Intracerebral administration of Interleukin-12 (IL-12) and IL-18 modifies the course of mouse scrapie

BACKGROUND: Prion diseases are characterised by a neurodegenerative pattern in which the function of immune system remains still elusive. In the present study, we evaluate if an exogenous treatment with Interleukin-12 (IL-12) and IL-18, able to activate microglia, is able to affect scrapie pathogenesis. RESULTS: Cytokines injected intracranially, induced a strong inflammatory response characterised by TNF-α production and microglia activation. Two groups of mice were injected intracerebrally with high dose of ME7 strain of scrapie containing IL-12 and IL-18 or sterile saline. Cytokines-treated mice showed a more pronounced accumulation of PrP(Sc )in brain tissues at 90 days post-inoculation and a shorter mean survival times than untreated mice. CONCLUSION: We can conclude that intracerebral administration of IL-12 and IL-18 can modulate scrapie pathogenesis possibly through a microglia-mediated pattern.