Role of gp63 and gIII of Aujeszky's 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 glycoproteins gp63 and gIII of Aujeszky's disease virus (ADV) are involved in neuropathogenesis in pigs. The Ka strain of ADV and its single deleted mutants were examined with respect to invasion and spread in the olfactory nervous pathway after intranasal inoculation in neonatal pigs. The olfactory mucosa, olfactory bulb and lateral olfactory tract representing the 1st, 2nd and 3rd neuronal level of the olfactory pathway respectively, were examined for virus by isolation and for antigen by immunocytochemical localization. The Ka undeleted strain and its gIII deleted mutant invaded and spread to all the neuronal levels in a similar way. The gp63 deleted mutant invaded and spread in the olfactory mucosa similarly to the Ka parental strain but its replication and degree of spread were diminished in all the levels of the central nervous system (CNS). It is, therefore, concluded that gp63 is involved in the neurotropism of ADV, while gIII is not.