高强度聚焦超声联合单纯疱疹病毒胸苷激酶/丙氧鸟苷自杀基因治疗对VX2荷瘤兔免疫力的影响

Effect of high intensity focused ultrasound in combination with HSV-tk/GCV on immunity of rabbits with VX2 tumor

目的探讨高强度聚焦超声(high intensity focused ultrasound,HIUF)联合单纯疱疹病毒胸苷激酶/丙氧鸟苷(HSV-tk/GCV)治疗对VX2荷瘤兔的肿瘤免疫耐受和特异性抗肿瘤免疫的影响。方法将40只实验兔按随机数字表法分为对照组、肿瘤组、HIFU组和联合治疗组,每组10只,其中HIFU组给予HIFU单独治疗,联合组给予HIFU和HSV-tk/GCV联合治疗。于治疗后第13天流式细胞术检测各组兔外周血CD4+CD25+Treg(Treg)细胞的数量变化情况,ELISA法检测外周血血浆IL-10,TGF-β的浓度,MTT法检测兔脾淋巴细胞对VX2肿瘤细胞的体外杀伤活性。结果肿瘤组外周血Treg细胞数量[(8.30±0.69)%]、IL-10水平[(67.82±4.52)pg/ml]和TGF-β水平[(6.55±0.45)μg/ml]相对于对照组[(5.30±0.45)%、(54.58±3.53)pg/ml、(5.51±0.27)μg/ml]均显著升高(P<0.01);HIFU组Treg细胞数量[(7.00±0.56)%]、IL-10水平[(60.32±4.70)pg/ml]、TGF-β水平[(6.22±0.19)μg/ml]明显低于肿瘤组(P<0.01,P<0.05);联合治疗组Treg细胞数量[(6.40±0.72)%]和TGF-β水平[(5.86±0.31)μg/ml]低于HIFU组(P<0.05),而IL-10水平[(58.79±4.42)pg/ml]变化则无统计学意义(P>0.05)。杀伤实验显示HIFU组和联合治疗组脾淋巴细胞对VX2肿瘤细胞的杀伤活性分别为(31.62±3.09)%、(29.48±2.68)%,明显高于对照组[(13.94±2.45)%]和肿瘤组[(12.00±2.96)%](P<0.01),但联合治疗组和HIFU组的比较差异无统计学意义(P>0.05)。结论 HIFU联合HSV-tk/GCV治疗后,宿主肿瘤免疫耐受情况得到改善,特异性抗肿瘤免疫力增强。

Objective To study the effect of high intensity focused ultrasound（HIFU） in combination with HSV-tk/GCV on tumor immunological tolerance and specific anti-tumor immune of rabbits with XX2 tumor.Methods Forty experimental rabbits were randomly divided into control group,tumor-bearing group,HIFU treatment group and combined treatment group,10 in each group.Rabbits in HIFU treatment group were treated with HIFU alone and those in combined treatment group were treated with HIFU plus HSV-tk/GCV.Thirteen days after treatment,prevalence of CD4＋CD25＋Treg cells（Treg） in peripheral blood of each rabbit was detected by flow cytometry,levels of IL-10 and TGF-β in plasma were measured with ELISA,and in vitro killing activity of splenic lymphocytes on VX2 tumor cells was detected by MTT assay.Results The prevalence of Treg cells in peripheral blood and the levels of IL-10 and TGF-β were significantly higher in tumor-bearing group than in control group [（8.30±0.69）%,67.82±4.52 pg/ml and 6.55±0.45 μg/ml vs（5.30±0.45）%,54.58±3.53 pg/ml and 5.51±0.27 μg/ml,P0.01],and significantly lower in HIFU treatment group than in tumor-bearing group [（7.00±0.56）%,60.32±4.70 pg/ml and 6.22±0.19 μg/ml vs（8.30±0.69）%,67.82±4.52 pg/ml and 6.55±0.45 μg/ml,P0.01].The prevalence of Treg cells in peripheral blood and the level of TGF-β were lower in combined treatment group than in HIFU treatment group [（6.40±0.72）% and 5.86±0.31 μg/ml） with no significant difference observed in the level of IL-10 between the two groups（P0.05）.Killing test showed that the killing activities of HIFU treatment and combined treatment on VX2 tumor cells were（31.62±3.09）% and（29.48±2.68）%,respectively,which were significantly higher than those in control group and tumor-bearing group [（13.94±2.45）% and（12.00±2.96）%] with no significant difference observed between combined and HIFU treatment groups.Conclusion HIFU in combination with HSV-tk/GCV can improve the tumor immunological tolerance and specific anti-tumor immune of hosts.