Marquet-Blouin E, Bouche F B, Steinmetz A, Muller C P
Institut de Biologie Moléculaire des Plantes-CNRS, 12 rue du Général Zimmer, 67084 Strasbourg, France.
Plant Mol Biol. 2003 Mar;51(4):459-69. doi: 10.1023/a:1022354322226.
Although edible vaccines seem to be feasible, antigens of human pathogens have mostly been expressed in plants that are not attractive for human consumption (such as potatoes) unless they are cooked. Boiling may reduce the immunogenicity of many antigens. More recently, the technology to transform fruit and vegetable plants have become perfected. We transformed carrot plants with Agrobacterium tumefaciens to generate plants (which can be eaten raw) transgenic for an immunodominant antigen of the measles virus, a major pathogen in man. The hemagglutinin (H) glycoprotein is the principle target of neutralizing and protective antibodies against measles. Copy numbers of the H transgene were verified by Southern blot and specific transcription was confirmed by RT-PCR. The H protein was detected by western blot in the membrane fraction of transformed carrot plants. The recombinant protein seemed to have a 8% lower molecular weight than the viral protein. Although this suggests a different glycosylation pattern, proper folding of the transgenic protein was confirmed by conformational-dependent monoclonal antibodies. Immunization of mice with leaf or root extracts induced high titres of IgG1 and IgG2a antibodies that cross-reacted strongly with the measles virus and neutralized the virus in vitro. These results demonstrate that transgenic carrot plants can be used as an efficient expression system to produce highly immunogenic viral antigens. Our study may pave the way towards an edible vaccine against measles which could be complementary to the current live-attenuated vaccine.
尽管可食用疫苗似乎可行，但人类病原体的抗原大多在对人类缺乏食用吸引力的植物（如土豆）中表达，除非经过烹饪。煮沸可能会降低许多抗原的免疫原性。最近，转化水果和蔬菜植物的技术已臻完善。我们用根癌农杆菌转化胡萝卜植株，以培育出对麻疹病毒（人类主要病原体）的一种免疫显性抗原呈转基因状态的植株（可生食）。血凝素（H）糖蛋白是抗麻疹中和性及保护性抗体的主要靶标。通过Southern印迹法验证了H转基因的拷贝数，并通过RT-PCR证实了特异性转录。通过蛋白质免疫印迹法在转化胡萝卜植株的膜组分中检测到了H蛋白。重组蛋白的分子量似乎比病毒蛋白低8%。尽管这表明糖基化模式不同，但通过构象依赖性单克隆抗体证实了转基因蛋白的正确折叠。用叶片或根提取物免疫小鼠可诱导产生高滴度的IgG1和IgG2a抗体，这些抗体与麻疹病毒强烈交叉反应并在体外中和该病毒。这些结果表明，转基因胡萝卜植株可作为一种高效表达系统来生产高免疫原性的病毒抗原。我们的研究可能为开发一种针对麻疹的可食用疫苗铺平道路，这种疫苗可作为当前减毒活疫苗的补充。
