Recent developments in latency and recombination of Aujeszky's disease (pseudorabies) virus

• Published in: Veterinary microbiology Vol. 55; no. 1; pp. 13 - 27
• Main Authors: Maes, Roger K., Sussman, Michael D., Vilnis, Aivars, Thacker, Brad J.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.1997; Elsevier Science
• Subjects: ANIMAL MODELS; Animal viral diseases; Animals; Aujeszky; AUJESZKY VIRUS; Biological and medical sciences; GENE; Gene Deletion; GENES; Herpesvirus 1, Suid - genetics; Herpesvirus 1, Suid - isolation & purification; Herpesvirus 1, Suid - physiology; INFECCIONES LATENTES; INFECTION LATENTE; Infectious diseases; Latency; LATENT INFECTIONS; Lymphoid Tissue - virology; Medical sciences; Mice; MODELE ANIMAL; MODELOS ANIMALES; Neurons - virology; PCR; Polymerase Chain Reaction; Pseudorabies; Pseudorabies - diagnosis; Pseudorabies - immunology; Pseudorabies - physiopathology; Pseudorabies Vaccines; RECOMBINACION; RECOMBINAISON; RECOMBINATION; Recombination, Genetic; Swine; Transcription, Genetic; VACCIN; VACCINES; Vaccines, Synthetic; VACUNA; Viral diseases; Viral Vaccines; Virulence; Virus Activation; VIRUS D'AUJESZKY; VIRUS DE AUJESZKY; Virus Latency; Virus Shedding; Aujeszky; Recombination; Pseudorabies; PCR; Latency; Genetic variability; Herpesviridae; Alphaherpesvirinae; Nervous system; Vaccine; Lymphoid tissue; Epidemiology; Infection; Virus; Aujeszky virus; Aujeszky disease; Viral disease; Persistent infection; Veterinary
• ISSN: 0378-1135; 1873-2542
• DOI: 10.1016/S0378-1135(96)01305-3

Latency is a characteristic and fascinating part of the biology of alphaherpesvirinae, including ADV. Tissue explantation, blot hybridization, in situ hybridization and more recently PCR are the experimental methods used to demonstrate that latent infections consistenly occur in ganglionic neurons and, at a lower level, in tonsillar and possibly other cells. In vivo reactivation of ADV, resulting in shedding of virulent ADV, has been demonstrated experimentally following administration of high doses of corticosteroids. To determine the influence of vaccination with currently use gene deleted vaccines on field virus latency load, it is essential to use quantitative latency detection methods. We have developed chemiluminescence-based quantitative PCR assays specific for gG and gE, and are currently using these to determine field virus latency loads in tissues of pigs vaccinated with one of several gene deleted vaccines. Recombination between ADV strains has been demonstrated both in vitro and in vivo and has raised concerns about the generation of gene deleted virulent ADV strains. Recent studies in a mouse model have shown that high concentrations of both strains have to be present at the same anatomical site for recombination to take place. This led to the conclusion that ongoing ADV eradication programs, based upon the use of gene deleted vaccines and differential serological testing, are not likely to be threatened by recombination between virulent ADV and gene deleted vaccine strains.