Effect of Th1/Th2 cytokine pretreatment on RSV-induced gene expression in airway epithelial cells.
BACKGROUND
Respiratory syncytial virus (RSV) infection in infants with Th2 predisposition is thought to increase the risk of allergic sensitization, recurrent wheezing, and bronchial asthma during childhood. We attempted to clarify the molecular mechanisms by which Th1/Th2 predisposition in the host alters RSV infection and facilitates airway inflammation.


METHODS
A549 human airway epithelial cells were inoculated with live or UV-treated RSV after pretreatment with either a combination of tumor necrosis factor (TNF)-α and interferon-γ (Th1-primed) or a combination of TNF-α and interleukin-4 (Th2-primed) for 48 h. The gene and protein expression profiles of RSV-infected A549 cells were examined.


RESULTS
GeneChip analysis indicated that, at 96 h after inoculation with RSV, the expression of 62 genes was specifically enhanced (more than 2-fold by normalized data) in Th2-primed cells compared to that in unprimed or Th1-primed cells. An increase in mRNA and protein levels of monocyte chemoattractant protein (MCP)-1/CCL2 among those 62 genes was confirmed by real-time PCR and cytometric bead assay, respectively. RSV replication was markedly diminished in Th1-primed airway epithelial cells but not in Th2-primed cells, which was presumably caused at least in part by the early induction of antiviral genes.


CONCLUSIONS
These results suggest that Th1/Th2 predisposition in the host prior to RSV infection critically regulates inflammatory reactions in the airways through alteration of gene expression, and that MCP-1/CCL2 plays an important role in the pathogenesis of severe RSV infection and the subsequent development of asthma in Th2-predisposed hosts.
Yamada
Yumi
Y
Department of Allergy and Immunology, National Research Institute for Child Health and Development, Okura, Tokyo, Japan. yu-yama@dokkyomed.ac.jp
Matsumoto
Kenji
K
Hashimoto
Noriko
N
Saikusa
Miwako
M
Homma
Toshiki
T
Yoshihara
Shigemi
S
Saito
Hirohisa
H
D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology*; D008168:Lung / Q000166:cytology / Q000187:drug effects / Q000276:immunology / Q000378:metabolism* / Q000821:virology; D020411:Oligonucleotide Array Sequence Analysis; D018113:Respiratory Syncytial Virus, Human / Q000276:immunology / Q000472:pathogenicity*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018417:Th1 Cells / Q000276:immunology / Q000378:metabolism; D018418:Th2 Cells / Q000276:immunology / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology*; D014779:Virus Replication
C111835:CCL2 protein, human; D018932:Chemokine CCL2; D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma