1984 Volume 46 Issue 2 Pages 155-165
Regularinterferon (IFN) was detected in the sera of mice infected with Toxoplasma gondii, RH or S-273 strain, only 24 hr postinoculation (p.i.). Mice which survived from subchronic (14 days p.i.) or chronic (more than 40 days p.i.) toxoplasmosis, were injected intraperitoneally with Toxoplasma lysate antigen (TLA), and IFN-γ was detected in their serum 6 hr after injection. No serum containing regular IFN inhibited Toxoplasma multiplication in mouse macrophage monolayers in vitro. The molecular weight (m.w.) of regular IFN and IFN-γ in the serum was mainly between 40, 000 and 70, 000. The highest regular IFN activity produced by normal spleen cells cultured in vitro was contained in fractions with approximate m.w. of 40, 000. It was contained in the portion of alpha-globulins of the serum. The IFN activity in L-929 cells cultured with poly I:C was contained in fractions with m.w. of 24, 000 to 70, 000. The highest IFN activity was observed in samples with approximate m.w. of 60, 000. IFN-γ contained in spleen lymphokines was estimated to have approximate m.w. of 55, 000 to 70, 000, with maximum activity with a m.w. of 67, 000.
