B7基因修饰的肿瘤细胞诱导抗大肠癌主动免疫

目的：研究Ｂ７基因修饰的肿瘤细胞诱导抗大肠癌ＣＴＬ的活化。方法：采用电击法将Ｂ７基因导入小鼠大肠癌细胞ＣＭＴ９３，Ｇ４１８筛选阳性克隆，免疫组化显示Ｂ７分子有高效表达，Ｂ７，ＣＭＴ９３（ＣＭＴ９３－Ｂ７）接种于Ｃ５７ＢＬ／６小鼠背部皮下，其致瘤性显著下降，ＣＭＴ９３－Ｂ７致敏的小鼠对野生型瘤细胞具有免疫保护作用；用ＣＭＴ９３和ＣＭＴ９３－Ｂ７细胞分别经腹腔免疫小鼠，得到腹腔浸润淋巴细胞及致敏脾细胞

Anti-colonic Cancer Active Immunity Induced by B7 Gene Modified Tumor Cells

Objective: To study the activation of CTLs against colorectal cancer cells induced by B7 gene modified tumor cells Methods: B7 gene was transfected into mouse colorectal cancer CMT93 cells The positive clones were selected by G418 The immunohistochemistry showed that B7 molecules were highly expressed The B7 CMT93 (CMT93-B7) cells were inoculated into the back of C57B1/6 mice subcutaneously and then it decreased their tumorigenicity greatly (P<0 01) The CMT93-B7 cell sensitized mice obtained the protective immune activity against the rechanllenge of wild type CMT93 cells (P<0 05) The abdominal infiltrating lymphocytes and sensitizing spleen cells were obtained from the mice who were immunized with CMT93-B7 or wild type CMT93 cells intraperitoneally , and the cytotoxicity of these CTLs against tumor cells was detected by MTT assay Results: It showed that the cytotoxicity of CTL induced by CMT93-B7 against CMT93 was significantly higher than the cytotoxicity of CTL induced by wild CMT93 against the same target cells (P<0 05) Conclusion: The results suggest that the B7 molecules can effectively promote the activity of CTL against colorectal cancer cells, and B7 molecules play an important role in CTL cytotoxicity function as well