A new regulatory region of the IL-2 locus that confers position-independent transgene expression.
Although the promoter/enhancer of the IL-2 gene mediates inducible reporter gene expression in vitro, it cannot drive consistent expression in transgenic mice. The location and existence of any regulatory elements that could open the IL-2 locus in vivo have remained unknown, preventing analysis of IL-2 regulation in developmental contexts. In this study, we report the identification of such a regulatory region, marked by novel DNase-hypersensitive sites upstream of the murine IL-2 promoter in unstimulated and stimulated T cells. Inclusion of most of these sites in an 8.4-kb IL-2 promoter green fluorescent protein transgene gives locus control region-like activity. Expression is efficient, tissue specific, and position independent. This transgene is expressed not only in peripheral T cells, but also in immature thymocytes and thymocytes undergoing positive selection, in agreement with endogenous IL-2 expression. In contrast, a 2-kb promoter green fluorescent protein transgene, lacking the new hypersensitive sites, is expressed in only a few founder lines, and expression is dysregulated in CD8(+) cells. Thus, the 6.4 kb of additional upstream IL-2 sequence contains regulatory elements that provide integration site independence and differential regulation of transgene expression in CD8 vs CD4 cells.
Yui
M A
MA
Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.
Hernández-Hoyos
G
G
Rothenberg
E V
EV
D020413:3' Untranslated Regions / Q000276:immunology; D020121:5' Untranslated Regions / Q000276:immunology; D000818:Animals; D001482:Base Composition / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D019070:Cell Lineage / Q000235:genetics / Q000276:immunology; D002469:Cell Separation; D002478:Cells, Cultured; D003850:Deoxyribonuclease I / Q000235:genetics; D018628:Gene Dosage; D005786:Gene Expression Regulation / Q000276:immunology*; D018507:Gene Expression Regulation, Developmental / Q000276:immunology; D005819:Genetic Markers / Q000276:immunology; D005822:Genetic Vectors / Q000138:chemical synthesis / Q000276:immunology; D049452:Green Fluorescent Proteins; D007156:Immunologic Memory / Q000235:genetics; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics*; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D008213:Lymphocyte Activation / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D016513:Mice, SCID; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid / Q000276:immunology*; D020218:Response Elements / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D019076:Transgenes / Q000276:immunology*; D014407:Tumor Cells, Cultured
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D005819:Genetic Markers; D007376:Interleukin-2; D008164:Luminescent Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D049452:Green Fluorescent Proteins; D003850:Deoxyribonuclease I