HOST-RANGE SPECIFICITY OF A NOVEL RUNAWAY-TYPE VECTOR FOR MAMMALIAN-CELLS

For industrial applications of our novel runaway-type vector for mamma lian cell based on simian virus 40, we studied host range specificity of this vector, especially with human-derived cell lines, since human cells as hosts seem to be very important for the production of pharmac euticals by genetic engineering. The runaway-type vector showed a high replication rate at a permissive temperature of 33 degrees C in HeLa cells and erythropoietin was produced effectively. The plasmid copy nu mber was dependent on the temperature but was relatively low in KB cel ls. KB cells produced erythropoietin effectively at a non-permissive t emperature of 37 degrees C despite the low plasmid copy number. On the other hand, neither runaway-type replication nor erythropoietin produ ction was observed with blood cell derivatives such as HL-60 and RPMI- 8226 cells.