EXTREMELY EFFICIENT GENE TRANSFECTION INTO LYMPHO-HEMATOPOIETIC CELL-LINES BY EPSTEIN-BARR VIRUS-BASED VECTORS

We have estimated the efficiency of Epstein-Barr virus (EBV)-based vec tors in transfecting genes into cell lines of lympho-hematopoietic lin eages. The transfection efficiency was estimated both at transient and stable phases, in terms of expression of a marker gene and acquisitio n of drug resistance, respectively. Plasmid vectors carrying EBV oriP (replication origin of plasmid), EBNA (EBV nuclear antigen)-1 and as t he marker genes, murine CD8 alpha cDNA and neo(R) (neomycin resistant) genes were transfected into various cell lines by electroporation. Wh en cell lines constitutively expressing EBNA-1 were transduced, virtua lly all the cells expressed CD8 alpha on day 3 and acquired G418 resis tance thereafter. In the case of K562 cells, which do not express EBNA -1, approximately 40% of cells expressed the marker gene product on da y 3 posttransfection, and 30% of cells became stable transfectants. Th ese data suggest a broader application of the EBV vector system in bas ic immunology and medicine.