靶向阻断转化生长因子-β信号通路对肿瘤特异性细胞毒性T淋巴细胞的影响  

Effect of blocking the transforming growth factor-beta signaling pathway on tumor-specific cytotoxic T lymphocytes

作　　者：田丰[1] 周凯[1] 车晓玲[2] 傅点[1] 程文[1] 周文泉[1] 张征宇[1] 秦卫军[3] 王龙信[1] 

机构地区：[1]南京军区南京总医院泌尿外科,南京医学博士210002 [2]浙江省衢州市人民医院肿瘤科,衢州324000 [3]第四军医大学附属西京医院泌尿外科,西安710032

出　　处：《医学研究生学报》2015年第3期240-244,共5页Journal of Medical Postgraduates

基　　金：国家自然科学基金(81472392;81372741);南京军区南京总医院科研基金(2013030)

摘　　要：目的细胞毒性T淋巴细胞(cytotoxic T lymphocyte,CTL)是体内杀伤肿瘤的最终效应细胞,但其免疫功能会被肿瘤分泌的转化生长因子β(transforming growth factorβ,TGF-β)所抑制,文中观察靶向阻断TGF-β信号通路对肿瘤特异性CTL的影响。方法利用包涵修饰过的TGF-βⅡ型受体(transforming growth factorβreceptor typeⅡ,TβRⅡ)质粒的逆转录病毒载体,转染经DC激活的小鼠肾癌Renca细胞敏感的CTL(tumor pulsed CTL,TP-CTL),获得对TGF-β不敏感而肿瘤特异性的CTL(TβRⅡDN-CTL),Western blot检测Smad-2的磷酸化情况,观察TGF-β对CTL体外增殖抑制情况,将TβRⅡDN-CTL与未阻断TGF-β信号通路TP-CTL分别与相关及无关肿瘤细胞共同孵育,应用51Cr释放实验测定其细胞毒作用,将已成瘤的动物模型分为TP-CTL组和TβRⅡDN-CTL组分别尾静脉过继性注射TP-CTL及TβRⅡDN-CTL,ELISA法检测小鼠体内IL-2和IFN-γ水平。结果 TβRⅡDN-CTL组对TGF-β增殖抑制率明显低于TP-CTL组(65.96%vs 2.08%,P<0.01);在效靶比为100∶1时,TβRⅡDN-CTL组较TP-CTL组显著提高免疫小鼠CTL的特异性杀伤作用[(50.40±4.48)%vs(17.70±1.42)%,P<0.01],而动物模型血浆中TβRⅡDN-CTL组较TP-CTL组的IL-2、IFN-γ水平也显著升高(P<0.01)。结论阻断肿瘤敏感的CTL的TGF-β信号通路可以克服肿瘤的免疫抑制作用,提高CTL对肿瘤的杀伤效率。Objective Cytotoxic T lymphocytes （ CTLs） are final effect tumor-killer cells in the body and their immune func-tion can be suppressed by the transforming growth factor-beta （ TGF-β） secreted from the tumor .We observed the effect of blocking the TGF-βsignaling pathway on tumor-specific CTLs. Methods Tumor lysate-pulsed CTLs （TP-CTLs） were activated to be sensitive to mouse renal cancer cells with dendritic cells and transfected with a retrovirus containing dominant -negative TGF-βtype Ⅱ receptor （ TβRⅡDN） for isolation of TGF-β-insensitive tumor-specific TβRⅡDN-CTLs.Western blot was used to measure the level of phos-phorylated Smad-2 and evaluate the inhibitory effect of TGF-βon the proliferation of CTLs .The cytotoxic effect of TGF-βwas detected by 51 Cr releasing test , and the levels of serum IL-2 and INF-γin the mouse model determined by ELISA . Results TGF-βshowed a significantly lower rate of inhibition on the proliferation of the TβRⅡDN-CTLs than on that of the TP-CTLs （2.08%vs 65.96%, P〈0.01）.In the effect-target ratio of 100∶1, the cytotoxic effect of TGF-βon the TβRⅡDN-CTLs was markedly higher than that on the TP-CTLs （[50.4 ±4.48]%vs [17.7 ±1.42]%, P〈0.01）, and so were the levels of serum IL-2 （[1541.05 ±36.75] pg/mL vs

关 键 词：转化生长因子Β 细胞毒性T淋巴细胞 免疫治疗 肾癌 

分 类 号：R730.5[医药卫生—肿瘤]