An adenovirus recombinant expressing the spike glycoprotein of porcine respiratory coronavirus is immunogenic in swine.
The full-length spike (S) gene of porcine respiratory coronavirus (PRCV) was inserted into the genome of human adenovirus type 5 downstream of the early transcription region 3 promoter. The recombinant virus replicated in cultures of the swine testicle ST cell line and directed the synthesis of S antigen with a maximum yield of approximately 26 micrograms per 10(6) cells. The antigen was cell-associated except in the late phase of the infection, when a small amount (3.5 micrograms per 10(6) cells) was released. The cell-associated antigen consisted of polypeptides of molecular mass 160 kDa and 175 kDa, comigrating with the authentic precursor S' and the mature S protein of PRCV, respectively. The extracellular recombinant antigen corresponded to the 175 kDa mature protein. Some recombinant S protein was exposed on the cell surface and was recognized by neutralization-mediating anti-S monoclonal antibodies. Piglets, inoculated oronasally with the recombinant adenovirus vector developed PRCV-neutralizing serum antibodies and were partially protected against PRCV challenge, demonstrating the potential of live adenovirus as vaccine vector.
Callebaut
P
P
Laboratory of Veterinary Virology, Faculty of Veterinary Medicine, University of Ghent, Merelbeke, Belgium.
Enjuanes
L
L
Pensaert
M
M
D000260:Adenoviruses, Human / Q000235:genetics*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001483:Base Sequence; D017934:Coronavirus / Q000276:immunology*; D006801:Humans; D008562:Membrane Glycoproteins / Q000276:immunology*; D008969:Molecular Sequence Data; D064370:Spike Glycoprotein, Coronavirus; D013552:Swine / Q000821:virology*; D014614:Vaccines, Synthetic / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus