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Silver nanoparticles (AgNPs) are a potential antiviral agent due to their ability to disrupt the viral particle or alter the virus metabolism inside the host cell. In vitro, AgNPs exhibit antiviral activity against the most common human respiratory viruses. However, their capacity to modulate immune responses during respiratory viral infections has yet to be explored. This study demonstrates that administering AgNPs directly into the lungs prior to infection can reduce viral loads and therefore virus-induced cytokines in mice infected with influenza virus or murine pneumonia virus. The prophylactic effect was diminished in mice with depleted lymphoid cells. We showed that AgNPs-treatment resulted in the recruitment and activation of lymphocytes in the lungs, particularly natural killer (NK) cells. Mechanistically, AgNPs enhanced the ability of alveolar macrophages to promote both NK cell migration and IFN-γ production. By contrast, following infection, in mice treated with AgNPs, NK cells exhibited decreased activation, indicating that these nanoparticles can regulate the potentially deleterious activation of these cells. Overall, the data suggest that AgNPs may possess prophylactic antiviral properties by recruiting and controlling the activation of lymphoid cells through interaction with alveolar macrophages.
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Introduction: Although many studies have underscored the importance of T cells, phenotypically and functionally, fewer have studied the functions of myeloid cells in COVID disease. In particular, the potential role of myeloid cells such as monocytes and low-density neutrophils (LDNs) in innate responses and particular in the defense against secondary bacterial infections has been much less documented. Methods: Here, we compared, in a longitudinal study, healthy subjects, idiopathic fibrosis patients, COVID patients who were either hospitalized/moderate (M-) or admitted to ICU (COV-ICU) and patients in ICU hospitalized for other reasons (non-COV-ICU). Results: We show that COVID patients have an increased proportion of low-density neutrophils (LDNs), which produce high levels of proteases (particularly, NE, MMP-8 and MMP-9) (unlike non-COV-ICU patients), which are partly responsible for causing type II alveolar cell damage in co-culture experiments. In addition, we showed that M- and ICU-COVID monocytes had reduced responsiveness towards further live Pseudomonas aeruginosa (PAO1 strain) infection, an important pathogen colonizing COVID patients in ICU, as assessed by an impaired secretion of myeloid cytokines (IL-1, TNF, IL-8, ). By contrast, lymphoid cytokines (in particular type 2/type 3) levels remained high, both basally and post PAO1 infection, as reflected by the unimpaired capacity of T cells to proliferate, when stimulated with anti-CD3/CD28 beads. Discussion: Overall, our results demonstrate that COVID circulatory T cells have a biased type 2/3 phenotype, unconducive to proper anti-viral responses and that myeloid cells have a dual deleterious phenotype, through their LDN-mediated damaging effect on alveolar cells and their impaired responsiveness (monocyte-mediated) towards bacterial pathogens such as P. aeruginosa.
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COVID-19 , Monocitos , Neutrófilos , Infecciones por Pseudomonas , Pseudomonas aeruginosa , SARS-CoV-2 , Humanos , COVID-19/inmunología , Pseudomonas aeruginosa/inmunología , Monocitos/inmunología , Masculino , Femenino , Persona de Mediana Edad , SARS-CoV-2/inmunología , SARS-CoV-2/fisiología , Infecciones por Pseudomonas/inmunología , Neutrófilos/inmunología , Anciano , Citocinas/metabolismo , Citocinas/inmunología , Adulto , Estudios Longitudinales , Leucocitos Mononucleares/inmunología , Pulmón/inmunología , Pulmón/patología , Pulmón/microbiologíaRESUMEN
Epidemiological studies showed a positive association between exposure to PM2.5 and the severity of influenza virus infection. However, the mechanisms by which PM2.5 can disrupt antiviral defence are still unclear. From this perspective, the objective of this study was to evaluate the effects of PM2.5 on antiviral signalling in the respiratory epithelium using the bronchial Calu-3 cell line grown at the air-liquid interface. Pre-exposure to PM2.5 before infection with the influenza virus was investigated, as well as a co-exposure. Although a physical interaction between the virus and the particles seems possible, no effect of PM2.5 on viral replication was observed during co-exposure, although a downregulation of IFN-ß release was associated to PM2.5 exposure. However, pre-exposure slightly increased the viral nucleoprotein production and the pro-inflammatory response. Conversely, the level of the myxovirus resistance protein A (MxA), an interferon-stimulated gene (ISG) induced by IFN-ß, was reduced. Therefore, these results suggest that pre-exposure to PM2.5 could alter the antiviral response of bronchial epithelial cells, increasing their susceptibility to viral infection.
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Gripe Humana , Orthomyxoviridae , Virosis , Humanos , Interferones , Gripe Humana/genética , Gripe Humana/metabolismo , Mucosa Respiratoria , Antivirales , Epitelio/metabolismo , Material Particulado/toxicidadRESUMEN
Introduction: Cystic Fibrosis (CF) is the commonest genetically inherited disease (1 in 4,500 newborns) and 70% of people with CF (pwCF) harbour the F508Del mutation, resulting in misfolding and incorrect addressing of the channel CFTR to the epithelial membrane and subsequent dysregulation of fluid homeostasis. Although studies have underscored the importance and over-activation of myeloid cells, and in particular neutrophils in the lungs of people with CF (pwCF), relatively less emphasis has been put on the potential immunological bias in CF blood cells, at homeostasis or following stimulation/infection. Methods: Here, we revisited, in an exhaustive fashion, in pwCF with mild disease (median age of 15, median % FEV1 predicted = 87), whether their PBMCs, unprimed or primed with a 'non specific' stimulus (PMA+ionomycin mix) and a 'specific' one (live P.a =PAO1 strain), were differentially activated, compared to healthy controls (HC) PBMCs. Results: 1) we analysed the lymphocytic and myeloid populations present in CF and Control PBMCs (T cells, NKT, Tgd, ILCs) and their production of the signature cytokines IFN-g, IL-13, IL-17, IL-22. 2) By q-PCR, ELISA and Luminex analysis we showed that CF PBMCs have increased background cytokines and mediators production and a partial functional tolerance phenotype, when restimulated. 3) we showed that CF PBMCs low-density neutrophils release higher levels of granule components (S100A8/A9, lactoferrin, MMP-3, MMP-7, MMP-8, MMP-9, NE), demonstrating enhanced exocytosis of potentially harmful mediators. Discussion: In conclusion, we demonstrated that functional lymphoid tolerance and enhanced myeloid protease activity are key features of cystic fibrosis PBMCs.
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Fibrosis Quística , Recién Nacido , Humanos , Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Citocinas , Linfocitos , PulmónRESUMEN
One billion people worldwide get flu every year, including patients with non-small cell lung cancer (NSCLC). However, the impact of acute influenza A virus (IAV) infection on the composition of the tumor microenvironment (TME) and the clinical outcome of patients with NSCLC is largely unknown. We set out to understand how IAV load impacts cancer growth and modifies cellular and molecular players in the TME. Herein, we report that IAV can infect both tumor and immune cells, resulting in a long-term protumoral effect in tumor-bearing mice. Mechanistically, IAV impaired tumor-specific T-cell responses, led to the exhaustion of memory CD8+ T cells and induced PD-L1 expression on tumor cells. IAV infection modulated the transcriptomic profile of the TME, fine-tuning it toward immunosuppression, carcinogenesis, and lipid and drug metabolism. Consistent with these data, the transcriptional module induced by IAV infection in tumor cells in tumor-bearing mice was also found in human patients with lung adenocarcinoma and correlated with poor overall survival. In conclusion, we found that IAV infection worsened lung tumor progression by reprogramming the TME toward a more aggressive state.
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Carcinoma de Pulmón de Células no Pequeñas , Virus de la Influenza A , Gripe Humana , Neoplasias Pulmonares , Infecciones por Orthomyxoviridae , Humanos , Animales , Ratones , Neoplasias Pulmonares/patología , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Microambiente Tumoral , Linfocitos T CD8-positivos , Pulmón , Infecciones por Orthomyxoviridae/patologíaRESUMEN
Eosinophils have been previously shown to be able to regulate early humoral responses during systemic vaccination. Here we investigated the role of eosinophils during pulmonary vaccination, comparing vaccine-induced responses in eosinophil-deficient (ΔdblGATA) and wild-type mice using a Th2 adjuvant. We observed that eosinophils were needed to induce a complete vaccine response, thereby eliciting specific antibody-secreting plasma cells in the regional lymph nodes and antibody secretion in the BAL at the early stage of the immune response. Reintroduction of eosinophils in the lungs of ΔdblGATA mice during the priming stage enhanced both specific IgM and IgG plasma cells but not specific IgA plasma cells. Upon vaccination, eosinophils migrated to the lungs and secreted cytokines involved in B-cell activation, which might promote antibody production. Importantly, however, the absence of eosinophils did not impair late immune responses in a prime/boost protocol because, in that setup, we uncovered a compensating mechanism involving a Th17 pathway. In conclusion, our data demonstrate for the first time a new role for eosinophils during lung mucosal vaccination, whereby they accelerate early immune responses (IgM and IgG) while regulating IgA production at the late stages.
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Formación de Anticuerpos , Eosinófilos , Ratones , Animales , Eosinófilos/metabolismo , Pulmón/patología , Vacunación , Inmunoglobulina G , Inmunoglobulina M , Inmunoglobulina A/metabolismo , Ratones Endogámicos BALB C , Inmunidad MucosaRESUMEN
Pseudomonas aeruginosa (P.a) is a pathogen causing significant morbidity and mortality, particularly in hospital patients undergoing ventilation and in individuals with cystic fibrosis. Although we and others have investigated mechanisms used by P.a to subvert innate immunity, relatively less is known about the potential strategies used by this bacterium to fight the adaptive immune system and, in particular, T cells. Here, using RAG KO (devoid of 'classical' αß and γδ TCR T lymphocytes) and double RAG γC KO mice (devoid of T, NK and ILC cells), we demonstrate that the lymphocytic compartment is important to combat P.a (PAO1 strain). Indeed, we show that PAO1 load was increased in double RAG γC KO mice. In addition, we show that PAO1 down-regulates IL-23 and IL-22 protein accumulation in the lungs of infected mice while up-regulating their RNA production, thereby pointing towards a specific post-transcriptional regulatory mechanism not affecting other inflammatory mediators. Finally, we demonstrate that an adenovirus-mediated over-expression of IL-1, IL-23 and IL-7 induced lung neutrophil and lymphocytic influx and rescued mice against P.a-induced lethality in all WT, RAG γC KO and RAG γC KO RAG-deficient mice, suggesting that this regimen might be of value in 'locally immunosuppressed' individuals such as cystic fibrosis patients.
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Fibrosis Quística , Infecciones por Pseudomonas , Animales , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Interleucina-23/metabolismo , Interleucinas , Pulmón/metabolismo , Ratones , Ratones Noqueados , Infecciones por Pseudomonas/metabolismo , Pseudomonas aeruginosa , Interleucina-22RESUMEN
Pseudomonas aeruginosa (P.a) infections are a major public health issue in ventilator-associated pneumoniae, cystic fibrosis, and chronic obstructive pulmonary disease exacerbations. P.a is multidrug resistant, and there is an urgent need to develop new therapeutic approaches. Here, we evaluated the effect of direct pulmonary transplantation of gene-modified (elafin and interleukin [IL]-6) syngeneic macrophages in a mouse model of acute P.a infection. Wild-type (WT) or Elafin-transgenic (eTg) alveolar macrophages (AMs) or bone marrow-derived macrophages (BMDMs) were recovered from bronchoalveolar lavage or generated from WT or eTg mouse bone marrow. Cells were modified with adenovirus IL-6 (Ad-IL-6), characterized in vitro, and transferred by oropharyngeal instillation in the lungs of naive mice. The protective effect was assessed during P.a acute infection (survival studies, mechanistic studies of the inflammatory response). We show that a single bolus of genetically modified syngeneic AMs or BMDMs provided protection in our P.a-induced model. Mechanistically, Elafin-modified AMs had an IL-6-IL-10-IL-4R-IL-22-antimicrobial molecular signature that, in synergy with IL-6, enhanced epithelial cell proliferation and tissue repair in the alveolar unit. We believe that this innovative cell therapy strategy could be of value in acute bacterial infections in the lung.
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Infecciones por Pseudomonas , Animales , Elafina , Inmunoterapia , Interleucina-6/genética , Pulmón/microbiología , Macrófagos , Macrófagos Alveolares , Ratones , Ratones Endogámicos C57BL , Infecciones por Pseudomonas/genética , Infecciones por Pseudomonas/microbiología , Infecciones por Pseudomonas/terapia , Pseudomonas aeruginosa/genéticaRESUMEN
Influenza virus infection leads to severe and complicated disease, particularly in patients with lung cancer. It alters the tumor microenvironment (TME), which may potentiate lung cancer progression and disrupt responses to antitumoral treatments. Consequently, influenza vaccination and antiviral treatments should be recommended to all patients with lung cancer.
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Antivirales/uso terapéutico , Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/terapia , Neoplasias Pulmonares/mortalidad , Progresión de la Enfermedad , Humanos , Gripe Humana/complicaciones , Gripe Humana/inmunología , Gripe Humana/virología , Pulmón/inmunología , Pulmón/patología , Pulmón/virología , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/inmunología , Neoplasias Pulmonares/patología , Oncología Médica/normas , Guías de Práctica Clínica como Asunto , Microambiente Tumoral/inmunología , Vacunación/normasRESUMEN
COVID-19 is caused by the Severe Acute Respiratory Syndrome (SARS) coronavirus (Cov)-2, an enveloped virus with a positive-polarity, single-stranded RNA genome. The initial outbreak of the pandemic began in December 2019, and it is affecting the human health of the global community. In common with previous pandemics (Influenza H1N1 and SARS-CoV) and the epidemics of Middle east respiratory syndrome (MERS)-CoV, CoVs target bronchial and alveolar epithelial cells. Virus protein ligands (e.g., haemagglutinin or trimeric spike glycoprotein for Influenza and CoV, respectively) interact with cellular receptors, such as (depending on the virus) either sialic acids, Dipeptidyl peptidase 4 (DPP4), or angiotensin-converting enzyme 2 (ACE2). Host proteases, e.g., cathepsins, furin, or members of the type II transmembrane serine proteases (TTSP) family, such as Transmembrane protease serine 2 (TMPRSS2), are involved in virus entry by proteolytically activating virus ligands. Also involved are Toll Like Receptor (TLR) family members, which upregulate anti-viral and pro-inflammatory mediators [interleukin (IL)-6 and IL-8 and type I and type III Interferons among others], through the activation of Nuclear Factor (NF)-kB. When these events (virus cellular entry and innate immune responses) are uncontrolled, a deleterious systemic response is sometimes encountered in infected patients, leading to the well-described "cytokine storm" and an ensuing multiple organ failure promoted by a downregulation of dendritic cell, macrophage, and T-cell function. We aim to describe how the lung and systemic host innate immune responses affect survival either positively, through downregulating initial viral load, or negatively, by triggering uncontrolled inflammation. An emphasis will be put on host cellular signaling pathways and proteases involved with a view on tackling these therapeutically.
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Betacoronavirus/inmunología , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/inmunología , Inmunidad Innata , Pulmón/inmunología , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/inmunología , Transducción de Señal , Animales , Antivirales/uso terapéutico , COVID-19 , Infecciones por Coronavirus/metabolismo , Sistemas de Liberación de Medicamentos , Células Epiteliales/virología , Humanos , Pulmón/virología , Ratones , Células Mieloides/virología , Pandemias , Neumonía Viral/metabolismo , Receptores de Superficie Celular/metabolismo , Receptores de Coronavirus , Receptores Virales/metabolismo , SARS-CoV-2 , Serina Proteasas/metabolismo , Internalización del Virus , Tratamiento Farmacológico de COVID-19RESUMEN
Individuals with impaired immune responses, such as ventilated and cystic fibrosis patients are often infected with Pseudomonas aeruginosa (P.a) bacteria, and a co-infection with the Influenza virus (IAV) is often present. It has been known for many years that infection with IAV predisposes the host to secondary bacterial infections (such as Streptococcus pneumoniae or Staphylococcus aureus), and there is an abundance of mechanistic studies, including those studying the role of desensitization of TLR signaling, type I IFN- mediated impairment of neutrophil chemokines and antimicrobial production, attenuation of IL1ß production etc., showing this. However, little is known about the mechanistic events underlying the potential deleterious synergy between Influenza and P.a co-infections. We demonstrate here in vitro in epithelial cells and in vivo in three independent models (two involving mice given IAV +/- P.a, and one involving mice given IAV +/- IL-1ß) that IAV promotes secondary P.a-mediated lung disease or augmented IL-1ß-mediated inflammation. We show that IAV-P.a-mediated deleterious responses includes increased matrix metalloprotease (MMP) activity, and MMP-9 in particular, and that the use of the MMP inhibitor improves lung resilience. Furthermore, we show that IAV post-transcriptionally inhibits the antimicrobial/anti-protease molecule elafin/trappin-2, which we have shown previously to be anti-inflammatory and to protect the host against maladaptive neutrophilic inflammation in P.a infections. Our work highlights the capacity of IAV to promote further P.a-mediated lung damage, not necessarily through its interference with host resistance to the bacterium, but by down-regulating tissue resilience to lung inflammation instead. Our study therefore suggests that restoring tissue resilience in clinical settings where IAV/P.a co-exists could prove a fruitful strategy.
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Coinfección/inmunología , Elafina/metabolismo , Virus de la Influenza A/inmunología , Metaloproteinasa 9 de la Matriz/metabolismo , Pseudomonas aeruginosa/inmunología , Animales , Línea Celular , Coinfección/inducido químicamente , Coinfección/metabolismo , Fibrosis Quística/inmunología , Citocinas/metabolismo , Susceptibilidad a Enfermedades/metabolismo , Células Epiteliales/metabolismo , Humanos , Inflamación/inducido químicamente , Inflamación/inmunología , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Modelos Animales , Neumonía/metabolismo , Infecciones Estafilocócicas/inmunologíaRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Most of current influenza virus vaccines fail to develop a strong immunity at lung mucosae (site of viral entry) due to sub-optimal vaccination protocols (e.g. inactivated virus administered by parenteral injections). Mucosal immunity could be improved by using locally-delivered vaccines containing appropriate adjuvants. Here we show, in a mouse model, that inclusion of silver nanoparticles (AgNPs) in virus-inactivated flu vaccine resulted in reduction of viral loads and prevention of excessive lung inflammation following influenza infection. Concomitantly, AgNPs enhanced specific IgA secreting plasma cells and antibodies titers, a hallmark of successful mucosal immunity. Moreover, vaccination in the presence of AgNPs but not with gold nanoparticles, protected mice from lethal flu. Compared with other commercial adjuvants (squalene/oil-based emulsion) or silver salts, AgNPs stimulated stronger antigen specific IgA production with lower toxicity by promoting bronchus-associated lymphoid tissue (BALT) neogenesis, and acted as a bona fide mucosal adjuvant.
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Adyuvantes Inmunológicos/farmacología , Inmunidad Mucosa , Inmunoglobulina A/metabolismo , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Tejido Linfoide/inmunología , Nanopartículas del Metal/química , Plata/química , Animales , Bronquios/inmunología , Perros , Centro Germinal/efectos de los fármacos , Centro Germinal/metabolismo , Humanos , Inmunidad Mucosa/efectos de los fármacos , Inflamación/patología , Subtipo H1N1 del Virus de la Influenza A/efectos de los fármacos , Subtipo H1N1 del Virus de la Influenza A/inmunología , Tejido Linfoide/efectos de los fármacos , Células de Riñón Canino Madin Darby , Nanopartículas del Metal/ultraestructura , Ratones Endogámicos C57BL , Infecciones por Orthomyxoviridae/inmunología , Infecciones por Orthomyxoviridae/prevención & control , Infecciones por Orthomyxoviridae/virología , VacunaciónRESUMEN
Cystic fibrosis (CF) is caused by defective Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) protein. Morbidity is mainly due to early airway infection. We hypothesized that S. aureus clearance during the first hours of infection was impaired in CF human Airway Surface Liquid (ASL) because of a lowered pH. The ASL pH of human bronchial epithelial cell lines and primary respiratory cells from healthy controls (WT) and patients with CF was measured with a pH microelectrode. The antimicrobial capacity of airway cells was studied after S. aureus apical infection by counting surviving bacteria. ASL was significantly more acidic in CF than in WT respiratory cells. This was consistent with a defect in bicarbonate secretion involving CFTR and SLC26A4 (pendrin) and a persistent proton secretion by ATP12A. ASL demonstrated a defect in S. aureus clearance which was improved by pH normalization. Pendrin inhibition in WT airways recapitulated the CF airway defect and increased S. aureus proliferation. ATP12A inhibition by ouabain decreased bacterial proliferation. Antimicrobial peptides LL-37 and hBD1 demonstrated a pH-dependent activity. Normalizing ASL pH might improve innate airway defense in newborns with CF during onset of S. aureus infection. Pendrin activation and ATP12A inhibition could represent novel therapeutic strategies to normalize pH in CF airways.
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Bronquios/citología , Fibrosis Quística/metabolismo , Células Epiteliales/metabolismo , Mucosa Respiratoria/metabolismo , Péptidos Catiónicos Antimicrobianos/farmacología , Bicarbonatos/química , Bicarbonatos/metabolismo , Línea Celular , Células Cultivadas , Niño , Preescolar , Fibrosis Quística/genética , Fibrosis Quística/microbiología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/microbiología , ATPasa Intercambiadora de Hidrógeno-Potásio/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Lactante , Recién Nacido , Mucosa Respiratoria/química , Mucosa Respiratoria/microbiología , Infecciones Estafilocócicas/metabolismo , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/prevención & control , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Transportadores de Sulfato/metabolismo , CatelicidinasRESUMEN
Pseudomonas aeruginosa (P.a) is a pathogen causing significant morbidity and mortality, in particular, in hospital patients undergoing ventilation and in patients with cystic fibrosis. Among the virulence factors secreted or injected into host cells, the physiopathological relevance of type II secretions system (T2SS) is less studied. Although there is extensive literature on the destructive role of LasB in vitro on secreted innate immune components and on some stromal cell receptors, studies on its direct action on myeloid cells are scant. Using a variety of methods, including the use of bacterial mutants, gene-targeted mice, and proteomics technology, we show here, using non-opsonic conditions (thus mimicking resting and naïve conditions in the alveolar space), that LasB, an important component of the P.a T2SS is highly virulent in vivo, and can subvert alveolar macrophage (AM) activity and bacterial killing, in vitro and in vivo by downregulating important secreted innate immune molecules (complement factors, cytokines, etc.) and receptors (IFNAR, Csf1r, etc.). In particular, we show that LasB downregulates the production of C3 and factor B complement molecules, as well as the activation of reactive oxygen species production by AM. In addition, we showed that purified LasB impaired significantly the ability of AM to clear an unrelated bacterium, namely Streptococcus pneumoniae. These data provide a new mechanism of action for LasB, potentially partly explaining the early onset of P.a, alone, or with other bacteria, within the alveolar lumen in susceptible individuals, such as ventilated, chronic obstructive pulmonary disease and cystic fibrosis patients.
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Silver nanoparticles (AgNPs) are microbicidal agents which could be potentially used as an alternative to antivirals to treat human infectious diseases, especially influenza virus infections where antivirals have generally proven unsuccessful. However, concerns about the use of AgNPs on humans arise from their potential toxicity, although mechanisms are not well-understood. We show here, in the context of an influenza virus infection of lung epithelial cells, that AgNPs down-regulated influenza induced CCL-5 and -IFN-ß release (two cytokines important in antiviral immunity) through RIG-I inhibition, while enhancing IL-8 production, a cytokine important for mobilizing host antibacterial responses. AgNPs activity was independent of coating and was not observed with gold nanoparticles. Down-stream analysis indicated that AgNPs disorganized the mitochondrial network and prevented the antiviral IRF-7 transcription factor influx into the nucleus. Importantly, we showed that the modulation of RIG-I-IRF-7 pathway was concomitant with inhibition of either classical or alternative autophagy (ATG-5- and Rab-9 dependent, respectively), depending on the epithelial cell type used. Altogether, this demonstration of a AgNPs-mediated functional dichotomy (down-regulation of IFN-dependent antiviral responses and up-regulation of IL-8-dependent antibacterial responses) may have practical implications for their use in the clinic.
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Antivirales/farmacología , Células Epiteliales/efectos de los fármacos , Pulmón/efectos de los fármacos , Nanopartículas del Metal/química , Mitocondrias/efectos de los fármacos , Orthomyxoviridae/efectos de los fármacos , Plata/farmacología , Tretinoina/farmacología , Animales , Antivirales/química , Autofagia/efectos de los fármacos , Línea Celular Tumoral , Perros , Células Epiteliales/metabolismo , Células Epiteliales/virología , Humanos , Pulmón/metabolismo , Pulmón/virología , Células de Riñón Canino Madin Darby/efectos de los fármacos , Células de Riñón Canino Madin Darby/virología , Pruebas de Sensibilidad Microbiana , Mitocondrias/metabolismo , Plata/química , Tretinoina/químicaRESUMEN
BACKGROUND: Pseudomonas aeruginosa lung infections are a huge problem in ventilator-associated pneumonia, cystic fibrosis (CF) and in chronic obstructive pulmonary disease (COPD) exacerbations. This bacterium secretes virulence factors that may subvert host innate immunity. OBJECTIVE: We evaluated the effect of P. aeruginosa elastase LasB, an important virulence factor secreted by the type II secretion system, on ion transport, innate immune responses and epithelial repair, both in vitro and in vivo. METHODS: Wild-type (WT) or cystic fibrosis transmembrane conductance regulator (CFTR)-mutated epithelial cells (cell lines and primary cells from patients) were treated with WT or ΔLasB pseudomonas aeruginosa O1 (PAO1) secretomes. The effect of LasB and PAO1 infection was also assessed in vivo in murine models. RESULTS: We showed that LasB was the most abundant protein in WT PAO1 secretomes and that it decreased epithelial CFTR expression and activity. In airway epithelial cell lines and primary bronchial epithelial cells, LasB degraded the immune mediators interleukin (IL)-6 and trappin-2, an important epithelial-derived antimicrobial molecule. We further showed that an IL-6/STAT3 signalling pathway was downregulated by LasB, resulting in inhibition of epithelial cell repair. In mice, intranasally instillated LasB induced significant weight loss, inflammation, injury and death. By contrast, we showed that overexpression of IL-6 and trappin-2 protected mice against WT-PAO1-induced death, by upregulating IL-17/IL-22 antimicrobial and repair pathways. CONCLUSIONS: Our data demonstrate that PAO1 LasB is a major P. aeruginosa secreted factor that modulates ion transport, immune response and tissue repair. Targeting this virulence factor or upregulating protective factors such as IL-6 or antimicrobial molecules such as trappin-2 could be beneficial in P. aeruginosa-infected individuals.
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Proteínas Bacterianas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/fisiología , Fibrosis Quística/inmunología , Células Epiteliales/fisiología , Inmunidad Innata/fisiología , Interleucina-6/fisiología , Metaloendopeptidasas , Animales , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
Idiopathic pulmonary fibrosis (IPF) is characterized by the deposition of excessive extracellular matrix and the destruction of lung parenchyma, resulting from an aberrant wound-healing response. Although IPF is often associated with an imbalance in protease activity, the mechanisms underlying the sustained repair mechanisms are not fully understood. Here, we addressed the role of the recently identified, membrane-anchored serine protease human airway trypsin-like protease (HAT). In the present study, we show that both HAT expression and activity were up-regulated in human IPF specimens. Next, adenoviral overexpression of HAT before bleomycin challenge attenuated lung injury as well as extracellular matrix deposition in the bleomycin-induced pulmonary fibrosis model. In vitro, HAT prevented specific fibrosis-associated responses in primary human pulmonary fibroblasts and induced the expression of mediators associated with the prostaglandin E2 pathway. Altogether, our findings suggested that HAT could have a protective role in IPF and other fibrotic lung disorders.-Menou, A., Flajolet, P., Duitmen, J., Justet, A., Moog, S., Jaillet, M., Tabèze, L., Solhonne, B., Garnier, M., Mal, H., Mordant, P., Castier, Y., Cazes, A., Sallenave, J.-M., Mailleux, A. A., Crestani, B. Human airway trypsin-like protease exerts potent, antifibrotic action in pulmonary fibrosis.
Asunto(s)
Lesión Pulmonar/prevención & control , Fibrosis Pulmonar/prevención & control , Serina Endopeptidasas/administración & dosificación , Animales , Antibióticos Antineoplásicos/toxicidad , Bleomicina/toxicidad , Estudios de Casos y Controles , Movimiento Celular , Proliferación Celular , Células Cultivadas , Fibroblastos/efectos de los fármacos , Fibroblastos/enzimología , Fibroblastos/patología , Humanos , Pulmón/efectos de los fármacos , Pulmón/enzimología , Pulmón/patología , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/enzimología , Lesión Pulmonar/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/enzimología , Fibrosis Pulmonar/patología , Serina Endopeptidasas/metabolismo , Transducción de SeñalRESUMEN
Fibroblast growth factor 9 (FGF9) is necessary for fetal lung development and is expressed by epithelium and mesothelium. We evaluated the role of FGF9 overexpression on adenoviral-induced pleural injury in vivo and determined the biological effects of FGF9 on mesothelial cells in vitro. We assessed the expression of FGF9 and FGF receptors by mesothelial cells in both human and mouse lungs. Intrapleural injection of an adenovirus expressing human FGF9 (AdFGF9) or a control adenovirus (AdCont) was performed. Mice were euthanized at days 3, 5, and 14 Expression of FGF9 and markers of inflammation and myofibroblastic differentiation was studied by qPCR and immunohistochemistry. In vitro, rat mesothelial cells were stimulated with FGF9 (20 ng/ml), and we assessed its effect on proliferation, survival, migration, and differentiation. FGF9 was expressed by mesothelial cells in human idiopathic pulmonary fibrosis. FGF receptors, mainly FGFR3, were expressed by mesothelial cells in vivo in humans and mice. AdCont instillation induced diffuse pleural thickening appearing at day 5, maximal at day 14 The altered pleura cells strongly expressed α-smooth muscle actin and collagen. AdFGF9 injection induced maximal FGF9 expression at day 5 that lasted until day 14 FGF9 overexpression prevented pleural thickening, collagen and fibronectin accumulation, and myofibroblastic differentiation of mesothelial cells. In vitro, FGF9 decreased mesothelial cell migration and inhibited the differentiating effect of transforming growth factor-ß1. We conclude that FGF9 has a potential antifibrotic effect on mesothelial cells.