Aim: To compare the inhibitory effect of the macrophages activated by IFN-gamma combined with TNF-alpha against RH strain and Fukaya strain.
Methods: The average parasite proliferation rates of the two strains within the cytokine-activated M phi s were calculated at different times post-challenge, the nitric oxide (NO) levels in the medium supernatant were simultaneously determined.
Results: In the macrophages activated by 100 U each of IFN-gamma and TNF-alpha, the invaded tachyzoites of RH strain were completely killed, while the invaded tachyzoites of Fukaya strain remained slow proliferation with significantly lower levels of NO detected at 24 h post challenge.
Conclusion: The difference in the anti-Toxoplasma effect of the activated macrophages against RH and Fukaya strains might be attributed to the different amount of NO produced by the macrophages.