FIG. 2.

Growth of N. caninum tachyzoites in macrophages. Macrophages infected with N. caninum tachyzoites were incubated with different doses of IFN-γ for 48 h. N. caninum growth capacity is expressed as the number of tachyzoites per parasitophorous vacuole (PV) among 50 vacuoles. Each value is the mean of the number of tachyzoites ± the standard deviation of triplicate samples. According to Student's t test, the differences between the absence and the presence of IFN-γ (50 and 500 U/ml) in each mouse were significant (asterisk, P < 0.05). Data are representative of two similar experiments.