Live-attenuated virus and methods of production and use

Patent metadata

Field	Value
Publication number	US-2016354460-A1
Application number	US-201615174348-A
Country	US
Kind code	A1
Filing date	Jun 6, 2016
Priority date	Jun 4, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Presented herein are live-attenuated viruses and methods of generating thereof from a parental virus through a plurality of nucleotide substitutions in the viral genome. The nucleotide substitutions result in a change in codon usage bias within codons of one or more protein encoding sequences and no change in amino acid sequences of the proteins. The live-attenuated viruses display unaltered replication in avian hosts for propagation, but attenuated replication in mammalian hosts, when compared to the replication of the parental virus. The live-attenuated viruses in a form of improved vaccines can be used to elicit protective immune responses.

First claim

We claim:

1 . A live-attenuated virus comprising a genome genetically engineered from a wild type virus to have mutated codons having an avian viral codon usage bias, the mutated codons having an avian viral codon usage bias present at conserved sites at the amino acid level and absent from genomic regions involving packaging or splicing, or overlapping reading frames encoding multiple proteins.

2 . The live-attenuated virus of claim 1 , wherein the mutated codons having an avian viral codon usage bias are synonymous substitutions.

3 . The live-attenuated virus of claim 1 , wherein the mutated codons having an avian viral codon usage bias are silent mutations.

4 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus does not have any amino acid mutations relative to the wild type virus.

5 . The live-attenuated virus of claim 1 , wherein the mutated codons having an avian viral codon usage bias are randomly but evenly distributed in the genome.

6 . The live-attenuated virus of claim 1 , wherein the mutated codons having an avian viral codon usage bias are present in at least one gene, in at least two genes, in at least three genes, in at least four genes, in at least five genes, in at least six genes, in at least seven genes, or in at least eight genes.

7 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus has slower replication in a mammalian host but not in an avian host, when compared to the replication of the wild type virus in the respective hosts.

8 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus produces antibody-mediated immunity similar to that produced by the wild type virus.

9 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus produces cell-mediated immunity similar to that produced by the wild type virus.

10 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus produces antibody-mediated immunity and cell-mediated immunity similar to that produced by the wild type virus.

11 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus replicates at substantially the same rate at 33° C. and at 37° C.

12 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus produces a protective immune response in a mammalian host against homologous and heterologous viral challenges.

13 . The live-attenuated virus of claim 1 , wherein the wild type virus is influenza type A or influenza type B.

14 . The live-attenuated virus of claim 13 , wherein the live-attenuated virus is 8-mut.

15 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus does not have any temperature-sensitive mutations relative to the wild type virus.

16 . The live-attenuated virus of claim 1 , wherein the live-attenuated virus is a master strain.

17 . A method of making the live-attenuated virus of claim 1 , the method comprising:
identifying regions of conserved sites at the amino acid level in the genome of the wild type virus; identifying codons in the conserved sites of the wild type virus that do not have avian viral codon usage bias; mutating one or more of the identified codons of the wild type virus that do not have avian viral codon usage bias into codons having avian viral codon usage bias to produce mutated codons having an avian viral codon usage bias.

18 . The method of claim 17 , further comprising producing the live-attenuated virus by contacting a host cell with one or more nucleic acid regions collectively forming the genome of the live-attenuated virus, wherein at least one of the regions comprises the mutated codons.

19 . The method of claim 17 , wherein at least two, at least three, at least four, at least five, at least six, at least seven, or at least eight regions comprise the mutated codons.

20 . A vaccine composition comprising the live-attenuated virus of claim 1 .

21 . The vaccine composition of claim 20 , further comprising a carrier.

22 . The vaccine composition of claim 21 , further comprising an adjuvant.

23 . A method comprising administering to a subject in need thereof an effective dose of the live-attenuated virus of claim 1 .

Assignees

• Univ Hong Kong

Inventors

• Poon Lit Man
• Fan Lok Yan

Classifications

• A61P31/16

  for influenza or rhinoviruses · CPC title

• C12N2760/16134

  Use of virus or viral component as vaccine, e.g. live-attenuated or inactivated virus, VLP, viral protein · CPC title

• A61K39/12

  Viral antigens · CPC title

• C12N7/00 Primary

  Viruses; Bacteriophages; Compositions thereof; Preparation or purification thereof (preparing medicinal viral antigen or antibody compositions, e.g. virus vaccines, A61K39/00) · CPC title

• A61K2039/5254

  avirulent or attenuated · CPC title