人诺如病毒衣壳蛋白的密码子优化及在昆虫细胞中的表达

Codon Optimization and Expression of Norovirus Capsid Proteins in Insect Cells

诺如病毒是当前在中国引起腹泻的主要人类杯状病毒,其中GGII4、GGII1和GGII3等为主要的流行遗传型。为了提高诺如病毒衣壳蛋白的表达量,我们将其编码基因按杆状病毒喜用密码子进行了优化设计和人工合成。以杆状病毒为载体,在昆虫细胞Sf9中对密码子优化后的诺如病毒GGII1、GGII3、GGII4和GGII7型衣壳蛋白基因进行了表达。结果显示,与野生型基因相比,经过密码子优化的基因在昆虫细胞中的表达水平得到明显提高,并可装配成病毒样颗粒。重组杆状病毒感染Sf9细胞72h表达量达到高峰。这些结果的取得,为我国人杯状病毒免疫学检测试剂和疫苗的开发打下了基础。

Norovirus is currently the predominant human calicivirus that causes diarrhea in China. Among the documented noroviruses, types 4, 1 and 3 are the leading genetics groups. In order to improve the expression of the norovirus capsid, we re-designed and artificially synthesized the full-length norovirus capsid genes by adopting the codons preferentially used in insect cells without any changing of the amino acid sequences. The codon optimized capsid genes of Norovirus GGⅡ1, GGⅡ3, GGⅡ4 and GGⅡ7 were respectively expressed in insect cell Sf9 using baculovirus vector. The results showed that, compared to the wild type, the expression levels of the optimized genes were remarkably increased. The assembly of norovims-like particles was observed in the Sf9 cells infected with the recombinant baculovirus expressing the capsid protein. The recombinant capsid expression peaked at 72h post infection of the recombinant baculoviruses. The results obtained in the present work will lay a foundation for the development of the immunological diagnostic reagents as well as vaccines for human caliciviruses.