Viral vector manufacture

Abstract

This present invention relates to a modified mammalian cell in which the genome of the cell is modified to comprise a sequence encoding CP77 under the control of a promoter such that the modified cell line sustains propagation of a poxvirus that is less able or unable to propagate in the unmodified cell.

1 . A modified mammalian cell in which the genome of the cell is modified to comprise a sequence encoding CP77 under the control of a constitutive promoter such that the modified cell line sustains propagation of a poxvirus that is less able or unable to propagate in the unmodified cell and wherein the genome of the cell further comprises a sequence encoding D13L under the control of a constitutive promoter. 
     
     
         2 . The cell of  claim 1 , wherein the genome of the cell further comprises a sequence encoding K1L under the control of a promoter. 
     
     
         3 . The cell of  claim 1 , wherein the cell is a continuous cell line. 
     
     
         4 . The cell of  claim 1 , wherein the cell is a CHO cell. 
     
     
         5 . The cell of  claim 1 , wherein the cell is a human cell, a primate cell, a hamster cell or a rabbit cell. 
     
     
         6 . The cell of  claim 2 , wherein expression of the K1L gene is under the control of a constitutive mammalian promoter. 
     
     
         7 . The cell of  claim 1 , wherein the expression of the CP77 gene supports propagation of the virus to generate virus yields equivalent to that observed in a permissive cell line. 
     
     
         8 . The cell of  claim 1 , wherein expression of the CP77 gene supports a virus replication amplification ratio of more than 500. 
     
     
         9 . The cell of  claim 1 , wherein the CP77 is encoded by a contiguous sequence of nucleotides codon optimised for expression in mammalian cells. 
     
     
         10 . A process for propagating an orthopoxvirus that does not propagate in CHO cells, the process comprising propagating the poxvirus in vitro in a mammalian cell line wherein the cell line is modified to encode and express CP77 under the control of a constitutive promoter and express D13L under the control of a constitutive promoter. 
     
     
         11 . The process of  claim 10 , wherein the cell line modified is modified to encode and express K1L under the control of a promoter. 
     
     
         12 . The process of  claim 10 , wherein the cell line modified is a human cell, a primate cell line, a hamster cell line or a rabbit cell line. 
     
     
         13 . The process of  claim 12 , wherein the cell line is a CHO cell line.