环孢素A联合IL-2融合蛋白在小鼠皮肤移植模型中增强乙肝疫苗免疫原性的研究

Enhancement of HBV vaccine immunogenicity with combination of CsA and IL-2 fusion protein in mice skin transplantation model

目的研究环孢素A（CsA）联合IL-2融合蛋白对小鼠移植术后乙肝疫苗的体液免疫反应影响，寻求肝移植术后预防乙型肝炎的有效方法。方法将C57BL／6小鼠40只，分为实验组、对照组和空白组，未免疫组，每组10只。实验组、对照组行皮肤移植后（DBA小鼠为供体），实验组给予CsA（30mg／kg，腹腔内注射）＋IL-2融合蛋白，对照组只给予CsA，空白组只行皮肤移植，3组均给予乙肝疫苗安在时，未免疫组不作任何处理。14d后测定各组乙肝抗体滴度水平、IL4、IL-10、IL-2、IFN-γ水平，流式细胞测定各组淋巴组织中滤泡辅助T细胞（foUicularhelperTcell，Tfh）的比例及应用RT-PCR测定各组淋巴组织中IL-21和叉状头转录因子FoxP3的表达。结果实验组移植术后14d乙肝抗体滴度明显高于对照组（F=29．886，P=0．010），皮肤移植物的存活时间也明显长于对照组（F=29．772，P=0．011），ELISA测定血清Th2类因子IL4，IL-10的水平实验组明显低于对照组（F=42．102，P=0．009；F=23．734，P=0．015），Thl类因子IL-2和IFN．1水平明显高于对照组（F=18．156，P=0．0020；F=90．042，P=0．003）。实验组混合淋巴细胞RT—PCR测定IL-21、FoxP3的表达水平明显高于对照组（F=9．784，P=0．048；F=27．883，P=0．012）。结论CsA联合IL-2融合蛋白能够增强乙肝疫苗的抗体滴度，同时能够延长小鼠皮肤移植物的存活时间，可能与促进IL-21及FoxP3基因的表达有关。

Objective To study the effect on humoral immunity with combination of CsA and IL-2 fusion protein. Methods Forty C57/B6 mice were evenly divided into four groups, after receiving skin graft from DBA mouse. Mice in the experimental group was given CsA（ 30 mg/kg, ip）plus IL-2/Fc （1μg, ip） while the control group was only given CsA, each group was given HBV vaccine after skin graft surgery （2 μg, ira） , while blank group was only given vaccine after skin transplantation. The fourth group were left intact. Fourteen days later, the level of HBSAb, IL-4, IL-10, IFN-Y, IL-2 were measured with ELISA and IL-21 and FoxP3 expression level and Tfh percentage of mixed lymphocytes detected. Results The HBSAb level in experimental group is significantly higher than that in the control group and the survival time of skin graft is longer than that in the control group （ F = 29. 886, P = 0. 010 ; F = 29. 772, P = 0. 011 ）. IL-2, IFN-Y are significantly higher than that in the control group （ F = 18. 156, P = 0. 0020 ; F = 90. 042, P = 0. 003）, but the Th2 cytokines such as IL-4, IL-10 are lower（ F = 42. 102, P = 0. 009 ; F = 23. 734, P = 0. 015 ）. The expression level of both IL-21 and FoxP3 are significantly higher than control group（ F = 9. 784, P = 0. 048 ; F = 27. 883, P = 0. 012）. Conclusions Combination of CsA and IL-2 fusion protein can significantly enhance the immunogenicity of HBV vaccine and prolong graft survival time. It may be related to the higher expression level of IL-21 and FoxP3.