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KR-20260066088-A - Novel DEV vector for avian vaccine

KR20260066088AKR 20260066088 AKR20260066088 AKR 20260066088AKR-20260066088-A

Abstract

The present invention relates to the field of animal health. In particular, the present invention relates to a modified duck enteritis virus (DEV). More particularly, the present invention relates to a modified DEV that is non-pathogenic or exhibits reduced pathogenicity in chickens. Furthermore, the present invention relates to a composition comprising the modified DEV of the present invention as a vector-vaccine for chickens, and to the use thereof.

Inventors

  • 마 쳉타이
  • 황푸 이판
  • 첸 닝
  • 추이 샤오핑
  • 주 시디
  • 장 칭슈이

Assignees

  • 베링거 잉겔하임 베트메디카 (차이나) 코포레이션 리미티드

Dates

Publication Date
20260512
Application Date
20240823
Priority Date
20230825

Claims (19)

  1. A modified duck enteritis virus (DEV), wherein one or more genes of the DEV genome selected from the group consisting of US3, UL24, UL40, UL39, UL23, UL41, and US8 are inactivated, and the modified DEV reduces or eliminates mortality in chickens compared to a non-modified DEV.
  2. A modified duck enteritis virus (DEV), comprising, in combination with the inactivation of one or more additional non-essential genes of the DEV, an inactivated gene selected from any one of i) the UL41 gene; ii) the US3 gene; iii) the UL24 gene; iv) the UL40 gene; v) the UL39 gene; vi) the UL23 gene; and vii) the US8 gene, wherein the modified DEV reduces or eliminates mortality in chickens compared to a non-modified DEV.
  3. In paragraph 2, a modified DEV in which one or more additional non-essential genes of the DEV differ from the first inactivation gene and are selected from i) the US7 gene, ii) the UL2 gene, iii) the UL41 gene; iv) the US3 gene; v) the UL24 gene; vi) the UL40 gene; vii) the UL39 gene; viii) the UL23 gene; or ix) the US8.
  4. As a modified duck enteritis virus (DEV), i) UL41 gene; ii) US3 gene; iii) UL24 gene; iv) UL40 gene; v) UL39 gene; vi) UL23 gene; vii) US7 gene and US8 gene; viii) UL24 gene and UL2 gene; ix) UL40 gene and UL2 gene; x) UL23 gene and UL41 gene; or xi) comprising inactivation gene(s) selected from either the UL41 gene and the US8 gene, and A modified DEV that reduces or eliminates mortality in chickens compared to a non-modified DEV.
  5. A modified DEV according to any one of claims 1 to 4, wherein the gene is inactivated by a mutation, interruption, replacement, or deletion of part or all of the gene sequence.
  6. A modified DEV according to any one of claims 1 to 5, wherein at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the sequence of the gene is replaced or deleted.
  7. A modified DEV according to any one of claims 1 to 6, wherein the modified DEV further comprises a heterologous polynucleotide encoding a heterologous antigen of a chicken.
  8. A modified DEV according to any one of claims 1 to 7, wherein the heterogeneous polynucleotide is inserted into a non-essential gene of the modified DEV.
  9. In claim 7 or 8, the modified DEV in which the modified heterologous polynucleotide is expressed after transfection into a suitable chicken host cell.
  10. A modified DEV for use as a vector vaccine in chickens, in any one of paragraphs 7 through 9.
  11. A composition comprising a modified DEV of any one of claims 7 to 10.
  12. In Clause 11, the composition is a vaccine.
  13. A modified DEV of any one of claims 7 to 9, a composition of claim 11 or 12, or a vector vaccine of claim 10 for use in a method of inducing a protective immune response in chickens against a chicken pathogen, comprising or consisting of administering the modified DEV of any one of claims 7 to 9, a composition of claim 11 or 12, or a vector vaccine of claim 10 to chickens one or more times.
  14. A method of vaccinating chickens by inducing a protective immune response in chickens against a chicken pathogen, comprising administering to the chickens at least once a modified DEV of any one of claims 7 to 9, a composition of claim 11 or 12, or a vector vaccine of claim 10.
  15. The use of paragraph 13 or the method of paragraph 14, wherein the above chicken is 1 day old, 2 days old, 3 days old, 4 days old, 5 days old, 6 days old, or 7 days old on the vaccination date.
  16. The use of claim 13 or 15 or the method of claim 14 or 15, wherein the above administration is made by oral-nasal, ophthalmic, spray, drinking water, in ovo, intramuscular, subcutaneous, intradermal, or transdermal.
  17. A host cell expressing a modified DEV of any one of claims 1 to 9.
  18. In paragraph 17, the host cell is a CEF cell, an EB66 cell, or a DEF cell.
  19. A method for producing a modified DEV according to any one of claims 1 to 9, comprising inactivating one or more genes of a DEV genome selected from the group consisting of US3, UL24, UL40, UL39, UL23, UL41, and US8, wherein the inactivation of said one or more selected genes reduces or eliminates the mortality of the modified DEV in chickens compared to the non-modified DEV.

Description

Novel DEV vector for avian vaccine Cross-reference regarding related applications This application claims priority to PCT/CN2023/114921, filed on August 25, 2023, under the title of the invention “Deformation DEV safe for chickens,” the full text of which is incorporated herein by reference. Technology field The present invention relates to the field of animal health. In particular, the present invention relates to a modified Duck Enteritis Virus (DEV). More particularly, the present invention relates to a modified DEV that is non-pathogenic or exhibits reduced pathogenicity in chickens. Furthermore, the present invention relates to a composition comprising the modified DEV of the present invention as a vector-vaccine for chickens, and to the use thereof. Duck plague, also known as duck viral enteritis, is an acute septicemic infection in Anseriformes , such as ducks and geese. It is caused by the duck enteritis virus (DEV), which naturally infects ducks and geese. However, DEV not only causes duck plague in ducks and geese but also infects and kills chickens. DEV is also known as Anatid herpesvirus, duck herpesvirus, duck viral enteritis virus (DVEV), or duck plague virus (DPV). The complete nucleotide sequence of DEV has been determined and is available online (see, for example, Genbank registry number JQ673560). The viral genome contains approximately 162 kb and encodes nearly 80 different proteins. Several DEV strains, such as the Jansen strain, CSC strain, CHv strain, VAC strain, and 2085 strain, have been isolated. The full sequences of several DEV strains, such as VAC strain: ID EU082088.2; Anatid isolate C-KCE: ID KF263690.1; Anatid strain CHv: ID JQ647509.1; Anatid strain 2085: ID JF999965; Anatid strain CV: ID KJ549663.1 or Anatid strain CSC: ID JQ673560.1, are available in Genbank. As a member of the herpesvirus family, the DEV genome possesses a stable double-stranded DNA structure and contains multiple non-essential regions for viral replication, which can facilitate the insertion of multiple heterologous genes. DEV strains attenuated through traditional passage in chicken or duck embryos have become a promising live vaccine vector system for the development of vaccines against avian diseases. However, attenuation via traditional passage in chicken or duck embryos results in non-specific and mostly unknown genetic modifications, posing a risk that these modifications may be lost, allowing the attenuated virus to regain its virulence. Currently, the expression of heterologous genes using DEV as a vector is being primarily studied for the development of vaccines against diseases in ducks. It has been reported that DEV vectorized vaccines expressing heterologous genes are safe in ducks but toxic in chickens (cf. Wang, J., (2015). Construction of a recombinant duck enteritis virus (DEV) expressing hemagglutinin of H5N1 avian influenza virus based on an infectious clone of DEV vaccine strain and evaluation of its efficacy in ducks and chickens. Virology Journal, 12(1).). Developing genetically modified, safe, and effective live DEV vectors for the development of vaccines against diseases in chickens remains a challenge for the industry. The present invention is based on the surprising discovery that a DEV containing inactive genes within the genome, e.g., i) UL41 gene; ii) US3 gene; iii) UL24 gene; iv) UL40 gene; v) UL39 gene; vi) UL23 gene; vii) US8 gene, either alone or in combination with other DEV genes, such as, e.g., i) US7 gene and US8 gene; ii) UL24 gene and UL2 gene; iii) UL40 gene and UL2 gene; iv) UL23 gene and UL41 gene; or v) UL41 gene and US8 gene combination, reduces or eliminates mortality in chickens compared to a non-modified DEV. While wild-type DEV is lethal to young chickens, the DEV of the present invention is safe and can effectively deliver and express genes of interest in vivo . In particular, these DEVs are (i) attenuated to chickens in vivo , and (ii) can express foreign genes in a manner suitable for inducing protective immunity, including during very early stages (i.e., day 0, day 1, day 2, or day 3 after hatching). Additionally, these modified DEVs maintain a rapid growth rate, enabling the production of high titers. Therefore, these modified DEVs represent a very potent vector for vaccinating non-human animals, particularly poultry, and conferring early protective immunity. In one aspect, the present invention provides a modified duck enteritis virus (DEV) in which one or more genes of the DEV genome selected from the group consisting of US3, UL24, UL40, UL39, UL23, UL41, and US8 are inactivated, wherein the modified DEV reduces or eliminates mortality in chickens (compared to non-modified DEV). In one aspect, the present invention provides a modified duck enteritis virus (DEV) comprising an inactivated gene selected from any one of i) the UL41 gene; ii) the US3 gene; iii) the UL24 gene; iv) the UL40 gene; v) the UL39 gene; vi) the UL23 gene; or vii) the US8 gene, eith