Isolation of the human interleukin 10 promoter. Characterization of the promoter activity in Burkitt's lymphoma cell lines.
Interleukin 10 (IL-10) is a pleiotropic growth and differentiation factor with potent suppressor functions on macrophages, T cells and NK cells and contributes to the regulation of proliferation and differentiation of B cells. The expression of IL-10 appears to be tightly regulated, as the levels of constitutive expression in normal cells is extremely low. In contrast to normal haematopoetic cells, Epstein-Barr virus (EBV)-immortalized B cells and EBV-positive Burkitt's lymphoma cells express high levels of IL-10 constitutively. In this report we have cloned and sequenced IL-10 promoter fragments and analysed their activity in EBV-positive Burkitt's lymphoma cells. A nested set of DNA fragments from the IL-10 gene 5'-flanking region was placed upstream of the luciferase gene and assayed for their ability to direct luciferase expression in Burkitt's lymphoma cells. We have identified elements within the 5'-flanking region of the human IL-10 gene which can activate or suppress the constitutive expression of IL-10. The essential promoter of the IL-10 gene, which induces low levels of luciferase expression, was found to require the major start site of transcription (+1), a TATA-box (-77) and up to 150 additional 5' nucleotides. Positive regulatory sequences are located between -1100/-900. Negative regulatory elements which abolish luciferase activity were identified between -800/-300.
Kube
D
D
Universitätskliniken Köln, Germany.
Platzer
C
C
von Knethen
A
A
Straub
H
H
Bohlen
H
H
Hafner
M
M
Tesch
H
H
D001483:Base Sequence; D002051:Burkitt Lymphoma / Q000473:pathology*; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral; D015972:Gene Expression Regulation, Neoplastic; D015967:Gene Expression Regulation, Viral; D005796:Genes; D017930:Genes, Reporter; D004854:Herpesvirus 4, Human / Q000502:physiology; D006801:Humans; D016753:Interleukin-10 / Q000235:genetics*; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D014407:Tumor Cells, Cultured
D011993:Recombinant Fusion Proteins; D016753:Interleukin-10; D008156:Luciferases