ICP0-mediated enhanced expression system
Methods and compositions for increasing the production of recombinant proteins by introducing ICP0 to cells capable of producing a recombinant protein are encompassed. In one method, the recombinant protein is a protein that is required for the replication of a replication defective virus, wherein the recombinant protein is provided to the replication defective virus in trans.
1. A method of increasing heterologous recombinant protein expression from a viral promoter in vitro, comprising:
introducing by transfection a herpes simplex virus (HSV) infected cell polypeptide zero (ICP0) to a cell comprising a transgene encoding the heterologous protein operably linked to the viral promoter, wherein the cell is a mammalian cell and is capable of expressing the recombinant protein from the viral promoter; and
isolating the recombinant protein from the cell, wherein:
(i) the recombinant protein is non-viral; and/or
(ii) the ICP0 is introduced by transfection with a plasmid comprising a sequence encoding ICP0 operably linked to a CMV promoter, an SV40 promoter, or a non-inducible promoter comprising a TATA box, GC-box, CCAAT box, B recognition element, and an initiator element; the heterologous recombinant protein is heterologous relative to the cell; and the heterologous protein is expressed by 24 hours after introduction of ICP0.
2. The method of claim 1 , wherein the recombinant protein is an antibody, a vaccine antigen, a hormone, or an enzyme.
3. The method of claim 1 , wherein the recombinant protein is a mammalian protein.
4. The method of claim 1 , wherein the recombinant protein is non-viral.
5. The method of claim 1 , wherein the ICP0 is introduced by transfection with a plasmid encoding ICP0 and comprising a non-inducible promoter, and the non-inducible promoter is a CMV promoter, an SV40 promoter, or a promoter comprising a TATA box, GC-box, CCAAT box, B recognition element, and an initiator element.
6. The method of claim 1 , wherein the cell is a Vero, BHK, CHO, HKB, HEK, NSO and U-2 OS, WI-38, MRC-5, MDCK, FRhL-2, or PERC6 cell.
7. The method of claim 1 , wherein the cell is a Vero cell.