Finding of IFNγ gene enhancers and their core sequences.

DNA segmentation methods were used to study which fragments of the human IFNγ gene possess enhancer activity. The human IFNγ gene was divided into 240-bp fragments, which were inserted between the GFP gene and the Alu tandem sequence to determine whether the inserted sequences eliminate the inhibition induced by the Alu tandem sequence. We found that five different 240-bp fragments (FUIFN3F3R, IFN4F4R, IFN6F6R, IFN21F21R, and IFN22F22R) and two 60-bp core sequences (IFN6-2F2R and IFN21-3-4F3-4R) derived from the IFNγ gene contain enhancers that can activate the GFP reporter gene. These enhancers may be targets of IFNγ gene expression regulation.