Previous Article | Next Article ![]()
Journal of Virology, December 2000, p. 11247-11253, Vol. 74, No. 23
Unité de Virologie et Immunologie
Moléculaires, Institut National de la Recherche Agronomique,
78352 Jouy-en-Josas Cedex, France
Received 5 June 2000/Accepted 6 September 2000
Infectious hematopoietic necrosis virus (IHNV) is a
Novirhabdovirus and is the causative agent of a devastating
acute, lethal disease in wild and farmed rainbow trout. The virus is
enzootic throughout western North America and has spread to Asia and
Europe. A full-length cDNA of the IHNV antigenome (pIHNV-Pst) was
assembled from subgenomic overlapping cDNA fragments and cloned in a
transcription plasmid between the T7 RNA polymerase promoter and the
autocatalytic hepatitis delta virus ribozyme. Recombinant IHNV (rIHNV)
was recovered from fish cells at 14°C, following infection with a
recombinant vaccinia virus expressing the T7 RNA polymerase (vTF7-3)
and cotransfection of pIHNV-Pst together with plasmids encoding the
nucleoprotein N (pT7-N), the phosphoprotein P (pT7-P), the RNA
polymerase L (pT7-L), and the nonvirion protein NV (pT7-NV). When pT7-N
and pT7-NV were omitted, rIHNV was also recovered, although less
efficiently. Incidental mutations introduced in pIHNV-Pst were all
present in the rIHNV genome; however, a targeted mutation located in
the L gene was eliminated from the recombinant genome by homologous recombination with the added pT7-L expression plasmid. To investigate the role of NV protein in virus replication, the pIHNV-Pst construct was engineered such that the entire NV open reading frame was deleted
and replaced by the genes encoding green fluorescent protein or
chloramphenicol acetyltransferase. The successful recovery of
recombinant virus expressing foreign genes instead of the NV gene
demonstrated that the NV protein was not absolutely required for viral
replication in cell cultures, although its presence greatly improves
virus growth. The ability to generate rIHNV from cDNA provides the
basis to manipulate the genome in order to engineer new live viral
vaccine strains.
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Recovery of NV Knockout Infectious Hematopoietic
Necrosis Virus Expressing Foreign Genes
and
*
Corresponding author. Mailing address: Unité de
Virologie et Immunologie Moléculaires, Institut National de la
Recherche Agronomique, 78352 Jouy-en-Josas Cedex, France. Phone: 33 (1) 34 65 26 15. Fax: 33 (1) 34 65 26 21. E-mail:
bremont{at}biotec.jouy.inra.fr.
Present address: Virology and Immunology Laboratory, Department of
Pharmacology and Experimental Therapeutics, University of Maryland,
Baltimore, MD 21201.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»