Recombinant interferon-gamma applied to the brain ventricular system protects rats against pseudorabies

We examined the prophylactic efficacy of recombinant rat interferon-gamma (IFN-gamma) administered directly into the brain ventricular system or via the intraperitoneal (i.p.) route against central and peripheral pseudorabies virus (PRV) infection. Intraperitoneally given IFN-gamma completely protected rats against a lethal i.p. PRV infection. The same regimen showed no protective effect against lethal intracerebroventricular (i.c.v.) PRV challenge even if IFN-gamma was given in high concentrations. When given via the i.c.v. route, IFN-gamma protected rats against lethal i.c.v. infection and also evoked partial protection with extended survival times of i.p. infected rats. Our results demonstrate an IFN-gamma-mediated antiviral effect in the central nervous system.