OBJECTIVETo screen enhancer-like sequences from vaccinia virus genome, to construct an expression vector harboring prokaryotic enhancer-like sequence and study the effect of interferon gene expression.

METHODSEnhancer-like element from vaccinia virus genome was obtained by using the chloramphenicol acetyl-transferase cat gene as reporter gene. An expression vector harboring prokaryotic enhancer-like sequence VV1 from vaccinia virus was constructed. Interferon was expressed and assayed.

RESULTSEighteen enhancing sequences were found. From them two enhancer-like sequences with distance and orientation independence property were screened and named VV1 and VV16 respectively. Quantification test showed that the direct and reverse orientation of VV1 could increase the activity of beta-galactosidase with 10.9 and 3.8 times and those of VV16 could increase by 9.0 times and 4.1 times respectively. The enhancing activity of the element was on transcription level. An expression vector harboring prokaryotic enhancer-like sequence VV1 was constructed. Using this vector the antiviral activity of interferon alpha-2b was increased by 2.6 times in comparison with the original expression plasmid.

CONCLUSIONTwo enhancer-like sequences were screened from vaccinia virus genome. Interferon gene was highly expressed by using an expression vector harboring enhancer-like sequences.