The pathogenicity of a double mutant of pseudorabies virus (PRV) with deletions in the latency gene and the early protein O gene was examined. In comparison to the parent Indiana-Funkhauser virus, the ability of this mutant to replicate and to cause disease in piglets is greatly reduced. At an infection dose that caused no clinical signs in 5-day-old neonatal piglets, this mutant was capable of eliciting solid protective immunity against a lethal PRV challenge. Thus, the double-gene deletion attenuates PRV but does not affect its immunogenicity. These features may be desirable for inclusion into future PRV vaccines.
References
1.
Ben-PoratTKaplanAS: 1985, Molecular biology of pseudorabies virusIn: The herpesvirus, ed. RoizmanB, vol. 3., pp. 105–173. Plenum, New York, NY
2.
CaiWSchafferPA: 1992, Herpes simplex virus type 1 ICPO regulates expression of immediate-early, early, and late genes in productively infected cellsJ Virol66:2904–2915
3.
ChenJSilversteinS: 1992, Herpes simplex viruses with mutations in the gene encoding ICPO are defective in gene expressionJ Virol66:2916–2927
4.
CheungAK: 1989, Detection of pseudorabies virus transcripts in trigeminal ganglia of latently infected swineJ Virol63:2908–2913
5.
CheungAK: 1991, Cloning of the latency gene and early protein O gene of pseudorabies virusJ Virol65:5260–5271
6.
CheungAKFangJWesleyRD: 1994, Characterization of a pseudorabies virus defective in the early protein O and latency genesAm J Vet Res55:1710–1716
7.
KlugeJPBeranGWHillHT.: 1992, Pseudorabies (Aujeszky's disease)In: Diseases of swine, ed. LemanADStrawBEMengelingWL., 7th ed., pp. 312–323. Iowa State University Press, Ames, IA
PriolaSAGustafsonDPWagnerEK.: 1990, A major portion of the latent pseudorabies virus genome is transcribed in trigeminal ganglia of pigsJ Virol64:4755–4760
10.
PriolaSAStevensJG: 1991, The 5′ and 3′ limits of transcription in the pseudorabies virus latency associated transcription unitVirology182:852–856
11.
WoodsRD: 1982, Studies of enteric coronaviruses in a feline cell lineVet Microbiol7:427–435
12.
ZhuXChenJYoungCHS.: 1990, Reactivation of latent herpes simplex virus by adenovirus recombinants encoding mutant IE-O gene productsJ Virol64:4489–4498
