| abstract |
The present invention is directed to DNA constructs suitable for gene expression in mammalian cells and which are characterized by the presence of a mammalian promoter under the control of a tet operator/repressor system. The DNA may be used as part of a system for expressing recombinant protein. In addition, the tet operator/repressor system can be used to engineer cis- and trans-destructive viruses which are capable of replicating in the presence of the tet repressor, but not in the absence of the repressor. These viruses can be used either directly in the treatment of patients with corresponding viral diseases, as vehicles for the delivery of nucleic acids that can serve as therapeutic agents and as part of vaccines designed to immunize people or animals against viral diseases. |