IP Library › Granted Patent US 12,616,745
Granted Patent B2
US 12,616,745 · App. 17/617,258 · Granted May 5, 2026

Influenza virus backbone

Inventors: Yasuko Hatta (Madison, WI); Michael J. Moser (Madison, WI); Pamuk Bilsel (Madison, WI)
Assignee: FLUGEN, INC.
A61K39/145A61P31/16C12N7/00A61K2039/5254A61K2039/543A61K2039/545A61K2039/58A61K2039/70
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Quick Facts
Patent No.
US 12,616,745
App. No.
17/617,258
Granted
May 5, 2026
Kind
B2
Abstract

The invention provides an influenza virus that demonstrates enhanced growth in Vero cells. The influenza virus includes PB1, PB2, PA, NP, and NS gene segments encoding proteins having amino acid sequences with selected amino acids. Optionally, at least one of the PB1, PB2, and PA gene segments includes a cytosine to uracil promoter mutation at nucleotide position 4. The invention also provides a pharmaceutical formulation containing the influenza virus, as well as a method of eliciting an immune response in a mammal by administering the influenza virus to the mammal, and a method for generating the influenza virus.

Claims (35)

1 . An influenza virus comprising PB1, PB2, PA, NP, and NS gene segments, wherein

(a) the PB1 gene segment encodes a PB1 protein having the amino acid sequence of SEQ ID NO: 7, the PB2 gene segment encodes a PB2 protein having the amino acid sequence of SEQ ID NO: 15, the PA gene segment encodes a PA protein having the amino acid sequence of SEQ ID NO: 17, the NP gene segment encodes an NP protein having the amino acid sequence of SEQ ID NO: 6, and the NS gene segment encodes an NS1 protein having the amino acid sequence of SEQ ID NO: 19, or

(b) the PB1 gene segment encodes a PB1 protein having the amino acid sequence of SEQ ID NO: 9, the PB2 gene segment encodes a PB2 protein having the amino acid sequence of SEQ ID NO: 10, the PA gene segment encodes a PA protein having the amino acid sequence of SEQ ID NO: 17, the NP gene segment encodes an NP protein having the amino acid sequence of SEQ ID NO: 8, and the NS gene segment encodes an NS1 protein having the amino acid sequence of SEQ ID NO: 19.

2 . The influenza virus of claim 1 , wherein the PB1 gene segment encodes a PB1 protein having the amino acid sequence of SEQ ID NO: 7, the PB2 gene segment encodes a PB2 protein having the amino acid sequence of SEQ ID NO: 15, the PA gene segment encodes a PA protein having the amino acid sequence of SEQ ID NO: 17, the NP gene segment encodes an NP protein having the amino acid sequence of SEQ ID NO: 6, and the NS gene segment encodes an NS1 protein having the amino acid sequence of SEQ ID NO: 19.

3 . The influenza virus of claim 2 , wherein the PB1 gene segment has the nucleotide sequence represented by SEQ ID NO: 2.

4 . The influenza virus of claim 2 , wherein the NP gene segment has the nucleotide sequence represented by SEQ ID NO: 1.

5 . The influenza virus of claim 2 , wherein the PB2 gene segment has the nucleotide sequence represented by SEQ ID NO: 14.

6 . The influenza virus of claim 2 , wherein (a) a leucine at position 40 , a tryptophan at position 180 , and an asparagine at position 464 in SEQ ID NO: 7 or (b) a leucine at position 116 and a lysine at position 294 in SEQ ID NO: 6 are conserved in after at least ten serial passages in a Vero cell line.

7 . The influenza virus of claim 2 , wherein (a) a leucine at position 40 , a tryptophan at position 180 , and an asparagine at position 464 in SEQ ID NO: 7 or (b) a leucine at position 116 and a lysine at position 294 in SEQ ID NO: 6 are conserved after at least ten serial passages in a Vero cell line that stably expresses the M2 ion channel protein of influenza A virus.

8 . The influenza virus of claim 2 , wherein the influenza virus is an influenza A virus, and (a) a leucine at position 40 , a tryptophan at position 180 , and an asparagine at position 464 in SEQ ID NO: 7 or (b) a leucine at position 116 and a lysine at position 294 in SEQ ID NO: 6 are conserved after at least ten serial passages in a Vero cell line that stably expresses the BM2 ion channel protein of influenza B virus.

9 . The influenza virus of claim 1 , wherein (b) the PB1 gene segment encodes a PB1 protein having the amino acid sequence of SEQ ID NO: 9, the PB2 gene segment encodes a PB2 protein having the amino acid sequence of SEQ ID NO: 10, the PA gene segment encodes a PA protein having the amino acid sequence of SEQ ID NO: 17, the NP gene segment encodes an NP protein having the amino acid sequence of SEQ ID NO: 8, and the NS gene segment encodes an NS1 protein having the amino acid sequence of SEQ ID NO: 19.

10 . The influenza virus of claim 9 , wherein the PB1 gene segment has the nucleotide sequence represented by SEQ ID NO: 4.

11 . The influenza virus of claim 9 , wherein the PB2 gene segment has the nucleotide sequence represented by SEQ ID NO: 5.

12 . The influenza virus of claim 9 , wherein the NP gene segment has the nucleotide sequence represented by SEQ ID NO: 3.

13 . The influenza virus of claim 9 , wherein (a) a leucine at position 40 , a tryptophan at position 180 , and a serine at position 607 in SEQ ID NO: 9, (b) a valine at position 504 , an isoleucine at position 467 , and a valine at position 529 in SEQ ID NO: 10, or (c) a leucine at position 116 and an arginine at position 311 in SEQ ID NO: 8 are conserved after at least ten serial passages of the virus in a Vero cell line.

14 . The influenza virus of claim 9 , wherein (a) a leucine at position 40 , a tryptophan at position 180 , and a serine at position 607 in SEQ ID NO: 9 , (b) a valine at position 504 , an isoleucine at position 467 , and a valine at position 529 in SEQ ID NO: 10, or (c) a leucine at position 116 and an arginine at position 311 in SEQ ID NO: 8 are conserved after at least ten serial passages in a Vero cell line that stably expresses the M2 ion channel protein of influenza A virus.

15 . The influenza virus of claim 1 , wherein at least one of the PB1, PB2, and PA genes segments comprises a cytosine to uracil promoter mutation at nucleotide position 4.

16 . The influenza virus of claim 1 , wherein the influenza virus is a recombinant influenza virus.

17 . The influenza virus of claim 1 , wherein the virus further comprises an NA gene segment and an HA gene segment.

18 . The influenza virus of claim 17 , wherein the HA gene segment encodes an HA protein having the amino acid sequence comprising at least one amino acid mutation in HA1.

19 . The influenza virus of claim 17 , wherein the HA gene segment encodes an HA protein having the amino acid sequence comprising at least one amino acid mutation in HA2.

20 . The influenza virus of claim 19 , wherein the at least one amino acid mutation in HA2 is an asparagine at position 107.

21 . The influenza virus of claim 17 , wherein the PB1, PB2, PA, NP, and NS gene segments are from a single influenza strain.

22 . The influenza virus of claim 21 , wherein the HA gene segment is derived from an influenza strain different from the single influenza strain from which the PB1, PB2, PA, NP, and NS gene segments are from.

23 . The influenza virus of claim 21 , wherein the NA gene segment is derived from an influenza strain different from the single influenza strain from which the PB1, PB2, PA, NP, and NS gene segments are from.

24 . The influenza virus of claim 1 , further comprising a mutant M gene segment.

25 . The influenza virus of claim 24 , wherein the influenza virus does not encode a functional M2 protein.

26 . The influenza virus of claim 1 , wherein the virus is capable of replication in human cells.

27 . The influenza virus of claim 1 , wherein, if the influenza virus is the influenza virus of (a), the influenza virus has enhanced growth as compared to an influenza virus that is the same except without a leucine at position 40 , a tryptophan at position 180 , and an asparagine at position 464 in SEQ ID NO: 7 and a leucine at positions 116 and a lysine at position 294 in SEQ ID NO: 6 in Vero cells under the same conditions, and, if the influenza virus is the influenza virus of (b), the influenza virus has enhanced growth as compared to an influenza virus that is the same except without a leucine at position 40 , a tryptophan at position 180 , and a serine at position 607 in SEQ ID NO: 9, a valine at position 504 , an isoleucine at position 467 , and a valine at position 529 in SEQ ID NO: 10, and a leucine at position 116 and an arginine at position 311 in SEQ ID NO: 8 in Vero cells under the same conditions.

28 . A pharmaceutical formulation comprising the influenza virus of claim 1 .

29 . The pharmaceutical formulation of claim 28 , wherein the pharmaceutical formulation is a vaccine.

30 . The pharmaceutical formulation of claim 29 , wherein the vaccine is formulated as a monovalent vaccine, a bivalent vaccine, a trivalent vaccine, or a quadrivalent vaccine.

31 . A method of eliciting an immune response in a mammal, the method comprising administering the influenza virus of claim 1 to the mammal, thereby eliciting an immune response to the influenza virus in the mammal.

32 . The method of claim 31 , wherein the mammal is a human.

33 . A method of generating the influenza virus of claim 1 , the method comprising serially passaging an influenza virus in a Vero cell line.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 16, 2024
From: HATTA, YASUKO; MOSER, MICHAEL J.; BILSEL, PAMUK
To: FLUGEN, INC.
Reel/Frame 066483/0354 →
Continuity (2)
Provisional Application 62858737 · Jun 7, 2019
Related Publication 20220241397A1 · Aug 4, 2022
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