抗胃癌生物活性肽对荷胃癌裸鼠酯酶同工酶代谢的影响

本文观察了协同刺激分子B7-1某因导入小鼠EL-4淋巴瘤细胞后在小鼠体内诱导的抗瘤效应.结果表明,逆转录病毒(PLXSN)载体重组的小鼠B7-1基因表达质粒导入小鼠EL-4淋巴瘤细胞,经有限稀释法克隆后获得高表达的B7-1~ EL-4细胞.B7-1~ 瘤细胞的形态,体外增殖能力及MHC Ⅰ类分子表达水平与野生型肿瘤细胞无显著差别,但致瘤性显著降低,用野生型肿瘤致死剂量接种C57BL/6小鼠完全排斥.同时免疫原性明显增强,以X-线灭活的B7-1~ 肿瘤细胞免疫后小鼠获得了对随后致死剂量野生型细胞攻击的免疫保护作用.以X-线灭活的肿瘤细胞作为瘤苗进行实验性免疫治疗,对早期(接种7天)形成的肿瘤有一定的治疗效果,但时晚期(接种14天)肿瘤.B7-1和B7-1~ 瘤细胞都未显示出明显的治疗效果.上述结果提示肿瘤细胞表达B7-1分子可有效激发机体的抗肿瘤免疫应答.

Antitumor Immunity Elicited by B7-1 Gene Transfected EL-4 Lymphoma inVIVO

We have studied the effects of B7-1 on antitumor immunity induced in vivo by murine B7-1 gene transfected EL-4 lymphoma. At a lethal dose of wild - type(wt) or plasmid controlled (pc) B7-1 negative tumor cells. B7-1 gone transfected EL-4 cells inoculated in syngeneic mice were regressed. In contrast to the mice immunized with B7-1 tumor cells, immunization of mice with B7-l~EL-4 tumor cells showed significant protective effects against the sequence rechallenge of wt EL-4 tumor. Vaccination with X-irradiated B7-1 positive tumor cells at the early stage ( 7 days) after inoculation of wt EL-4 tumor cells showed some therapeutically effects but not at the late stage (14 days after inoculation). Vaccination with B7-l~ EL-4 tumor cells delayed the occurrence of wt EL-4 tumors and prolonged the survival period of tumor-bearing mice. Our results indicate that the transfcction of B7-1 into tumor cells can increase the immunogenicity of EL-4 tumor and improve host response to wt EL-4 lymphoma. Immunization with B7-1 positive tumors can elicit effective antitumor immunity.