Production of mink enteritis parvovirus empty capsids by expression in a baculovirus vector system: a recombinant vaccine for mink enteritis parvovirus in mink.
The VP-2 gene of mink enteritis parvovirus (MEV) was amplified by the polymerase chain reaction using MEV DNA isolated from the faeces of a naturally infected mink. Subsequently the VP-2 gene was cloned into a baculovirus expression vector. Recombinant baculoviruses were isolated and the MEV VP-2 gene product was characterized after expression in Sf9 insect cells. The MEV VP-2 product had the same size as that reported for the wild-type MEV VP-2 protein and was recognized by convalescent sera from MEV-infected mink and a panel of monoclonal antibodies reactive to MEV. Furthermore, the VP-2 protein was able to form parvovirus-like particles, which had haemagglutinating properties comparable with the wild-type MEV. The cloned VP-2 gene was sequenced and only five nucleotide differences were found after alignment with the known sequences of the MEV type 1 and type 2 isolates. Surprisingly, the VP-2 gene encoded a valine and a tyrosine at amino acid positions 232 and 234, identical to the situation found in MEV type 1, but at position 300 there was a valine which is a determinant of MEV type 2. Immunization of mink with approximately 40,000 haemagglutinating units of recombinant MEV VP-2 induced a measurable antibody response as tested by haemagglutination inhibition. Furthermore, the immunized mink did not excrete virus and did not develop clinical disease upon challenge with a virulent isolate of MEV.
Christensen
J
J
Department of Veterinary Microbiology, Royal Veterinary and Agricultural University of Copenhagen, Denmark.
Alexandersen
S
S
Bloch
B
B
Aasted
B
B
Uttenthal
A
A
D000818:Animals; D000911:Antibodies, Monoclonal; D016367:Baculoviridae / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002213:Capsid / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D002478:Cells, Cultured; D003001:Cloning, Molecular; D028301:Feline Panleukopenia Virus / Q000235:genetics / Q000276:immunology*; D005822:Genetic Vectors; D006385:Hemagglutination Inhibition Tests; D008907:Mink / Q000276:immunology / Q000382:microbiology*; D008969:Molecular Sequence Data; D014614:Vaccines, Synthetic / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology
D000911:Antibodies, Monoclonal; D014614:Vaccines, Synthetic