Project description:We studied RSV infection in an appropriate in vitro model of respiratory epithelium, a pseudostratified and fully differentiated mucociliary epithelium of normal human bronchial epithelial (NHBE) cells. RSV infection increased actin cytoskeleton without compromising adherent-, tight-, and tricellular-junctions as well as ciliary functions and epithelial tissue barrier integrity. This increased cytoskeleton depends on actin polymerization and the induction of proinflammatory cytokines and chemokines. Thus, we observed a novel signature “increased cytoskeleton” termed “cytoskeletal inflammation” in RSV-infected respiratory epithelium that presumably lacks classical antigen presenting cells, such as resident dendritic cells and macrophages. Our results suggest that RSV-induced cytoskeletal inflammation is a noncanonical earliest host response to the pathogen and contributes to airway inflammation.
Project description:Human bronchial epithelial cells (BEAS-2B cells) were treated with RSV at 1.0 MOI for 4 and 24 hours or control (vehicle-treated for 4 hours). Global gene expression was measured by Affy Hu133 plus 2.0 microarray chips. Keywords: Inflammation, microtubules, RSV, time course
Project description:In order to further explore the expression of proteins in RSV-infected macrophages, RSV type-L19 was used to stimulate RAW264.7 cells, and then mass spectrometry was conducted to detect the expression of different proteins after RSV infection. The results showed that there were different expression of proteins in RSV activated and inactive RAW264.7 cells.
Project description:Rationale: Respiratory syncytial virus (RSV) and Streptococcus pneumoniae are major respiratory pathogens. Co-infection with RSV and S. pneumoniae is associated with severe and often fatal pneumonia but the molecular basis for this remains unclear. Objectives: To determine if interaction between RSV and pneumococci enhances pneumococcal virulence. Methods: We used confocal microscopy and western blot to identify the receptors involved in direct binding of RSV and pneumococci, the effects of which were studied in both in vivo and in vitro models of infection. Human ciliated respiratory epithelial cell cultures were infected with RSV for 72h and then challenged with pneumococci. Pneumococci were collected after 2h exposure and changes in gene expression determined using qRT-PCR. Results: Following incubation with RSV or purified G protein, pneumococci demonstrated a significant increase in the inflammatory response and bacterial adherence to human ciliated epithelial cultures and markedly increased virulence in a pneumonia model in mice. This was associated with extensive changes in the pneumococcal transcriptome and significant upregulation in the expression of key pneumococcal virulence genes, including the gene for the pneumococcal toxin, pneumolysin. We show that mechanistically this is due to RSV G glycoprotein binding penicillin binding protein 1a. Conclusion: The direct interaction between a respiratory virus protein and the pneumococcus resulting in increased bacterial virulence and worsening disease outcome is a new paradigm in respiratory infection. Comparison of the Streptococcus pneumoniae D39 RSV treated compared to BSA Treated in BEBM medium One condition design comparision of two strains including a dye swap
Project description:Respiratory Syncytial Virus (RSV) causes severe inflammation and airway pathology in children and the elderly by infecting the epithelial cells of the upper and lower respiratory tract. RSV replication is sensed by intracellular pattern recognition receptors upstream of the IRF and NF-$\upkappa$B transcription factors. These proteins coordinate an innate inflammatory response via Bromodomain containing protein 4 (BRD4), a protein that functions as a scaffold for unknown transcriptional regulators. To better understand the pleiotropic regulatory function of BRD4, we examine the BRD4 interactome and identify how RSV infection dynamically alters it. To accomplish these goals, we leverage native immunoprecipitation and Parallel Accumulation – Serial Fragmentation (PASEF) mass spectrometry to examine BRD4 complexes isolated from human alveolar epithelial cells in the absence or presence of RSV infection. In addition, we explore the role of BRD4's acetyl-lysine binding bromodomains in mediating these interactions by using a highly selective competitive bromodomain inhibitor. We identify 101 proteins that are significantly enriched in the BRD4 complex and are responsive to both RSV-infection and BRD4 inhibition. These proteins are highly enriched in transcription factors and transcriptional coactivators. Among them, we identify members of the AP1 transcription factor complex, a complex important in innate signaling and cell stress responses. We independently confirm the BRD4/AP1 interaction in primary human small airway epithelial cells. We conclude that BRD4 recruits multiple transcription factors during RSV infection in a manner dependent on acetyl-lysine binding domain interactions. This data suggests that BRD4 recruits transcription factors to target its RNA processing complex to regulate gene expression in innate immunity and inflammation.
Project description:RSV, a leading cause of severe respiratory illnesses in vulnerable populations, lacks effective, affordable treatments for pediatric use. The potential of traditional Chinese medicine for relieving viral symptoms prompted this investigation into Xuanfei Formula (XFF) as an anti-RSV agent. This study employed H&E staining, cytokine profiling, and RSV titer quantification in BALB/c mice to evaluate the impact of XFF on RSV infection. Strikingly, immediate post-treatment observation showed a precipitous drop in both serum pro-inflammatory cytokine levels and pulmonary RSV-N gene copies in comparison to infected controls, suggesting XFF’s direct anti-RSV action. Transcriptome analyses were used to pinpointed the underlying mechanism behind formula’s immune-independent anti-RSV, a leading cause of severe respiratory illnesses in vulnerable populations, lacks effective, affordable treatments for pediatric use. The potential of traditional Chinese medicine for relieving viral symptoms prompted this investigation into Xuanfei Formula (XFF) as an anti-RSV agent. This study employed H&E staining, cytokine profiling, and RSV titer quantification in BALB/c mice to evaluate the impact of XFF on RSV infection. Strikingly, immediate post-treatment observation showed a precipitous drop in both serum pro-inflammatory cytokine levels and pulmonary RSV-N gene copies in comparison to infected controls, suggesting XFF’s direct anti-RSV action. Transcriptome analyses were used to pinpointed the underlying mechanism behind formula’s immune-independent anti-RSV effects during infection.
Project description:Rationale: Respiratory syncytial virus (RSV) and Streptococcus pneumoniae are major respiratory pathogens. Co-infection with RSV and S. pneumoniae is associated with severe and often fatal pneumonia but the molecular basis for this remains unclear. Objectives: To determine if interaction between RSV and pneumococci enhances pneumococcal virulence. Methods: We used confocal microscopy and western blot to identify the receptors involved in direct binding of RSV and pneumococci, the effects of which were studied in both in vivo and in vitro models of infection. Human ciliated respiratory epithelial cell cultures were infected with RSV for 72h and then challenged with pneumococci. Pneumococci were collected after 2h exposure and changes in gene expression determined using qRT-PCR. Results: Following incubation with RSV or purified G protein, pneumococci demonstrated a significant increase in the inflammatory response and bacterial adherence to human ciliated epithelial cultures and markedly increased virulence in a pneumonia model in mice. This was associated with extensive changes in the pneumococcal transcriptome and significant upregulation in the expression of key pneumococcal virulence genes, including the gene for the pneumococcal toxin, pneumolysin. We show that mechanistically this is due to RSV G glycoprotein binding penicillin binding protein 1a. Conclusion: The direct interaction between a respiratory virus protein and the pneumococcus resulting in increased bacterial virulence and worsening disease outcome is a new paradigm in respiratory infection.
Project description:Respiratory Syncytial virus (RSV) is the most common cause of childhood viral bronchiolitis and lung injury. Inflammatory responses significantly contribute to lung pathologies during RSV infections and bronchiolitis but the exact mechanisms have not been completely defined. The double-stranded RNA-activated protein kinase (PKR) functions to inhibit viral replication and participates in several signaling pathways associated with innate inflammatory immune responses. Using a functionally defective PKR (PKR-/-) mouse model, we investigated the role of this kinase in early events of RSV-induced inflammation. Our data showed that bronchoalveolar lavage (BAL) fluid of infected PKR-/- mice had significantly lower levels of several innate inflammatory cytokines and chemokines. Histological examinations revealed that there was less lung injury in infected PKR-/- mice as compared to the wild type. A genome-wide analysis showed that several early anti viral and immune regulatory genes were affected by PKR activation. These data suggest that PKR is a signaling molecule for immune responses during RSV infections.
Project description:A few transformed cell lines and two historic strains have been extensively used to study respiratory syncytial virus (RSV). We report a thorough molecular and cell biological characterization of HEp-2 and A549 cells infected with four strains of RSV representing both major subgroups as well as historic and more contemporary genotypes -- [RSV/A/Tracy (GA1), RSV/A/Ontario (ON), RSV/B/18537 (GB1), RSV/B/Buenos Aires (BA)] -- via measurements of viral replication kinetics and viral gene expression, immunofluorescence-based imaging of gross cellular morphology and cell-associated RSV, and measurements of host response including transcriptional changes and levels of secreted cytokines and growth factors. Our findings strongly suggest 1) the existence of a conserved difference in gene expression between RSV subgroups A and B; 2) the A549 cell line is a more stringent and natural host of replicating RSV than the HEp-2 cell line; and 3) consistent with previous studies, determining the full effects of viral genetic variation in RSV pathogenesis requires model systems as tractable as transformed cell lines but better representative of the human host.
Project description:Epithelial cells are the primary target of respiratory viral infections and play a pivotal role in virus-induced lung inflammation and in anti viral immune response. A common signal for the presence of viral infections and induction of inflammation is recognition of double stranded RNA (dsRNA). Thus far, there has not been a high-throughput transcrptome analysis of RSV- or dsRNA-induced genes in primary human bronchial epithelial cells (PHBE), nor there has been a comparison between dsRNA- and RSV-induced genes. To establish the transcriptome profiles and to determine the contribution of dsRNA in the induction of inflammation during respiratory virus infection, we compared the gene expression profiles of PHBE cells that were infected with RSV or were treated with dsRNA. Our transcriptome analysis showed that RSV infection and and dsRNA treatment induced up-regulation of 2024 and 159 genes in PHBE respectively. Comparison of genes revealed that RSV and dsRNA commonly induced 80 genes in PHBE cells. The common up-regulated genes were functionally grouped in multiple response pathways involved in inflammation and immune responses. Interestingly, there were several previously unreported genes that were up-regulated in primary human epithelial cells that are relevant to a TH2 allergic phenotype. This comparison of a high-throughput gene expression study offers a comprehensive view of transcriptional changes induced by dsRNA and RSV, and importantly compares dsRNA-induced genes with RSV-induced genes in PHBE cells.