The Biodesign Institute and College of Technology and Innovation, Arizona State University, Tempe, AZ, USA.
Plant Biotechnol J. 2012 Jan;10(1):95-104. doi: 10.1111/j.1467-7652.2011.00649.x. Epub 2011 Aug 26.
Pharmaceutical protein production in plants has been greatly promoted by the development of viral-based vectors and transient expression systems. Tobacco and related Nicotiana species are currently the most common host plants for the generation of plant-made pharmaceutical proteins (PMPs). Downstream processing of target PMPs from these plants, however, is hindered by potential technical and regulatory difficulties owing to the presence of high levels of phenolics and toxic alkaloids. Here, we explored the use of lettuce, which grows quickly yet produces low levels of secondary metabolites and viral vector-based transient expression systems to develop a robust PMP production platform. Our results showed that a geminiviral replicon system based on the bean yellow dwarf virus permits high-level expression in lettuce of virus-like particles (VLP) derived from the Norwalk virus capsid protein and therapeutic monoclonal antibodies (mAbs) against Ebola and West Nile viruses. These vaccine and therapeutic candidates can be readily purified from lettuce leaves with scalable processing methods while fully retaining functional activity. Furthermore, this study also demonstrated the feasibility of using commercially produced lettuce for high-level PMP production. This allows our production system to have access to unlimited quantities of inexpensive plant material for large-scale production. These results establish a new production platform for biological pharmaceutical agents that are effective, safe, low cost, and amenable to large-scale manufacturing.
植物源药用蛋白的生产在病毒载体和瞬时表达系统发展的推动下取得了巨大进展。烟草和相关的黄花烟属植物是目前用于生产植物源药用蛋白（PMP）的最常见的宿主植物。然而，由于存在高水平的酚类物质和有毒生物碱，这些植物来源的目标 PMP 的下游加工受到潜在技术和监管困难的阻碍。在这里，我们探索了使用生长迅速但次生代谢物和基于病毒载体的瞬时表达系统产量较低的生菜来开发强大的 PMP 生产平台。我们的结果表明，基于豆黄花叶病毒的双生病毒复制子系统允许高水平表达来自诺如病毒衣壳蛋白的病毒样颗粒（VLP）和针对埃博拉病毒和西尼罗河病毒的治疗性单克隆抗体（mAb）。这些疫苗和治疗候选物可以通过可扩展的处理方法从生菜叶片中轻易地纯化出来，同时完全保留其功能活性。此外，这项研究还证明了使用商业生产的生菜进行高水平 PMP 生产的可行性。这使得我们的生产系统能够获得大量廉价的植物材料，用于大规模生产。这些结果为有效、安全、低成本且适合大规模生产的生物药物制剂建立了一个新的生产平台。
