types of hypoxia polarized AM into M2 (pro-proliferative) type. While the presence of control BALF attenuated superoxide production in AM cultivated in normoxia, BALF from the hypoxia-exposed rats had no effect. In AM cultivated in hypoxia, superoxide production was not altered by control BALF and elevated by BALF obtained from hypoxic rats. SIGNIFICANCE: Hypoxia does not influence superoxide production by AM directly but rather by modulating their milieu and their sensitivity to external influences.

• MeSH
• alveolární makrofágy metabolismus   patologie   MeSH
• bronchoalveolární lavážní tekutina chemie   MeSH
• hypoxie patofyziologie   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• potkani Wistar MeSH
• superoxidy metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Macrophage cells are present in high abundance in the lung to intercept invading microorganisms that gain access through airway mucosal surfaces. Several bacterial pathogens have evolved the capacity to evade the innate immune response by establishing infections within pulmonary macrophages upon phagocytosis, leading to prolonged disease. Macrolide antibiotics such as azithromycin and clarithromycin accumulate in phagocytic cells and have been shown to preferentially distribute in tissues where populations of these cells reside. We employed this class of molecules as targeting ligands to direct virus-like particles (VLPs) to lung-resident macrophages. VLP-macrolide conjugates showed enhanced uptake into RAW 264.7 macrophage cells in culture, with azithromycin displaying the greatest effect; distinct differences were also observed for different macrocycle structures and orientations on the particle surface. Activation of macrophage cells was stimulated by particle uptake toward an intermediate activation state, in contrast to previous reports using macrolide-functionalized gold nanorods that stimulated a cytotoxic macrophage response. Attached azithromycin was also able to direct VLPs to the lungs in mice, with significant accumulation within 2 h of systemic injection. These results suggest that this new class of bioconjugate could serve as an effective platform for intracellular drug delivery in the context of pulmonary infections.

• MeSH
• Allolevivirus chemie   MeSH
• alveolární makrofágy metabolismus   MeSH
• antibakteriální látky chemie   farmakokinetika   MeSH
• azithromycin chemie   farmakokinetika   MeSH
• cytokiny metabolismus   MeSH
• Escherichia coli genetika   MeSH
• fagocytóza MeSH
• fenotyp MeSH
• klarithromycin chemie   farmakokinetika   MeSH
• myši MeSH
• plíce účinky léků   metabolismus   MeSH
• příprava léků metody   MeSH
• RAW 264.7 buňky MeSH
• systémy cílené aplikace léků metody   MeSH
• tkáňová distribuce MeSH
• virové plášťové proteiny chemie   farmakokinetika   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

• MeSH
• alveolární makrofágy metabolismus   MeSH
• aspirace žaludečního obsahu komplikace   MeSH
• bronchoalveolární laváž MeSH
• bronchoskopie * MeSH
• gastroezofageální reflux * diagnóza   komplikace   MeSH
• lidé MeSH
• nemoci dýchací soustavy * diagnóza   etiologie   komplikace   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• směrnice pro lékařskou praxi MeSH

Acute respiratory distress syndrome (ARDS) is a serious medical condition occurring in patients with polytrauma, pulmonary or non-pulmonary sepsis, pneumonia and many other circumstances. It causes inflammation of the lung parenchyma leading to impaired gas exchange with a systemic release of inflammatory mediators, causing consequential lung tissue injury, hypoxemia and frequently multiple organ failure. The aim of current study was to describe expression of inflammatory markers (myeloperoxidase, CD163 and vascular endothelial growth factor) by the cells in acute phase of ARDS. The lung samples of a 20-year-old man who had suffered a serious motorbike accident were obtained for histological examination. He died on the seventh day as a consequence of respiratory failure. Our results imply that expression of CD163 was restricted to activated alveolar macrophages and monocytes. Immunopositivityof MPO was observed in neutrophil granulocytes within lung alveoli and lung blood vessels. Myeloperoxidase positivity was observed in alveolar macrophages, too. Vascular endothelial growth factor was expressed in cytoplasm of neutrophil granulocytes, monocytes, small-sized alveolar macrophages and type II pneumocytes localized mostly inside lung alveoli. On the contrary, no positivity was observed in lung endothelial cells of blood vessels.

• MeSH
• alveolární makrofágy imunologie   metabolismus   MeSH
• antigeny diferenciační myelomonocytární biosyntéza   MeSH
• CD antigeny biosyntéza   MeSH
• dopravní nehody MeSH
• imunohistochemie MeSH
• lidé MeSH
• mimosilniční motorová vozidla MeSH
• mladý dospělý MeSH
• monocyty imunologie   metabolismus   MeSH
• neutrofily imunologie   metabolismus   MeSH
• peroxidasa biosyntéza   MeSH
• pneumocyty imunologie   metabolismus   MeSH
• receptory buněčného povrchu biosyntéza   MeSH
• syndrom dechové tísně imunologie   metabolismus   patologie   MeSH
• vaskulární endoteliální růstový faktor A biosyntéza   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH

Two major effector systems are frequently implicated in the immune and endothelial cell alternations associated with inflammation. They include the enhanced production of reactive oxygen species and diminished bioavailability of nitric oxide (NO). Importantly, these processes can be regulated by endogenously produced methylarginines, inhibitors for NO derived from macrophages and endothelial cells. Therefore, the aim of this study was to show the potential pharmacological intervention of methylarginines (N(G)-methyl-L-arginine, L-NMMA; N(G), N(G)'-dimethyl-L-arginine-symmetric dimethylarginine, SDMA; and N(G), N(G)-dimethyl-L-arginine-asymmetric dimethylarginine, ADMA) in activation of murine peritoneal (RAW 264.7) and alveolar (MHS) macrophages with lipopolysaccharide from Gram-negative bacteria (LPS). The data presented in this study clearly declare that L-NMMA (1-50μM) and ADMA (10-50 μM) significantly inhibited the LPS-induced NO production from macrophages in a concentration-dependent manner. It was demonstrated, for the first time, that the ADMA- and L-NMMA-induced down regulation of NO production was accompanied by reduced expression of mRNA and protein for inducible NO synthase as well as decreased activation of nuclear factor-κB. Importantly, we found a negative correlation between the ADMA-dependent reduction of NO production and ADMA-increased superoxide formation, which indicates that ADMA can negatively affect the balance in LPS-induced macrophage-derived production of reactive mediators. The only effect of SDMA was observed for LPS-triggered superoxide production, which was significantly decreased in its highest concentration (50 μM). In summary, L-NMMA and ADMA can mediate their effects on macrophage activation via regulation of intracellular signaling pathways, which can affect critical functions in activated macrophages.

• MeSH
• alveolární makrofágy účinky léků   imunologie   metabolismus   MeSH
• arginin analogy a deriváty   chemie   farmakologie   MeSH
• buněčné kultury MeSH
• buněčné linie MeSH
• exprese genu účinky léků   MeSH
• lipopolysacharidy toxicita   MeSH
• myši MeSH
• NF-kappa B antagonisté a inhibitory   biosyntéza   genetika   MeSH
• oxid dusnatý biosyntéza   MeSH
• peritoneální makrofágy účinky léků   imunologie   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• superoxidy metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   biosyntéza   genetika   MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Genes localized at Salmonella pathogenicity island-1 (SPI-1) are involved in Salmonella enterica invasion of host non-professional phagocytes. Interestingly, in macrophages, SPI-1-encoded proteins, in addition to invasion, induce cell death via activation of caspase-1 which also cleaves proIL-1β and proIL-18, precursors of 2 proinflammatory cytokines. In this study we were therefore interested in whether SPI-1-encoded type III secretion system (T3SS) may influence proinflammatory response of macrophages. To test this hypothesis, we infected primary porcine alveolar macrophages with wild-type S. Typhimurium and S. Enteritidis and their isogenic SPI-1 deletion mutants. ΔSPI1 mutants of both serovars invaded approx. 5 times less efficiently than the wild-type strains and despite this, macrophages responded to the infection with ΔSPI1 mutants by increased expression of proinflammatory cytokines IL-1β, IL-8, TNFα, IL-23α and GM-CSF. Identical macrophage responses to that induced by the ΔSPI1 mutants were also observed to the infection with sipB but not the sipA mutant. The hilA mutant exhibited an intermediate phenotype between the ΔSPI1 mutant and the wild-type S. Enteritidis. Our results showed that the SPI-1-encoded T3SS is required not only for cell invasion but in macrophages also for the suppression of early proinflammatory cytokine expression.

• MeSH
• alveolární makrofágy imunologie   metabolismus   MeSH
• cytokiny genetika   metabolismus   MeSH
• genomové ostrovy * MeSH
• nemoci prasat imunologie   mikrobiologie   MeSH
• prasata MeSH
• Salmonella enteritidis genetika   MeSH
• Salmonella typhimurium genetika   metabolismus   MeSH
• salmonelová infekce u zvířat imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The aim of this work was to compare in vitro nitric oxide (NO) production by rat, bovine and porcine macrophages. NO production was induced by lipopolysaccharide (LPS) or by phorbol 12-myristate 13-acetate (PMA) with ionomycin or recombinant interferon gamma (rIFN-gamma) and was assessed by Griess reaction. NO synthase type II (NOS II) expression was quantified by immunocytochemistry, Western blot and real-time polymerase chain reaction (RT-PCR). There were differences in NO production by pulmonary alveolar macrophages (PAM) in all species tested. The largest amounts of NO were produced by rat PAM. Less NO was produced by bovine PAM. Moreover, PAM in rats and cows differed in their abilities to respond to various stimulators. Neither porcine PAM nor Kupffer cells produced NO. Stimulation of porcine PAM with alternative concentrations of LPS did not lead to inducing NO production. Stimulation of porcine PAM with rIFN-gamma together with LPS led to a significant increase in the expression of NOS II mRNA, albeit without detectable NO production or NOS II expression on the protein level.

• MeSH
• alveolární makrofágy metabolismus   patologie   MeSH
• biotest MeSH
• ethylendiaminy MeSH
• financování organizované MeSH
• imunohistochemie MeSH
• interferon gama toxicita   MeSH
• ionomycin toxicita   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• lipopolysacharidy toxicita   MeSH
• messenger RNA metabolismus   MeSH
• oxid dusnatý analýza   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• prasata MeSH
• regulace genové exprese enzymů MeSH
• skot MeSH
• sulfanilamidy MeSH
• synthasa oxidu dusnatého, typ II genetika   metabolismus   MeSH
• tetradekanoylforbolacetát toxicita   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• skot MeSH
• zvířata MeSH