Interleukin-8 production by the human colon epithelial cell line HT-29: modulation by interleukin-13.
1. We have determined which cytokines induce and modulate the production of the chemokine interleukin-8 (IL-8) by the human colonic epithelial cell line HT-29. 2. Growth arrested cell cultures were stimulated with the human recombinant cytokines interleukin-1 alpha (IL-1 alpha), tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin-13 (IL-13), interleukin-10 (IL-10) or vehicle added alone or in combination. The production of IL-8 was determined by enzyme-linked immunosorbent assay (ELISA) and IL-8 messenger RNA expression by Northern blot analysis. 3. The production of IL-8 in unstimulated cells was undetectable by both ELISA and Northern blot analysis. 4. HT-29 cells produced IL-8 following stimulation with IL-1 alpha or TNF-alpha in a time- and a concentration-dependent manner, while IFN-gamma, IL-10 and IL-13 did not induce IL-8 production by HT-29 cells. 5. IL-13 was found to up-regulate significantly (P < 0.01) the IL-1 alpha but not the TNF-alpha-induced IL-8 generation by HT-29 cells. In contrast, IL-10 had no effect on either IL-1 alpha or TNF-alpha-induced IL-8 production. 6. Experiments using cycloheximide demonstrated that this synergistic effect of IL-13 and IL-1 alpha on IL-8 secretion was not through de novo protein synthesis. Using actinomycin-D, we demonstrated that the IL-13 up-regulation was at the level of transcription rather than messenger RNA stability. 7. These findings suggest that colonic epithelial cells have a functional IL-13 receptor, which is coupled to an up-regulation of IL-1 alpha, but not TNF-alpha induced IL-8 generation.
Kolios
G
G
Department of Pharmacology, University of Bath.
Robertson
D A
DA
Jordan
N J
NJ
Minty
A
A
Caput
D
D
Ferrara
P
P
Westwick
J
J
D004357:Drug Synergism; D019073:HT29 Cells / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D016753:Interleukin-10 / Q000494:pharmacology; D018793:Interleukin-13 / Q000494:pharmacology*; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
D007375:Interleukin-1; D018793:Interleukin-13; D016209:Interleukin-8; D012333:RNA, Messenger; D016753:Interleukin-10