Human tumor necrosis factor-alpha gene 3' untranslated region confers inducible toxin responsiveness to homologous promoter in monocytic THP-1 cells.
To better define the role of 3' untranslated region (3'UTR) on transcriptional regulation of the human tumor necrosis factor (TNF)-alpha gene, monocytic human THP-1 cells were transfected with two TNF-alpha promoter constructs spanning base pairs -1897/-1 and -1214/-1, respectively, and linked to the rabbit beta-globin gene. Quantitative globin gene expression of chimerae was measured by reverse transcription-polymerase chain reaction. A construct linking the chicken beta-actin promoter and a deleted portion of the beta-globin gene was cotransfected and used as internal standard. Unexpectedly, when THP-1 cells were stimulated with lipopolysaccharide or toxic shock syndrome toxin-1, gene regulation was hardly detected. In contrast, endogenous TNF-alpha gene regulation measured by the same reverse transcription-polymerase chain reaction procedure was vigorous. Remarkably, ligation of 3'UTR to chimeric constructs led to a drastic drop in the basal level of chimeric gene expression, resulting in a 15- to 40-fold induction of the reporter gene. Consistently, when the TNF-alpha promoter was replaced by the cytomegalovirus early immediate promoter, gene expression was also uniformly reduced but was no longer up-regulated upon stimulation with lipopolysaccharide and toxic shock syndrome toxin-1. These data provide the first line of evidence that, in addition to its role in TNF-alpha transcript stability and translation, human TNF-alpha 3'UTR also participates in modulating gene expression at the transcriptional level.
Division of Immunology and Allergy, Department of Medicine, Centre Hospitalier Universitaire Vaudois, CH-1011 Lausanne, Switzerland.
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A
Seiler-Tuyns
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Dufour
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F
Spertini
D020413:3' Untranslated Regions / Q000235:genetics*; D000199:Actins / Q000235:genetics; D000818:Animals; D001427:Bacterial Toxins; D002460:Cell Line; D002645:Chickens; D003587:Cytomegalovirus / Q000235:genetics; D004768:Enterotoxins / Q000633:toxicity*; D005786:Gene Expression Regulation / Q000187:drug effects*; D017781:Genes, Immediate-Early; D017930:Genes, Reporter; D005914:Globins / Q000235:genetics; D006801:Humans; D008070:Lipopolysaccharides / Q000633:toxicity*; D009000:Monocytes; D011401:Promoter Regions, Genetic; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018089:Superantigens / Q000633:toxicity; D014158:Transcription, Genetic; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D020413:3' Untranslated Regions; D000199:Actins; D001427:Bacterial Toxins; D004768:Enterotoxins; D008070:Lipopolysaccharides; D011993:Recombinant Fusion Proteins; D018089:Superantigens; D014409:Tumor Necrosis Factor-alpha; C030107:enterotoxin F, Staphylococcal; D005914:Globins