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
出处
《医学研究生学报》
CAS
北大核心
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)
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
Transforming growth factor beta
Cytotoxic T lymphocyte
Immunotherapy
Renal carcinoma
