title: Virulence and pathogenesis of non-virulent and virulent strains of pseudorabies virus expressing envelope glycoprotein E1 of hog cholera virus.
abstract: Pseudorabies virus (PRV) expressing the envelope glycoprotein E1 (E1) of hog cholera virus (HCV) was used as a model to study the potential risks connected with the use of a live herpesvirus vaccine expressing a foreign gene. The gene encoding E1 was inserted into the glycoprotein X (gX) locus of both a virulent PRV strain and a non-virulent PRV strain in which the virulence genes encoding glycoprotein I (gI) and thymidine kinase (TK) had been inactivated. We investigated whether strain M205 (gI-, TK-, gX-, E1+) had a changed cell or host tropism or virulence compared with strain M206 (gI-, TK-, gX-) in pigs, rabbits, hamsters, rats, mice and rhesus monkeys. The insertion of E1 into this non-virulent PRV strain caused no change in cell or host tropism. However, pigs inoculated with M205 shed less virus over a shorter period than pigs inoculated with M206. Theoretically, virulent PRV strains expressing E1 (gX-, E1+) could arise through transfer of the E1 gene of M205 to a virulent PRV strain. Therefore, we inoculated pigs with strain M12 (gX-, E1+) or the control strain M104 (gX-) and compared the virulence and pathogenesis. M12 and M104 were of approximately equal virulence and the pathogenesis of both strains was similar. We concluded that incorporating E1 of HCV into the gX locus of PRV did not change cell or host tropism, nor did it change the virulence of either non-virulent or virulent PRV.
authors.affiliation: Central Veterinary Institute, Department of Virology, Lelystad, The Netherlands.
authors.forename: W A
authors.initials: WA
authors.lastname: Mulder
authors.forename: J
authors.initials: J
authors.lastname: Priem
authors.forename: K L
authors.initials: KL
authors.lastname: Glazenburg
authors.forename: F
authors.initials: F
authors.lastname: Wagenaar
authors.forename: E
authors.initials: E
authors.lastname: Gruys
authors.forename: A L
authors.initials: AL
authors.lastname: Gielkens
authors.forename: J M
authors.initials: JM
authors.lastname: Pol
authors.forename: T G
authors.initials: TG
authors.lastname: Kimman
mesh_terms: D000818:Animals; D002460:Cell Line; D006692:Classical Swine Fever Virus / Q000235:genetics / Q000472:pathogenicity*; D006224:Cricetinae; D005814:Genes, Viral / Q000235:genetics*; D011558:Herpesvirus 1, Suid / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D008253:Macaca mulatta; D008647:Mesocricetus; D051379:Mice; D008807:Mice, Inbred BALB C; D016253:Microscopy, Immunoelectron; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D013552:Swine; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D014774:Virulence / Q000235:genetics
chemical_list: D014759:Viral Envelope Proteins