Differential expression of transcription directed by a discrete NF-AT binding element from the IL-4 promoter in naive and effector CD4 T cells.
Acquiring the ability to selectively produce IFN-gamma or IL-4 is a fundamental property of the immune system and enables T cell subsets (Th1, Th2) to deliver their effector functions. To create an experimental system to examine regulation of critical promoter elements within the IL-4 gene, we have prepared and analyzed transgenic mice expressing the luciferase gene under the control of the distal NF-AT binding site from the IL-4 promoter. This site is immediately adjacent to an AP-1 site, and this NF-AT/AP-1 composite site is termed either P1 or PubB. The distal NF-AT site we have used to prepare these reporter transgenic mice lacks the AP-1 binding site but contains the NF-AT binding site (P1(NF-AT)) These transgenic mice were also intercrossed with transgenic mice expressing a single MHC class II-restricted TCR. Expression of transcriptional activity under the control of P1(NF-AT) was observed only in effector T cells, and not naive T cells, after stimulation with Ag or polyclonal stimuli. By contrast, gel mobility shift assays showed that nuclear extracts from both naive and effector T cells contained NF-AT, which could effectively bind to the P1(NF-AT) element. IL-4-stimulated Th2 differentiation did not increase the TCR responsiveness of the P1(NF-AT) element by more than 2-fold but increased production of IL-4 protein by more than 10-fold. These data suggest that factors interacting with the P1(NF-AT) element regulate transcriptional activity in a naive/effector T cell-specific manner but not in a Th1/Th2-specific manner. Th1/Th2-specific regulation of the composite P1 element may result from regulation of transacting factors that bind to the AP-1 portion of this element.
Aune
T M
TM
Section of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA.
Flavell
R A
RA
D000818:Animals; D001665:Binding Sites / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015847:Interleukin-4 / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D015847:Interleukin-4