scholarly journals Inhibition of viral replication reverses respiratory syncytial virus-induced NF-kappaB activation and interleukin-8 gene expression in A549 cells.

1996 ◽  
Vol 70 (12) ◽  
pp. 9079-9082 ◽  
Author(s):  
M A Fiedler ◽  
K Wernke-Dollries ◽  
J M Stark
Keyword(s):  
Gene Expression ◽  
Respiratory Syncytial Virus ◽  
Viral Replication ◽  
A549 Cells ◽  
Interleukin 8 ◽  
Syncytial Virus ◽  
Nf Kappab

Respiratory syncytial virus increases IL-8 gene expression and protein release in A549 cells

1995 ◽  
Vol 269 (6) ◽  
pp. L865-L872 ◽  
Author(s):  
M. A. Fiedler ◽  
K. Wernke-Dollries ◽  
J. M. Stark
Keyword(s):  
Gene Expression ◽  
Respiratory Syncytial Virus ◽  
Viral Replication ◽  
Mrna Expression ◽  
A549 Cells ◽  
Protein Release ◽  
Tnf Alpha ◽  
Epithelial Cell Line ◽  
Airway Epithelial ◽  
Syncytial Virus

The mechanism of respiratory syncytial virus (RSV)-induced inflammation in the airways of infants and children is not fully understood. We hypothesized that RSV directly induces interleukin (IL)-8 gene expression in airway epithelial cells, independent of IL-1 beta and tumor necrosis factor-alpha (TNF-alpha) production. Exposure of A549 cells (an airway epithelial cell line) to RSV resulted in increased IL-8 mRNA expression and IL-8 protein release from the cells as early as 2 h after treatment. Neither IL-1 beta nor TNF-alpha (mRNA or protein) were detected. Viral replication was not necessary for the effects of RSV on IL-8 mRNA expression and protein release early in the infectious process. However, sustained levels of increased IL-8 production required RSV replication. A dose-response relationship was observed between the multiplicity of infection and IL-8 production with both active and nonreplicative RSV at the 2-h time point. Both active RSV and nonreplicative RSV increased the transcriptional activity of the 1.6-kb 5' flanking region of the IL-8 gene. Neither active RSV nor nonreplicative RSV increased the stability of the IL-8 mRNA in A549 cells. We conclude that RSV increases IL-8 gene expression in A549 cells in a biphasic pattern independent of viral replication early (2 h) but dependent on viral replication late (24 h).

Mechanism of RSV-induced IL-8 gene expression in A549 cells before viral replication

1996 ◽  
Vol 271 (6) ◽  
pp. L963-L971 ◽  
Author(s):  
M. A. Fiedler ◽  
K. Wernke-Dollries ◽  
J. M. Stark
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Viral Replication ◽  
Transcriptional Activation ◽  
Mutational Analysis ◽  
A549 Cells ◽  
Nf Kappa B ◽  
Mobility Shift ◽  
Syncytial Virus ◽  
Time Point

Previous studies demonstrated that respiratory syncytial virus (RSV) infection of A549 cells induced interleukin (IL)-8 gene expression and protein release from the cells as early as 2 h after treatment [M. A. Fiedler, K. Wernke-Dollries, and J. M. Stark. Am. J. Physiol. 269 (Lung Cell. Mol. Physiol. 13): L865-L872, 1995; J. G. Mastronarde, M. M. Monick, and G. W. Hunninghake. Am. J. Respir. Cell Mol. Biol. 13: 237-244, 1995]. Furthermore, the effects of RSV at the 2-h time point were not dependent on viral replication. The studies reported here were designed to test the hypothesis that active and inactive RSV induce IL-8 gene expression in A549 cells at the 2-h time point by a mechanism dependent on the activation of the nuclear transcription factor NF-kappa B Northern blot analysis indicated that IL-8 gene expression occurred independent of protein synthesis 2 h after A549 cells were treated with RSV. Analysis of nuclear extracts from RSV-treated A549 cells by electrophoretic mobility shift assays demonstrated that NF-kappa B was activated as early as 15 min after RSV was added to the cells and remained activated for at least 90 min. In contrast, baseline levels of NF-IL-6 and activator protein-1 (AP-1) did not change over this period of time. Deoxyribonuclease footprint analysis of a portion of the 5'-flanking region of the IL-8 gene demonstrated two potential regions for transcription factor binding, which corresponded to the potential AP-1 binding site, and potential NF-IL-6 and NF-kappa B binding sites. Mutational analysis of the 200-bp 5'-untranslated region of the IL-8 gene demonstrated that activation of NF-kappa B and NF-IL-6 were required for RSV-induced transcriptional activation of the IL-8 gene.

scholarly journals Respiratory Syncytial Virus-Inducible BCL-3 Expression Antagonizes the STAT/IRF and NF-κB Signaling Pathways by Inducing Histone Deacetylase 1 Recruitment to the Interleukin-8 Promoter

2005 ◽  
Vol 79 (24) ◽  
pp. 15302-15313 ◽  
Author(s):  
Mohammad Jamaluddin ◽  
Sanjeev Choudhary ◽  
Shaofei Wang ◽  
Antonella Casola ◽  
Ruksana Huda ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Signaling Pathways ◽  
Histone Deacetylase ◽  
Trichostatin A ◽  
A549 Cells ◽  
B Cell Lymphoma ◽  
Interleukin 8 ◽  
Nuclear Targeting ◽  
Histone Deacetylase 1 ◽  
Syncytial Virus

ABSTRACT Respiratory syncytial virus (RSV) is a paramyxovirus that produces airway inflammation, in part by inducing interleukin-8 (IL-8) expression, a CXC-type chemokine, via the NF-κB/RelA and STAT/IRF signaling pathways. In RSV-infected A549 cells, IL-8 transcription attenuates after 24 h in spite of ongoing viral replication and persistence of nuclear RelA, suggesting a mechanism for transcriptional attenuation. RSV infection induces B-cell lymphoma protein -3 (Bcl-3) expression 6 to 12 h after viral infection, at times when IL-8 transcription is inhibited. By contrast, 293 cells, deficient in inducible Bcl-3 expression, show no attenuation of IL-8 transcription. We therefore examined Bcl-3's role in terminating virus-inducible IL-8 transcription. Transient expression of Bcl-3 potently inhibited virus-inducible IL-8 transcription by disrupting both the NF-κB and STAT/IRF pathways. Although previously Bcl-3 was thought to capture 50-kDa NF-κB1 isoforms in the cytoplasm, immunoprecipitation (IP) and electrophoretic mobility shift assays indicate that nuclear Bcl-3 associates with NF-κB1 without affecting DNA binding. Additionally, Bcl-3 potently inhibited the STAT/IRF pathway. Nondenaturing co-IP assays indicate that nuclear Bcl-3 associates with STAT-1 and histone deacetylase 1 (HDAC-1), increasing HDAC-1 recruitment to the IL-8 promoter. Treatment with the HDAC inhibitor trichostatin A blocks attenuation of IL-8 transcription. A nuclear targeting-deficient Bcl-3 is unable to enhance HDAC-1-mediated chemokine repression. Finally, small inhibitory RNA-mediated Bcl-3 “knockdown” resulted in enhanced RSV-induced chemokine expression in A549 cells. These data indicate that Bcl-3 is a virus-inducible inhibitor of chemokine transcription by interfering with the NF-κB and STAT/IRF signaling pathways by complexing with them and recruiting HDAC-1 to attenuate target promoter activity.

ACTIVATION OF ERK2 BY RESPIRATORY SYNCYTIAL VIRUS IN A549 CELLS IS LINKED TO THE PRODUCTION OF INTERLEUKIN 8

2000 ◽  
Vol 26 (1) ◽  
pp. 13-26 ◽  
Author(s):  
Weizu Chen ◽  
Martha M. Monick ◽  
Aaron B. Carter ◽  
Gary W. Hunninghake
Keyword(s):  
Respiratory Syncytial Virus ◽  
A549 Cells ◽  
Interleukin 8 ◽  
Syncytial Virus

scholarly journals Synergistic Upregulation of Interleukin-8 Secretion from Pulmonary Epithelial Cells by Direct and Monocyte-Dependent Effects of Respiratory Syncytial Virus Infection

2000 ◽  
Vol 74 (18) ◽  
pp. 8425-8433 ◽  
Author(s):  
Lynette H. Thomas ◽  
Melissa I. Y. Wickremasinghe ◽  
Mike Sharland ◽  
Jon S. Friedland
Keyword(s):  
Respiratory Syncytial Virus ◽  
Epithelial Cells ◽  
A549 Cells ◽  
Interleukin 8 ◽  
Respiratory Epithelial Cells ◽  
Necrosis Factor Alpha ◽  
Leukocyte Influx ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Respiratory Epithelial

ABSTRACT Respiratory syncytial virus (RSV) infection is the major cause of severe bronchiolitis in infants. Pathology of this infection is partly due to excessive proinflammatory leukocyte influx mediated by chemokines. Although direct infection of the respiratory epithelium by RSV may induce chemokine secretion, little is known about the role of cytokine networks. We investigated the effects of conditioned medium (CM) from RSV-infected monocytes (RSV-CM) on respiratory epithelial (A549) cell chemokine release. RSV-CM, but not control CM (both at a 1:5 dilution), stimulated interleukin-8 (IL-8) secretion from A549 cells within 2 h, and secretion increased over 72 h to 11,360 ± 1,090 pg/ml without affecting cell viability. In contrast, RSV-CM had only a small effect on RANTES secretion. RSV-CM interacted with direct RSV infection to synergistically amplify IL-8 secretion from respiratory epithelial cells (levels of secretion at 48 h were as follows: RSV-CM alone, 8,140 ± 2,160 pg/ml; RSV alone, 12,170 ± 300 pg/ml; RSV-CM plus RSV, 27,040 ± 5,260 pg/ml; P < 0.05). RSV-CM induced degradation of IκBα within 5 min but did not affect IκBβ. RSV-CM activated transient nuclear binding of NF-κB within 1 h, while activation of NF-IL6 was delayed until 8 h and was still detectable at 24 h. Promoter-reporter analysis demonstrated that NF-κB binding was essential and that NF-IL6 was important for IL-8 promoter activity in RSV-CM-activated cells. Blocking experiments revealed that the effects of RSV-CM depended on monocyte-derived IL-1 but that tumor necrosis factor alpha was not involved in this network. In summary, RSV infection of monocytes results in and amplifies direct RSV-mediated IL-8 secretion from respiratory epithelial cells by an NF-κB-dependent, NF-IL6-requiring mechanism.

scholarly journals Gene Expression of Nucleic Acid-Sensing Pattern Recognition Receptors in Children Hospitalized for Respiratory Syncytial Virus-Associated Acute Bronchiolitis

2009 ◽  
Vol 16 (6) ◽  
pp. 816-823 ◽  
Author(s):  
Carolina Scagnolari ◽  
Fabio Midulla ◽  
Alessandra Pierangeli ◽  
Corrado Moretti ◽  
Enea Bonci ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pattern Recognition ◽  
Viral Load ◽  
Respiratory Syncytial Virus ◽  
Pattern Recognition Receptors ◽  
Mrna Levels ◽  
Acute Bronchiolitis ◽  
Expression Levels ◽  
Rsv Infection ◽  
Syncytial Virus

ABSTRACT Given the critical role of pattern recognition receptors (PRRs) in acid nucleic recognition in the initiation of innate immunity and the orchestration of adaptive immunity, the aim of this study was to determine whether any heterogeneity of PRR expression in the airway tracts of infants with respiratory syncytial virus (RSV) infection might explain the broad clinical spectrum of RSV-associated bronchiolitis in infants. For this purpose, the levels of melanoma differentiation-associated protein-5 (MDA-5), retinoic acid inducible gene-1 (RIG-1), and Toll-like receptor 3 (TLR-3), TLR-7, TLR-8, and TLR-9 mRNAs were evaluated, using TaqMan quantitative reverse transcription-PCR, in cells from nasopharyngeal washes collected from 157 infants suffering from acute bronchiolitis whether or not they were associated with respiratory viruses. High interindividual variability was observed in both virus-positive and -negative infants; however, the relative gene expression levels of MDA-5, RIG-1, TLR-7, and TLR-8 were significantly higher in the virus-infected group, whereas the expression levels of TLR-3 and TLR-9 were not significantly different. The differences in the gene expression of MDA-5, RIG-1, TLR-7, and TLR-8 were more evident in infants with RSV infection than in those with bocavirus or rhinovirus infection. In RSV-infected infants, PRR-mRNA levels also were analyzed in relation to interferon protein levels, viral load, clinical severity, days of hospitalization, age, and body weight. A significant positive correlation was observed only between RSV viral load and RIG-1 mRNA levels. These findings provide the first direct evidence that, in infants with respiratory virus-associated bronchiolitis, especially RSV, there are substantial changes in PRR gene expression; this likely is an important determinant of the clinical outcome of bronchiolitis.

ELEVATED PLASMA INTERLEUKIN 8 IN RESPIRATORY SYNCYTIAL VIRUS BRONCHIOLITIS

1995 ◽  
Vol 14 (10) ◽  
pp. 919 ◽  
Author(s):  
S. Biswas ◽  
J. S. Friedland ◽  
D. G. Remick ◽  
E. G. Davies ◽  
M. Sharland
Keyword(s):  
Respiratory Syncytial Virus ◽  
Interleukin 8 ◽  
Elevated Plasma ◽  
Respiratory Syncytial Virus Bronchiolitis ◽  
Syncytial Virus
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