Daemen T, Regts J, Holtrop M, Wilschut J
University of Groningen, Department of Medical Microbiology, Molecular Virology Section, Groningen, The Netherlands.
Gene Ther. 2002 Jan;9(2):85-94. doi: 10.1038/sj.gt.3301627.
We are developing immunization strategies against cervical carcinoma and premalignant disease, based on the use of recombinant Semliki Forest virus (SFV) encoding the oncoproteins E6 and E7 from high-risk human papilloma viruses (HPV). Thus far, protein-based, as well as genetic immunization studies have demonstrated low to moderate cellular immune responses against E6 and E7. To improve these responses, we modified the structure and expression level of the E6 and E7 proteins produced by the SFV vector. Specifically, a construct was generated encoding a fusion protein of E6 and E7, while furthermore a translational enhancer was included (enhE6,7). Infection of cells with recombinant SFV-enhE6,7 resulted in the production of large amounts of the E6,7 fusion protein. The fusion protein was more stable than either one of the separate proteins. Immunization of mice with SFV-enhE6,7 resulted in strong, long-lasting HPV-specific cytotoxic T lymphocyte responses. Tumor challenge experiments in mice demonstrated that immunization with SFV-enhE6,7 resulted in prevention of tumor outgrowth and subsequent protection against tumor re-challenge.
我们正在研发针对宫颈癌及癌前病变的免疫策略，该策略基于使用编码高危型人乳头瘤病毒（HPV）癌蛋白E6和E7的重组塞姆利基森林病毒（SFV）。到目前为止，基于蛋白质的免疫研究以及基因免疫研究均显示，针对E6和E7产生的细胞免疫反应为低到中等水平。为了增强这些反应，我们对SFV载体产生的E6和E7蛋白的结构及表达水平进行了修饰。具体而言，构建了一个编码E6和E7融合蛋白的基因，并进一步加入了一个翻译增强子（enhE6,7）。用重组SFV-enhE6,7感染细胞可产生大量的E6,7融合蛋白。该融合蛋白比单独的任何一种蛋白都更稳定。用SFV-enhE6,7免疫小鼠可产生强烈且持久的HPV特异性细胞毒性T淋巴细胞反应。小鼠肿瘤攻击实验表明，用SFV-enhE6,7免疫可预防肿瘤生长，并在后续抵抗肿瘤再次攻击。
