abstract |
What is described is a selection system for the cloning and expression of open reading frames in poxviruses, particularly vaccinia virus. The selection system is based on a conditional lethal mutant (host range) of poxviruses. A deletion/recombinant mutant of the vaccinia virus was generated which is capable of plaquing on primary chick embryo fibroblasts and two monkey cell lines (BSC-40 or VERO) but is defective in replication in the human cell line MRC-5. Insertion of the host range gene into the deletion/recombinant restores the ability for growth on MCR-5 cells. A series of plasmids were constructed which allow for the rapid single-step cloning and expression of any open reading frame when recombined with the deletion/recombinant and scored for growth on MCR-5 cells. |