Efficient self-assembly and protective efficacy of infectious bursal disease virus-like particles by a recombinant baculovirus co-expressing precursor polyprotein and VP4.
BACKGROUND
Virus-like particle (VLP) technology is considered one of the most promising approaches in animal vaccines, due to the intrinsic immunogenic properties as well as high safety profile of VLPs. In this study, we developed a VLP vaccine against infectious bursal disease virus (IBDV), which causes morbidity and mortality in chickens, by expressing a baculovirus in insect cells.


METHODS
To improve the self-proteolytic processing of precursor polyprotein (PP), we constructed a recombinant baculovirus transfer vector that co-expresses PP and the VP4 protease gene of IBDV.


RESULTS
Expression and VLP assembly of recombinant proteins and antigenicity of the VLP were examined by Western blotting, ELISA, and transmission electron microscopy. In animal experiments, vaccination with the recombinant VLP induced strong and uniform humoral immunity and provided complete protection against challenge with very virulent (vv) IBDV in SPF chickens (n = 12). As determined by the bursa of Fabricius (BF)/body weight (B/BW) ratio, the protection against post-challenge bursal atrophy was significantly higher (P < 0.001) in VLP-vaccinated birds than in non-vaccinated controls.


CONCLUSIONS
Since the protective efficacy of the VLP vaccine was comparable to that of a commercially available inactivated vaccine, the recombinant VLP merits further investigation as an alternative means of protection against vvIBD.
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. hyunjlee@korea.kr.
Hyun-Jeong
HJ
Lee
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. jiyekim@korea.kr.
Ji-Ye
JY
Kim
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. cessna70@korea.kr.
Soo-Jeong
SJ
Kye
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. glwjd82@korea.kr.
Hee-Jung
HJ
Seul
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. brujung@korea.kr.
Suk-Chan
SC
Jung
Avian Disease Division, Animal and Plant Quarantine Agency, 175 Anyangro, Anyang, Gyeonggi, 430-757, Republic of Korea. kchoi0608@korea.kr.
Kang-Seuk
KS
Choi
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D016367:Baculoviridae / Q000235:genetics; D018175:Birnaviridae Infections / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D015153:Blotting, Western; D002060:Bursa of Fabricius / Q000473:pathology; D002460:Cell Line; D002645:Chickens; D004797:Enzyme-Linked Immunosorbent Assay; D005822:Genetic Vectors; D007243:Infectious bursal disease virus / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D007313:Insecta; D046529:Microscopy, Electron, Transmission; D020815:Polyproteins; D011201:Poultry Diseases / Q000473:pathology / Q000517:prevention & control*; D055503:Protein Multimerization; D016896:Treatment Outcome; D058425:Vaccines, Virus-Like Particle / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000648:ultrastructure; D015678:Viral Structural Proteins / Q000235:genetics / Q000378:metabolism; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D022701:Virosomes / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure
D000914:Antibodies, Viral; D020815:Polyproteins; C478245:VP4 protein, infectious bursal disease virus; D058425:Vaccines, Virus-Like Particle; D015678:Viral Structural Proteins; D014765:Viral Vaccines; D022701:Virosomes