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MBio May 2019Infectious viruses so precisely fit their hosts that the study of natural viral infection depends on host-specific mechanisms that affect viral infection. For human...
Infectious viruses so precisely fit their hosts that the study of natural viral infection depends on host-specific mechanisms that affect viral infection. For human parainfluenza virus 3, a prevalent cause of lower respiratory tract disease in infants, circulating human viruses are genetically different from viruses grown in standard laboratory conditions; the surface glycoproteins that mediate host cell entry on circulating viruses are suited to the environment of the human lung and differ from those of viruses grown in cultured cells. Polarized human airway epithelium cultures have been used to represent the large, proximal airways of mature adult airways. Here we modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids derived from human pluripotent stem cells contain mesoderm and pulmonary endoderm and develop into branching airway and alveolar structures. Whole-genome sequencing analysis of parainfluenza viruses replicating in the organoids showed maintenance of nucleotide identity, suggesting that no selective pressure is exerted on the virus in this tissue. Infection with parainfluenza virus led to viral shedding without morphological changes, while respiratory syncytial virus infection induced detachment and shedding of infected cells into the lung organoid lumens, reminiscent of parainfluenza and respiratory syncytial virus in human infant lungs. Measles virus infection, in contrast, induced syncytium formation. These human stem cell-derived lung organoids may serve as an authentic model for respiratory viral pathogenesis in the developing or infant lung, recapitulating respiratory viral infection in the host. Respiratory viruses are among the first pathogens encountered by young children, and the significant impact of these viral infections on the developing lung is poorly understood. Circulating viruses are suited to the environment of the human lung and are different from those of viruses grown in cultured cells. We modeled respiratory virus infections that occur in children or infect the distal lung using lung organoids that represent the entire developing infant lung. These 3D lung organoids, derived from human pluripotent stem cells, develop into branching airway and alveolar structures and provide a tissue environment that maintains the authentic viral genome. The lung organoids can be genetically engineered prior to differentiation, thereby generating tissues bearing or lacking specific features that may be relevant to viral infection, a feature that may have utility for the study of host-pathogen interaction for a range of lung pathogens.
Topics: Alveolar Epithelial Cells; Cell Differentiation; Cells, Cultured; Genome, Viral; Humans; Infant; Lung; Measles virus; Organoids; Parainfluenza Virus 3, Human; Pluripotent Stem Cells; Respiratory Syncytial Virus, Human; Respirovirus Infections; Virus Internalization; Whole Genome Sequencing
PubMed: 31064833
DOI: 10.1128/mBio.00723-19 -
Respiratory Research Sep 2014Influenza virus infection causes significantly higher levels of morbidity and mortality in the elderly. Studies have shown that impaired immunity in the elderly... (Comparative Study)
Comparative Study
BACKGROUND
Influenza virus infection causes significantly higher levels of morbidity and mortality in the elderly. Studies have shown that impaired immunity in the elderly contributes to the increased susceptibility to influenza virus infection, however, how aging affects the lung tissue damage and repair has not been completely elucidated.
METHODS
Aged (16-18 months old) and young (2-3 months old) mice were infected with influenza virus intratracheally. Body weight and mortality were monitored. Different days after infection, lung sections were stained to estimate the overall lung tissue damage and for club cells, pro-SPC+ bronchiolar epithelial cells, alveolar type I and II cells to quantify their frequencies using automated image analysis algorithms.
RESULTS
Following influenza infection, aged mice lose more weight and die from otherwise sub-lethal influenza infection in young mice. Although there is no difference in damage and regeneration of club cells between the young and the aged mice, damage to alveolar type I and II cells (AT1s and AT2s) is exacerbated, and regeneration of AT2s and their precursors (pro-SPC-positive bronchiolar epithelial cells) is significantly delayed in the aged mice. We further show that oseltamivir treatment reduces virus load and lung damage, and promotes pulmonary recovery from infection in the aged mice.
CONCLUSIONS
These findings show that aging increases susceptibility of the distal lung epithelium to influenza infection and delays the emergence of pro-SPC positive progenitor cells during the repair process. Our findings also shed light on possible approaches to enhance the clinical management of severe influenza pneumonia in the elderly.
Topics: Age Factors; Aging; Alveolar Epithelial Cells; Animals; Antiviral Agents; Cell Proliferation; Disease Models, Animal; Female; Influenza A Virus, H1N1 Subtype; Mice, Inbred C57BL; Orthomyxoviridae Infections; Oseltamivir; Pneumonia, Viral; Pulmonary Alveoli; Regeneration; Risk Factors; Time Factors; Viral Load
PubMed: 25265939
DOI: 10.1186/s12931-014-0116-z -
Journal of Infection and Public Health 2019As one of the most debilitating and underdiagnosed hereditary conditions across the globe, cystic fibrosis requires intensive support from the healthcare system -... (Review)
Review
As one of the most debilitating and underdiagnosed hereditary conditions across the globe, cystic fibrosis requires intensive support from the healthcare system - particularly due to the increased susceptibility to chronic infection and resulting respiratory failure which can rapidly lead to death. In turn, the prevalence and action of a certain strain of bacterium - Pseudomonas aeruginosa - has gained a great deal of interest. Life-threatening chronic infections by P. aeruginosa have been shown to involve biofilm formation, proliferation and the release of quorum-sensing signaling molecules. Understanding the mechanism cascade by which this strain attacks cells within the respiratory epithelium, most notably airway epithelial cells, could offer insight into the pathway and components, which are attractive targets for therapeutic interventions.
Topics: Chronic Disease; Cystic Fibrosis; Epithelial Cells; Host-Pathogen Interactions; Humans; Lung; Pneumonia, Bacterial; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 30459101
DOI: 10.1016/j.jiph.2018.10.014 -
Nature Communications 2013Preventing and treating influenza virus infection remain a challenge because of incomplete understanding of the host-pathogen interactions, limited therapeutics and lack...
Preventing and treating influenza virus infection remain a challenge because of incomplete understanding of the host-pathogen interactions, limited therapeutics and lack of a universal vaccine. So far, methods for monitoring the course of infection with influenza virus in real time in living animals are lacking. Here we report the visualization of influenza viral infection in living mice using an engineered replication-competent influenza A virus carrying luciferase reporter gene. After intranasal inoculation, bioluminescence can be detected in the chest and nasopharyngeal passage of living mice. The intensity of bioluminescence in the chest correlates with the dosage of infection and the viral load in the lung. Bioluminescence in the chest of infected mice diminishes on antiviral treatment. This work provides a novel approach that enables real-time study of influenza virus infection and effects of antiviral therapeutics in living animals.
Topics: Administration, Intranasal; Animals; Antiviral Agents; Body Weight; Chickens; Computer Systems; Dogs; Female; Genes, Reporter; HEK293 Cells; Humans; Imaging, Three-Dimensional; Influenza A virus; Luciferases; Luminescent Measurements; Lung; Madin Darby Canine Kidney Cells; Mice; Mice, Inbred BALB C; Orthomyxoviridae Infections; Virus Replication
PubMed: 24022374
DOI: 10.1038/ncomms3369 -
Journal of Virology Feb 2019Cytomegaloviruses (CMVs) establish systemic infections across diverse cell types. Glycoproteins that alter tropism can potentially guide their spread. Glycoprotein O...
Cytomegaloviruses (CMVs) establish systemic infections across diverse cell types. Glycoproteins that alter tropism can potentially guide their spread. Glycoprotein O (gO) is a nonessential fusion complex component of both human CMV (HCMV) and murine CMV (MCMV). We tested its contribution to MCMV spread from the respiratory tract. , MCMV lacking gO poorly infected fibroblasts and epithelial cells. Cell binding was intact, but penetration was delayed. In contrast, myeloid infection was preserved, and in the lungs, where myeloid and type 2 alveolar epithelial cells are the main viral targets, MCMV lacking gO showed a marked preference for myeloid infection. Its poor epithelial cell infection was associated with poor primary virus production and reduced virulence. Systemic spread, which proceeds via infected CD11c myeloid cells, was initially intact but then diminished, because less epithelial infection led ultimately to less myeloid infection. Thus, the tight linkage between peripheral and systemic MCMV infections gave gO-dependent infection a central role in host colonization. Human cytomegalovirus is a leading cause of congenital disease. This reflects its capacity for systemic spread. A vaccine is needed, but the best viral targets are unclear. Attention has focused on the virion membrane fusion complex. It has 2 forms, so we need to know what each contributes to host colonization. One includes the virion glycoprotein O. We used murine cytomegalovirus, which has equivalent fusion complexes, to determine the importance of glycoprotein O after mucosal infection. We show that it drives local virus replication in epithelial cells. It was not required to infect myeloid cells, which establish systemic infection, but poor local replication reduced systemic spread as a secondary effect. Therefore, targeting glycoprotein O of human cytomegalovirus has the potential to reduce both local and systemic infections.
Topics: Animals; Cells, Cultured; Epithelial Cells; Fibroblasts; Herpesviridae Infections; Lung; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Muromegalovirus; Viral Envelope Proteins; Virus Internalization; Virus Replication
PubMed: 30404805
DOI: 10.1128/JVI.01378-18 -
PLoS Neglected Tropical Diseases Oct 2017Hantavirus, the hemorrhagic causative agent of two clinical diseases, is found worldwide with variation in severity, incidence and mortality. The most lethal...
BACKGROUND
Hantavirus, the hemorrhagic causative agent of two clinical diseases, is found worldwide with variation in severity, incidence and mortality. The most lethal hantaviruses are found on the American continent where the most prevalent viruses like Andes virus and Sin Nombre virus are known to cause hantavirus pulmonary syndrome. New World hantavirus infection of immunocompetent hamsters results in an asymptomatic infection except for Andes virus and Maporal virus; the only hantaviruses causing a lethal disease in immunocompetent Syrian hamsters mimicking hantavirus pulmonary syndrome in humans.
METHODOLOGY/PRINCIPAL FINDINGS
Hamsters, immunosuppressed with dexamethasone and cyclophosphamide, were infected intramuscularly with different New World hantavirus strains (Bayou virus, Black Creek Canal virus, Caño Delgadito virus, Choclo virus, Laguna Negra virus, and Maporal virus). In the present study, we show that immunosuppression of hamsters followed by infection with a New World hantavirus results in an acute disease that precisely mimics both hantavirus disease in humans and Andes virus infection of hamsters.
CONCLUSIONS/ SIGNIFICANCE
Infected hamsters showed specific clinical signs of disease and moreover, histological analysis of lung tissue showed signs of pulmonary edema and inflammation within alveolar septa. In this study, we were able to infect immunosuppressed hamsters with different New World hantaviruses reaching a lethal outcome with signs of disease mimicking human disease.
Topics: Animals; Anti-Inflammatory Agents; Cricetinae; Cyclophosphamide; Dexamethasone; Disease Models, Animal; Female; Orthohantavirus; Hantavirus Infections; Hantavirus Pulmonary Syndrome; Humans; Immunocompromised Host; Immunosuppression Therapy; Immunosuppressive Agents; Lung; Mesocricetus; Survival Analysis
PubMed: 29077702
DOI: 10.1371/journal.pntd.0006042 -
Journal of Visualized Experiments : JoVE Jul 2018Patients who survive pneumonia have elevated death rates in the months following hospital discharge. It has been hypothesized that infection of pulmonary tissue during...
Patients who survive pneumonia have elevated death rates in the months following hospital discharge. It has been hypothesized that infection of pulmonary tissue during pneumonia results in the production of long-lived cytotoxins that can lead to subsequent end organ failure. We have developed in vitro assays to test the hypothesis that cytotoxins are produced during pulmonary infection. Isolated rat pulmonary endothelial cells and the bacterium Pseudomonas aeruginosa are used as model systems, and the production of cytoxins following infection of the endothelial cells by the bacteria is demonstrated using cell culture followed by direct quantitation using lactate dehydrogenase assays and a novel microscopic method utilizing ImageJ technology. The amyloid nature of these cytotoxins was demonstrated by thioflavin T binding assays and by immunoblotting and immunodepletion using A11 anti-amyloid antibody. Further analyses using immunoblotting demonstrated that oligomeric tau and Aβ were produced and released by endothelial cells following infection by P. aeruginosa. These methods should be readily adaptable to analyses of human clinical samples.
Topics: Amyloid; Endothelial Cells; Humans; Lung; Pneumonia; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 30059033
DOI: 10.3791/57447 -
Parasites & Vectors Nov 2020Pulmonary manifestations are regularly reported in both human and animal filariasis. In human filariasis, the main known lung manifestations are the tropical pulmonary...
BACKGROUND
Pulmonary manifestations are regularly reported in both human and animal filariasis. In human filariasis, the main known lung manifestations are the tropical pulmonary eosinophilia syndrome. Its duration and severity are correlated with the presence of microfilariae. Litomosoides sigmodontis is a filarial parasite residing in the pleural cavity of rodents. This model is widely used to understand the immune mechanisms that are established during infection and for the screening of therapeutic molecules. Some pulmonary manifestations during the patent phase of infection with L. sigmodontis have been described in different rodent hosts more or less permissive to infection.
METHODS
Here, the permissive Mongolian gerbil (Meriones unguiculatus) was infected with L. sigmodontis. Prevalence and density of microfilariae and adult parasites were evaluated. Lungs were analyzed for pathological signatures using immunohistochemistry and 3D imaging techniques (two-photon and light sheet microscopy).
RESULTS
Microfilaremia in gerbils was correlated with parasite load, as amicrofilaremic individuals had fewer parasites in their pleural cavities. Fibrotic polypoid structures were observed on both pleurae of infected gerbils. Polyps were of variable size and developed from the visceral mesothelium over the entire pleura. The larger polyps were vascularized and strongly infiltrated by immune cells such as eosinophils, macrophages or lymphocytes. The formation of these structures was induced by the presence of adult filariae since small and rare polyps were observed before patency, but they were exacerbated by the presence of gravid females and microfilariae.
CONCLUSIONS
Altogether, these data emphasize the role of host-specific factors in the pathogenesis of filarial infections.
Topics: Animals; Eosinophils; Female; Fibrosis; Filariasis; Filarioidea; Gerbillinae; Lung; Male; Microfilariae; Parasite Load; Pleural Cavity; Polyps
PubMed: 33160409
DOI: 10.1186/s13071-020-04428-0 -
Infection and Immunity May 1972Virulence and infectivity of nine strains of Paracoccidioides brasiliensis were investigated in groups of mice which were inoculated intranasally or intravenously, and...
Virulence and infectivity of nine strains of Paracoccidioides brasiliensis were investigated in groups of mice which were inoculated intranasally or intravenously, and some of each were treated with corticosteroids. Fatal infections were not often seen among untreated mice, but mortality usually occurred when corticosteroids were given, regardless of the route of fungus inoculation. Prior treatment did not uniformly increase the incidence of infection, however; only in the case of intranasally inoculated mice was this effect seen. Most strains appeared to be more virulent when administered intravenously, with the exception of a single strain which, under the influence of corticosteroids, repeatedly displayed greatest virulence when given intranasally. All animals that died early in the course of the disease, irrespective of route of inoculation, always had acute pulmonary lesions and usually no other organ was involved. Animals which died later or were sacrificed always had chronic lung lesions. Whether or not chronically diseased animals had additional organ involvement correlated with how the organisms were administered; intravenously inoculated animals usually had extrapulmonary as well as pulmonary lesions, but lesions of those inoculated intranasally were almost exclusively pulmonary. Corticosteroids did not alter the histologic characteristics of either the acute or the chronic type of lesion, but the lesions of treated animals were usually more extensive. Most of the survivors appeared healthy even when infection was extensive.
Topics: Administration, Intranasal; Adrenal Cortex Hormones; Animals; Coccidioidomycosis; Culture Media; Fungi; Injections, Intravenous; Lung; Male; Mice; Mice, Inbred Strains; Paracoccidioides; Pneumonia; Virulence
PubMed: 4637603
DOI: 10.1128/iai.5.5.681-687.1972 -
Research in Veterinary Science Dec 2017Coronaviruses as well as influenza A viruses are widely spread in pig fattening and can cause high economical loss. Here we infected porcine precision-cut lung slices...
Coronaviruses as well as influenza A viruses are widely spread in pig fattening and can cause high economical loss. Here we infected porcine precision-cut lung slices with porcine respiratory coronavirus and two Influenza A viruses to analyze if co-infection with these viruses may enhance disease outcome in swine. Ciliary activity of the epithelial cells in the bronchus of precision-cut lung slices was measured. Co-infection of PCLS reduced virulence of both virus species compared to mono-infection. Similar results were obtained by mono- and co-infection experiments on a porcine respiratory cell line. Again lower titers in co-infection groups indicated an interference of the two RNA viruses. This is in accordance with in vivo experiments, revealing cell innate immune answers to both PRCoV and SIV that are able to restrict the virulence and pathogenicity of the viruses.
Topics: Animals; Coinfection; Epithelial Cells; Influenza A virus; Lung; Orthomyxoviridae Infections; Porcine Respiratory Coronavirus; Swine; Swine Diseases
PubMed: 28779714
DOI: 10.1016/j.rvsc.2017.07.016