TRANSCRIPTIONAL ACTIVATION OF INDOLEAMINE DIOXYGENASE BY INTERLEUKIN 1 AND TUMOR NECROSIS FACTOR α IN INTERFERON-TREATED EPITHELIAL CELLS
| Autor: | Tricia A. Babcock, Joseph M. Carlin |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Transcriptional Activation
Green Fluorescent Proteins Immunology Transfection Biochemistry Flow cytometry Green fluorescent protein HeLa Interferon-gamma Interferon medicine Humans Indoleamine-Pyrrole 2 3 -Dioxygenase Immunology and Allergy Promoter Regions Genetic Molecular Biology Reporter gene biology medicine.diagnostic_test Tumor Necrosis Factor-alpha Interleukin Drug Synergism Hematology biology.organism_classification Molecular biology Recombinant Proteins Tryptophan Oxygenase Luminescent Proteins Tumor necrosis factor alpha HeLa Cells Interleukin-1 medicine.drug |
| Zdroj: | Cytokine. 12:588-594 |
| ISSN: | 1043-4666 |
| DOI: | 10.1006/cyto.1999.0661 |
| Popis: | Interferon (IFN)-gamma-induced indoleamine 2,3-dioxygenase (IDO) activity is enhanced synergistically by interleukin (IL-)1, tumor necrosis factor-alpha (TNF-alpha) and LPS in IFN-treated macrophages by increasing IDO mRNA concentration. These studies demonstrate that IFN-treated HeLa cells also exhibit dose-dependent enhancement of IDO induction by TNF-alpha and IL-1, with maximal effects at concentrations of 5 ng/ml and 3 ng/ml, respectively. Furthermore, with sub-optimal IFN concentrations, cells treated with maximally effective concentrations of TNF-alpha or IL-1alpha required 3-5 times less IFN to induce the same level of IDO activity as that observed with IFN alone. To detect changes in transcriptional activation of the IDO gene, HeLa cells were transfected with a plasmid containing the IDO 5' regulatory region upstream of a green fluorescent protein (GFP) reporter gene. In transfected cells, IFN induced both IDO activity and GFP that was detected by flow cytometry. When cell-sorted, transfected cells were stimulated with IFN in combination with TNF-alpha or IL-1 but not LPS, increased GFP was detected in comparison to transfected cells treated with IFN alone. Furthermore, increases in GFP expression correlated with IDO enzymatic activity, indicating that combinations of IFN with IL-1 or TNF-alpha increase the transcriptional activity of the IDO promoter region. |
| Databáze: | OpenAIRE |
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