Khattak Shahryar, Darai Gholamreza, Rösen-Wolff Angela
University Clinic Carl Gustav Carus, Department of Pediatrics, Technical University Dresden, Germany.
Virus Genes. 2004 Aug;29(1):109-16. doi: 10.1023/B:VIRU.0000032794.24032.72.
Transgenic plants expressing foreign genes are suitable systems for the production of relevant immunogens in high amounts that can be used to develop a new generation of vaccines against a variety of infectious diseases. Transgenic tobacco and potato plants expressing the nucleocapsid protein of Hantavirus serotype Puumala were generated and established. Puumala virus is a human pathogen causing hemorrhagic fever with renal syndrome. To investigate oral immunogenicity of the nucleocapsid protein expressed in plants, mice were fed with tubers of transgenic potato and tobacco leaf powder. The resulting antibodies were compared among groups. No significant difference could be found between the control group and the groups of animals, which had been fed with the recombinant plants expressing Puumala nucleocapsid protein. Hence, the effect of different enzymes, present in the gastro-intestinal tract, on the plant-derived antigen was investigated. It was found that the recombinant viral protein was completely degraded by trypsin and/or pepsin. In conclusion, the enzymes present in the intestine can degrade major antigenic domains of antigens, expressed in transgenic plants, thus preventing the induction of antibodies against the ingested viral antigen.
表达外源基因的转基因植物是大量生产相关免疫原的合适系统，这些免疫原可用于开发针对多种传染病的新一代疫苗。表达普马拉型汉坦病毒核衣壳蛋白的转基因烟草和马铃薯植株已被培育并建立。普马拉病毒是一种导致肾综合征出血热的人类病原体。为了研究植物中表达的核衣壳蛋白的口服免疫原性，用转基因马铃薯块茎和烟草叶粉喂养小鼠。比较了各实验组产生的抗体。在对照组与喂食表达普马拉核衣壳蛋白的重组植物的动物组之间未发现显著差异。因此，研究了胃肠道中不同酶对植物源抗原的作用。发现重组病毒蛋白被胰蛋白酶和/或胃蛋白酶完全降解。总之，肠道中的酶可降解转基因植物中表达的抗原的主要抗原结构域，从而阻止针对摄入的病毒抗原产生抗体。
