Immunogenic composition
Inventors
Yu, Qingzhong • Spatz, Stephen J. • Zsak, Laszlo
Assignees
US Department of Agriculture USDA
Publication Number
US-9950059-B2
Publication Date
2018-04-24
Expiration Date
2035-02-13
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Abstract
Recombinant chimeric viruses based on NDV LaSota strain and containing either ILTV gB or gD are produced. Administration of the chimeric viruses to chickens induces an immune response in the animal against both NDV and ILTV. Immunogenic compositions, plasmids, kits and methods are described.
Core Innovation
The invention describes recombinant chimeric viruses based on the Newcastle disease virus (NDV) LaSota strain which contain heterologous antigens from infectious laryngotracheitis virus (ILTV), specifically the gB or gD glycoproteins. Administration of these chimeric viruses to chickens induces an immune response against both NDV and ILTV, offering protection from diseases caused by these viruses. Immunogenic compositions containing one or both chimeric viruses, methods of generating immune responses, and kits including these components are detailed.
The problem addressed arises from the limitations of existing ILTV vaccines. Live attenuated ILTV vaccines, although protective, retain residual virulence, risk reversion to virulence via bird-to-bird passage, and can transmit horizontally among naive birds, creating safety concerns and persistent reservoirs of virulent virus in poultry populations. Inactivated and vectored vaccines, while safer, induce only partial protection, highlighting the need for inexpensive, safer next-generation vaccines that do not revert to virulence or spread among birds.
To solve this, the invention constructs chimeric viruses where the ILTV glycoproteins gB or gD are genetically inserted between the phosphoprotein (P) and matrix (M) genes of the NDV LaSota strain. This novel configuration surprisingly elicits a robust and protective immune response in vaccinated animals against both NDV and ILTV, overcoming noted failures of prior recombinant NDV vectors carrying other heterologous antigens. Immunogenic compositions containing either or both chimeric viruses can be administered in various formulations and dosages and are suitable for immunization of poultry to prevent NDV and ILTV diseases.
Claims Coverage
The patent includes two independent claims directed to chimeric viruses comprising the NDV LaSota strain and heterologous ILTV antigens (gB or gD), and claims covering immunogenic compositions and methods of immunization and disease prevention using these viruses, as well as expression vectors.
Chimeric virus comprising NDV LaSota strain expressing ILTV gB antigen
A chimeric virus comprising the NDV LaSota strain and the ILTV gB antigen, wherein the chimeric virus has the cDNA sequence of SEQ ID NO: 14 or contains a negative-strand RNA having the RNA sequence of SEQ ID NO: 15.
Chimeric virus comprising NDV LaSota strain expressing ILTV gD antigen
A chimeric virus comprising the NDV LaSota strain and the ILTV gD antigen, wherein the chimeric virus has the cDNA sequence of SEQ ID NO: 17 or contains a negative-strand RNA having the RNA sequence of SEQ ID NO: 18.
Immunogenic composition containing the chimeric virus
An immunogenic composition comprising one of the claimed chimeric viruses (either with ILTV gB or gD), one or more diluents, and optionally an adjuvant and/or carrier.
Methods of generating immune response and preventing disease
Methods of generating an immune response to NDV and ILTV, preventing ILTV disease and NDV disease, and reducing viral shedding in avian animals by administering an immunogenic effective amount of the immunogenic composition containing the chimeric viruses.
Purified expression vectors for chimeric viruses
Novel purified expression vectors comprising polynucleotide sequences selected from SEQ ID NO: 13 or SEQ ID NO: 16, which encode the chimeric viruses.
The claims cover novel chimeric viruses comprising NDV LaSota strain expressing ILTV gB or gD antigens with defined nucleotide sequences, immunogenic compositions comprising these chimeric viruses, methods for immunization and disease prevention in avian animals, and expression vectors encoding these chimeric viruses.
Stated Advantages
The chimeric virus induces a robust and protective immune response in animals against both NDV and ILTV infections.
The vaccine strategy overcomes problems of existing ILTV live attenuated vaccines, such as residual virulence, risk of reversion to virulence, and horizontal transmission among birds.
The recombinant NDV LaSota vector is safe, stable, and lacks reports of virulence reversion or recombination generating virulent strains.
Immunogenic compositions can reduce viral shedding of ILTV and NDV in vaccinated birds, thereby potentially limiting transmission.
The chimeric vaccines are suitable for administration to young birds, including those with maternally derived NDV antibodies, without adverse effects.
Documented Applications
Vaccination of poultry, including chickens and broilers, to induce an immune response protecting against infectious laryngotracheitis virus (ILTV) and Newcastle disease virus (NDV).
Prevention of ILTV and NDV diseases in avian animals by immunization with the chimeric virus-based immunogenic compositions.
Reduction of viral shedding of ILTV and NDV by vaccinated poultry, potentially reducing disease spread in flocks.
Use in commercial broiler chickens, including young day-old chicks with maternally derived NDV antibodies, for safe and effective immunization.
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