Identification of IL-4 promoter elements conferring Th2-restricted expression during T helper cell subset development.
Selective cytokine gene expression by T cell subsets underlies polarization of cellular and humoral immune responses. Our interest has been to define the molecular basis for restricted cytokine expression by Th1 and Th2 cells. IL-4 is selectively expressed by Th2 cells, providing a model for Th2-specific gene expression. To allow for promoter analysis during the process of Th1/Th2 differentiation within a normal cellular context, we have taken a transgenic approach. We generated a series of murine transgenic lines harboring both the DO11.10 alphabeta-TCR transgene and the luciferase gene driven by regions of the IL-4 promoter. The results identify proximal promoter regions that provide significantly Th2-restricted IL-4 gene expression. The IL-4 -741- to +60-bp region allows, on the average, 40-fold higher inducible reporter activity in Th2 cells than in Th1 cells. When trimerized, the region spanning -88 to -61 bp, containing a composite NF-AT/AP-1 site, also confers significant Th2-specific reporter activity. These results suggest that trans-acting factors binding this NF-AT/AP-1 composite site cooperate to allow substantial Th2-selective reporter expression. Finally, because reporter expression is low relative to endogenous IL-4 mRNA in activated Th2 cells, we suggest that additional control elements outside of the IL-4 promoter may be required to enhance overall IL-4 gene activity.
Wenner
C A
CA
Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Szabo
S J
SJ
Murphy
K M
KM
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis; D005260:Female; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics* / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000187:drug effects / Q000276:immunology*; D018418:Th2 Cells / Q000187:drug effects / Q000378:metabolism*; D014157:Transcription Factors / Q000096:biosynthesis; D019076:Transgenes / Q000235:genetics
D033965:Adaptor Protein Complex alpha Subunits; D033942:Adaptor Proteins, Vesicular Transport; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D015847:Interleukin-4