Differential regulation of IL-6 gene transcription and expression by IL-4 and IL-10 in human monocytic cell lines.
IL-4 and IL-10 inhibit the cytokine production and mRNA expression by monocytes/macrophages. To investigate the molecular mechanism of the inhibitory effect on transcriptional or post-transcriptional regulation of IL-6 gene expression by IL-4 and IL-10, we studied IL-6 production, expression level of IL-6 mRNA, IL-6 promoter activity, transcriptional activity of NF-kappaB and NF-IL-6, and IL-6 mRNA stability in human monocytic cell lines, THP-1 and U937, stimulated by PMA and LPS in the absence or the presence of IL-4 or IL-10. Both IL-4 and IL-10 were seen to inhibit IL-6 production and the expression of IL-6 mRNA in both monocytic cell lines studied. In chloramphenicol acetyltransferase assays, utilizing the transient transfection of a chloramphenicol acetyltransferase reporter plasmid containing the IL-6 gene promoter, IL-4, but not IL-10, suppressed the transcriptional activity of the IL-6 gene promoter stimulated by PMA and LPS. Electrophoretic mobility shift assays showed that IL-4, but not IL-10, inhibited nuclear NF-kappaB activity, and that IL-4 and IL-10 did not affect NF-IL-6 activity. On the other hand, IL-10 enhanced the degradation of IL-6 mRNA in a mRNA stability assay. These results suggest that IL-4 may inhibit the transcription of the IL-6 gene by affecting NF-kappaB binding activity, while IL-10 may inhibit the IL-6 mRNA levels post-transcriptionally, without suppressing promoter activity. Therefore, we conclude that IL-4 and IL-10 inhibit IL-6 production by different mechanisms in human monocytic cell lines.
Takeshita
S
S
UCLA School of Nursing, UCLA School of Medicine, Los Angelas, 90095, USA.
Gage
J R
JR
Kishimoto
T
T
Vredevoe
D L
DL
Martínez-Maza
O
O
D001483:Base Sequence; D051743:CCAAT-Enhancer-Binding Protein-delta; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D015342:DNA Probes / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D016753:Interleukin-10 / Q000494:pharmacology*; D015847:Interleukin-4 / Q000494:pharmacology*; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000187:drug effects / Q000276:immunology*; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors; D014158:Transcription, Genetic / Q000187:drug effects
D022762:CCAAT-Enhancer-Binding Proteins; C497252:CEBPD protein, human; D015342:DNA Probes; D004268:DNA-Binding Proteins; D015850:Interleukin-6; D016328:NF-kappa B; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D016753:Interleukin-10; D051743:CCAAT-Enhancer-Binding Protein-delta; D015847:Interleukin-4