Conry R M, LoBuglio A F, Wright M, Sumerel L, Pike M J, Johanning F, Benjamin R, Lu D, Curiel D T
Department of Medicine, University of Alabama at Birmingham 35294-3300.
Cancer Res. 1995 Apr 1;55(7):1397-400.
We have constructed mRNA transcripts encoding luciferase and human carcinoembryonic antigen (CEA) which are capped, polyadenylated, and stabilized by human beta-globin 5' and 3' untranslated regions. The mRNA construct encoding human CEA directed CEA expression in mouse fibroblasts in vitro following liposome-mediated transfection. The luciferase encoding mRNA transcripts mediated luciferase expression in vivo following i.m. injection. Based on the demonstration of protein expression in vitro and in vivo, the feasibility of using such a vector as a tumor vaccine was examined. In this pilot study, seven mice received 50 micrograms mRNA transcripts encoding CEA twice weekly for 5 weeks by i.m. injection followed by challenge with syngeneic, CEA-expressing tumor cells. This dose and schedule "primed" an immune response to CEA. Five of seven mRNA-immunized mice demonstrated anti-CEA antibody 3 weeks after tumor challenge whereas control mice had no evidence of antibody response. This strategy might be particularly useful to induce an immune response to a proto-oncogene product or growth factor which poses a risk of inducing malignant transformation consequent to prolonged protein expression.
我们构建了编码荧光素酶和人癌胚抗原（CEA）的mRNA转录本，这些转录本经过加帽、聚腺苷酸化处理，并通过人β-珠蛋白5'和3'非翻译区实现稳定化。编码人CEA的mRNA构建体在脂质体介导的转染后，可在体外小鼠成纤维细胞中指导CEA表达。编码荧光素酶的mRNA转录本在肌肉注射后可在体内介导荧光素酶表达。基于在体外和体内均证实了蛋白表达，我们研究了使用这种载体作为肿瘤疫苗的可行性。在这项初步研究中，7只小鼠每周两次通过肌肉注射接受50微克编码CEA的mRNA转录本，持续5周，随后用同基因的、表达CEA的肿瘤细胞进行攻击。这个剂量和方案“引发”了针对CEA的免疫反应。7只接受mRNA免疫的小鼠中有5只在肿瘤攻击3周后出现了抗CEA抗体，而对照小鼠没有抗体反应的迹象。这种策略对于诱导针对原癌基因产物或生长因子的免疫反应可能特别有用，因为长时间的蛋白表达可能会引发恶性转化。
