RESUMEN
Severe defects in human IFNγ immunity predispose individuals to both Bacillus Calmette-Guérin disease and tuberculosis, whereas milder defects predispose only to tuberculosis1. Here we report two adults with recurrent pulmonary tuberculosis who are homozygous for a private loss-of-function TNF variant. Neither has any other clinical phenotype and both mount normal clinical and biological inflammatory responses. Their leukocytes, including monocytes and monocyte-derived macrophages (MDMs) do not produce TNF, even after stimulation with IFNγ. Blood leukocyte subset development is normal in these patients. However, an impairment in the respiratory burst was observed in granulocyte-macrophage colony-stimulating factor (GM-CSF)-matured MDMs and alveolar macrophage-like (AML) cells2 from both patients with TNF deficiency, TNF- or TNFR1-deficient induced pluripotent stem (iPS)-cell-derived GM-CSF-matured macrophages, and healthy control MDMs and AML cells differentiated with TNF blockers in vitro, and in lung macrophages treated with TNF blockers ex vivo. The stimulation of TNF-deficient iPS-cell-derived macrophages with TNF rescued the respiratory burst. These findings contrast with those for patients with inherited complete deficiency of the respiratory burst across all phagocytes, who are prone to multiple infections, including both Bacillus Calmette-Guérin disease and tuberculosis3. Human TNF is required for respiratory-burst-dependent immunity to Mycobacterium tuberculosis in macrophages but is surprisingly redundant otherwise, including for inflammation and immunity to weakly virulent mycobacteria and many other infectious agents.
Asunto(s)
Macrófagos , Tuberculosis Pulmonar , Factores de Necrosis Tumoral , Adulto , Femenino , Humanos , Masculino , Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Homocigoto , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/inmunología , Células Madre Pluripotentes Inducidas/citología , Inflamación/inmunología , Interferón gamma/inmunología , Mutación con Pérdida de Función , Pulmón/citología , Pulmón/efectos de los fármacos , Macrófagos/citología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/patología , Macrófagos Alveolares/citología , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/microbiología , Macrófagos Alveolares/patología , Mycobacterium tuberculosis/inmunología , Fenotipo , Especies Reactivas de Oxígeno/metabolismo , Receptores Tipo I de Factores de Necrosis Tumoral/deficiencia , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Estallido Respiratorio , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/microbiología , Tuberculosis Pulmonar/genética , Inhibidores del Factor de Necrosis Tumoral/farmacología , Factores de Necrosis Tumoral/deficiencia , Factores de Necrosis Tumoral/genética , Adolescente , Adulto JovenRESUMEN
Introduction: TAM receptor-mediated efferocytosis plays an important function in immune regulation and may contribute to antigen tolerance in the lungs, a site with continuous cellular turnover and generation of apoptotic cells. Some studies have identified failures in efferocytosis as a common driver of inflammation and tissue destruction in lung diseases. Our study is the first to characterize the in vivo function of the TAM receptors, Axl and MerTk, in the innate immune cell compartment, cytokine and chemokine production, as well as the alveolar macrophage (AM) phenotype in different settings in the airways and lung parenchyma. Methods: We employed MerTk and Axl defective mice to induce acute silicosis by a single exposure to crystalline silica particles (20 mg/50 µL). Although both mRNA levels of Axl and MerTk receptors were constitutively expressed by lung cells and isolated AMs, we found that MerTk was critical for maintaining lung homeostasis, whereas Axl played a role in the regulation of silica-induced inflammation. Our findings imply that MerTk and Axl differently modulated inflammatory tone via AM and neutrophil recruitment, phenotype and function by flow cytometry, and TGF-ß and CXCL1 protein levels, respectively. Finally, Axl expression was upregulated in both MerTk-/- and WT AMs, confirming its importance during inflammation. Conclusion: This study provides strong evidence that MerTk and Axl are specialized to orchestrate apoptotic cell clearance across different circumstances and may have important implications for the understanding of pulmonary inflammatory disorders as well as for the development of new approaches to therapy.
Asunto(s)
Tirosina Quinasa del Receptor Axl , Homeostasis , Pulmón , Macrófagos Alveolares , Ratones Noqueados , Proteínas Proto-Oncogénicas , Proteínas Tirosina Quinasas Receptoras , Silicosis , Tirosina Quinasa c-Mer , Animales , Ratones , Tirosina Quinasa c-Mer/metabolismo , Tirosina Quinasa c-Mer/genética , Citocinas/metabolismo , Modelos Animales de Enfermedad , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Ratones Endogámicos C57BL , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas Tirosina Quinasas Receptoras/metabolismo , Proteínas Tirosina Quinasas Receptoras/genética , Silicosis/metabolismo , Silicosis/inmunología , Silicosis/patología , MasculinoRESUMEN
Macrophages play a central role in lung physiology and pathology. In this study, we show in mice that alveolar macrophages (AMs), unlike other macrophage types (interstitial, peritoneal, and splenic macrophages), constitutively express programmed death-1 ligand 1 (PD-L1), thereby possessing a superior phagocytic ability and the capacity to repress CTLs by cis- and trans-interacting with CD80 and programmed death-1 (PD-1), respectively. This extraordinary ability of AMs assures optimal protective immunity and tolerance within the lung. These findings uncover a unique characteristic of AMs and an innate immune function of PD-L1 and CD80 and therefore help in the understanding of lung physiology, diseases, and PD-L1/PD-1-based immunotherapy.
Asunto(s)
Antígeno B7-H1/inmunología , Macrófagos Alveolares/inmunología , Animales , Antígeno B7-1/inmunología , Ratones , Ratones Endogámicos , Ratones NoqueadosRESUMEN
The oral administration of Lacticaseibacillus rhamnosus CRL1505 differentially modulates the respiratory innate antiviral immune response triggered by Toll-like receptor 3 (TLR3) activation in infant mice, improving the resistance to Respiratory Syncytial Virus (RSV) infection. In this work, by using macrophages depletion experiments and a detailed study of their production of cytokines and antiviral factors we clearly demonstrated the key role of this immune cell population in the improvement of both viral elimination and the protection against lung tissue damage induced by the CRL1505 strain. Orally administered L. rhamnosus CRL1505 activated alveolar macrophages and enhanced their ability to produce type I interferons (IFNs) and IFN-γ in response to RSV infection. Moreover, an increased expression of IFNAR1, Mx2, OAS1, OAS2, RNAseL, and IFITM3 was observed in alveolar macrophages after the oral treatment with L. rhamnosus CRL1505, which was consistent with the enhanced RSV clearance. The depletion of alveolar macrophages by the time of L. rhamnosus CRL1505 administration abolished the ability of infant mice to produce increased levels of IL-10 in response to RSV infection. However, no improvement in IL-10 production was observed when primary cultures of alveolar macrophages obtained from CRL1505-treated mice were analyzed. Of note, alveolar macrophages from the CRL1505 group had an increased production of IL-6 and IL-27 suggesting that these cells may play an important role in limiting inflammation and protecting lung function during RSV infection, by increasing the maturation and activation of Treg cells and their subsequent production of IL-10. In addition, we provided evidence of the important role of CD4+ cells and IFN-γ in the activation of alveolar macrophages highlighting a putative pathway through which the intestinal and respiratory mucosa are communicated under the influence of L. rhamnosus CRL1505.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Lacticaseibacillus rhamnosus , Macrófagos Alveolares/inmunología , Probióticos/farmacología , Infecciones por Virus Sincitial Respiratorio/inmunología , Administración Oral , Animales , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Chlorocebus aethiops , Citocinas/inmunología , Mucosa Intestinal/inmunología , Ratones Endogámicos BALB C , Poli I-C/farmacología , Mucosa Respiratoria/inmunología , Células VeroRESUMEN
Exposure to ambient air particulate matter (PM) is associated with increased cardiorespiratory morbidity and mortality. In this context, alveolar macrophages exhibit proinflammatory and oxidative responses as a result of the clearance of particles, thus contributing to lung injury. However, the mechanisms linking these pathways are not completely clarified. Therefore, the oxinflammation phenomenon was studied in RAW 264.7 macrophages exposed to Residual Oil Fly Ash (ROFA), a PM surrogate rich in transition metals. While cell viability was not compromised under the experimental conditions, a proinflammatory phenotype was observed in cells incubated with ROFA 100 µg/mL, characterized by increased levels of TNF-α and NO production, together with PM uptake. This inflammatory response seems to precede alterations in redox metabolism, characterized by augmented levels of H2O2, diminished GSH/GSSG ratio, and increased SOD activity. This scenario resulted in increased oxidative damage to phospholipids. Moreover, alterations in mitochondrial respiration were observed following ROFA incubation, such as diminished coupling efficiency and spare respiratory capacity, together with augmented proton leak. These findings were accompanied by a decrease in mitochondrial membrane potential. Finally, NADPH oxidase (NOX) and mitochondria were identified as the main sources of superoxide anion () in our model. These results indicate that PM exposure induces direct activation of macrophages, leading to inflammation and increased reactive oxygen species production through NOX and mitochondria, which impairs antioxidant defense and may cause mitochondrial dysfunction.
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Macrófagos Alveolares/efectos de los fármacos , Mitocondrias/efectos de los fármacos , NADPH Oxidasas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Material Particulado/toxicidad , Superóxidos/metabolismo , Contaminantes Atmosféricos/toxicidad , Animales , Antioxidantes/metabolismo , Ceniza del Carbón/toxicidad , Peróxido de Hidrógeno/metabolismo , Inflamación , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Ratones , Mitocondrias/inmunología , Mitocondrias/metabolismo , Oxidación-Reducción , Estrés Oxidativo/inmunología , Células RAW 264.7 , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
The innate response plays a crucial role in the protection against tuberculosis development. Moreover, the initial steps that drive the host-pathogen interaction following Mycobacterium tuberculosis infection are critical for the development of adaptive immune response. As alveolar MÏs, airway epithelial cells, and dendritic cells can sense the presence of M. tuberculosis and are the first infected cells. These cells secrete mediators, which generate inflammatory signals that drive the differentiation and activation of the T lymphocytes necessary to clear the infection. Throughout this review article, we addressed the interaction between epithelial cells and M. tuberculosis, as well as the interaction between dendritic cells and M. tuberculosis. The understanding of the mechanisms that modulate those interactions is critical to have a complete view of the onset of an infection and may be useful for the development of dendritic cell-based vaccine or immunotherapies.
Asunto(s)
Inmunidad Adaptativa , Células Epiteliales Alveolares/inmunología , Células Dendríticas/inmunología , Interacciones Huésped-Patógeno/inmunología , Mycobacterium tuberculosis/fisiología , Tuberculosis Pulmonar/inmunología , Células Epiteliales Alveolares/patología , Células Dendríticas/patología , Humanos , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/patología , Tuberculosis Pulmonar/patologíaRESUMEN
The nasal priming with nonviable Lactobacillus rhamnosus CRL1505 (NV1505) or its purified peptidoglycan (PG1505) differentially modulates the respiratory innate immune response in infant mice, improving their resistance to primary respiratory syncytial virus (RSV) infection and secondary pneumococcal pneumonia. In association with the protection against RSV-pneumococcal superinfection, it was found that NV1505 or PG1505 significantly enhance the numbers of CD11c+SiglecF+ alveolar macrophages (AMs) producing interferon (IFN)-ß. In this work, we aimed to further advance in the characterization of the beneficial effects of NV1505 and PG1505 in the context of a respiratory superinfection by evaluating whether their immunomodulatory properties are dependent on AM functions. Macrophage depletion experiments and a detailed study of their production of cytokines and antiviral factors clearly demonstrated the key role of this immune cell population in the improvement of both the reduction of pathogens loads and the protection against lung tissue damage induced by the immunobiotic CRL1505 strain. Studies at basal conditions during primary RSV or S. pneumoniae infections, as well as during secondary pneumococcal pneumonia, brought the following five notable findings regarding the immunomodulatory effects of NV1505 and PG1505: (a) AMs play a key role in the beneficial modulation of the respiratory innate immune response and protection against RSV infection, (b) AMs are necessary for improved protection against primary and secondary pneumococcal pneumonia, (c) the generation of activated/trained AMs would be essential for the enhanced protection against respiratory pathogens, (d) other immune and nonimmune cell populations in the respiratory tract may contribute to the protection against bacterial and viral infections, and (e) the immunomodulatory properties of NV1505 and PG1505 are strain-specific. These findings significantly improve our knowledge about the immunological mechanisms involved in the modulation of respiratory immunity induced by beneficial microbes.
Asunto(s)
Factores Inmunológicos/uso terapéutico , Macrófagos Alveolares/inmunología , Peptidoglicano/uso terapéutico , Infecciones Neumocócicas/inmunología , Infecciones por Virus Sincitial Respiratorio/inmunología , Animales , Antígenos CD11/genética , Antígenos CD11/metabolismo , Células Cultivadas , Chlorocebus aethiops , Inmunidad Innata , Factores Inmunológicos/farmacología , Lacticaseibacillus rhamnosus/metabolismo , Macrófagos Alveolares/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Peptidoglicano/farmacología , Infecciones Neumocócicas/terapia , Infecciones por Virus Sincitial Respiratorio/terapia , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico/genética , Lectinas Similares a la Inmunoglobulina de Unión a Ácido Siálico/metabolismo , Células VeroRESUMEN
Mycobacterium tuberculosis (Mtb) infects alveolar macrophages (AMs), causing pulmonary tuberculosis (PTB), the most common form of the disease. Less frequently, Mtb is disseminated to many other organs and tissues, resulting in different extrapulmonary forms of TB. Nevertheless, very few studies have addressed the global mRNA response of human AMs, particularly from humans with the active form of the disease. Strikingly, almost no studies have addressed the response of human extrapulmonary macrophages to Mtb infection. In this pilot study, using microarray technology, we examined the transcriptomic ex vivo response of AMs from PTB patients (AMTBs) and AMs from control subjects (AMCTs) infected with two clinical isolates of Mtb. Furthermore, we also studied the infection response of human splenic macrophages (SMs) to Mtb isolates, as a model for extrapulmonary infection, and compared the transcriptomic response between AMs and SMs. Our results showed a striking difference in global mRNA profiles in response to infection between AMs and SMs, implicating a tissue-specific macrophage response to Mtb.
Asunto(s)
Macrófagos Alveolares/inmunología , Mycobacterium tuberculosis/inmunología , Bazo/inmunología , Transcriptoma , Tuberculosis Pulmonar/inmunología , Adulto , Estudios de Casos y Controles , Femenino , Perfilación de la Expresión Génica/métodos , Redes Reguladoras de Genes , Interacciones Microbiota-Huesped/genética , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , ARN Mensajero/genética , Bazo/patología , Tuberculosis Pulmonar/microbiología , Adulto JovenRESUMEN
Human respiratory syncytial virus (hRSV) and human metapneumovirus (hMPV) cause acute respiratory tract infections in children worldwide. Natural killer T (NKT) cells are unconventional T lymphocytes, and their TCRs recognize glycolipids bound to the MHC-I-like molecule, CD1d. These cells modulate the inflammatory response in viral infections. Here, we evaluated the contribution of NKT cells in both hRSV and hMPV infections. A significant decrease in the number of neutrophils, eosinophils, and CD103+DCs infiltrating to the lungs, as well as an increased production of IFN-γ, were observed upon hRSV-infection in CD1d-deficient BALB/c mice, as compared to wild-type control mice. However, this effect was not observed in the CD1d-deficient BALB/c group, upon infection with hMPV. Importantly, reduced expression of CD1d in CD11b+ DCs and epithelial cells was found in hRSV -but not hMPV-infected mice. Besides, a reduction in the expression of CD1d in alveolar macrophages of lungs from hRSV- and hMPV-infected mice was found. Such reduction of CD1d expression interfered with NKT cells activation, and consequently IL-2 secretion, as characterized by in vitro experiments for both hRSV and hMPV infections. Furthermore, increased numbers of NKT cells recruited to the lungs in response to hRSV- but not hMPV-infection was detected, resulting in a reduction in the expression of IFN-γ and IL-2 by these cells. In conclusion, both hRSV and hMPV might be differently impairing NKT cells function and contributing to the immune response triggered by these viruses.
Asunto(s)
Células T Asesinas Naturales/inmunología , Infecciones por Paramyxoviridae/inmunología , Infecciones por Virus Sincitial Respiratorio/inmunología , Infecciones del Sistema Respiratorio/virología , Replicación Viral/inmunología , Animales , Antígenos CD1d/genética , Antígenos CD1d/inmunología , Humanos , Pulmón/inmunología , Pulmón/virología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/virología , Masculino , Metapneumovirus/patogenicidad , Metapneumovirus/fisiología , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Células T Asesinas Naturales/patología , Virus Sincitial Respiratorio Humano/patogenicidad , Virus Sincitial Respiratorio Humano/fisiologíaRESUMEN
Brucella spp. infection is frequently acquired through contaminated aerosols. The role of interleukin-1 beta (IL-1ß) in the early pulmonary response to respiratory Brucella infection is unknown. As shown here, IL-1ß levels in lung homogenates and bronchoalveolar lavage fluid (BALF) of mice intratracheally inoculated with B. abortus were increased at 3 and 7 days p.i. At 7 days p.i., pulmonary CFU numbers were higher in IL-1 receptor (IL-1R) knockout (KO) mice than in wild type (WT) mice. At different times p.i. CFU in lungs and BALF were higher in mice lacking some inflammasome components (caspase-1, AIM2, NLRP3) than in WT mice. At 2 days p.i. pulmonary levels of IL-1ß and CXCL1 (neutrophils chemoattractant) were lower in caspase-1/11 KO mice. At day 3 p.i., neutrophils counts in BALF were lower in caspase-1/11 KO mice than in WT mice. During in vitro infections, IL-1ß secretion was lower in alveolar macrophages from caspase-1/11, NLRP3 or AIM2 KO mice than in WT controls. Similarly, IL-1ß production by B. abortus-infected alveolar epithelial cells was reduced by pretreatment with a specific caspase-1 inhibitor. This study shows that IL-1R, probably through IL-1ß action, and the NLRP3 and AIM2 inflammasomes are involved in pulmonary innate immune protective mechanisms against respiratory B. abortus infection.
Asunto(s)
Brucella abortus/inmunología , Brucelosis/inmunología , Inflamasomas/metabolismo , Pulmón/inmunología , Receptores de Interleucina-1/metabolismo , Animales , Líquido del Lavado Bronquioalveolar/inmunología , Brucella abortus/patogenicidad , Caspasa 1/metabolismo , Caspasas/genética , Caspasas/metabolismo , Caspasas Iniciadoras , Quimiocina CXCL1/genética , Quimiocina CXCL1/metabolismo , Citocinas/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Modelos Animales de Enfermedad , Inmunidad Innata , Inflamasomas/farmacología , Interleucina-1beta/metabolismo , Macrófagos Alveolares/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Sustancias Protectoras/farmacología , Serpinas/metabolismo , Proteínas Virales/metabolismoRESUMEN
The magnetic targeting (MT) technique improves delivery of mesenchymal stromal cells (MSCs) to target sites. However, the moderate-intensity static magnetic fields (SMF) used for MT may exert adverse effects on MSCs. Thus, we aimed to evaluate the effects of SMF on MSCs in vitro. Cells were initially magnetized using citrate-coated magnetite nanoparticles. Then, control and magnetized MSCs were transferred to an in vitro MT system and exposed to 0.3-0.45 Tesla SMFs. MSC viability, morphology, ultrastructure, proliferation rates, differentiation, and immunomodulation were evaluated after 24 and 48â¯hours of exposure. MSCs temporarily lost viability and exhibited ultrastructural changes after exposure to SMFs, regardless of magnetization. Moreover, exposure to SMF reduced magnetized MSC proliferation rates. Nevertheless, MSCs remained functional (i.e., capable of differentiating, secreting repair mediators, and modulating alveolar macrophage phenotype). Thus, the experimental protocol tested in this experiment can be applied in future in vivo MT studies.
Asunto(s)
Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Macrófagos Alveolares/inmunología , Campos Magnéticos , Nanopartículas de Magnetita/administración & dosificación , Células Madre Mesenquimatosas/citología , Animales , Células Cultivadas , Macrófagos Alveolares/efectos de los fármacos , Nanopartículas de Magnetita/química , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BLRESUMEN
Pneumonia is one of the leading causes of death and mortality worldwide. The inflammatory responses that follow respiratory infections are protective leading to pathogen clearance but can also be deleterious if unregulated. The microbiota is known to be an important protective barrier against infections, mediating both direct inhibitory effects against the potential pathogen and also regulating the immune responses contributing to a proper clearance of the pathogen and return to homeostasis. GPR43 is one receptor for acetate, a microbiota metabolite shown to induce and to regulate important immune functions. Here, we addressed the role of GPR43 signaling during pulmonary bacterial infections. We have shown for the first time that the absence of GPR43 leads to increased susceptibility to Klebsiella pneumoniae infection, which was associated to both uncontrolled proliferation of bacteria and to increased inflammatory response. Mechanistically, we showed that GPR43 expression especially in neutrophils and alveolar macrophages is important for bacterial phagocytosis and killing. In addition, treatment with the GPR43 ligand, acetate, is protective during bacterial lung infection. This was associated to reduction in the number of bacteria in the airways and to the control of the inflammatory responses. Altogether, GPR43 plays an important role in the "gut-lung axis" as a sensor of the host gut microbiota activity through acetate binding promoting a proper immune response in the lungs.
Asunto(s)
Infecciones por Klebsiella/inmunología , Klebsiella pneumoniae , Receptores Acoplados a Proteínas G/inmunología , Animales , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Citocinas/inmunología , Macrófagos Alveolares/inmunología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/inmunología , Fagocitosis , Receptores Acoplados a Proteínas G/genéticaRESUMEN
Considering its role in inflammation and recently described "alternative" roles in epithelial homeostasis and Th1/Th2 balance, we hypothesize that inflammasome genetics could contribute to the development of asthma. Selected functional polymorphisms in inflammasome genes are evaluated in a cohort of asthmatic children and their families. Gain-of-function NLRP1 variants rs11651270, rs12150220 and rs2670660 resulted significantly associated to asthma in trios (TDT) analysis; and rs11651270 and rs2670660 also with asthma severity and total IgE level in asthmatic children. NLRP1 activators in humans are still unknown, however we hypothesized that individuals with gain-of-function SNPs in NLRP1 could be more prone in activating inflammasome in the presence of asthma-related cell stressors (i.e. ER stress or ROS), and this activation contribute to exacerbate inflammatory response and asthma development. Gain-of-function IL1A rs17561 resulted significantly associated with a reduced pulmonary capacity in asthmatic children. IL18 rs5744256 which lead to lower serum level of IL-18 appeared to be associated to a worse response to bronchodilators. Concluding, this work provides evidences about the contribution of inflammasome genetics in the development of paediatric asthma, both considering its inflammatory role in alveolar macrophages (i.e.: NLRP1) or its homeostatic role in lung epithelial cells (i.e.: IL1A, IL18).
Asunto(s)
Asma/genética , Inflamasomas/genética , Polimorfismo de Nucleótido Simple , Proteínas Adaptadoras Transductoras de Señales/genética , Adolescente , Alarminas/fisiología , Proteínas Reguladoras de la Apoptosis/genética , Asma/epidemiología , Asma/inmunología , Brasil/epidemiología , Niño , Células Epiteliales/patología , Femenino , Mutación con Ganancia de Función , Humanos , Inmunoglobulina E/análisis , Interleucina-18/sangre , Interleucina-1alfa/genética , Interleucina-1beta/genética , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/metabolismo , Masculino , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteínas NLR , RegeneraciónRESUMEN
Leukotriene B4 (LTB4) is essential for host immune defence. It increases neutrophil recruitment, phagocytosis and pathogen clearance, and decreases oedema and inflammasome activation. The host response and the role of LTB4 during Achromobacter xylosoxidans infection remain unexplored. Wild-type (129sv) and LTB4 deficient (Alox5 -/-) mice were intratracheally infected with A. xylosoxidans. Wild-type 129sv infected mice survived beyond the 8th day post-infection, exhibited increased levels of LTB4 in the lung on the 1st day, while levels of PGE2 increased on the 7th day post-infection. Infected Alox5 -/- mice showed impaired bacterial clearance, increased lung inflammation, and succumbed to the infection by the 7th day. We found that exogenous LTB4 does not affect the phagocytosis of A. xylosoxidans by alveolar macrophages in vitro. However, treatment of infected animals with LTB4 protected from mortality, by reducing the bacterial load and inflammation via BLT1 signalling, the high affinity receptor for LTB4. Of importance, we uncovered that LTB4 induces gene and protein expression of α-defensin-1 during the infection. This molecule is essential for bacterial clearance and exhibits potent antimicrobial activity by disrupting A. xylosoxidans cell wall. Taken together, our data demonstrate a major role for LTB4 on the control of A. xylosoxidans infection.
Asunto(s)
Achromobacter denitrificans/fisiología , Infecciones por Bacterias Gramnegativas/inmunología , Inflamación/inmunología , Leucotrieno B4/metabolismo , Pulmón/inmunología , Macrófagos Alveolares/inmunología , Proteínas Activadoras de la 5-Lipooxigenasa/genética , Animales , Carga Bacteriana , Células Cultivadas , Dinoprostona/metabolismo , Ratones , Ratones de la Cepa 129 , Ratones Noqueados , Fagocitosis , Receptores de Leucotrieno B4/metabolismo , Transducción de Señal , alfa-Defensinas/metabolismoRESUMEN
Alveolar macrophages (AMs) are major targets of Mycobacterium tuberculosis (Mtb) infection, critical during the progression of active tuberculosis (TB). The complex immunopathology of TB generates diverse microenvironments in the lung, which shape immune responses by AMs. In the current study, we perform whole genome microarray transcriptional profiling on RNA isolated from AMs from TB patients (AMsTB) compared to AMs from control subjects (AMsCT) using bronchoalveolar lavage (BAL). Our hypothesis was that systemic effects on the local lung microenvironment during TB affect the transcriptional response of AMsTB. We found a unique gene expression profile of 51 genes, including up-regulated CHIT1, CHI3L1, CCL5, CCL22, CCL8, CXCL9, MMP9, MMP7 and MMP12, associated with a robust pro-inflammatory response, cell recruitment and tissue damage, and genes of the cyclin family (CCND1, CCND2, and CCNA1) associated with cell proliferation. These expression profiles may account for the inflammatory condition in the lungs of TB patients. CXCL5, IL1B, CAMP, and TGFB1 were down-regulated, suggesting an altered control of Mtb infection. Also, MARCO and COLEC12, affecting phagocytosis, and CES1, associated with an increase in free cholesterol, were down-regulated. The observed changes in mRNA expression profiles may partially account for the inability of AMsTB to effectively control Mtb infection, suggesting that a balanced control of pro- and anti-inflammatory immune responses is crucial for infection control.
Asunto(s)
Citocinas/genética , Perfilación de la Expresión Génica/métodos , Mediadores de Inflamación , Macrófagos Alveolares/metabolismo , Mycobacterium tuberculosis/patogenicidad , Transcriptoma , Tuberculosis Pulmonar/genética , Adulto , Estudios de Casos y Controles , Células Cultivadas , Citocinas/metabolismo , Femenino , Redes Reguladoras de Genes , Interacciones Huésped-Patógeno , Humanos , Mediadores de Inflamación/metabolismo , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/microbiología , Masculino , Mycobacterium tuberculosis/inmunología , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Transducción de Señal , Transcripción Genética , Tuberculosis Pulmonar/inmunología , Tuberculosis Pulmonar/metabolismo , Tuberculosis Pulmonar/microbiologíaRESUMEN
Alveolar macrophages (AMs) are multitasking cells that maintain lung homeostasis by clearing apoptotic cells (efferocytosis) and performing antimicrobial effector functions. Different PRRs have been described to be involved in the binding and capture of non-opsonized Streptococcus pneumoniae, such as TLR-2, mannose receptor (MR) and scavenger receptors (SRs). However, the mechanism by which the ingestion of apoptotic cells negatively influences the clearance of non-opsonized S. pneumoniae remains to be determined. In this study, we evaluated whether the prostaglandin E2 (PGE2) produced during efferocytosis by AMs inhibits the ingestion and killing of non-opsonized S. pneumoniae. Resident AMs were pre-treated with an E prostanoid (EP) receptor antagonist, inhibitors of cyclooxygenase and protein kinase A (PKA), incubated with apoptotic Jurkat T cells, and then challenged with S. pneumoniae. Efferocytosis slightly decreased the phagocytosis of S. pneumoniae but greatly inhibited bacterial killing by AMs in a manner dependent on PGE2 production, activation of the EP2-EP4/cAMP/PKA pathway and inhibition of H2O2 production. Our data suggest that the PGE2 produced by AMs during efferocytosis inhibits H2O2 production and impairs the efficient clearance non-opsonized S. pneumoniae by EP2-EP4/cAMP/PKA pathway.
Asunto(s)
Dinoprostona/metabolismo , Macrófagos Alveolares/inmunología , Fagocitosis , Infecciones Neumocócicas/inmunología , Streptococcus pneumoniae/inmunología , Animales , Apoptosis , Bacteriólisis , AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Femenino , Homeostasis , Humanos , Peróxido de Hidrógeno/metabolismo , Células Jurkat , Macrófagos Alveolares/microbiología , Ratas , Ratas Wistar , Subtipo EP2 de Receptores de Prostaglandina E/metabolismo , Subtipo EP4 de Receptores de Prostaglandina E/metabolismo , Transducción de SeñalRESUMEN
Previously we showed that 65-kDa Mycobacterium leprae heat shock protein (Hsp65) is a target for the development of a tuberculosis vaccine. Here we evaluated peripheral blood mononuclear cells (PBMC) from healthy individuals or tuberculosis patients stimulated with two forms of Hsp65 antigen, recombinant DNA that encodes Hsp65 (DNA-HSP65) or recombinant Hsp65 protein (rHsp65) in attempting to mimic a prophylactic or therapeutic study in vitro, respectively. Proliferation and cytokine-producing CD4+ or CD8+ cell were assessed by flow cytometry. The CD4+ cell proliferation from healthy individuals was stimulated by DNA-HSP65 and rHsp65, while CD8+ cell proliferation from healthy individuals or tuberculosis patients was stimulated by rHSP65. DNA-HSP65 did not improve the frequency of IFN-gamma+ cells from healthy individuals or tuberculosis patients. Furthermore, we found an increase in the frequency of IL-10-producing cells in both groups. These findings show that Hsp65 antigen activates human lymphocytes and plays an immune regulatory role that should be addressed as an additional antigen for the development of antigen-combined therapies.
Asunto(s)
Proteínas Bacterianas/inmunología , Chaperonina 60/inmunología , Inmunidad Celular , Activación de Linfocitos , Tuberculosis/inmunología , Adulto , Proteínas Bacterianas/genética , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Chaperonina 60/genética , Citotoxicidad Inmunológica , Femenino , Voluntarios Sanos , Humanos , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-10/biosíntesis , Interleucina-10/inmunología , Leucocitos Mononucleares/inmunología , Macrófagos Alveolares/inmunología , Masculino , Persona de Mediana Edad , Mycobacterium tuberculosis/inmunología , Proteínas Recombinantes/inmunología , Vacunas contra la Tuberculosis/inmunología , Regulación hacia Arriba , Vacunas de ADN/farmacología , Adulto JovenRESUMEN
PURPOSE: To investigate the effects of neonatal malnutrition followed by nutritional replacement on the signaling mechanisms developed by the inflammasome complex by analyzing the expression of the targeted TLR2, TLR4, NLRP3, caspase-1 and release of IL-1ß and IL-18 by alveolar macrophages infected in vitro with Candida albicans. METHODS: Male Wistar rats (n = 24), 90-120 days, were suckled by mothers whose diet during lactation contained 17 % protein in the nourish group and 8 % protein in the malnourished group. After weaning, both groups were fed a normal protein diet. Macrophages were obtained after tracheostomy, through the collection of bronchoalveolar lavage fluid. The quantification of the expression levels of targets (TLR2, TLR4, NLRP3 and caspase-1) was performed by real-time RT-PCR. Production of cytokines was performed by ELISA. RESULTS: The malnourished animals during lactation showed reduced body weight from the fifth day of life, remaining until adulthood. Further, the model applied malnutrition induced a lower expression of TLR4 and caspase-1. The quantification of the TLR2 and NLRP3, as well as the release of IL-1ß and IL-18, was not different between groups of animals nourished and malnourished. The system challenged with Candida albicans showed high expression levels of all targets in the study. CONCLUSIONS: The tests demonstrate nutritional restriction during critical periods of development, although nutritional supplementation may compromise defense patterns in adulthood in a timely manner, preserving distinct signaling mechanism, so that the individual does not become widely vulnerable to infections by opportunistic pathogens.
Asunto(s)
Candidiasis/metabolismo , Dieta con Restricción de Proteínas/efectos adversos , Regulación del Desarrollo de la Expresión Génica , Inflamasomas/metabolismo , Macrófagos Alveolares/metabolismo , Fenómenos Fisiologicos Nutricionales Maternos , Infecciones Oportunistas/metabolismo , Animales , Animales Recién Nacidos , Líquido del Lavado Bronquioalveolar/inmunología , Líquido del Lavado Bronquioalveolar/microbiología , Candida albicans/inmunología , Candidiasis/inmunología , Candidiasis/microbiología , Candidiasis/patología , Caspasa 1/genética , Caspasa 1/metabolismo , Células Cultivadas , Regulación hacia Abajo , Femenino , Inmunidad Innata , Inflamasomas/inmunología , Lactancia , Activación de Macrófagos/inmunología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/microbiología , Macrófagos Alveolares/patología , Masculino , Infecciones Oportunistas/inmunología , Infecciones Oportunistas/microbiología , Infecciones Oportunistas/patología , Ratas Wistar , Delgadez/etiología , Delgadez/inmunología , Delgadez/microbiología , Delgadez/patología , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
Coxiella burnetii is a Gram-negative bacterium that causes Q fever in humans. Q fever is an atypical pneumonia transmitted through inhalation of contaminated aerosols. In mammalian lungs, C. burnetii infects and replicates in several cell types, including alveolar macrophages (AMs). The innate immunity and signaling pathways operating during infection are still poorly understood, in part because of the lack of relevant host cell models for infection in vitro In the study described here, we investigated and characterized the infection of primary murine AMs by C. burnetii phase II in vitro Our data reveal that AMs show a pronounced M2 polarization and are highly permissive to C. burnetii multiplication in vitro Murine AMs present an increased susceptibility to infection in comparison to primary bone marrow-derived macrophages. AMs support more than 2 logs of bacterial replication during 12 days of infection in culture, similar to highly susceptible host cells, such as Vero and THP-1 cells. As a proof of principle that AMs are useful for investigation of C. burnetii replication, we performed experiments with AMs from Nos2(-/-) or Ifng(-/-) mice. In the absence of gamma interferon and nitric oxide synthase 2 (NOS2), AMs were significantly more permissive than wild-type cells. In contrast, AMs from Il4(-/-) mice were more restrictive to C. burnetii replication, supporting the importance of M2 polarization for the permissiveness of AMs to C. burnetii replication. Collectively, our data account for understanding the high susceptibility of alveolar macrophages to bacterial replication and support the use of AMs as a relevant model of C. burnetii growth in primary macrophages.
Asunto(s)
Coxiella burnetii/inmunología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/microbiología , Alveolos Pulmonares/inmunología , Alveolos Pulmonares/microbiología , Animales , Células Cultivadas , Inmunidad Innata/inmunología , Interferón gamma/inmunología , Ratones , Ratones Endogámicos C57BL , Óxido Nítrico Sintasa de Tipo II/inmunología , Fiebre Q/inmunología , Fiebre Q/microbiología , Transducción de Señal/inmunologíaRESUMEN
Cysteinyl leukotrienes (CysLTs) and lipoxins (LXs) are lipid mediators that control inflammation, with the former inducing and the latter inhibiting this process. Because the role played by these mediators in paracoccidioidomycosis was not investigated, we aimed to characterize the role of CysLT in the pulmonary infection developed by resistant (A/J) and susceptible (B10.A) mice. 48 h after infection, elevated levels of pulmonary LTC4 and LXA4 were produced by both mouse strains, but higher levels were found in the lungs of susceptible mice. Blocking the CysLTs receptor by MTL reduced fungal loads in B10.A, but not in A/J mice. In susceptible mice, MLT treatment led to reduced influx of PMN leukocytes, increased recruitment of monocytes, predominant synthesis of anti-inflammatory cytokines, and augmented expression of 5- and 15-lipoxygenase mRNA, suggesting a prevalent LXA4 activity. In agreement, MTL-treated macrophages showed reduced fungal burdens associated with decreased ingestion of fungal cells. Furthermore, the addition of exogenous LX reduced, and the specific blockade of the LX receptor increased the fungal loads of B10.A macrophages. This study showed for the first time that inhibition of CysLTs signaling results in less severe pulmonary paracoccidioidomycosis that occurs in parallel with elevated LX activity and reduced infection of macrophages.