Activation of interleukin-32 pro-inflammatory pathway in response to influenza A virus infection.
BACKGROUND
Interleukin (IL)-32 is a recently described pro-inflammatory cytokine that has been reported to be induced by bacteria treatment in culture cells. Little is known about IL-32 production by exogenous pathogens infection in human individuals.


RESULTS
In this study, we found that IL-32 level was increased by 58.2% in the serum samples from a cohort of 108 patients infected by influenza A virus comparing to that of 115 healthy individuals. Another pro-inflammatory factor cyclooxygenase (COX)-2-associated prostaglandin E2 was also upregulated by 2.7-fold. Expression of IL-32 in influenza A virus infected A549 human lung epithelial cells was blocked by either selective COX-2 inhibitor NS398 or Aspirin, a known anti-inflammatory drug, indicating IL-32 was induced through COX-2 in the inflammatory cascade. Interestingly, we found that COX-2-associate PGE(2) production activated by influenza virus infection was significantly suppressed by over-expression of IL-32 but increased by IL-32-specific siRNA, suggesting there was a feedback mechanism between IL-32 and COX-2.


CONCLUSIONS
IL-32 is induced by influenza A virus infection via COX-2 in the inflammatory cascade. Our results provide that IL-32 is a potential target for anti-inflammatory medicine screening.
Li
Wei
W
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, People's Republic of China.
Liu
Yan
Y
Mukhtar
Muhammad Mahmood
MM
Gong
Rui
R
Pan
Ying
Y
Rasool
Sahibzada T
ST
Gao
Yecheng
Y
Kang
Lei
L
Hao
Qian
Q
Peng
Guiqing
G
Chen
Yanni
Y
Chen
Xin
X
Wu
Jianguo
J
Zhu
Ying
Y
D000328:Adult; D001241:Aspirin / Q000494:pharmacology; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation; D009980:Influenza A virus / Q000378:metabolism*; D007378:Interleukins / Q000378:metabolism*; D019746:Intramolecular Oxidoreductases / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009578:Nitrobenzenes / Q000494:pharmacology; D000071876:Prostaglandin-E Synthases; D034741:RNA, Small Interfering / Q000378:metabolism; D013449:Sulfonamides / Q000494:pharmacology; D014162:Transfection
D016207:Cytokines; C496971:IL32 protein, human; D007378:Interleukins; D009578:Nitrobenzenes; D034741:RNA, Small Interfering; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D019746:Intramolecular Oxidoreductases; D000071876:Prostaglandin-E Synthases; D001241:Aspirin