细粒棘球蚴重组铁蛋白和重组线粒体苹果酸脱氢酶免疫差异的初步观察

Preliminary Study on the Difference in Immune Protection between Echinococcus granulosus Recombinant Ferritin and Recombinant mMDH

目的比较细粒棘球蚴重组铁蛋白(rEgferritin)和重组线粒体苹果酸脱氢酶(rEgmMDH)对感染细粒棘球蚴(Echinococcus granulosus)小鼠的免疫差异。方法 30只雌性ICR小鼠随机分为3组(rEgferritin免疫组、rEgmMDH免疫组和对照组)。将rEgferritin、rEgmMDH和PBS与佐剂乳化后,分别于背部皮下多点注射免疫小鼠,每次注射100μl/只(含抗原10μg),共免疫3次,每次间隔2周。末次免疫后2周,3组小鼠分别于腹腔注射0.1 ml原头节悬液(约1 500个)进行攻击感染,22周后剖杀,无菌取脾组织,并记录包囊数量和直径,评价免疫保护力。用流式细胞仪检测脾组织中CD4+T细胞和CD8+T细胞,计算两者比例。结果 rEgferritin免疫组30%(3/10)小鼠有包囊,包囊总数为5个;rEgmMDH免疫组小鼠均有包囊,包囊总数为118个;对照组9只小鼠中7只有包囊,包囊总数为35个。rEgferritin免疫组小鼠获得了84.7%的免疫保护力,而rEgmMDH组无免疫保护力。小鼠脾淋巴细胞CD4+亚群百分比,rEgferritin免疫组[(57.50±7.02)%]显著高于对照组[(43.60±6.09)%](P<0.05)。小鼠脾淋巴细胞CD8+亚群百分比,rEgferritin免疫组[(25.66±6.18)%]和rEgmMDH免疫组[(19.23±5.40)%]与对照组[(21.80±6.12)%]比较,差异均无统计学意义(P>0.05)。小鼠脾淋巴细胞CD4+/CD8+亚群比值,rEgferritin免疫组和rEgmMDH免疫组与对照组比较,差异均无统计学意义(P>0.05)结论 rEgferritin能抑制细粒棘球蚴的生长,而rEgmMDH促进了细粒棘球蚴的生长。

Objective To evaluate the immunoprotective activity of the Egrecombinant ferritin and Egrecombinant mMDH proteins in mice. Methods Thirty ICR mice were divided into 3 groups and immunized by injection of adjuvantemulsified rEgferritin, rEgmMDH and PBS, respectively, in multiple spots at back, for 3 times with an interval of 2 wk. Two weeks after the last immunization, the mice of the 3 groups were infected intraperitoneally with 0.1 ml suspension containing about 1 500 Echinococcus granulosus （Eg） protoscoleces. The mice were sacrificed 22 wk after infection and the Eg cysts were collected and measured. Spleens were taken for detecting CD4＋ T ceils and CD8~ T cells and ratio calculated. Results Eg cysts were found in 30% （3/10） of the mice in the rEgferritin group with 5 cysts altogether; cysts were received in all the mice in the rEgmMDH group with 118 cysts totally; and cysts were found in 7 of 9 mice in the PBS control with 35 cysts totally. The mice in the rEgferritin group showed an 84.7% protection but revealed no protection in the rEgmMDH group. The CD4＋T cells were significantly higher in the rEgferritin group than the control, but no statistical difference was found in CD8＋ T cells and CD4＋/CD8＋ ratio between the 2 groups. There was no considerable change in the T cells and ratio in the rEgmMDH group compared to the control. Conclusion The Egrecombinant fer- ritin can inhibit the growth of Eg while the Egrecombinant mMDH seems promoting its growth in mice.