Immune Effect of STAg Combined with BCG-DNA and Aluminum Hydroxide in Mice

Objective To observe the immune effect of soluble tachyzoite antigen(STAg) of Toxoplasma gondii combined with BCG-DNA and aluminum hydroxide in mice.Methods BALB / c mice were divided into five groups randomly.The mice in four test groups were injected s.c.with 20 μg STAg,50 μg BCG-DNA + 20 μg STAg,50 μg Al(OH)3 + 20 μg STAg and 50 μg BCG-DNA + 50 μg Al(OH)3 + 20 μg STAg,respectively,while those in control group with physiological saline,for 4 times.The mice were killed one week after the last injection,of which the sera were separated,and the splenotye suspensions were prepared.The level and titer of serum IgG was determined by ELISA,while the count of lymphocytes secreting specific IFNγ by ELISPOT method.Results The titer and level of serum IgG as well as the count of lymphocytes secreting specific IFNγ of mice in Al(OH)3 + BCG-DNA + STAg group were significantly higher than those in STAg,BCG-DNA + STAg and Al(OH)3 + STAg groups(P 0.05).Conclusion STAg combined with BCG-DNA and aluminum hydroxide induced strong humoral and cellular immune responses in mice as compared with STAg alone,and aluminum hydroxide and BCG-DNA adjuvant showed synergistic action with STAg.