Interleukin-13 increases prostaglandin E2 (PGE2) production by normal human polymorphonuclear neutrophils by enhancing cyclooxygenase 2 (COX-2) gene expression.
OBJECTIVE
To investigate whether interleukin-13 (IL-13) can affect arachidonic acid metabolism and phagocytic activity of normal human polymorphonuclear neutrophils (PMN).


METHODS
Normal human PMN (1 x 10(6) cells/ml) were incubated with different concentrations of IL-13 (0.1-10 ng/ml) for a variety of times (30-120 min). Phagocytosis and intracellular cyclooxygenase-2 (COX-2) were detected by flow cytometry. The expression of COX-1 and COX-2 mRNA was detected by RT-PCR. The concentration of PGE2 in the PMN cultured supernatants was determined by EIA.


RESULTS
We found that IL-13 at an optimal concentration of 1 ng/ml significantly enhanced COX-2 gene expression and PGE2 production (121.57 +/- 22.17 pg/ml in IL-13 stimulation vs. 73.16 +/- 11.72 pg/ml in controls) by PMN. In addition, IL-13 stimulated PMN phagocytosis via increased complement receptor type 1 (CR1) and type 3 (CR3), but not IgG Fcgamma receptor type 3 (FcgammaRIII). The cytoplasmic neutral esterase activity of PMN was also enhanced by IL-13 stimulation for 24 h.


CONCLUSIONS
These results suggest that IL-13 can stimulate PMN and modulates the inflammatory reactions via the cyclooxygenase pathway.
Yu
C L
CL
Department of Medicine and Institute of Clinical Medicine, Veterans General Hospital-Taipei, Taiwan.
Huang
M H
MH
Kung
Y Y
YY
Tsai
C Y
CY
Tsai
Y Y
YY
Tsai
S T
ST
Huang
D F
DF
Sun
K H
KH
Han
S H
SH
Yu
H S
HS
D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000096:biosynthesis*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006801:Humans; D007124:Immunoenzyme Techniques; D018793:Interleukin-13 / Q000494:pharmacology*; D007527:Isoenzymes / Q000096:biosynthesis*; D016177:Macrophage-1 Antigen / Q000187:drug effects; D008565:Membrane Proteins; D018375:Neutrophil Activation / Q000187:drug effects; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology; D010587:Phagocytosis / Q000187:drug effects; D016133:Polymerase Chain Reaction; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000032:analysis; D017463:Receptors, Complement 3b / Q000187:drug effects
D018793:Interleukin-13; D007527:Isoenzymes; D016177:Macrophage-1 Antigen; D008565:Membrane Proteins; D012333:RNA, Messenger; D017463:Receptors, Complement 3b; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone