Cytokine amplification by respiratory syncytial virus infection in human nasal epithelial cells.
OBJECTIVE
Respiratory syncytial virus (RSV) is an important cause of upper respiratory infections and is known to play a causal role in the pathogenesis of rhinitis, sinusitis, acute otitis media, and pneumonia. RSV appears to prime the respiratory tract to secondary inciting events, such as bacterial or antigen challenges. To study the proinflammatory priming effects of RSV infection, cytokine expression was measured in well-differentiated human nasal epithelial cells (WD-NE) after RSV infection alone or after subsequent tumor necrosis factor (TNF)-alpha stimulation.


METHODS
In vitro investigation.


METHODS
Human nasal epithelial cells were obtained from surgical specimens and allowed to differentiate in air-liquid interface cultures until ciliation and mucus production were evident. Two experimental paradigms were used. First, accumulation of cytokines in the media was measured by real-time, quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay after RSV infection alone. In the second set of experiments, cytokines were also measured after TNF-alpha stimulation in both RSV-infected and uninfected cultures.


RESULTS
RSV infection of WD-NE resulted in significant accumulations of interleukin (IL)-6, IL-8, and RANTES when compared with findings in control samples. Real-time, quantitative RT-PCR demonstrated significant increases in IL-8 gene expression following RSV infection when compared to controls. Secondary TNF-alpha stimulation following well-established (i.e., 72 h) RSV infection induced marked increases in IL-6, IL-8, and RANTES when compared with both RSV infection alone and TNF-alpha stimulation alone.


CONCLUSIONS
These findings suggest that RSV infection primes nasal epithelial cells to secondary proinflammatory challenge, resulting in a hyperimmune response. RSV-induced priming of a hyperimmune response may be important in the pathogenesis of sinusitis, acute otitis media, and pneumonia.
Das
Subinoy
S
Department of Otolaryngology-Head & Neck Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Palmer
Owen P
OP
Leight
W Derek
WD
Surowitz
Joshua B
JB
Pickles
Raymond J
RJ
Randell
Scott H
SH
Buchman
Craig A
CA
D018946:Chemokine CCL5 / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology; D006801:Humans; D015850:Interleukin-6 / Q000276:immunology*; D016209:Interleukin-8 / Q000235:genetics / Q000276:immunology*; D009297:Nasal Mucosa / Q000276:immunology* / Q000473:pathology; D010033:Otitis Media / Q000276:immunology / Q000382:microbiology; D011014:Pneumonia / Q000276:immunology / Q000382:microbiology; D018357:Respiratory Syncytial Virus Infections / Q000150:complications / Q000276:immunology* / Q000473:pathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
D018946:Chemokine CCL5; D015850:Interleukin-6; D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha