Claims for Patent: 8,163,523

Summary for Patent: 8,163,523

Title:	Cell-based systems for producing influenza vaccines
Abstract:	The present invention relates to a cell-based method for producing influenza virus vaccines by enriching the population of surface-bound .alpha.2,6-sialic acid receptors on a cell surface, such as on a Chinese Hamster Ovary (CHO) cell surface. The host cell therefore presents numerous binding sites to which an influenza virus can bind via its hemagglutinin spike protein and infect the host cell. In contrast to wild-type CHO cells, the surface of the mutated CHO cells of the present invention contains an enriched population of .alpha.2,6-sialic acid receptors which makes the inventive CHO cells highly susceptible to viral infection, and therefore safe, effective, and highly efficient cells for rapidly producing influenza vaccines.
Inventor(s):	Bilsel; Pamuk (Madison, WI), Kawaoka; Yoshihiro (Middleton, WI), Neumann; Gabriele (Madison, WI)
Assignee:	Flugen, Inc. (Madison, WI)
Application Number:	12/481,402
Patent Claims:	1. A cell culture-based method for producing influenza virus vaccine, comprising (A) infecting a Chinese Hamster Ovary cell (CHO) with a human influenza virus that binds to cell surface 2,6-linked sialic acids, and (B) isolating human influenza viruses produced from the CHO cell, and (C) formulating the isolated human influenza viruses into an influenza virus vaccine, wherein the CHO cell expresses a ST6GAL1 gene and comprises cell-surface bound 2,6-linked sialic acids, and wherein the susceptibility of the CHO cell to human influenza virus infection is greater than a CHO cell that does not express the ST6GAL 1 gene. 2. The cell culture-based method of claim 1, further comprising incubating the CHO cells with lectins against 2,3-sialic acid receptors. 3. The cell culture-based method of claim 1, wherein the generation time for producing the influenza vaccine is about 12 weeks from the time of viral infection of the CHO cells. 4. The cell culture-based method of claim 1, wherein 10 to 6,000 liters of CHO cells are infected with the human influenza virus. 5. The cell culture-based method of claim 1, wherein the human influenza virus is selected from the group consisting of H1N1, H2N2 and H3N2 influenza subtypes. 6. A cell culture-based method for producing influenza virus for making a human influenza vaccine, comprising infecting a CHO cell that expresses ST6GAL 1 with a human influenza virus that binds to cell surface 2,6-linked sialic acids, wherein the susceptibility of the CHO cell to human influenza virus infection is greater than a CHO cell that does not express the ST6GAL 1 gene, and wherein the CHO cell produces infectious human influenza viruses. 7. The cell culture-based method of claim 6, wherein the human influenza virus is selected from the group consisting of H1N1, H2N2 and H3N2 influenza subtypes. 8. The cell culture-based method of claim 6, further comprising incubating the CHO cells with lectins against 2,3-sialic acid receptors. 9. The cell culture-based method of claim 6, wherein the generation time for producing the influenza vaccine is about 12 weeks from the time of viral infection of the CHO cells. 10. The cell culture-based method of claim 6, wherein 10 to 6,000 liters of CHO cells are infected with the human influenza virus. 11. The cell culture-based method of claim 6, wherein the CHO cell has an increased cell surface expression of 2,6-linked sialic acids, compared to a wild-type CHO cell. 12. The cell culture-based method of claim 6, wherein the ST6GAL 1 gene is a human ST6GAL 1 gene. 13. The cell culture-based method of claim 6, wherein the CHO cell yields a pfu/ml titer of human influenza virus that is at least 2 times higher than the pfu/ml titer yield of a CHO cell which does not express the ST6GAL 1 gene. 14. The cell culture-based method of claim 6, further comprising isolating human influenza viruses produced from the CHO cell. 15. The cell culture-based method of claim 14, further comprising formulating the isolated human influenza viruses into a vaccine. 16. A cell culture-based method for producing influenza virus for making a human influenza vaccine, comprising (A) infecting a Chinese Hamster Ovary cell (CHO) with a human influenza virus that binds to cell surface 2,6-linked sialic acids, wherein the CHO cell (i) expresses a 2,6-sialyltransferase gene (ST6GAL 1), and (ii) has an increased cell surface expression of 2,6-linked sialic acids, compared to a wild-type CHO cell; and (B) isolating human influenza viruses produced from the CHO cell, wherein the CHO cell yields a pfu/ml titer of human influenza virus that is at least 2 times higher than the pfu/ml titer yield of a CHO cell which does not express the ST6GAL 1 gene.

Details for Patent 8,163,523

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Seqirus Vaccines Limited	FLUVIRIN	influenza virus vaccine	Injection	103837	11/03/1998		2028-06-11
Sanofi Pasteur Inc.	FLUZONE, FLUZONE HD QUADRIVALENT, FLUZONE HIGH DOSE, FLUZONE INTRADERMAL, FLUZONE QUADRIVALENT	influenza virus vaccine	Injection	103914	12/09/1999		2028-06-11
Sanofi Pasteur Inc.	FLUZONE, FLUZONE HD QUADRIVALENT, FLUZONE HIGH DOSE, FLUZONE INTRADERMAL, FLUZONE QUADRIVALENT	influenza virus vaccine	Injection	103914	12/23/1909		2028-06-11
Sanofi Pasteur Inc.	FLUZONE, FLUZONE HD QUADRIVALENT, FLUZONE HIGH DOSE, FLUZONE INTRADERMAL, FLUZONE QUADRIVALENT	influenza virus vaccine	Injection	103914	05/09/2011		2028-06-11
Sanofi Pasteur Inc.	FLUZONE, FLUZONE HD QUADRIVALENT, FLUZONE HIGH DOSE, FLUZONE INTRADERMAL, FLUZONE QUADRIVALENT	influenza virus vaccine	Injection	103914	06/07/2013		2028-06-11