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In the present studies the assessment of how viral exacerbation of asthmatic responses with and without pulmonary steroid treatment altered the microbiome in conjunction with immune responses presents striking data. The overall findings identify that while steroid treatment of allergic animals diminished the severity of the respiratory syncytial virus (RSV)-induced exacerbation of airway function and mucus hypersecretion, there were local increases in IL-17A expression. Analysis of lung and gut microbiome suggested that there are differences in the RSV exacerbation that are further altered by fluticasone (FLUT) treatment. Using metagenomic inference software, PICRUSt2, we were able to predict that the metabolite profile that the changed gut microbiome produced was significantly different with multiple metabolic pathways and associated with specific treatments with or without FLUT. Importantly, measuring plasma metabolites, our data indicate that there are significant changes associated with chronic allergen exposure, RSV exacerbation, and with FLUT treatment. The changes to the metabolites have contributions from both host and microbial pathways. To understand if airway steroids on their own altered lung and gut microbiome along with host responses to RSV infection, naïve animals were treated with FLUT prior to RSV infection. The naïve animals with FLUT prior to RSV infection demonstrated enhanced disease corresponding to altered microbiome and the PICRUSt2 metagenomic inference analysis. Altogether, these findings set the foundation for identifying important correlations of severe viral exacerbated allergic disease with microbiome changes a potential for early life pulmonary steroid influence on subsequent viral induced disease.
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Early-life respiratory virus infections have been correlated with enhanced development of childhood asthma. In particular, significant numbers of respiratory syncytial virus (RSV)-hospitalized infants go on to develop lung disease. It has been suggested that early-life viral infections may lead to altered lung development or repair that negatively impacts lung function later in life. Our data demonstrate that early-life RSV infection modifies lung structure, leading to decreased lung function. At 5 wk postneonatal RSV infection, significant defects are observed in baseline pulmonary function test (PFT) parameters consistent with decreased lung function as well as enlarged alveolar spaces. Lung function changes in the early-life RSV-infected group continue at 3 mo of age. The altered PFT and structural changes induced by early-life RSV were mitigated in TSLPR-/- mice that have previously been shown to have reduced immune cell accumulation associated with a persistent Th2 environment. Importantly, long-term effects were demonstrated using a secondary RSV infection 3 mo following the initial early-life RSV infection and led to significant additional defects in lung function, with severe mucus deposition within the airways, and consolidation of the alveolar spaces. These studies suggest that early-life respiratory viral infection leads to alterations in lung structure/repair that predispose to diminished lung function later in life.NEW & NOTEWORTHY These studies outline a novel finding that early-life respiratory virus infection can alter lung structure and function long-term. Importantly, the data also indicate that there are critical links between inflammatory responses and subsequent events that produce a more severe pathogenic response later in life. The findings provide additional data to support that early-life infections during lung development can alter the trajectory of airway function.
Assuntos
Pneumopatias , Pneumonia , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Humanos , Lactente , Animais , Camundongos , Pulmão/patologia , Pneumonia/complicações , Pneumopatias/complicações , Camundongos Endogâmicos BALB CRESUMO
Our studies have previously shown a role for persistent TSLP production in the lungs of mice after early-life respiratory syncytial virus (RSV) infection that leads to an altered immune phenotype, including accumulation of "inflammatory" dendritic cells (DC). This study investigates the role of TSLP driving systemic trained immunity in DC in early-life RSV-infected mice. Bone marrow-derived DCs (BMDC) from early-life RSV-infected mice at 4 wk postinfection showed enhanced expression of costimulatory molecules and cytokines, including Tslp, that regulate immune cell function. The adoptive transfer of BMDC grown from early-life RSV-infected mice was sufficient to exacerbate allergic disease development. The addition of recombinant TSLP during differentiation of BMDC from naive mice induced a similar altered phenotype as BMDC grown from early-life RSV-infected mice, suggesting a role for TSLP in the phenotypic changes. To assess the role of TSLP in these changes, global transcriptomic characterization of TSLPR-/- BMDC infected with RSV was performed and showed a higher upregulation of type 1 IFN genes and concomitant downregulation of inflammatory genes. Assay for transposase-accessible chromatin using sequencing analysis demonstrated that TSLPR-/- BMDC had a parallel gain in physical chromatin accessibility near type 1 genes and loss in accessibility near genes related to RSV pathology, with IFN regulatory factor 4 (IRF4) and STAT3 predicted as top transcription factors binding within differentially accessible regions in wild-type. Importantly, these studies show that in the absence of TSLP signaling, BMDC are able to mount an appropriate type 1 IFN-associated antiviral response to RSV. In summary, RSV-induced TSLP alters chromatin structure in DC to drive trained innate immunity and activates pathogenic gene programs in mice.
Assuntos
Montagem e Desmontagem da Cromatina/imunologia , Citocinas/metabolismo , Células Dendríticas/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Fatores Etários , Animais , Animais Recém-Nascidos , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Imunoglobulinas/genética , Imunoglobulinas/metabolismo , Lactente , Fatores Reguladores de Interferon/metabolismo , Interferon Tipo I/genética , Masculino , Camundongos , Camundongos Knockout , Receptores de Citocinas/genética , Receptores de Citocinas/metabolismo , Infecções por Vírus Respiratório Sincicial/genética , Infecções por Vírus Respiratório Sincicial/virologia , Fator de Transcrição STAT3/metabolismo , Regulação para Cima/imunologia , Linfopoietina do Estroma do TimoRESUMO
Severe disease following respiratory syncytial virus (RSV) infection has been linked to enhanced proinflammatory cytokine production that promotes a Th2-type immune environment. Epigenetic regulation in immune cells following viral infection plays a role in the inflammatory response and may result from upregulation of key epigenetic modifiers. In this study, we show that RSV-infected bone marrow-derived dendritic cells (BMDC) as well as pulmonary dendritic cells (DC) from RSV-infected mice upregulated the expression of Kdm6b/Jmjd3 and Kdm6a/Utx, H3K27 demethylases. KDM6-specific chemical inhibition (GSK J4) in BMDC led to decreased production of chemokines and cytokines associated with the inflammatory response during RSV infection (i.e., CCL-2, CCL-3, CCL-5, IL-6) as well as decreased MHC class II and costimulatory marker (CD80/86) expression. RSV-infected BMDC treated with GSK J4 altered coactivation of T cell cytokine production to RSV as well as a primary OVA response. Airway sensitization of naive mice with RSV-infected BMDCs exacerbate a live challenge with RSV infection but was inhibited when BMDCs were treated with GSK J4 prior to sensitization. Finally, in vivo treatment with the KDM6 inhibitor, GSK J4, during RSV infection reduced inflammatory DC in the lungs along with IL-13 levels and overall inflammation. These results suggest that KDM6 expression in DC enhances proinflammatory innate cytokine production to promote an altered Th2 immune response following RSV infection that leads to more severe immunopathology.
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Histona Desmetilases/imunologia , Inflamação/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Regulação para Cima , Animais , Linhagem Celular Tumoral , Células Dendríticas/imunologia , Células Dendríticas/patologia , Feminino , Humanos , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Infecções por Vírus Respiratório Sincicial/patologiaRESUMO
Allergic asthma is a chronic airway inflammatory response to different triggers like inhaled allergens. Excessive ATP in fluids from patients with asthma is considered an inflammatory signal and an important autocrine/paracrine modulator of airway physiology. Here, we investigated the deleterious effect of increased extracellular ATP (eATP) concentration on the mucociliary clearance (MCC) effectiveness and determined the role of ATP releasing channels during airway inflammation in an ovalbumin (OVA)-sensitized mouse model. Our allergic mouse model exhibited high levels of eATP measured in the tracheal fluid with a luciferin-luciferase assay and reduced MCC velocity determined by microspheres tracking in the trachea ex vivo. Addition of ATP had a dual effect on MCC, where lower ATP concentration (µM) increased microspheres velocity, whereas higher concentration (mM) transiently stopped microspheres movement. Also, an augmented ethidium bromide uptake by the allergic tracheal airway epithelium suggests an increase in ATP release channel functionality during inflammatory conditions. The use of carbenoxolone, a nonspecific inhibitor of connexin and pannexin1 channels reduced the eATP concentration in the allergic mouse tracheal fluid and dye uptake by the airway epithelium, providing evidence that these ATP release channels are facilitating the net flux of ATP to the lumen during airway inflammation. However, only the specific inhibition of pannexin1 with 10Panx peptide significantly reduced eATP in bronchoalveolar lavage and decreased airway hyperresponsiveness in OVA-allergic mouse model. These data provide evidence that blocking eATP may be a pharmacological alternative to be explored in rescue therapy during episodes of airflow restriction in patients with asthma.
Assuntos
Trifosfato de Adenosina/imunologia , Asma/imunologia , Carbenoxolona/farmacologia , Conexinas/imunologia , Proteínas do Tecido Nervoso/imunologia , Mucosa Respiratória/imunologia , Traqueia/imunologia , Animais , Asma/induzido quimicamente , Asma/tratamento farmacológico , Asma/patologia , Conexinas/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Microesferas , Peptídeos/imunologia , Peptídeos/farmacologia , Mucosa Respiratória/patologia , Traqueia/patologiaRESUMO
BACKGROUND: Respiratory syncytial virus (RSV) affects most infants early in life and is associated with increased asthma risk. The specific mechanism remains unknown. OBJECTIVE: To investigate the role of uric acid (UA) and IL-1ß in RSV immunopathology and asthma predisposition. METHODS: Tracheal aspirates from human infants with and without RSV were collected and analyzed for pro-IL-1ß mRNA and protein to establish a correlation in human disease. Neonatal mouse models of RSV were employed, wherein mice infected at 6-7 days of life were analyzed at 8 days postinfection, 5 weeks postinfection, or after a chronic cockroach allergen asthma model. A xanthine oxidase inhibitor or IL-1 receptor antagonist was administered during RSV infection. RESULTS: Human tracheal aspirates from RSV-infected infants showed elevated pro-IL-1ß mRNA and protein. Inhibition of UA or IL-1ß during neonatal murine RSV infection decreased mucus production, reduced cellular infiltrates to the lung (especially ILC2s), and decreased type 2 immune responses. Inhibition of either UA or IL-1ß during RSV infection led to chronic reductions in pulmonary immune cell composition and reduced type 2 immune responses and reduced similar responses after challenge with cockroach antigen. CONCLUSIONS: Inhibiting UA and IL-1ß during RSV infection ameliorates RSV immunopathology, reduces the consequences of allergen-induced asthma, and presents new therapeutic targets to reduce early-life viral-induced asthma development.
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Asma , Infecções por Vírus Respiratório Sincicial , Animais , Imunidade Inata , Pulmão , Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Vírus Sinciciais Respiratórios , Ácido ÚricoRESUMO
PURPOSE OF REVIEW: Allergy and asthma are growing problems in the developed world. The accelerated increase of these diseases may be related to microbiome modification that leads to aberrant activation of Toll-like receptors (TLRs). Current research supports the concept that changes in microbial communities in early life impact TLR activation, resulting in an altered risk for the development of asthma and allergies. RECENT FINDINGS: Prenatal and early childhood events that generate microbiome modification are closely related with TLR activation. Early childhood exposure to a rich array of TLR agonists, particularly lipopolysaccharide, strongly predicts protection against allergic disease later in life even when other lifestyle factors are accounted for. Genetic deletion of TLR signaling components in mice results in reduced function of tolerogenic cell populations in the gut. In contrast, weak TLR signaling can promote allergic sensitization later in life. This review summarizes the role of TLR signaling in microbiome-mediated protection against allergy.
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Hipersensibilidade , Microbiota , Receptores Toll-Like/imunologia , Animais , Humanos , Hipersensibilidade/tratamento farmacológico , Hipersensibilidade/imunologia , Hipersensibilidade/microbiologia , Transdução de SinaisRESUMO
Entamoeba histolytica is the protozoan parasite causative of human amoebiasis, disease responsible for 40 000-100 000 deaths annually. The cysteine proteinase-adhesin complex of this parasite (EhCPADH) is a heterodimeric protein formed by a cysteine protease (EhCP112) and an adhesin (EhADH) that plays an important role in the cytopathic mechanism of this parasite. The coding genes for EhCP112 and EhADH are adjacent in the E. histolytica genome, suggesting that their expression may be co-regulated, but this hypothesis has not yet been confirmed. Here, we performed the knockdown of EhCP112 and EhADH using gene-specific short-hairpin RNAs (shRNA), and the effect of these knockdowns on the expression of both complex components as well as on the in vitro and in vivo virulence was analysed. Results showed that the knockdown of one of the EhCPADH components produced a simultaneous downregulation of the other protein. Accordingly, a concomitant reduction in the overall expression of the complex was observed. The downregulation of each component also produced a significant decrease in the in vitro and in vivo virulence of trophozoites. These results demonstrated that the expression of EhCP112 and EhADH is co-regulated and confirmed that the EhCPADH complex plays an important role in E. histolytica virulence.
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Anticorpos Antiprotozoários/imunologia , Cisteína Proteases/genética , Entamoeba histolytica/enzimologia , Entamebíase/parasitologia , Regulação da Expressão Gênica , Proteínas de Protozoários/genética , Animais , Cricetinae , Cisteína Proteases/metabolismo , Entamoeba histolytica/genética , Entamoeba histolytica/imunologia , Entamoeba histolytica/patogenicidade , Feminino , Técnicas de Silenciamento de Genes , Humanos , Masculino , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Complexos Multiproteicos , Proteínas de Protozoários/metabolismo , RNA Interferente Pequeno/genética , Trofozoítos/metabolismo , VirulênciaRESUMO
Infections with influenza and respiratory syncytial virus (RSV) rank high among the most common human respiratory diseases worldwide. Previously, we developed a replication-incompetent influenza virus by replacing the coding sequence of the PB2 gene, which encodes one of the viral RNA polymerase subunits, with that of a reporter gene. Here, we generated a PB2-knockout recombinant influenza virus expressing the F protein of RSV (PB2-RSVF virus) and tested its potential as a bivalent vaccine. In mice intranasally immunized with the PB2-RSVF virus, we detected high levels of antibodies against influenza virus, but not RSV. PB2-RSVF virus-immunized mice were protected from a lethal challenge with influenza virus but experienced severe body weight loss when challenged with RSV, indicating that PB2-RSVF vaccination enhanced RSV-associated disease. These results highlight one of the difficulties of developing an effective bivalent vaccine against influenza virus and RSV infections.
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Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vírus Sinciciais Respiratórios/imunologia , Proteínas Virais de Fusão/metabolismo , Animais , Feminino , Regulação Viral da Expressão Gênica , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Vírus Respiratório Sincicial/prevenção & controle , Vírus Sinciciais Respiratórios/metabolismo , Vacinas Sintéticas/imunologia , Replicação ViralRESUMO
Early-life (EL) respiratory infections increase pulmonary disease risk, especially EL-Respiratory Syncytial Virus (EL-RSV) infections linked to asthma. Mechanisms underlying asthma predisposition remain unknown. In this study, we examined the long-term effects on the lung after four weeks post EL-RSV infection. We identified alterations in the lung epithelial cell, with a rise in the percentage of alveolar type 2 epithelial cells (AT2) and a decreased percentage of cells in the AT1 and AT2-AT1 subclusters, as well as upregulation of Bmp2 and Krt8 genes that are associated with AT2-AT1 trans-differentiation, suggesting potential defects in lung repair processes. We identified persistent upregulation of asthma-associated genes, including Il33. EL-RSV-infected mice allergen-challenged exhibited exacerbated allergic response, with significant upregulation of Il33 in the lung and AT2 cells. Similar long-term effects were observed in mice exposed to EL-IL-1ß. Notably, treatment with IL-1ra during acute EL-RSV infection mitigated the long-term alveolar alterations and the allergen-exacerbated response. Finally, epigenetic modifications in the promoter of the Il33 gene were detected in AT2 cells harvested from EL-RSV and EL-IL1ß groups, suggesting that long-term alteration in the epithelium after RSV infection is dependent on the IL-1ß pathway. This study provides insight into the molecular mechanisms of asthma predisposition after RSV infection.
RESUMO
Eosinophilic esophagitis (EoE) is a T helper (Th)2-mediated inflammatory disorder characterized endoscopically by eosinophilic infiltration leading to fibrosis of the esophagus. Stem cell factor (SCF), a multifunctional cytokine, is upregulated in several allergic diseases, including in patients with EoE. Mast cells and eosinophils express c-kit, the cell surface receptor for SCF, and have been found to play an important role in EoE. Therefore, we investigated whether blocking SCF represents a potential therapeutic approach for EoE. Esophageal inflammation was induced in mice using peanut allergen. In mice with experimental EoE, we found that SCF was upregulated in the esophageal tissue. In EoE mice injected with a polyclonal antibody specific for SCF, we observed a decrease in both mast cells and eosinophils by histological and flow cytometric analysis. Furthermore, Th2 cytokines in the esophagus were decreased in anti-SCF treated mice, as were levels of Th2 cytokines from lung-draining and esophageal lymph nodes. Serum levels of peanut-specific immunoglobulin E were reduced following treatment with anti-SCF. In Kitlf/f-Col1-Cre-ERT mice, which have SCF deleted primarily in myofibroblasts that develop in EoE, we observed similar results as the anti-SCF treated animals for inflammatory cell accumulation, cytokines, and histopathology. These results indicate that therapeutic treatments targeting SCF can reduce allergic inflammation in EoE.
Assuntos
Esofagite Eosinofílica , Humanos , Camundongos , Animais , Esofagite Eosinofílica/tratamento farmacológico , Fator de Células-Tronco/metabolismo , Inflamação/metabolismo , Modelos Animais de Doenças , Citocinas/metabolismo , Eosinófilos , AlérgenosRESUMO
This study investigates sex-associated systemic innate immune differences by examining bone marrow-derived dendritic cells (BMDCs). BMDC grown from 7-day-old mice show enhanced type-I interferon (IFN) signaling in female compared to male BMDC. Upon respiratory syncytial virus (RSV) infection of 7-day-old mice, a significantly altered phenotype of BMDC at 4 weeks post-infection is observed in a sex-dependent manner. The alterations include heightened Ifnb/ interleukin (Il12a) and enhanced IFNAR1+ expression in BMDC from early-life RSV-infected female mice that leads to increased IFN-γ production by T cells. Phenotypic differences were verified upon pulmonary sensitization whereby EL-RSV male-derived BMDC promoted enhanced T helper 2/17 responses and exacerbated disease upon RSV infection while EL-RSV/F BMDC sensitization was relatively protective. Assay for transposase-accessible chromatin using sequencing analysis (ATAC-seq) demonstrated that EL-RSV/F BMDC had enhanced chromatin accessibility near type-I immune genes with JUN, STAT1/2, and IRF1/8 transcription factors predicted to have binding sites in accessible regions. Importantly, ATAC-seq of human cord blood-derived monocytes displayed a similar sex-associated chromatin landscape with female-derived monocytes having more accessibility in type-I immune genes. These studies enhance our understanding of sex-associated differences in innate immunity by epigenetically controlled transcriptional programs amplified by early-life infection in females via type-I immunity.
Assuntos
Interferon Tipo I , Infecções por Vírus Respiratório Sincicial , Masculino , Camundongos , Feminino , Humanos , Animais , Montagem e Desmontagem da Cromatina , Imunidade Inata , Pulmão , Interferon Tipo I/metabolismo , Cromatina/genética , Cromatina/metabolismoRESUMO
The pathogenesis of asthma has been partially linked to lung and gut microbiome. We utilized a steroid-resistant chronic model of cockroach antigen-induced (CRA) asthma with corticosteroid (fluticasone) treatment to examine lung and gut microbiome during disease. The pathophysiology assessment demonstrated that mucus and airway hyperresponsiveness were increased in the chronic CRA with no alteration in the fluticasone (Flut)-treated group, demonstrating steroid resistance. Analysis of mRNA from lungs showed no decrease of MUC5AC or Gob5 in the Flut-treated group. Furthermore, flow-cytometry in lung tissue showed eosinophils and neutrophils were not significantly reduced in the Flut-treated group compared to the chronic CRA group. When the microbiome profiles were assessed, data showed that only the Flut-treated animals were significantly different in the gut microbiome. Finally, a functional analysis of cecal microbiome metabolites using PiCRUSt showed several biosynthetic pathways were significantly enriched in the Flut-treated group, with tryptophan pathway verified by ELISA with increased kynurenine in homogenized cecum samples. While the implications of these data are unclear, they may suggest a significant impact of steroid treatment on future disease pathogenesis through microbiome and associated metabolite pathway changes.
Assuntos
Asma , Baratas , Microbiota , Animais , Pulmão/patologia , Asma/etiologia , Alérgenos , FluticasonaRESUMO
Several environmental factors can influence the development and establishment of the early-life microbiota. For example, exposure to different environmental factors from birth to childhood will shape the lung and gut microbiota and the development of the immune system, which will impact respiratory tract infection and widespread disease occurrence during infancy and later in life. Respiratory syncytial virus (RSV) infects most infants by the age of two and is the primary cause of bronchiolitis in children worldwide. Approximately a third of infants hospitalized with bronchiolitis develop asthma later in life. However, it is unclear what factors increase susceptibility to severe RSV-bronchiolitis and the subsequent asthma development. In recent years, the role of the gut and lung microbiota in airway diseases has received increased interest, and more studies have focused on this field. Different epidemiological studies and experimental animal models have associated early-life gut microbiota dysbiosis with an increased risk of lung disease later in life. This work will review published evidence that correlated environmental factors that affect the early-life microbiota composition and their role in developing severe RSV infection.
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Asma , Bronquiolite , Microbioma Gastrointestinal , Microbiota , Infecções por Vírus Respiratório Sincicial , Vírus Sincicial Respiratório Humano , Animais , Asma/etiologia , Bronquiolite/complicações , Criança , Humanos , PulmãoRESUMO
Innate lymphoid type-2 cells (ILC2) are a population of innate cells of lymphoid origin that are known to drive strong Type 2 immunity. ILC2 play a key role in lung homeostasis, repair/remodeling of lung structures following injury, and initiation of inflammation as well as more complex roles during the immune response, including the transition from innate to adaptive immunity. Remarkably, dysregulation of this single population has been linked with chronic lung pathologies, including asthma, chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrotic diseases (IPF). Furthermore, ILC2 have been shown to increase following early-life respiratory viral infections, such as respiratory syncytial virus (RSV) and rhinovirus (RV), that may lead to long-term alterations of the lung environment. The detrimental roles of increased ILC2 following these infections may include pathogenic chronic inflammation and/or alterations of the structural, repair, and even developmental processes of the lung. Respiratory viral infections in older adults and patients with established chronic pulmonary diseases often lead to exacerbated responses, likely due to previous exposures that leave the lung in a dysregulated functional and structural state. This review will focus on the role of ILC2 during respiratory viral exposures and their effects on the induction and regulation of lung pathogenesis. We aim to provide insight into ILC2-driven mechanisms that may enhance lung-associated diseases throughout life. Understanding these mechanisms will help identify better treatment options to limit not only viral infection severity but also protect against the development and/or exacerbation of other lung pathologies linked to severe respiratory viral infections.
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Imunidade Inata , Pneumopatias/etiologia , Pneumopatias/metabolismo , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Viroses/complicações , Viroses/virologia , Imunidade Adaptativa , Animais , Biomarcadores , Progressão da Doença , Suscetibilidade a Doenças , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Pneumopatias/diagnóstico , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismoRESUMO
Food allergy is a growing public health problem with ~15 million people affected in the United States. In allergic food disease, IgE on mast cells bind to ingested antigens leading to the activation and degranulation of mast cells. Stem cell factor (SCF) is mast cell growth and activation factor that is required for peripheral tissue mast cells. We targeted a specific isoform of SCF, the larger 248 amino acid form, that drives peripheral tissue mast cell differentiation using a specific monoclonal antibody in a model of food allergy. Ovalbumin sensitized and intragastrically challenged mice were monitored for symptoms of anaphylaxis including respiratory distress, diarrhea, and a reduction in body temperature. During the second week of challenges, allergic mice were injected with an antibody to block SCF248 or given IgG control. Mice treated with α-SCF248 had a decreased incidence of diarrhea and no reduction in body temperature suggesting a reduction in anaphylaxis compared to IgG control treated animals. Re-stimulated mesenteric lymph nodes indicated that α-SCF248 treated mice had decreased OVA-specific Th2 cytokine production compared to IgG control treated allergic animals. The reduction of food induced anaphylaxis was accompanied by a significant reduction in gut leak. The mesenteric lymph node cells were analyzed by flow cytometry and showed a decrease in the number of type 2 innate lymphoid cells in mice injected with α-SCF248. Morphometric enumeration of esterase+ mast cells demonstrated a significant reduction throughout the small intestine. Using a more chronic model of persistent food-induced anaphylaxis, short term therapeutic treatment with α-SCF248 during established disease effectively blocked food induced anaphylaxis. Together, these data suggest that therapeutically blocking SCF248 in food allergic animals can reduce the severity of food allergy by reducing mast cell mediated disease activation.
Assuntos
Anafilaxia/imunologia , Anafilaxia/prevenção & controle , Anticorpos Monoclonais/farmacocinética , Anticorpos Neutralizantes/farmacologia , Hipersensibilidade Alimentar/imunologia , Fator de Células-Tronco/antagonistas & inibidores , Alérgenos/imunologia , Anafilaxia/diagnóstico , Anafilaxia/tratamento farmacológico , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Biomarcadores , Biópsia , Quimiocina CCL2/metabolismo , Modelos Animais de Doenças , Feminino , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/tratamento farmacológico , Imunoglobulina E/imunologia , Imunofenotipagem , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mastócitos/efeitos dos fármacos , Mastócitos/imunologia , Mastócitos/metabolismo , Camundongos , Células Th2/imunologia , Células Th2/metabolismoRESUMO
Respiratory syncytial virus (RSV) infects most infants by two years of age. It can cause severe disease leading to an increased risk of developing asthma later in life. Previously, our group has shown that RSV infection in mice and infants promotes IL-1ß production. Here, we characterized the role of NLRP3-Inflammasome activation during RSV infection in adult mice and neonates. We observed that the inhibition of NLRP3 activation using the small molecule inhibitor, MCC950, or in genetically modified NLRP3 knockout (Nlrp3-/-) mice during in vivo RSV infection led to decreased lung immunopathology along with a reduced expression of the mucus-associated genes and reduced production of innate cytokines (IL-1ß, IL-33 and CCL2) linked to severe RSV disease while leading to significant increases in IFN-ß. NLRP3-inflammasome inhibition or deletion diminished Th2 cytokines and inflammatory cell infiltration into the lungs. Furthermore, NLRP3 inhibition or deletion during early-life RSV infection led to reducing viral-exacerbated allergic response in a mouse model of RSV-induced allergy exacerbation. Here, we demonstrated the critical role of NLRP3-inflammasome activation in RSV immunopathology and the related long-term airway alteration. Moreover, these findings suggest the NLRP3-inflammasome as a potential therapeutic target to attenuate severe RSV disease and limit childhood asthma development.
Assuntos
Inflamassomos/antagonistas & inibidores , Pulmão/imunologia , Pulmão/virologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Doenças Respiratórias/prevenção & controle , Animais , Animais Recém-Nascidos , Citocinas/imunologia , Feminino , Furanos/administração & dosagem , Indenos/administração & dosagem , Inflamassomos/genética , Inflamassomos/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Vírus Sincicial Respiratório Humano/imunologia , Doenças Respiratórias/imunologia , Doenças Respiratórias/virologia , Sulfonamidas/administração & dosagemRESUMO
BACKGROUND AND OBJECTIVES: African Americans and males have elevated risks of infection, hospitalization, and death from SARS-CoV-2 in comparison with other populations. We report immune responses and renal injury markers in African American male patients hospitalized for COVID-19. METHODS: This was a single-center, retrospective study of 56 COVID-19 infected hospitalized African American males 50+ years of age selected from among non-intensive care unit (ICU) and ICU status patients. Demographics, hospitalization-related variables, and medical history were collected from electronic medical records. Plasma samples collected close to admission (≤2 days) were evaluated for cytokines and renal markers; results were compared to a control group (n = 31) and related to COVID-19 in-hospital mortality. RESULTS: Among COVID-19 patients, eight (14.2%) suffered in-hospital mortality; seven (23.3%) in the ICU and one (3.8%) among non-ICU patients. Interleukin (IL)-18 and IL-33 were elevated at admission in COVID-19 patients in comparison with controls. IL-6, IL-18, MCP-1/CCL2, MIP-1α/CCL3, IL-33, GST, and osteopontin were upregulated at admission in ICU patients in comparison with controls. In addition to clinical factors, MCP-1 and GST may provide incremental value for risk prediction of COVID-19 in-hospital mortality. CONCLUSIONS: Qualitatively similar inflammatory responses were observed in comparison to other populations reported in the literature, suggesting non-immunologic factors may account for outcome differences. Further, we provide initial evidence for cytokine and renal toxicity markers as prognostic factors for COVID-19 in-hospital mortality among African American males.
Assuntos
Biomarcadores/sangue , COVID-19/imunologia , Hospitais , Rim/imunologia , Negro ou Afro-Americano , Idoso , COVID-19/mortalidade , Citocinas/sangue , Citocinas/metabolismo , Mortalidade Hospitalar , Hospitalização , Humanos , Unidades de Terapia Intensiva , Rim/lesões , Masculino , Michigan , Pessoa de Meia-Idade , Estudos Retrospectivos , SARS-CoV-2RESUMO
Development of the immune system can be influenced by diverse extrinsic and intrinsic factors that influence the risk of disease. Severe early life respiratory syncytial virus (RSV) infection is associated with persistent immune alterations. Previously, our group had shown that adult mice orally supplemented with Lactobacillus johnsonii exhibited decreased airway immunopathology following RSV infection. Here, we demonstrate that offspring of mice supplemented with L. johnsonii exhibit reduced airway mucus and Th2 cell-mediated response to RSV infection. Maternal supplementation resulted in a consistent gut microbiome in mothers and their offspring. Importantly, supplemented maternal plasma and breastmilk, and offspring plasma, exhibited decreased inflammatory metabolites. Cross-fostering studies showed that prenatal Lactobacillus exposure led to decreased Th2 cytokines and lung inflammation following RSV infection, while postnatal Lactobacillus exposure diminished goblet cell hypertrophy and mucus production in the lung in response to airway infection. These studies demonstrate that Lactobacillus modulation of the maternal microbiome and associated metabolic reprogramming enhance airway protection against RSV in neonates.
Assuntos
Microbioma Gastrointestinal/imunologia , Infecções por Vírus Respiratório Sincicial/imunologia , Animais , Citocinas/imunologia , Modelos Animais de Doenças , Feminino , Pulmão/imunologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Gravidez , Células Th2/imunologiaRESUMO
Respiratory syncytial virus (RSV) is often the first clinically relevant pathogen encountered in life, with nearly all children infected by two years of age. Many studies have also linked early-life severe respiratory viral infection with more pathogenic immune responses later in life that lead to pulmonary diseases like childhood asthma. This phenomenon is thought to occur through long-term immune system alterations following early-life respiratory viral infection and may include local responses such as unresolved inflammation and/or direct structural or developmental modifications within the lung. Furthermore, systemic responses that could impact the bone marrow progenitors may be a significant cause of long-term alterations, through inflammatory mediators and shifts in metabolic profiles. Among these alterations may be changes in transcriptional and epigenetic programs that drive persistent modifications throughout life, leaving the immune system poised toward pathogenic responses upon secondary insult. This review will focus on early-life severe RSV infection and long-term alterations. Understanding these mechanisms will not only lead to better treatment options to limit initial RSV infection severity but also protect against the development of childhood asthma linked to severe respiratory viral infections.