Patent ID: 11931361
Assignee: HER MAJESTY THE QUEEN IN RIGHT OF CANADA, AS REPRESENTED BY THE MINISTER OF AGRICULTURE AND AGRI-FOOD
Field: Pharmaceuticals (Chemistry)
Classification: CPC A  C | IPC A  C

Claim 0:
1. A method of preparing a recombinant poxvirus comprising;
providing a host cell comprising a parent poxvirus in which the coding sequences for native poxvirus E3 and K3 proteins have been disrupted or deleted, said host cell being pemlissive for growth of the parent poxvirus;
introducing an insertion cassette for inserting a gene of interest into the parent poxvirus genome at an insertion site into the host cell, said insertion cassette comprising a first crossover region, an expression cassette and a second crossover region, wherein the first crossover region has sufficient homology to an upstream region of the parent poxvirus genome that is upstream of the insertion site to initiate a crossover event with the parent poxvirus genome; the second crossover region has sufficient homology to a downstream region of the parent poxvirus genome that is downstream of the insertion site to initiate a crossover event with the parent poxvirus genome; and the insertion cassette comprises a first poxvirus promoter operably linked to a K3 ortholog for expression of the K3 ortholog from the first poxvirus promoter and a second poxvirus promoter operably linked to a gene of interest for expression of the gene of interest from the second poxvirus promoter;
subjecting the host cell to conditions permitting crossover events to occur between the insertion cassette and the parent poxvirus genome,
subjecting the host cell to conditions suitable for generating a population of poxvirus particles, said population comprising parent poxvirus virus particles and recombinant poxvirus particles;
introducing said population into a second cell line non-permissive fix growth of the parent poxvirus but permissive for growth of the recombinant poxvirus;
subjecting the second cell line to conditions promoting production of recombinant virus particles; and
recovering the recombinant virus particles.