Effects of transferrins and cytokines on nitric oxide production by an avian lymphoblastoid cell line infected with Marek's disease virus

Marek's disease virus (MDV), the causative agent of Marek's disease (MD), is a herpesvirus that infects poultry causing T lymphomas. Although vaccination may prevent lymphomas formation, it is not known whether it controls viral replication and spreading in the environment. Ovotransferrin (Otrf), a member of the transferrin family, is known to exert in vitro antiviral activity in primary cultures of chicken embryo fibroblasts (CEF). In addition Otrf is produced by CEF and by an avian lymphoblastoid cell line (MDCC-MSB1) following infection/reinfection with MDV. The present work was designed to investigate the effects of reinfection and of Otrf and lactoferrin (Lf) on the production by MDCC-MSB1 of nitric oxide (NO), a molecule naturally exerting an antiviral activity. These effects were also tested with two cytokines (IL-8 and IFN-γ), alone and in association with transferrins. Synergy was found between Otrf and IFN-γ, thus suggesting a possible role in a complementary or alternative strategy against MDV spreading.