Expression of YAV proteins and vaccination against viral ascites among cultured juvenile yellowtail.
Yellowtail ascites virus (YAV) is a member of the family Birnaviridae and causes viral ascites among juvenile yellowtail (Seriola quinqueradiata). We have reported the cloning and expression of two viral cDNAs, the first being segment A encoding a polyprotein of viral capsid proteins (VP2 and VP3) and a protease (NS), and the second being VP2-epitope encoding serotype-specific epitope region on VP2, using a baculovirus expression system. Another viral cDNA encoding a polyprotein of NS and VP3 was cloned and expressed in this study. For the expression of NS/VP3 (YAV nt 1626 to 3066) in insect cells a 31-kDa protein, corresponding to VP3 was detected, indicating an appropriate posttranslational processing of NS/VP3 polypeptide by NS protease itself. The analysis of the N-terminal amino acid sequence of this protein showed that NS protease may cleave an Ala-Ser bond. A study of the potential for vaccination of yellowtail fry by injection of insect cell lysates infected with baculovirus, containing either cDNA of segment A, VP2-epitope, or NS/VP3 was undertaken. Only a vaccination with cell lysates infected with a recombinant virus carrying the full length of YAV segment A gene demonstrated approximately the same effect as that of inactivated YAV. This result suggested that all proteins VP2, VP3, and NS are required for an effective vaccination.
Sato
H
H
Department of Applied Biology, Kyoto Institute of Technology, Japan.
Nakajima
K
K
Maeno
Y
Y
Kamaishi
T
T
Kamata
T
T
Mori
H
H
Kamei
K
K
Takano
R
R
Kudo
K
K
Hara
S
S
D000818:Animals; D001201:Ascites / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D001483:Base Sequence; D018059:Birnaviridae / Q000235:genetics / Q000276:immunology*; D002213:Capsid / Q000235:genetics / Q000276:immunology*; D036022:Capsid Proteins; D002460:Cell Line; D002478:Cells, Cultured; D004279:DNA, Viral; D005393:Fish Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D015870:Gene Expression; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D012474:Salmon; D018411:Spodoptera / Q000166:cytology; D014611:Vaccination; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000235:genetics / Q000276:immunology*
D036022:Capsid Proteins; D004279:DNA, Viral; D011993:Recombinant Fusion Proteins; D014614:Vaccines, Synthetic; D014765:Viral Vaccines