共刺激分子B7-2对小鼠肝癌治疗作用的实验研究

目的 :应用转染有小鼠B7- 2基因片段的肝癌细胞 ,建立小鼠肝癌模型 ,观察小鼠肿瘤生长和消退情况 ,研究共刺激分子B7- 2对肿瘤的免疫治疗作用。方法 :建立BALB/c小鼠转B7- 2基因肝癌细胞株H2 2 /B7- 2 ,细胞计数法测定肿瘤细胞体外增殖能力 ;BALB/c鼠皮下接种H2 2 /B7- 2及野生型H2 2细胞H2 2 /Wt,以空载体转染细胞H2 2 /neo为对照 ,建立小鼠肝癌模型 ,观察小鼠成瘤期、荷瘤小鼠存活期及肿瘤结节大小 ;同源淋巴细胞肿瘤细胞混合培养 (MTLCs)后测定淋巴细胞增殖指数和CTLs活性 ,同时测定培养上清IL -2、IFNγ ,研究B7- 2分子的抗肿瘤免疫效果。结果 :细胞在体外增殖能力一致 (P =0 .782 ) ;当接种不同肿瘤细胞后 ,三组动物都发生肿瘤 ,接种H2 2 /B7- 2组肿瘤形成有迟发性 ,并在接种 18d后肿瘤都开始缩小 ,但最终不会完全消失 ;接种H2 2 /Wt和H2 2 /neo组动物肿瘤呈进行性生长。H2 2 /B7- 2在体外刺激淋巴细胞增殖和诱导CTLs的能力明显强于对照细胞 (P <0 .0 5 )。结论 :共刺激分子B7- 2能增强肝癌细胞的免疫原性 ,它在抗肿瘤早期发挥作用。用其治疗肝癌是有效的 ,但不能介导完全和长期的抗肿瘤效应。

EXPERIMENTAL STUDYT ON THE ROLE OF B7-2 COSTIMULATION MOLECULE AGAINST MOUSE HEPATOCELLULASR CARCINOMA

Objective:To study the effectof B7-2 molecule on antitumor immunity against poorly immunogenic H22 mouse hepatocellular carcinoma (HCC) cells.Methods:We introduce mouse B7-2 gene into H22 cells. The animal model of BALB/c mice was established by injected with growing transfected cell lines for further research. The effect of gene transduction on antimmor immunity was studied. B7-2 molecules expression of H22 was detected by flow cytometry(FCM). Lymphocyte proliferation was tested in vitro, and cytotoxic activity of CTL cells were evaluated by LDH assay; tumor size was measured and survival time was recorded.Results:In vivo, H22/B7-2 cells grew slower than H22/neo cells ( P <0.05) ,although there was no different in the growth rate of H22 variants in vitro. All the mice appeared inoculating rumor successfully, but the volum in H22/B7-2 group reduced drastically and survival days got prolonged compared with the control group after a certain day, and a stronger CTL activity and lymphocyte proliferation against H22/Wt cells were obtained after the use of B7-2 than that of the other two groups, showing the tumorigenicity of B7-2 transfectant in BALB/c mice was decreased significantly in vivo experiment.Conclusions:B7-2 co-stimulation is able to enhance immunogenicity of HCC cells, although it can't mediate a long-lasting and complete antitumor immunity. It indicate that the combined B7-2 gene therapy is successful and these in vivo data will provide an experimental basis for gene-therapy and for furtherresearch of B7-gene therapy in hepatocellular carcinoma.