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Helene F. Rosenberg - One of the best experts on this subject based on the ideXlab platform.
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critical adverse impact of il 6 in acute Pneumovirus infection
Journal of Immunology, 2019Co-Authors: Caroline M Percopo, Todd A Brenner, Julia O Krumholz, Timothy J Break, Karen Laky, Helene F. RosenbergAbstract:Severe respiratory virus infections feature robust local host responses that contribute to disease severity. Immunomodulatory strategies that limit virus‐induced inflammation may be of critical importance, notably in the absence of antiviral vaccines. In this study, we examined the role of the pleiotropic cytokine IL-6 in acute infection with pneumonia virus of mice (PVM), a natural rodent pathogen that is related to respiratory syncytial virus and that generates local inflammation as a feature of severe infection. In contrast to Influenza A, PVM is substantially less lethal in IL-6 −/− mice than it is in wild-type, a finding associated with diminished neutrophil recruitment and reduced fluid accumulation in lung tissue. Ly6C hi proinflammatory monocytes are recruited in response to PVM via a CCR2 -dependent mechanism, but they are not a major source of IL-6 nor do they contribute to lethal sequelae of infection. By contrast, alveolar macrophages are readily infected with PVM in vivo; ablation of alveolar macrophages results in prolonged survival in association with a reduction in virus-induced IL-6. Finally, as shown previously, administration of immunobiotic Lactobacillus plantarum to the respiratory tracts of PVM-infected mice promoted survival in association with diminished levels of IL-6. We demonstrated in this study that IL-6 suppression is a critical feature of the protective mechanism; PVM-infected IL-6 −/− mice responded to low doses of L. plantarum , and administration of IL-6 overcame L. plantarum –mediated protection in PVM-infected wild-type mice. Taken together, these results connect the actions of IL-6 to PVM pathogenesis and suggest cytokine blockade as a potential therapeutic modality in severe infection.
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8Differential Expression of Proinflammatory Cytokine Genes In Vivo in Response to Pathogenic and Nonpathogenic Pneumovirus Infections
2016Co-Authors: Joseph B. Domachowske, Andrew J. Easton, Cynthia A. Bonville, Helene F. RosenbergAbstract:Pneumonia virus of mice (PVM; Paramyxoviridae, subfamily Pneumovirinae) is an important pathogen for the study of physiologically relevant acute inflammatory responses in rodent hosts. In contrast to the severe symptomatology observed in response to infection with PVM strain J3666, infection with strain 15 resulted in few clinical symptoms, limited cellular in-flammatory response, and no production of macrophage inflammatory protein–1a or mono-cyte chemoattractant peptide (MCP)–1. Microarray analysis of transcripts from lung tissue indicates that PVM J3666 infection promotes up-regulation of specific proinflammatory genes, most notably interferon (IFN)–1b, IFN response genes, and chemokines MCP-1, MCP-3, RANTES (regulated on activation, normally T cell–expressed and secreted), and eotaxin. Of these, only RANTES expression increased in response to infection with strain 15, with no increased expression of IFN or IFN response genes, despite ongoing viral replication. These results suggest that Pneumovirus replication alone is insufficient to promote antiviral inflam-mation and that evaluation of the more divergent strain-specific Pneumovirus proteins may provide some intriguing leads toward the molecular basis of this differential response. Our recent work focused on the elucidation of inflammator
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Sustained inflammation and differential expression of interferons type I and III in PVM-infected interferon-gamma (IFNγ) gene-deleted mice.
Virology, 2014Co-Authors: Stephanie F Glineur, Joseph B. Domachowske, Kimberly D. Dyer, Caroline M Percopo, Sergei I Ochkur, James J Lee, Nancy A Lee, Aaron B Bowen, Katia E Garcia-crespo, Helene F. RosenbergAbstract:Interferon gamma (IFNγ) has complex immunomodulatory and antiviral properties. While IFNγ is detected in the airways in response to infection with the Pneumovirus pathogen, pneumonia virus of mice (PVM; Family Paramyxoviridae), its role in promoting disease has not been fully explored. Here, we evaluate PVM infection in IFNγ(-/-) mice. Although the IFNγ gene-deletion has no impact on weight loss, survival or virus kinetics, expression of IFNβ, IFNλ2/3 and IFN-stimulated 2-5' oligoadenylate synthetases was significantly diminished compared to wild-type counterparts. Furthermore, PVM infection in IFNγ(-/-) mice promoted prominent inflammation, including eosinophil and neutrophil infiltration into the airways and lung parenchyma, observed several days after peak virus titer. Potential mechanisms include over-production of chemoattractant and eosinophil-active cytokines (CXCL1, CCL11, CCL3 and IL5) in PVM-infected IFNγ(-/-) mice; likewise, IFNγ actively antagonized IL5-dependent eosinophil survival ex vivo. Our results may have clinical implications for Pneumovirus infection in individuals with IFNγ signaling defects.
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RESEARCH Open Access Inflammatory responses to acute Pneumovirus infection in neonatal mice
2013Co-Authors: Cynthia A. Bonville, Helene F. Rosenberg, Caroline M Percopo, Catherine Ptaschinski, Joseph B. DomachowskeAbstract:Background: The innate immune responses of neonates differ dramatically from those of adults. Here we examine the acute inflammatory responses of neonatal and weanling mice infected with pneumonia virus of mice (PVM), a rodent pathogen (family Paramyxoviridae, genus Pneumovirus) that replicates the sequelae of severe respiratory syncytial virus infection. Results: We demonstrate that virus replication proceeds indistinguishably in all age groups (inoculated at 1, 2, 3 and 4 weeks of age), although inflammatory responses vary in extent and character. Some of the biochemical mediators detected varied minimally with age at inoculation. Most of the mediators evaluated demonstrated elevated expression over baseline correlating directly with age at the time of virus inoculation. Among the latter group are CCL2, CCL3, and IFN-g, all cytokines previously associated with PVM-induced inflammatory pathology in mature mice. Likewise, we detect neutrophil recruitment to lung tissue in all age groups, but recruitment is most pronounced among the older (3- 4 week old) mice. Interestingly, all mice exhibit failure to thrive, lagging in expected weight gain for given age, including the youngest mice that present little overt evidence of inflammation. Conclusions: Our findings among the youngest mice may explain in part the phenomenon of atypical or minimall
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depletion of alveolar macrophages prolongs survival in response to acute Pneumovirus infection
Virology, 2012Co-Authors: Peter Rigaux, Kristin E Killoran, Zhijun Qiu, Helene F. RosenbergAbstract:Alveolar macrophages are immunoregulatory effector cells that interact directly with respiratory virus pathogens in vivo. We examined the role of alveolar macrophages in acute infection with pneumonia virus of mice (PVM), a rodent Pneumovirus that replicates the clinical sequelae of severe human respiratory syncytial virus disease. We show that PVM replicates in primary mouse macrophage culture, releasing infectious virions and proinflammatory cytokines. Alveolar macrophages isolated from PVM-infected mice express activation markers Clec43 and CD86, cytokines TNFα, IL-1, IL-6, and numerous CC and CXC chemokines. Alveolar macrophage depletion prior to PVM infection results in small but statistically significant increases in virus recovery but paradoxically prolonged survival. In parallel, macrophage depleted PVM-infected mice exhibit enhanced NK cell recruitment and increased production of IFNγ by NK, CD4+ and CD8+ T cells. These results suggest a protective, immunomodulatory role for IFNγ, as overproduction secondary to macrophage depletion may promote survival despite increased virus recovery.
Joseph B. Domachowske - One of the best experts on this subject based on the ideXlab platform.
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8Differential Expression of Proinflammatory Cytokine Genes In Vivo in Response to Pathogenic and Nonpathogenic Pneumovirus Infections
2016Co-Authors: Joseph B. Domachowske, Andrew J. Easton, Cynthia A. Bonville, Helene F. RosenbergAbstract:Pneumonia virus of mice (PVM; Paramyxoviridae, subfamily Pneumovirinae) is an important pathogen for the study of physiologically relevant acute inflammatory responses in rodent hosts. In contrast to the severe symptomatology observed in response to infection with PVM strain J3666, infection with strain 15 resulted in few clinical symptoms, limited cellular in-flammatory response, and no production of macrophage inflammatory protein–1a or mono-cyte chemoattractant peptide (MCP)–1. Microarray analysis of transcripts from lung tissue indicates that PVM J3666 infection promotes up-regulation of specific proinflammatory genes, most notably interferon (IFN)–1b, IFN response genes, and chemokines MCP-1, MCP-3, RANTES (regulated on activation, normally T cell–expressed and secreted), and eotaxin. Of these, only RANTES expression increased in response to infection with strain 15, with no increased expression of IFN or IFN response genes, despite ongoing viral replication. These results suggest that Pneumovirus replication alone is insufficient to promote antiviral inflam-mation and that evaluation of the more divergent strain-specific Pneumovirus proteins may provide some intriguing leads toward the molecular basis of this differential response. Our recent work focused on the elucidation of inflammator
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Sustained inflammation and differential expression of interferons type I and III in PVM-infected interferon-gamma (IFNγ) gene-deleted mice.
Virology, 2014Co-Authors: Stephanie F Glineur, Joseph B. Domachowske, Kimberly D. Dyer, Caroline M Percopo, Sergei I Ochkur, James J Lee, Nancy A Lee, Aaron B Bowen, Katia E Garcia-crespo, Helene F. RosenbergAbstract:Interferon gamma (IFNγ) has complex immunomodulatory and antiviral properties. While IFNγ is detected in the airways in response to infection with the Pneumovirus pathogen, pneumonia virus of mice (PVM; Family Paramyxoviridae), its role in promoting disease has not been fully explored. Here, we evaluate PVM infection in IFNγ(-/-) mice. Although the IFNγ gene-deletion has no impact on weight loss, survival or virus kinetics, expression of IFNβ, IFNλ2/3 and IFN-stimulated 2-5' oligoadenylate synthetases was significantly diminished compared to wild-type counterparts. Furthermore, PVM infection in IFNγ(-/-) mice promoted prominent inflammation, including eosinophil and neutrophil infiltration into the airways and lung parenchyma, observed several days after peak virus titer. Potential mechanisms include over-production of chemoattractant and eosinophil-active cytokines (CXCL1, CCL11, CCL3 and IL5) in PVM-infected IFNγ(-/-) mice; likewise, IFNγ actively antagonized IL5-dependent eosinophil survival ex vivo. Our results may have clinical implications for Pneumovirus infection in individuals with IFNγ signaling defects.
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activated mouse eosinophils protect against lethal respiratory virus infection
Blood, 2014Co-Authors: Caroline M Percopo, Joseph B. Domachowske, Kimberly D. Dyer, Sergei I Ochkur, Janice L Luo, Elizabeth R Fischer, James J Lee, Nancy A LeeAbstract:Eosinophils are recruited to the airways as a prominent feature of the asthmatic inflammatory response where they are broadly perceived as promoting pathophysiology. Respiratory virus infections exacerbate established asthma; however, the role of eosinophils and the nature of their interactions with respiratory viruses remain uncertain. To explore these questions, we established acute infection with the rodent Pneumovirus, pneumonia virus of mice (PVM), in 3 distinct mouse models of Th2 cytokine–driven asthmatic inflammation. We found that eosinophils recruited to the airways of otherwise naive mice in response to Aspergillus fumigatus, but not ovalbumin sensitization and challenge, are activated by and degranulate specifically in response to PVM infection. Furthermore, we demonstrate that activated eosinophils from both Aspergillus antigen and cytokine-driven asthma models are profoundly antiviral and promote survival in response to an otherwise lethal PVM infection. Thus, although activated eosinophils within a Th2-polarized inflammatory response may have pathophysiologic features, they are also efficient and effective mediators of antiviral host defense.
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RESEARCH Open Access Inflammatory responses to acute Pneumovirus infection in neonatal mice
2013Co-Authors: Cynthia A. Bonville, Helene F. Rosenberg, Caroline M Percopo, Catherine Ptaschinski, Joseph B. DomachowskeAbstract:Background: The innate immune responses of neonates differ dramatically from those of adults. Here we examine the acute inflammatory responses of neonatal and weanling mice infected with pneumonia virus of mice (PVM), a rodent pathogen (family Paramyxoviridae, genus Pneumovirus) that replicates the sequelae of severe respiratory syncytial virus infection. Results: We demonstrate that virus replication proceeds indistinguishably in all age groups (inoculated at 1, 2, 3 and 4 weeks of age), although inflammatory responses vary in extent and character. Some of the biochemical mediators detected varied minimally with age at inoculation. Most of the mediators evaluated demonstrated elevated expression over baseline correlating directly with age at the time of virus inoculation. Among the latter group are CCL2, CCL3, and IFN-g, all cytokines previously associated with PVM-induced inflammatory pathology in mature mice. Likewise, we detect neutrophil recruitment to lung tissue in all age groups, but recruitment is most pronounced among the older (3- 4 week old) mice. Interestingly, all mice exhibit failure to thrive, lagging in expected weight gain for given age, including the youngest mice that present little overt evidence of inflammation. Conclusions: Our findings among the youngest mice may explain in part the phenomenon of atypical or minimall
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il 21 promotes the pathologic immune response to Pneumovirus infection
Journal of Immunology, 2012Co-Authors: Rosanne Spolski, Joseph B. Domachowske, Cynthia A. Bonville, Lu Wang, Chikeung Wan, Hyoungpyo Kim, Warren J LeonardAbstract:IL-21 is a cytokine with pleiotropic actions, promoting terminal differentiation of B cells, increased Ig production, and the development of Th17 and T follicular helper cells. IL-21 is also implicated in the development of autoimmune disease and has antitumor activity. In this study, we investigated the role of IL-21 in host defense to pneumonia virus of mice (PVM), which initiates an infection in mice resembling that of respiratory syncytial virus disease in humans. We found that PVM-infected mice expressed IL-21 in lung CD4 + T cells. Following infection, Il21r −/− mice exhibited less lung infiltration by neutrophils than did wild-type (WT) mice and correspondingly had lower levels of the chemokine CXCL1 in bronchoalveolar lavage fluid and lung parenchyma. CD8 + , CD4 + , and γδ T cell numbers were also lower in the lungs of PVM-infected Il21r −/− mice than in infected WT mice, with normal Th17 cytokines but diminished IL-6 production in PVM-infected Il21r −/− mice. Strikingly, Il21r −/− mice had enhanced survival following PVM infection, and moreover, treatment of WT mice with soluble IL-21R-Fc fusion protein enhanced their survival. These data reveal that IL-21 promotes the pathogenic inflammatory effect of PVM and indicate that manipulating IL-21 signaling may represent an immunomodulatory strategy for controlling PVM and potentially other respiratory virus infections.
Job B. M. Van Woensel - One of the best experts on this subject based on the ideXlab platform.
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Pneumovirus-Induced Lung Disease in Mice Is Independent of Neutrophil-Driven Inflammation.
PLOS ONE, 2016Co-Authors: Bart Cortjens, Reinout A., René Lutter, Louis Boon, Job B. M. Van WoenselAbstract:The human Pneumovirus respiratory syncytial virus (RSV) is the most common pathogen causing lower respiratory tract disease in young children worldwide. A hallmark of severe human RSV infection is the strong neutrophil recruitment to the airways and lungs. Massive neutrophil activation has been proven detrimental in numerous diseases, yet in RSV the contribution of neutrophils to disease severity, and thereby, the relevance of targeting them, is largely unknown. To determine the relevance of potential neutrophil targeting therapies, we implemented antibody-mediated neutrophil depletion in a mouse pneumonia virus of mice (PVM) model. PVM is a host specific murine Pneumovirus closely related to human RSV, which reproduces many of the features of RSV infection, such as high viral replication and neutrophil recruitment. Clinical disease and markers of lung inflammation and injury were studied in PVM-infected mice treated with either depleting or isotype control antibodies. To confirm our results we performed all experiments in two mice strains: C57Bl6 and BALBc mice. Neutrophil depletion in blood and lungs was efficient throughout the disease. Remarkably, in both mouse strains we found no difference in clinical disease severity between neutrophil-depleted and control arms. In line with this observation, we found no differences between groups in histopathological lung injury and lung viral loads. In conclusion, our study shows that in mice neutrophil recruitment to the lungs does not affect disease outcome or viral clearance during severe PVM infection. As such, this model does not support the notion that neutrophils play a key role in mouse Pneumovirus disease.
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The caspase inhibitor zVAD increases lung inflammation in Pneumovirus infection in mice
Physiological Reports, 2015Co-Authors: Elske Van Den Berg, Job B. M. Van Woensel, René Lutter, Albert P. Bos, Suzanne M. Bal, Maria T. Kuipers, Gustavo Matute-bello, Reinout A.Abstract:Severe respiratory syncytial virus (RSV) disease is a frequent cause of acute respiratory distress syndrome (ARDS) in young children, and is associated with marked lung epithelial injury and neutrophilic inflammation. Experimental studies on ARDS have shown that inhibition of apoptosis in the lungs reduces lung epithelial injury. However, the blockade of apoptosis in the lungs may also have deleterious effects by hampering viral clearance, and importantly, by enhancing or prolonging local proinflammatory responses. The aim of this study was to determine the effect of the broad caspase inhibitor Z-VAD(OMe)-FMK (zVAD) on inflammation and lung injury in a mouse Pneumovirus model for severe RSV disease. Eight- to 11-week-old female C57BL/6OlaHsd mice were inoculated with the rodent-specific Pneumovirus pneumonia virus of mice (PVM) strain J3666 and received multiple injections of zVAD or vehicle (control) during the course of disease, after which they were studied for markers of apoptosis, inflammation, and lung injury on day 7 after infection. PVM-infected mice that received zVAD had a strong increase in neutrophil numbers in the lungs, which was associated with decreased neutrophil apoptosis. Furthermore, zVAD treatment led to higher concentrations of several proinflammatory cytokines in the lungs and more weight loss in PVM-infected mice. In contrast, zVAD did not reduce apoptosis of lung epithelial cells and did not affect the degree of lung injury, permeability, and viral titers in PVM disease. We conclude that zVAD has an adverse effect in severe Pneumovirus disease in mice by enhancing the lung proinflammatory response.
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the effect of tip on Pneumovirus induced pulmonary edema in mice
PLOS ONE, 2014Co-Authors: Elske Van Den Berg, Albert P. Bos, René Lutter, Reinout A Bem, Job B. M. Van WoenselAbstract:Background Pulmonary edema plays a pivotal role in the pathophysiology of respiratory syncytial virus (RSV)-induced respiratory failure. In this study we determined whether treatment with TIP (AP301), a synthetic cyclic peptide that mimics the lectin-like domain of human TNF, decreases pulmonary edema in a mouse model of severe human RSV infection. TIP is currently undergoing clinical trials as a therapy for pulmonary permeability edema and has been shown to decrease pulmonary edema in different lung injury models. Methods C57BL/6 mice were infected with pneumonia virus of mice (PVM) and received TIP or saline (control group) by intratracheal instillation on day five (early administration) or day seven (late administration) after infection. In a separate set of experiments the effect of multiple dose administration of TIP versus saline was tested. Pulmonary edema was determined by the lung wet-to-dry (W/D) weight ratio and was assessed at different time-points after the administration of TIP. Secondary outcomes included clinical scores and lung cellular response. Results TIP did not have an effect on pulmonary edema in different dose regimens at different time points during PVM infection. In addition, TIP administration did not affect clinical severity scores or lung cellular response. Conclusion In this murine model of severe RSV infection TIP did not affect pulmonary edema nor course of disease.
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Apoptosis in Pneumovirus Infection
Viruses, 2013Co-Authors: Elske Van Den Berg, Job B. M. Van Woensel, Reinout A.Abstract:Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of Pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages) during Pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in Pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during Pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.
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Granzyme A- and B-Cluster Deficiency Delays Acute Lung Injury in Pneumovirus-Infected Mice
The Journal of Immunology, 2009Co-Authors: Reinout A., Job B. M. Van Woensel, René Lutter, Joseph B. Domachowske, Jan Paul Medema, Helene F. Rosenberg, Albert P. BosAbstract:Lower respiratory tract infection by the human Pneumovirus respiratory syncytial virus is a frequent cause of acute lung injury in children. Severe Pneumovirus disease in humans is associated with activation of the granzyme pathway by effector lymphocytes, which may promote pathology by exaggerating proapoptotic caspase activity and proinflammatory activity. The main goal of this study was to determine whether granzymes contribute to the development of acute lung injury in Pneumovirus-infected mice. Granzyme-expressing mice and granzyme A- and B-cluster single- and double-knockout mice were inoculated with the rodent Pneumovirus pneumonia virus of mice strain J3666, and were studied for markers of lung inflammation and injury. Expression of granzyme A and B is detected in effector lymphocytes in mouse lungs in response to Pneumovirus infection. Mice deficient for granzyme A and the granzyme B cluster have unchanged virus titers in the lungs but show a significantly delayed clinical response to fatal Pneumovirus infection, a feature that is associated with delayed neutrophil recruitment, diminished activation of caspase-3, and reduced lung permeability. We conclude that granzyme A- and B-cluster deficiency delays the acute progression of Pneumovirus disease by reducing alveolar injury.
Sean P J Whelan - One of the best experts on this subject based on the ideXlab platform.
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structure of a rabies virus polymerase complex from electron cryo microscopy
Proceedings of the National Academy of Sciences of the United States of America, 2020Co-Authors: Joshua A Horwitz, Simon Jenni, Stephen C Harrison, Sean P J WhelanAbstract:Nonsegmented negative-stranded (NNS) RNA viruses, among them the virus that causes rabies (RABV), include many deadly human pathogens. The large polymerase (L) proteins of NNS RNA viruses carry all of the enzymatic functions required for viral messenger RNA (mRNA) transcription and replication: RNA polymerization, mRNA capping, and cap methylation. We describe here a complete structure of RABV L bound with its phosphoprotein cofactor (P), determined by electron cryo-microscopy at 3.3 A resolution. The complex closely resembles the vesicular stomatitis virus (VSV) L-P, the one other known full-length NNS-RNA L-protein structure, with key local differences (e.g., in L-P interactions). Like the VSV L-P structure, the RABV complex analyzed here represents a preinitiation conformation. Comparison with the likely elongation state, seen in two structures of Pneumovirus L-P complexes, suggests differences between priming/initiation and elongation complexes. Analysis of internal cavities within RABV L suggests distinct template and product entry and exit pathways during transcription and replication.
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structure of a rabies virus polymerase complex from electron cryo microscopy
bioRxiv, 2019Co-Authors: Joshua A Horwitz, Simon Jenni, Stephen C Harrison, Sean P J WhelanAbstract:ABSTRACT Non-segmented negative-stranded (NNS) RNA viruses, among them the virus that causes rabies (RABV), include many deadly human pathogens. The large polymerase (L) proteins of NNS-RNA viruses carry all the enzymatic functions required for viral mRNA transcription and replication: RNA polymerization, mRNA capping, cap methylation. We describe here a complete structure of RABV L bound with its phosphoprotein cofactor (P), determined by electron cryo-microscopy at 3.3 A resolution. The complex closely resembles vesicular stomatitis virus (VSV) L-P, the one other known full-length NNS-RNA L protein structure, with key local differences (e.g., in L-P interactions). Like the VSV L-P structure, the RABV complex analyzed here represents a pre-initiation conformation. Comparison with the likely elongation state, seen in two partial structures of Pneumovirus L-P complexes, suggests differences between priming/initiation and elongation complexes. Analysis of internal cavities within RABV L suggests distinct template and product entry and exit pathways during transcription and replication.
Reinout A. - One of the best experts on this subject based on the ideXlab platform.
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Pneumovirus-Induced Lung Disease in Mice Is Independent of Neutrophil-Driven Inflammation.
PLOS ONE, 2016Co-Authors: Bart Cortjens, Reinout A., René Lutter, Louis Boon, Job B. M. Van WoenselAbstract:The human Pneumovirus respiratory syncytial virus (RSV) is the most common pathogen causing lower respiratory tract disease in young children worldwide. A hallmark of severe human RSV infection is the strong neutrophil recruitment to the airways and lungs. Massive neutrophil activation has been proven detrimental in numerous diseases, yet in RSV the contribution of neutrophils to disease severity, and thereby, the relevance of targeting them, is largely unknown. To determine the relevance of potential neutrophil targeting therapies, we implemented antibody-mediated neutrophil depletion in a mouse pneumonia virus of mice (PVM) model. PVM is a host specific murine Pneumovirus closely related to human RSV, which reproduces many of the features of RSV infection, such as high viral replication and neutrophil recruitment. Clinical disease and markers of lung inflammation and injury were studied in PVM-infected mice treated with either depleting or isotype control antibodies. To confirm our results we performed all experiments in two mice strains: C57Bl6 and BALBc mice. Neutrophil depletion in blood and lungs was efficient throughout the disease. Remarkably, in both mouse strains we found no difference in clinical disease severity between neutrophil-depleted and control arms. In line with this observation, we found no differences between groups in histopathological lung injury and lung viral loads. In conclusion, our study shows that in mice neutrophil recruitment to the lungs does not affect disease outcome or viral clearance during severe PVM infection. As such, this model does not support the notion that neutrophils play a key role in mouse Pneumovirus disease.
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The caspase inhibitor zVAD increases lung inflammation in Pneumovirus infection in mice
Physiological Reports, 2015Co-Authors: Elske Van Den Berg, Job B. M. Van Woensel, René Lutter, Albert P. Bos, Suzanne M. Bal, Maria T. Kuipers, Gustavo Matute-bello, Reinout A.Abstract:Severe respiratory syncytial virus (RSV) disease is a frequent cause of acute respiratory distress syndrome (ARDS) in young children, and is associated with marked lung epithelial injury and neutrophilic inflammation. Experimental studies on ARDS have shown that inhibition of apoptosis in the lungs reduces lung epithelial injury. However, the blockade of apoptosis in the lungs may also have deleterious effects by hampering viral clearance, and importantly, by enhancing or prolonging local proinflammatory responses. The aim of this study was to determine the effect of the broad caspase inhibitor Z-VAD(OMe)-FMK (zVAD) on inflammation and lung injury in a mouse Pneumovirus model for severe RSV disease. Eight- to 11-week-old female C57BL/6OlaHsd mice were inoculated with the rodent-specific Pneumovirus pneumonia virus of mice (PVM) strain J3666 and received multiple injections of zVAD or vehicle (control) during the course of disease, after which they were studied for markers of apoptosis, inflammation, and lung injury on day 7 after infection. PVM-infected mice that received zVAD had a strong increase in neutrophil numbers in the lungs, which was associated with decreased neutrophil apoptosis. Furthermore, zVAD treatment led to higher concentrations of several proinflammatory cytokines in the lungs and more weight loss in PVM-infected mice. In contrast, zVAD did not reduce apoptosis of lung epithelial cells and did not affect the degree of lung injury, permeability, and viral titers in PVM disease. We conclude that zVAD has an adverse effect in severe Pneumovirus disease in mice by enhancing the lung proinflammatory response.
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Apoptosis in Pneumovirus Infection
Viruses, 2013Co-Authors: Elske Van Den Berg, Job B. M. Van Woensel, Reinout A.Abstract:Pneumovirus infections cause a wide spectrum of respiratory disease in humans and animals. The airway epithelium is the major site of Pneumovirus replication. Apoptosis or regulated cell death, may contribute to the host anti-viral response by limiting viral replication. However, apoptosis of lung epithelial cells may also exacerbate lung injury, depending on the extent, the timing and specific location in the lungs. Differential apoptotic responses of epithelial cells versus innate immune cells (e.g., neutrophils, macrophages) during Pneumovirus infection can further contribute to the complex and delicate balance between host defense and disease pathogenesis. The purpose of this manuscript is to give an overview of the role of apoptosis in Pneumovirus infection. We will examine clinical and experimental data concerning the various pro-apoptotic stimuli and the roles of apoptotic epithelial and innate immune cells during Pneumovirus disease. Finally, we will discuss potential therapeutic interventions targeting apoptosis in the lungs.
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Granzyme A- and B-Cluster Deficiency Delays Acute Lung Injury in Pneumovirus-Infected Mice
The Journal of Immunology, 2009Co-Authors: Reinout A., Job B. M. Van Woensel, René Lutter, Joseph B. Domachowske, Jan Paul Medema, Helene F. Rosenberg, Albert P. BosAbstract:Lower respiratory tract infection by the human Pneumovirus respiratory syncytial virus is a frequent cause of acute lung injury in children. Severe Pneumovirus disease in humans is associated with activation of the granzyme pathway by effector lymphocytes, which may promote pathology by exaggerating proapoptotic caspase activity and proinflammatory activity. The main goal of this study was to determine whether granzymes contribute to the development of acute lung injury in Pneumovirus-infected mice. Granzyme-expressing mice and granzyme A- and B-cluster single- and double-knockout mice were inoculated with the rodent Pneumovirus pneumonia virus of mice strain J3666, and were studied for markers of lung inflammation and injury. Expression of granzyme A and B is detected in effector lymphocytes in mouse lungs in response to Pneumovirus infection. Mice deficient for granzyme A and the granzyme B cluster have unchanged virus titers in the lungs but show a significantly delayed clinical response to fatal Pneumovirus infection, a feature that is associated with delayed neutrophil recruitment, diminished activation of caspase-3, and reduced lung permeability. We conclude that granzyme A- and B-cluster deficiency delays the acute progression of Pneumovirus disease by reducing alveolar injury.