title: IL-4 pretreatment selectively enhances cytokine and chemokine production in lipopolysaccharide-stimulated mouse peritoneal macrophages.
abstract: Although well recognized for its anti-inflammatory effect on gene expression in stimulated monocytes and macrophages, IL-4 is a pleiotropic cytokine that has also been shown to enhance TNF-alpha and IL-12 production in response to stimulation with LPS. In the present study we expand these prior studies in three areas. First, the potentiating effect of IL-4 pretreatment is both stimulus and gene selective. Pretreatment of mouse macrophages with IL-4 for a minimum of 6 h produces a 2- to 4-fold enhancement of LPS-induced expression of several cytokines and chemokines, including TNF-alpha, IL-1alpha, macrophage-inflammatory protein-2, and KC, but inhibits the production of IL-12p40. In addition, the production of TNF-alpha by macrophages stimulated with IFN-gamma and IL-2 is inhibited by IL-4 pretreatment, while responses to both LPS and dsRNA are enhanced. Second, the ability of IL-4 to potentiate LPS-stimulated cytokine production appears to require new IL-4-stimulated gene expression, because it is time dependent, requires the activation of STAT6, and is blocked by the reversible protein synthesis inhibitor cycloheximide during the IL-4 pretreatment period. Finally, IL-4-mediated potentiation of TNF-alpha production involves specific enhancement of mRNA translation. Although TNF-alpha protein is increased in IL-4-pretreated cells, the level of mRNA remains unchanged. Furthermore, LPS-stimulated TNF-alpha mRNA is selectively enriched in actively translating large polyribosomes in IL-4-pretreated cells compared with cells stimulated with LPS alone.
authors.affiliation: Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Major
authors.forename: Julia E
authors.initials: JE
authors.lastname: Fletcher
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Hamilton
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018925:Chemokines / Q000096:biosynthesis* / Q000235:genetics; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics; D004357:Drug Synergism; D015847:Interleukin-4 / Q000494:pharmacology*; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000096:biosynthesis; D050800:STAT6 Transcription Factor; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology; D015533:Transcriptional Activation; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics
chemical_list: D018925:Chemokines; D016207:Cytokines; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D050800:STAT6 Transcription Factor; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4