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Methods in Molecular Biology (Clifton,... 2018The lung is constantly exposed to both environmental and microbial challenge. As a "contained" organ, it also constitutes an excellent "self-contained" tissue to examine...
The lung is constantly exposed to both environmental and microbial challenge. As a "contained" organ, it also constitutes an excellent "self-contained" tissue to examine inflammatory responses and cellular infiltration into a diseased organ. Influenza A virus (IAV) causes both mild and severe inflammation that is strain specific following infection of the lung epithelium that spreads to other cells of the lung environment. Here, we describe a method of intranasal inoculation of the lung with IAV that can be used as a preclinical model of infection. Mice can be monitored for clinical signs of infection and tissue and lung fluid collected for further analysis to dissect the immunological consequences of IAV infection. Importantly, this method can be modified to introduce other pathogens, therapies and environmental stimuli to examine immune responses in the lung.
Topics: Administration, Intranasal; Animals; Bronchoalveolar Lavage Fluid; Cytokines; Disease Models, Animal; Female; Influenza A virus; Lung; Male; Mice; Mice, Inbred C57BL; Orthomyxoviridae Infections; Pneumonia
PubMed: 29322411
DOI: 10.1007/978-1-4939-7568-6_8 -
Frontiers in Immunology 2021Eukaryotic translation initiation factor 4B (eIF4B) plays an important role in mRNA translation initiation, cell survival and proliferation . However, its function is...
Eukaryotic translation initiation factor 4B (eIF4B) plays an important role in mRNA translation initiation, cell survival and proliferation . However, its function is poorly understood. Here, we identified that eIF4B knockout (KO) in mice led to embryonic lethality, and the embryos displayed severe liver damage. Conditional KO (CKO) of eIF4B in adulthood profoundly increased the mortality of mice, characterized by severe pathological changes in several organs and reduced number of peripheral blood lymphocytes. Strikingly, eIF4B CKO mice were highly susceptible to viral infection with severe pulmonary inflammation. Selective deletion of eIF4B in lung epithelium also markedly promoted replication of influenza A virus (IAV) in the lung of infected animals. Furthermore, we observed that eIF4B deficiency significantly enhanced the expression of several important inflammation-associated factors and chemokines, including serum amyloid A1 (Saa1), Marco, Cxcr1, Ccl6, Ccl8, Ccl20, Cxcl2, Cxcl17 that are implicated in recruitment and activation of neutrophiles and macrophages. Moreover, the eIF4B-deficient mice exhibited impaired natural killer (NK) cell-mediated cytotoxicity during the IAV infection. Collectively, the results reveal that eIF4B is essential for mouse survival and host antiviral responses, and establish previously uncharacterized roles for eIF4B in regulating normal animal development and antiviral immunity .
Topics: Animals; Antiviral Agents; Eukaryotic Initiation Factors; Female; Host-Pathogen Interactions; Influenza A virus; Lung; Male; Mice; Orthomyxoviridae Infections; Protein Biosynthesis; Virus Replication
PubMed: 34566982
DOI: 10.3389/fimmu.2021.723885 -
Therapeutic Advances in Respiratory... Apr 2016Asthma and chronic obstructive pulmonary disease (COPD) are major causes of global morbidity and mortality worldwide. The clinical course of both asthma and COPD are... (Review)
Review
Asthma and chronic obstructive pulmonary disease (COPD) are major causes of global morbidity and mortality worldwide. The clinical course of both asthma and COPD are punctuated by the occurrence of exacerbations, acute events characterized by increased symptoms and airflow obstruction. Exacerbations contribute most of the morbidity, mortality and excess healthcare costs associated with both asthma and COPD. COPD and asthma exacerbations are frequently associated with respiratory virus infections and this has led to an intense research focus into the mechanisms of virus-induced exacerbations over the past decade. Current therapies are effective in reducing chronic symptoms but are less effective in preventing exacerbations, particularly in COPD. Understanding the mechanisms of virus-induced exacerbation will lead to the development of new targeted therapies that can reduce the burden of virus-induced exacerbations. In this review we discuss current knowledge of virus-induced exacerbations of asthma and COPD with a particular focus on mechanisms, human studies, virus-bacteria interactions and therapeutic advances.
Topics: Anti-Asthmatic Agents; Antiviral Agents; Asthma; Bacterial Infections; Bronchodilator Agents; Coinfection; Disease Progression; Host-Pathogen Interactions; Humans; Lung; Pulmonary Disease, Chronic Obstructive; Respiratory Tract Infections; Risk Factors; Virus Diseases; Viruses
PubMed: 26611907
DOI: 10.1177/1753465815618113 -
Archives of Pathology & Laboratory... Apr 2008Diagnosing the range of pulmonary disorders caused by Aspergillus spp can be challenging. In instances of hypersensitivity responses to Aspergillus spp (ie, allergic... (Review)
Review
Diagnosing the range of pulmonary disorders caused by Aspergillus spp can be challenging. In instances of hypersensitivity responses to Aspergillus spp (ie, allergic bronchopulmonary aspergillosis, bronchocentric granulomatosis, and hypersensitivity pneumonitis), the surgical pathologist must be cognizant of their relationship to infection, as fungal organisms may be rare or absent from the biopsy specimens. Within the spectrum of opportunistic infection, it is critical to distinguish Aspergillus spp from other fungal mimics, as well as to discern whether infection is limited, progressive, or immanently life threatening. However, the surgical pathologist who establishes expertise in this area will be rewarded by the satisfaction of having contributed primarily to an important area of patient care. This article reviews the spectrum of pulmonary disorders due to infection by Aspergillus spp, with emphasis on the clinical implications of diagnosis.
Topics: Aspergillosis; Aspergillus; Biopsy; Humans; Lung; Lung Diseases, Fungal; Pathology
PubMed: 18384212
DOI: 10.5858/2008-132-606-TPOPDD -
Journal of Virology Sep 2020The newly emerged human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic of respiratory illness. Current evidence...
The newly emerged human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a pandemic of respiratory illness. Current evidence suggests that severe cases of SARS-CoV-2 are associated with a dysregulated immune response. However, little is known about how the innate immune system responds to SARS-CoV-2. In this study, we modeled SARS-CoV-2 infection using primary human airway epithelial (pHAE) cultures, which are maintained in an air-liquid interface. We found that SARS-CoV-2 infects and replicates in pHAE cultures and is directionally released on the apical, but not basolateral, surface. Transcriptional profiling studies found that infected pHAE cultures had a molecular signature dominated by proinflammatory cytokines and chemokine induction, including interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-α), and CXCL8, and identified NF-κB and ATF-4 as key drivers of this proinflammatory cytokine response. Surprisingly, we observed a complete lack of a type I or III interferon (IFN) response to SARS-CoV-2 infection. However, pretreatment and posttreatment with type I and III IFNs significantly reduced virus replication in pHAE cultures that correlated with upregulation of antiviral effector genes. Combined, our findings demonstrate that SARS-CoV-2 does not trigger an IFN response but is sensitive to the effects of type I and III IFNs. Our studies demonstrate the utility of pHAE cultures to model SARS-CoV-2 infection and that both type I and III IFNs can serve as therapeutic options to treat COVID-19 patients. The current pandemic of respiratory illness, COVID-19, is caused by a recently emerged coronavirus named SARS-CoV-2. This virus infects airway and lung cells causing fever, dry cough, and shortness of breath. Severe cases of COVID-19 can result in lung damage, low blood oxygen levels, and even death. As there are currently no vaccines approved for use in humans, studies of the mechanisms of SARS-CoV-2 infection are urgently needed. Our research identifies an excellent system to model SARS-CoV-2 infection of the human airways that can be used to test various treatments. Analysis of infection in this model system found that human airway epithelial cell cultures induce a strong proinflammatory cytokine response yet block the production of type I and III IFNs to SARS-CoV-2. However, treatment of airway cultures with the immune molecules type I or type III interferon (IFN) was able to inhibit SARS-CoV-2 infection. Thus, our model system identified type I or type III IFN as potential antiviral treatments for COVID-19 patients.
Topics: Animals; Betacoronavirus; Bronchi; COVID-19; Cell Line; Cells, Cultured; Chemokines; Chlorocebus aethiops; Coronavirus Infections; Cytokines; Dogs; Epithelial Cells; Humans; Interferon Type I; Interferons; Lung; Madin Darby Canine Kidney Cells; Pandemics; Pneumonia, Viral; SARS-CoV-2; Vero Cells; Virus Replication; Interferon Lambda
PubMed: 32699094
DOI: 10.1128/JVI.00985-20 -
Infection and Immunity Dec 2012Genetic factors that regulate the pathogenesis of pneumonia caused by the fungus Cryptococcus neoformans are poorly understood. Through a phenotypic strain survey we...
Genetic factors that regulate the pathogenesis of pneumonia caused by the fungus Cryptococcus neoformans are poorly understood. Through a phenotypic strain survey we observed that inbred C3H/HeN mice develop a significantly greater lung fungal burden than mice of the resistant CBA/J strain 4 weeks following intratracheal infection with C. neoformans ATCC 24067. The aim of the present study was to characterize the inflammatory response of C3H/HeN mice following C. neoformans pulmonary infection and to identify genetic loci that regulate host defense. Following cryptococcal infection, C3H/HeN mice demonstrated a Th2 immune response with heightened airway and tissue eosinophilia, goblet cell metaplasia, and significantly higher lung interleukin-5 (IL-5) and IL-13 protein expression relative to CBA/J mice. Conversely, CBA/J mice exhibited greater airway and tissue neutrophilia that was associated with significantly higher pulmonary expression of gamma interferon, CXCL10, and IL-17 proteins than C3H/HeN mice. Using the fungal burden at 4 weeks postinfection as a phenotype, genome-wide quantitative trait locus (QTL) analysis among 435 segregating (C3H/HeN × CBA/J)F2 (C3HCBAF2) hybrids identified two significant QTLs on chromosomes 1 (Cnes4) and 9 (Cnes5) that control susceptibility to cryptococcal pneumonia in an additive manner. Susceptible C3H/HeN mice carry a resistance allele at Cnes4 and a susceptibility allele at Cnes5. These studies reveal additional genetic complexity of the host response to C. neoformans that is associated with divergent patterns of pulmonary inflammation.
Topics: Animals; Chromosomes, Mammalian; Cryptococcosis; Cryptococcus neoformans; Cytokines; Genetic Predisposition to Disease; Lung; Lung Diseases, Fungal; Mice; Mice, Inbred C3H; Mice, Inbred CBA; Quantitative Trait Loci; Th1 Cells; Th2 Cells
PubMed: 22988020
DOI: 10.1128/IAI.00417-12 -
PloS One 2016Pulmonary nocardiosis is a granulomatous disease with high mortality that affects both immunosuppressed and immunocompetent patients. The mechanisms leading to the...
Pulmonary nocardiosis is a granulomatous disease with high mortality that affects both immunosuppressed and immunocompetent patients. The mechanisms leading to the establishment and progression of the infection are currently unknown. An animal model to study these mechanisms is sorely needed. We report the first in vivo model of granulomatous pulmonary nocardiosis that closely resembles human pathology. BALB/c mice infected intranasally with two different doses of GFP-expressing Nocardia brasiliensis ATCC700358 (NbGFP), develop weight loss and pulmonary granulomas. Mice infected with 109 CFUs progressed towards death within a week while mice infected with 108 CFUs died after five to six months. Histological examination of the lungs revealed that both the higher and lower doses of NbGFP induced granulomas with NbGFP clearly identifiable at the center of the lesions. Mice exposed to 108 CFUs and subsequently to 109 CFUs were not protected against disease severity but had less granulomas suggesting some degree of protection. Attempts to identify a cellular target for the infection were unsuccessful but we found that bacterial microcolonies in the suspension used to infect mice were responsible for the establishment of the disease. Small microcolonies of NbGFP, incompatible with nocardial doubling times starting from unicellular organisms, were identified in the lung as early as six hours after infection. Mice infected with highly purified unicellular preparations of NbGFP did not develop granulomas despite showing weight loss. Finally, intranasal delivery of nocardial microcolonies was enough for mice to develop granulomas with minimal weight loss. Taken together these results show that Nocardia brasiliensis microcolonies are both necessary and sufficient for the development of granulomatous pulmonary nocardiosis in mice.
Topics: Animals; Disease Models, Animal; Granuloma; Green Fluorescent Proteins; Host-Pathogen Interactions; Humans; Lung; Mice, Inbred BALB C; Microscopy, Confocal; Nocardia; Nocardia Infections; Survival Rate; Viral Load; Weight Loss
PubMed: 27303806
DOI: 10.1371/journal.pone.0157475 -
Journal of Visualized Experiments : JoVE Nov 2011γ-Herpesviruses (γ-HVs) are notable for their ability to establish latent infections of lymphoid cells(1). The narrow host range of human γ-HVs, such as EBV and KSHV,...
γ-Herpesviruses (γ-HVs) are notable for their ability to establish latent infections of lymphoid cells(1). The narrow host range of human γ-HVs, such as EBV and KSHV, has severely hindered detailed pathogenic studies. Murine γ-herpesvirus 68 (γHV68) shares extensive genetic and biological similarities with human γ-HVs and is a natural pathogen of murid rodents(2). As such, evaluation of γHV68 infection of mice inbred strains at different stages of viral infection provides an important model for understanding viral lifecycle and pathogenesis during γ-HVs infection. Upon intranasal inoculation, γHV68 infection results in acute viremia in the lung that is later resolved into a latent infection of splenocytes and other cells, which may be reactivated throughout the life of the host(3,4). In this protocol, we will describe how to use the plaque assay to assess infectious virus titer in the lung homogenates on Vero cell monolayers at the early stage (5 - 7 days) of post-intranasal infection (dpi). While acute infection is largely cleared 2 - 3 weeks postinfection, a latent infection of γHV68 is established around 14 dpi and maintained later on in the spleen of the mice. Latent infection usually affects a very small population of cells in the infected tissues, whereby the virus stays dormant and shuts off most of its gene expression. Latently-infected splenocytes spontaneously reactivate virus upon explanting into tissue culture, which can be recapitulated by an infectious center (IC) assay to determine the viral latent load. To further estimate the amount of viral genome copies in the acutely and/or latently infected tissues, quantitative real-time PCR (qPCR) is used for its maximal sensitivity and accuracy. The combined analyses of the results of qPCR and plaque assay, and/or IC assay will reveal the spatiotemporal profiles of viral replication and infectivity in vivo.
Topics: Animals; Chlorocebus aethiops; Disease Models, Animal; Gammaherpesvirinae; Herpesviridae Infections; Lung; Mice; Mice, Inbred BALB C; NIH 3T3 Cells; Real-Time Polymerase Chain Reaction; Spleen; Vero Cells; Viral Load; Viral Plaque Assay; Viremia
PubMed: 22127138
DOI: 10.3791/3472 -
BMC Cancer Jan 2020Patients with lymphoma are at risk for developing pulmonary opportunistic infections due to immunocompromise. However, clinical reports of concurrent lymphoma and... (Review)
Review
BACKGROUND
Patients with lymphoma are at risk for developing pulmonary opportunistic infections due to immunocompromise. However, clinical reports of concurrent lymphoma and opportunistic infection at presentation are rare and often confined to single cases. A delayed diagnosis of either opportunistic infection or lymphoma usually occurs in this complex situation. Here, we report such a case and analyse 18 similar cases searched in the PubMed database to deepen clinicians' understanding.
CASE PRESENTATION
A 48-year-old man presented with a 3-month history of fever, cough and emaciation. High-resolution computed tomography revealed bilateral cavitating lesions of different sizes. Aspergillus fumigatus complex was identified from a bronchoalveolar lavage fluid culture. However, antifungal treatment combined with multiple rounds of antibacterial therapy was unsuccessful, and the patient's lung lesions continued to deteriorate. Multiple puncture biopsies finally confirmed the coexistence of diffuse large B-cell lymphoma. Despite the initiation of combination chemotherapy, the patient died of progressive respiratory failure.
CONCLUSIONS
Synchronous pulmonary lymphoma and simultaneous opportunistic infection is rare and usually lacks specific clinical and imaging manifestations. Lymphoma should be considered as part of the differential diagnosis of patients with an opportunistic infection when treatment fails or other symptoms are present that could be considered "atypical" for the condition. Tissue biopsy is the gold standard, and multiple biopsies are essential for making the final diagnosis and should be performed upon early suspicion.
Topics: Aspergillus fumigatus; Biopsy; Diagnosis, Differential; Humans; Invasive Pulmonary Aspergillosis; Lung; Lymphoma, Large B-Cell, Diffuse; Male; Middle Aged; Opportunistic Infections; Tomography, X-Ray Computed
PubMed: 31906982
DOI: 10.1186/s12885-019-6471-x -
American Journal of Respiratory Cell... Nov 2021Human rhinovirus (RV) is a major risk factor for chronic obstructive pulmonary disease (COPD) and asthma exacerbations. The exploration of RV pathogenesis has been...
Human rhinovirus (RV) is a major risk factor for chronic obstructive pulmonary disease (COPD) and asthma exacerbations. The exploration of RV pathogenesis has been hampered by a lack of disease-relevant model systems. We performed a detailed characterization of host responses to RV infection in human lung tissue and investigated whether these responses are disease relevant for patients with COPD and asthma. In addition, impact of the viral replication inhibitor rupintrivir was evaluated. Human precision-cut lung slices (PCLS) were infected with RV1B with or without rupintrivir. At Days 1 and 3 after infection, RV tissue localization, tissue viability, and viral load were determined. To characterize host responses to infection, mediator and whole genome analyses were performed. RV successfully replicated in PCLS airway epithelial cells and induced both antiviral and proinflammatory cytokines such as IFNα2a, CXCL10, CXCL11, IFN-γ, TNFα, and CCL5. Genomic analyses revealed that RV not only induced antiviral immune responses but also triggered changes in epithelial cell-associated pathways. Strikingly, the RV response in PCLS was reflective of gene expression changes described in patients with COPD and asthma. Although RV-induced host immune responses were abrogated by rupintrivir, RV-triggered epithelial processes were largely refractory to antiviral treatment. Detailed analysis of RV-infected human PCLS and comparison with gene signatures of patients with COPD and asthma revealed that the human RV PCLS model represents disease-relevant biological mechanisms that can be partially inhibited by a well-known antiviral compound and provide an outstanding opportunity to evaluate novel therapeutics.
Topics: Aged; Antiviral Agents; Asthma; Bronchi; Epithelial Cells; Female; Gene Expression Profiling; Genome, Human; Host-Pathogen Interactions; Humans; Isoxazoles; Lung; Male; Middle Aged; Phenylalanine; Picornaviridae Infections; Pulmonary Disease, Chronic Obstructive; Pyrrolidinones; Rhinovirus; Valine
PubMed: 34181859
DOI: 10.1165/rcmb.2020-0337OC