Hypomethylation of the proximal and intronic regulatory regions of the IFN-gamma gene is not essential for its transcription by naive CD4+ T cells cultured with IL-4.
Recently, long-term preculture with IL-4 or IL-7 has been reported to induce IFN-gamma-producing ability in naive CD4+ T cells without stimulation via TCR. The mechanism of IFN-gamma-transcription in naive CD4+ T cells precultured with IL-4 was analyzed and compared with that in typical Th1 cells by focusing on the TATA proximal and first intronic regulatory regions of the IFN-gamma gene. Both regulatory regions in these IL-4-primed naive CD4+ T cells, which produce a large amount of IFN-gamma upon stimulation with PMA and ionomycin, were completely methylated in contrast to the same hypomethylated regions in Th1 cells. DNase I hypersensitive site analysis suggested that both regulatory regions in IL-4-primed naive CD4+ T cells were not active for IFN-gamma-expression. Moreover, we demonstrated that the composition of transcriptional factors that can bind to the proximal regulatory region is different between IL-4-primed naive CD4+ T cells and Th1 cells. These results indicated that the transcriptional machinery involved in the expression of the IFN-gamma gene by CD4+ T cells varied depending on their modes of differentiation in both the responsive regulatory regions and the specific nuclear factors.
Kiyomasu
T
T
Department of Pediatrics, Graduate School of Medicine, Kyoto University, Japan.
Katamura
K
K
Ueno
H
H
Iio
J
J
Ohmura
K
K
Heike
T
T
Furusho
K
K
D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D005312:Fetal Blood / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics* / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology*; D007438:Introns / Q000235:genetics*; D015759:Ionomycin / Q000494:pharmacology; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D011994:Recombinant Proteins; D012045:Regulatory Sequences, Nucleic Acid; D016385:TATA Box / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018417:Th1 Cells / Q000187:drug effects / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D011994:Recombinant Proteins; D014157:Transcription Factors; D015847:Interleukin-4; C030365:leucine methyl ester; D015759:Ionomycin; D007371:Interferon-gamma; D004247:DNA; D007930:Leucine; D013755:Tetradecanoylphorbol Acetate