Adaptation and attenuation of duck Tembusu virus strain Du/CH/LSD/110128 following serial passage in chicken embryos

Ling Sun; Yunxia Li; Yue Zhang; Zongxi Han; Yang Xu; Xiangang Kong; Shengwang Liu

doi:10.1128/CVI.00154-14

Adaptation and attenuation of duck Tembusu virus strain Du/CH/LSD/110128 following serial passage in chicken embryos

Clin Vaccine Immunol. 2014 Aug;21(8):1046-53. doi: 10.1128/CVI.00154-14. Epub 2014 May 28.

Authors

Ling Sun¹, Yunxia Li¹, Yue Zhang¹, Zongxi Han¹, Yang Xu¹, Xiangang Kong², Shengwang Liu²

Affiliations

¹ Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.
² Division of Avian Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China [email protected] [email protected].

Abstract

Duck Tembusu virus (DTMUV) is a newly emerging pathogenic flavivirus that has caused massive economic losses to the duck industry in China. In the current study, a virulent strain of DTMUV, designated Du/CH/LSD/110128, was isolated from the livers of diseased ducks and attenuated by serial passage in embryonated chicken eggs. The virus was partially attenuated after 50 and 70 passages and was fully attenuated after 90 passages, based on mortality and morbidity rates and viral loads in inoculated ducklings. Fourteen amino acid substitutions were observed in the capsid, prM, envelope, NS1, NS3, NS4A, NS4B, and NS5 proteins of the fully attenuated strain of Du/CH/LSD/110128, which might be responsible for the observed changes in replication and pathogenicity. A 72-nucleotide deletion was also observed in the 3' untranslated region of the virus after 30 passages. The fully attenuated virus retained the immunogenicity of the parental strain, providing effective protection to challenge with virulent Du/CH/LSD/110128, and may represent a suitable candidate as a vaccine strain against DTMUV infection in ducks. Our results also lay the foundation for future studies on the replication and pathogenic mechanisms of DTMUV.

MeSH terms

3' Untranslated Regions / genetics
Amino Acid Sequence
Amino Acid Substitution / genetics
Animals
Antibodies, Viral / immunology
Antigens, Viral / genetics
Antigens, Viral / immunology
Base Sequence
Chick Embryo
Ducks / immunology
Ducks / virology*
Flavivirus / classification
Flavivirus / genetics
Flavivirus / immunology*
Flavivirus Infections / immunology*
Flavivirus Infections / prevention & control
Flavivirus Infections / virology
Molecular Sequence Data
Poultry Diseases / immunology*
Poultry Diseases / prevention & control
Poultry Diseases / virology
RNA Helicases / genetics
Sequence Analysis, RNA
Sequence Deletion / genetics
Serial Passage / methods
Serine Endopeptidases / genetics
Vaccines, Attenuated / immunology*
Viral Envelope Proteins / genetics
Viral Load / immunology
Viral Nonstructural Proteins / genetics
Viral Vaccines / immunology
Virus Replication / genetics

Substances

3' Untranslated Regions
Antibodies, Viral
Antigens, Viral
NS1 protein, Flavivirus
NS3 protein, flavivirus
NS4A protein, flavivirus
NS4B protein, flavivirus
NS5 protein, flavivirus
Vaccines, Attenuated
Viral Envelope Proteins
Viral Nonstructural Proteins
Viral Vaccines
prM protein, Flavivirus
Serine Endopeptidases
RNA Helicases

Associated data

GENBANK/KC136210
GENBANK/KJ782377
GENBANK/KJ782378
GENBANK/KJ782379
GENBANK/KJ782380