Regulation of cytokine gene expression in T helper cell subsets.
We have examined the transcriptional regulation of the Th1-specific IL-2 gene and the Th2-specific IL-4 gene by transient transfection of promoter-chloramphenicol acetyl transferase (CAT) constructs into T cell clones and by electrophoretic mobility shift assays. Transfection of the Th2 clone D10.G4 with IL-4 promoter-CAT constructs demonstrated anti-CD3 inducible IL-4 promoter activity. In contrast, CAT constructs containing murine IL-2 promoter sequences were not inducible in D10.G4 cells. Transfection analyses in the Th1 clone D1.1 demonstrated inducible IL-2 promoter activity but no IL-4 promoter activity. Electrophoretic mobility shift assays using well-defined regulatory elements in the murine IL-2 gene promoter showed that anti-CD3 stimulation of Th2 clones failed to induce a characteristic increase in the ratio of p65-p50:p50-p50 NF-kappa B binding complexes in the nucleus that did occur in IL-2-producing clones. In addition, other protein complexes with NF-kappa B binding sequences were seen using lysates from Th1 and Th0 cells but not Th2 cells. Thus, expression of the promoter-CAT constructs directly correlates with endogenous IL-2 and IL-4 gene expression in Th1 and Th2 clones, confirming that the differential expression of IL-2 and IL-4 genes in these T cells is transcriptionally controlled. Furthermore, the lack of IL-2 transcription in activated Th2 cells is associated with the failure to generate required IL-2 gene promoter binding proteins, particularly NF-kappa B in the nucleus.
Lederer
J A
JA
Department of Pathology, Brigham and Women's Hospital, Boston, MA 02115.
Liou
J S
JS
Todd
M D
MD
Glimcher
L H
LH
Lichtman
A H
AH
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002999:Clone Cells; D004268:DNA-Binding Proteins / Q000502:physiology; D005786:Gene Expression Regulation; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000502:physiology; D011401:Promoter Regions, Genetic; D016176:T-Lymphocyte Subsets / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D007376:Interleukin-2; D009687:Nuclear Proteins; D015847:Interleukin-4