A BK VIRUS EPISOMAL VECTOR FOR CONSTITUTIVE HIGH EXPRESSION OF EXOGENOUS CDNAS IN HUMAN-CELLS

A BK virus (BKV) episomal vector (pRPneoCMV) was constructed for expre ssion of cDNAs under control of the cytomegalovirus (CMV) immediate-ea rly promoter. Transfection of pRPneoCMV for expression of the chloramp henicol acetyltransferase (CAT) gene in several human cell lines showe d that the CMV promoter is more efficient than the HIV-1 and RSV LTRs in directing gene expression from episomal vectors. In 293 human cells pRPneoCMV/CAT is twenty times more active in CAT expression than the well known pSV2CAT vector in COS7 cells. Stable expression of the gene of the herpes simplex virus type 1 and type 2 glycoprotein G, cloned into pRPneoCMV, was obtained in 293 cells. This vector will allow dire ct cloning of newly synthesized cDNAs whose expression can be monitore d in human cells.