Multi plasmid system for the production of influenza virus
AssigneeMedImmune, LLC
InventorsErich Hoffmann, Hong Jin, George Kemble, Zhongying Chen
Life of this patent
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Abstract
Vectors and methods for the production of influenza viruses suitable as recombinant influenza vaccines in cell culture are provided. Bi-directional expression vectors for use in a multi-plasmid influenza virus expression system are provided. Additionally, the invention provides methods of producing influenza viruses with enhanced ability to replicate in embryonated chicken eggs and/or cells (e.g., Vero and/or MDCK) and further provides influenza viruses with enhanced replication characteristics. A method of producing a cold adapted (ca) influenza virus that replicates efficiently at, e.g., 25° C. (and immunogenic compositions comprising the same) is also provided.
Claims21
An isolated, reassortant influenza B virus, comprising:
- a modified, full-length NP polypeptide comprising an amino acid substitution at position 114 to alanine and an amino acid substitution at position 410 to histidine, wherein the modified, full-length NP polypeptide comprises a threonine at position 55;
- and
- a modified, full-length PA polypeptide comprising an amino acid substitution at position 431 to methionine;
- wherein the isolated, reassortant influenza B virus has a temperature sensitive phenotype.
A method for making a reassortant influenza B virus, comprising:
- (a) introducing mutations in an influenza B virus genome that result in (i) a modified, full-length NP polypeptide comprising an amino acid substitution at position 114 to alanine and an amino acid substitution at position 410 to histidine, wherein the modified, full-length NP polypeptide comprises a threonine at position 55, and (ii) a modified, full-length PA polypeptide comprising an amino acid substitution at position 431 to methionine;
- (b) introducing a plurality of vectors into a population of cultured host cells, wherein the plurality of vectors corresponds to the influenza B virus genome and the plurality of vectors comprises the mutations recited in (a);
- (c) culturing the population of host cells;
- and
- (d) recovering the reassortant influenza B virus produced by the host cells in step (c), wherein the influenza B virus has a temperature sensitive phenotype.
Dependencies are inferred from the claim text.