Smith Mark L, Richter Lizabeth, Arntzen Charles J, Shuler Michael L, Mason Hugh S
Department of Chemical Engineering, Cornell University, Ithaca, NY 14853, USA.
Vaccine. 2003 Sep 8;21(25-26):4011-21. doi: 10.1016/s0264-410x(03)00268-8.
Several subunit vaccine antigens have been successfully expressed in plants and recently the hepatitis B surface antigen (HBsAg), expressed in potatoes, was shown to be orally immunogenic in animal studies. However, to date, a detailed analysis of the plant-derived antigen is lacking. Herein, we comprehensively characterize the structure and post-translational processing of HBsAg from potato tuber and two plant cell suspension cultures. The HBsAg was found to accumulate intracellularly as tubular structures, with a complex size distribution, differing substantially from the virus-like particle (VLP) preparations of the current commercial vaccines. Extensive disulfide-bond cross-linking, which is important for immunogenicity, was evident and 21-37% of total HBsAg protein displayed epitopes which correlate with vaccine potency. The significance of these results with regard to the production of cost-effective orally delivered vaccines is discussed.
几种亚单位疫苗抗原已在植物中成功表达，最近在土豆中表达的乙肝表面抗原（HBsAg）在动物研究中显示出具有口服免疫原性。然而，迄今为止，缺乏对植物源抗原的详细分析。在此，我们全面表征了来自马铃薯块茎和两种植物细胞悬浮培养物的HBsAg的结构和翻译后加工过程。发现HBsAg作为管状结构在细胞内积累，其大小分布复杂，与当前商业疫苗的病毒样颗粒（VLP）制剂有很大不同。广泛的二硫键交联对免疫原性很重要，这一点很明显，并且总HBsAg蛋白的21%-37%显示出与疫苗效力相关的表位。讨论了这些结果对于生产具有成本效益的口服疫苗的意义。
