The inhibitory effect of interferon gamma and tumor necrosis factor alpha on intracellular multiplication of Neospora caninum in primary bovine braincells

Primary culture of bovine brain cells was examined for its susceptibility t o Neospora caninum infections, and this model was used to investigate the e ffects of bovine interferon gamma (IFN-gamma) and tumor necrosis factors al pha (TNF-alpha) on tachyzoite growth. Tachyzoites of N. caninum grew well i n this culture, and tachyzoite growth in astroglia and microglia were confi rmed by immunocytochemical staining. IFN-gamma inhibited the tachyzoite gro wth, and this inhibition was not reversed by the addition of nitric oxide a ntagonist. TNF-alpha to a lesser extent, also inhibited the tachyzoite grow th. Th-1 type cytokines may play an important role in host defense mechanis ms in N. caninum infection.