ROLE OF GP63 AND GIII OF AUJESZKYS-DISEASE VIRUS IN THE INVASION OF THE OLFACTORY NERVOUS PATHWAY IN NEONATAL PIGS

The purpose of this study was to examine in which way envelope glycopr oteins gp63 and gIII of Aujeszky's disease virus (ADV) are involved in neuropathogenesis in pigs. The Ka strain of ADV and its single delete d mutants were examined with respect to invasion and spread in the olf actory nervous pathway after intranasal inoculation in neonatal pigs. The olfactory mucosa, olfactory bulb and lateral olfactory tract repre senting the 1st, 2nd and 3rd neuronal level of the olfactory pathway r espectively, were examined for virus by isolation and for antigen by i mmunocytochemical localization. The Ka undeleted strain and its gIII d eleted mutant invaded and spread to all the neuronal levels in a simil ar way. The gp63 deleted mutant invaded and spread in the olfactory mu cosa similarly to the Ka parental strain but its replication and degre e of spread were diminished in all the levels of the central nervous s ystem (CNS). It is, therefore, concluded that gp63 is involved in the neurotropism of ADV, while gIII is not.