Effects of interleukin-13 on human neutrophil functions.
It was recently shown that interleukin-13 (IL-13) induces the expression and release of the IL-1 decoy receptor (type II) in human neutrophils along with the production of the IL-1 receptor antagonist. In the present study we focused on further studying the modulatory effects of IL-13 on these cells. We found that recombinant human IL-13 (rhIL-13) induces cellular morphological changes in neutrophils that are typical of activated cells. Furthermore, rhIL-13 was shown to increase tyrosine phosphorylation of several neutrophil proteins. We also demonstrate that this cytokine stimulates de novo RNA synthesis in a concentration-dependent fashion as measured by [5-3H]uridine incorporation and that rhIL-13 induces the synthesis of several neutrophil proteins according to high-resolution two-dimensional gel electrophoresis of metabolically [35S]-labeled cells. We observed that the IL-8 levels in the external milieu of IL-13-stimulated cells was almost fivefold increased when compared with control cells. Finally, we observed that rhIL-13 has no significant effect on phagocytosis and apoptosis. Taken together, our results demonstrate that IL-13 is a modulator of several human neutrophil functions. This leads us to conclude that the modulatory role of IL-13 on human neutrophils, a potentially important anti-inflammatory cytokine, is more complex than previously believed. Furthermore, because we show that the synthesis of several as yet unidentified proteins was up-regulated by IL-13, our findings open new avenues of research on the effects of this cytokine on human neutrophils.
Girard
D
D
Centre de Recherche en Rhumatologie-Immunologie du Centre de Recherche du CHUL, Ste-Foy, Québec, Canada.
Paquin
R
R
Naccache
P H
PH
Beaulieu
A D
AD
D017209:Apoptosis / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D018793:Interleukin-13 / Q000494:pharmacology*; D053661:Interleukin-13 Receptor alpha1 Subunit; D016209:Interleukin-8 / Q000096:biosynthesis*; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology*; D010587:Phagocytosis / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D014176:Protein Biosynthesis; D011506:Proteins / Q000737:chemistry; D012333:RNA, Messenger / Q000235:genetics; D018123:Receptors, Interleukin / Q000502:physiology; D053660:Receptors, Interleukin-13
C508181:IL13RA1 protein, human; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D016209:Interleukin-8; D011506:Proteins; D012333:RNA, Messenger; D018123:Receptors, Interleukin; D053660:Receptors, Interleukin-13; D019000:Phosphotyrosine