Abstract: 【Abstract】 Objective To compare the immuno-protection induced by the recombinant BCG vaccine of Toxoplasma gondii GRA4 gene （rBCG-GRA4） and SAG2 gene （rBCG-SAG2） in BALB/c mice. Methods 108 SPF BALB/c mice were divided into 6 groups： PBS， BCG， rBCG， rBCG-GRA4， rBCG-SAG2 and rBCG-GRA4+SAG2， each with 18 mice. Each mouse was injected by 100 μl corresponding materials for 2 times. Blood was taken from tail vein before inoculation. 4，6 and 8 weeks after inoculation， spleen was moved and blood was taken from orbit vein of 3 mice from each group for the detection of cytokines， IgG and IgM antibodies， T lymphocyte subgroups and transformation efficiency. 3 weeks after the last inoculation， 9 mice from each group were challenged intraperitoneally with 50 tachyzoites of T.gondii RH strain and their survival time was observed. Results rBCG vaccine of T.gondii induced immune response. The value of CD3⁺CD4⁺/CD3⁺CD8⁺ of group BCG-GRA4+SAG2 was the highest （14.06±1.17） in the 4th week; the IgG titer in the BCG-GRA4+SAG2 group was the highest （0.18±0.02） in the 6th week and the IgM titer in the BCG-SAG2 group was the highest （0.82±0.05） in the 8th week. The average survival time of the mice in BCG-SAG2 group was about 8.61 days after challenged with tachyzoites， and that of the PBS control group， 7.33 days. The average survival time in the 3 immunized groups was one day longer than that of the control. Conclusion The rBCG vaccine of T.gondii shows certain immuno-protection in mice.

Key words: Toxoplasma gondii, Dense granule protein 4 （GRA4）, Surface antigen 2 （SAG2）, Recombinant vaccine, Bacillie Calmette-Guérin, Immuno-protection