摘要目的　构建IFN-γ基因真核表达重组质粒作为基因佐剂，观察其与pcDNA3-ROP1（pc-ROP1）重组质粒DNA共同免疫小鼠所诱导抗弓形虫免疫应答。 方法　将IFN-γ基因片段定向插入真核表达载体pcDNA3，双酶切鉴定，获得pcIFN重组子；碱裂解法大量制备，经肌肉免疫BALB/c小鼠，每只小鼠注射pcIFN 和pc-ROP1各100μg，两周后同量加强免疫一次，以pcDNA3空质粒和生理盐水组作对照。分别于免疫后第30天、50天和70天共三次用MTT法测定小鼠脾脏T淋巴细胞增殖活性及NK细胞活性；双夹心ELISA法测定血清细胞因子IFN-γ、IL-2、IL-10和酶标测定NO含量；ELISA法测定IgG抗体滴度。结果　构建成功pcIFN重组质粒；pc-ROP1质粒DNA可刺激免疫鼠脾T淋巴细胞增生及NK细胞杀伤活性，在pcIFN的作用下，该两项指标皆明显增高，且IFN-γ、IL-2及NO水平较不加佐剂组明显提高（P<0.01），而对IgG抗体滴度无显著影响（P>0.05）。结论　IFN-γ基因佐剂具有协同pcROP1 DNA免疫的作用，可增强免疫鼠细胞免疫应答、IFN-γ、IL-2细胞因子及NO的产生。

abstractsObjective　To construct the eukaryotic expression recombinant plasmid, pcIFN-γ, as a genetic adjuvant and observe the immune responses elicited by pcDNA3-rhoptry protein 1 （pc-ROP1） combined with pcIFN-γ against Toxoplasma gondii (T. gondii) infection in mice. Methods　A fragment of the IFN-γ gene was directly inserted into the pcDNA3 plasmid and identified by two restriction endonucleases digestion. pcIFN and pcROP1 DNA was injected into the left leg muscle of mice at a dosage of 100*!μg, and a booster vaccination was given at the same dosage after two weeks. Control groups were injected with pcDNA3 blank plasmid or normal saline. At 30, 50 and 70 days after booster injection, kinetic tests were carried out: MTT assay for the proliferation response of T lymphocyte cells and the activity of NK cells, sandwich ABC-ELISA for the determination of IFN-γ, IL-2 and IL-10; a serum enzymetic aassay for nitric oxide (NO) in sera and ELISA for the titer of IgG antibody in sera.Results　The recombinant plasmid, pcIFN-γ was constructed. The proliferation response of spleen T lymph cells, NK cell killing activity, and serum levels of IFN-γ, IL-2 and NO in mice injected with pcROP1 and pcIFN-γ were higher than in those injected with pcROP1 alone. There was no difference in IgG antibody levels between the two groups. Conclusion　The genetic adjuvant, pcIFN-γ, could enhance the cellular immune response induced by DNA vaccine of pcROP1 in mice against Toxoplasma gondii infection.