title: Undermethylation of interferon-gamma gene in human T cell lines and normal T lymphocytes.
abstract: The relative levels of DNA methylation at CCGG sequences within and around the interferon-gamma (IFN-gamma) gene in normal human tissues and cell lines were examined by Southern blot analysis using isoschizomeric restriction enzymes, HpaII and MspI. On the test of normal tissues, the IFN-gamma gene was undermethylated only in a small population of T lymphocyte, whereas the gene was fully methylated in T cell-depleted lymphocytes and uterus cells. In TCL-Fuj cell line which is a T cell line producing a high level of IFN-gamma spontaneously, the IFN-gamma gene was undermethylated. Moreover, the extent of DNA methylation was inversely correlated to the level of expression of the IFN-gamma gene in several T cell lines including sublines derived from TCL-Fuj cells. However, partial or complete unmethylation at the CCGG sites of IFN-gamma gene was observed in a promyelocytic leukemia cell line and two epithelial cell lines that fail to produce IFN-gamma irrespective of induction. These results suggest that undermethylation of IFN-gamma gene is necessary but not sufficient for its efficient expression.
mesh_terms: D002460:Cell Line; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004848:Epithelium / Q000502:physiology; D005786:Gene Expression Regulation; D005796:Genes; D005914:Globins / Q000235:genetics; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics*; D008745:Methylation; D013601:T-Lymphocytes / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D007371:Interferon-gamma; D005914:Globins; D004247:DNA