Transcription of the interleukin 4 gene is regulated by multiple promoter elements.
Activation of T helper cell 1 (Th1) and Th2 results in transcription of the interleukin 2 (IL-2) and IL-4 cytokine genes, respectively. Whereas many of the regulatory elements and factors responsible for IL-2 transcription in T cells are well defined, little is known about parallel mechanisms that drive transcription of the IL-4 gene. Here we have analyzed the murine IL-4 promoter, both in vivo and in a Th2 clone. 3 kb of IL-4 upstream sequence is shown to be sufficient to achieve tissue-specific and inducible expression of a thymidine kinase reporter gene in vivo in a manner that mirrors the expression of endogenous IL-4. Tissue-specific and inducible expression is also demonstrated in a Th2 clone, but not in a B cell line. Deletional and mutational analysis of the IL-4 promoter demonstrated that sequences from -100 to -28 were necessary for a transcriptional response to Concanavalin A or anti-CD3 monoclonal antibody. An overlapping, yet smaller region, spanning the sequences from -60 to -28 bp was shown to be required for the response to ionomycin. Mutation of an 8-bp region from -43 to -35 of the IL-4 promoter completely abrogated IL-4 gene transcription in response to all stimuli tested. In addition, our results show that the effects of the immunosuppressive agent Cyclosporin A map to the same DNA sequences as the positive control elements. These results identify DNA sequences that are functionally important for the control of IL-4 gene transcription both in vivo and in vitro. Although these sequences are highly conserved in the human and murine IL-4 genes, they are largely not present in the IL-2 enhancer complex. Thus, cytokine-specific cis-acting elements may be one mechanism by which these two cytokine genes are differentially regulated.
Todd
M D
MD
Department of Cancer Biology, Harvard School of Public Health, Boston, Massachusetts 02115.
Grusby
M J
MJ
Lederer
J A
JA
Lacy
E
E
Lichtman
A H
AH
Glimcher
L H
LH
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D016572:Cyclosporine / Q000494:pharmacology; D005786:Gene Expression Regulation; D015847:Interleukin-4 / Q000235:genetics*; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000502:physiology; D014158:Transcription, Genetic
D017260:Receptor-CD3 Complex, Antigen, T-Cell; D015847:Interleukin-4; D016572:Cyclosporine