超抗原金黄色葡萄球菌肠毒素A锚定的膜表达热休克蛋白70的肠癌瘤苗的抗癌治疗作用研究

目的 研制超抗原金黄色葡萄球菌肠毒素A（SEA）锚定的膜表达热休克蛋白（HSP）70的肠癌细胞瘤苗，研究其抗肿瘤治疗作用。方法 以先期实验制备的膜表达HSP70肠癌细胞株CT26。扩增后以本研究组早先研制的跨膜型SEA蛋白转染法锚定肠癌细胞，灭活并制备双重修饰的肠癌细胞瘤苗。观察瘤苗在体外对小鼠脾淋巴细胞的增殖刺激效应；在BALB／c小鼠结直肠癌移植模型中观察瘤苗的抗癌治疗作用：瘤体生长抑制和荷瘤鼠的生存时间；并同时检测实验鼠的自然杀伤细胞（NK）和细胞毒淋巴细胞（CTL）活性。结果 激光共聚焦显微镜和流式细胞术均证明瘤苗细胞的双重修饰：SEA锚定，HSPT0表达并结合在瘤苗细胞膜表面。比较对照。SEA锚定或膜表达HSPT0的单一修饰瘤苗均显示出较高的鼠淋巴细胞增殖刺激效应；较强的瘤体生长抑制。并使荷瘤鼠的生存时间延长。而SEA锚定的膜表达HSP70的双重修饰瘤苗比单一修饰瘤苗，有着更高的淋巴增殖刺激效应，更强的瘤体生长抑制作用，并使荷瘤鼠的生存时间进一步延长。结论 成功研制了超抗原SEA锚定的膜表达HSPT0的肠癌细胞瘤苗，此双重修饰瘤苗对结直肠癌荷瘤小鼠有更强的治疗作用。

Anticancer therapeutic effect of SEA-linked and membrane-bound HSP70-expressed intestine carcinoma vaccine

Objective To develop a novel dual-modified vaccine,the superantigen-linked intestine- carcinoma cells expressing membrane-bound heat shock protein 70(HSP70),and further examine its anticancer therapeutic effect.Methods The pre-established intestine carcinoma CT26 line expressing membrane-bound heat shock protein 70 (HSP70) was amplified and incubated with superantigen fusion protein,staphylococcal enterotoxin A (SEA) fused with transmembrane sequence (SEA-TM),thereby the dual-modified vaccine was prepared after inactivation.The anticancer efficacy of the vaccine was examined. Results The laser confocal microscopy and flow cytometry showed that there co-existed much HSP70 and SEA on the vaccine membrane surface.Both of the single-modified vaccines,the SEA-linked vaccine and membrane-bound-HSP70-expressing one,displayed marked tumor suppression,a prolonged survival period, augmented lymphocyte proliferation and higher NK and CTL activity in the vaccinated mice when compared with its counterpart.Furthermore,the dually modified vaccine induced lymphocyte proliferation most intensively,generated the highest NK and CTL activity as well as the strongest tumor rejection in the vaccinated mice.The survival period of the mice was further prolonged.Conclusion A new vaccine, SEA-linked and membrane-bound-HSP70-expressing intestine-carcinoma cells can induce more potent anticancer immunity and produce better therapeutic efficacy.