粒细胞-巨噬细胞集落刺激因子与生长抑素融合表达质粒对断奶仔猪生长及相关激素的影响

Effect of fusion-expression plasmid contained GM-CSF and SS on growth and relative hormone of weaned piglets

选择40头断奶的长大二元杂交仔猪,随机分为4组,每组10头,公母各半,其中Ⅰ组为对照组,Ⅱ-Ⅳ组分别口服以减毒沙门氏菌为载体的DNA疫苗pcS/2SS、pGM-CSF/SS和pGM-CSF＋pcS/2SS,分析这些DNA疫苗对断奶仔猪的生产性能和相关激素分泌的影响。结果显示,与Ⅱ组和Ⅳ组相比,Ⅲ组平均日增重分别提高了8.37%（P〉0.05）和17.2%（P〈0.05）,饲料利用率分别提高了14.8%和6.7%。Ⅱ组、Ⅲ组和Ⅳ组血浆中GH的含量有升高的趋势。Ⅱ组IGF-Ⅰ的含量一直处于较高的水平,Ⅲ和Ⅳ组在第2周后处于较低的分泌水平,Ⅲ组IGF-Ⅰ的峰值高于其他组。Ⅰ、Ⅱ和Ⅳ组T3的含量呈下降的趋势,而Ⅲ组呈上升趋势,免疫后第8周,Ⅲ组的T3分泌水平显著高于Ⅱ和Ⅳ组（P〈0.05）,而与对照组差异不显著。Ⅰ组T4的含量不断降低,而Ⅱ、Ⅲ和Ⅳ组有不断升高的趋势,Ⅱ组和Ⅲ组T4的分泌一直保持在较高的水平。上述结果表明,粒细胞-巨噬细胞集落刺激因子（GM-CSF）对SS DNA疫苗有一定的免疫增强作用,pGM-CSF/SS的免疫效果要优于pGM-CSF＋pcS/2SS共免疫。

To study the effect of SS DNA vaccine on the growth and hormone, a total of 40 weaned Landrace x Yorkshire crossbred piglets were divided into 4 groups and immunized with 0. 85% salt solution （Group Ⅰ as control）, pcS/2SS （Group Ⅱ ）, pGMCSF/SS （ Group Ⅲ ） and pGM-CSF ＋ pcS/2SS （ Group Ⅳ ） delivered by attenuated Salmonella as carrier at a dose of 4 × 10^10 CFU per piglet, respectively. A booster was given two weeks later. The results demonstrated that daily gain of pGM-CSF/SS increased 8.37% and 17.2%, respectively, and feed efficiency increased 14. 8% and 6. 7%, respectively, compared with Group Ⅱ and Ⅳ. pcS/2SS and pGM-CSF ＋ pcS/2SS had no effect on growth, but improved their feed efficiency. Plasma GH level of Group Ⅱ , Ⅲ and IV increased after immunization, while plasma GH level in the control group retained stable during the whole period. Plasma IGF- Ⅰ level of pcS/2SS kept in higher level all the times. Peak level of plasma IGF- Ⅰ level in pGM-CSF/SS was higher than that in other groups. Plasma T3 level of Group Ⅰ , Ⅱ and Ⅳ exhibited declination, while ascenting of Group Ⅲ. Plasma T3 level of pGM-CSF/SS was higher than that of Group Ⅰ , Ⅱ and IV at 8th week （P 〈0. 05）. Plasma T4 level of Group Ⅱ and Ⅲ kept in higher level all the while. These results indicated that GM-CSF could enhance immunization effect on SS DNA vaccine, and the immune response of pGM-CSF/SS was prior to that of pGM-CSF ＋ pcS/2SS.