Tacket C O, Mason H S, Losonsky G, Clements J D, Levine M M, Arntzen C J
Center for Vaccine Development, Department of Medicine, University of Maryland School of Medicine, Baltimore 21201, USA.
Nat Med. 1998 May;4(5):607-9. doi: 10.1038/nm0598-607.
Compared with vaccine delivery by injection, oral vaccines offer the hope of more convenient immunization strategies and a more practical means of implementing universal vaccination programs throughout the world. Oral vaccines act by stimulating the immune system at effector sites (lymphoid tissue) located in the gut. Genetic engineering has been used with variable success to design living and non-living systems as a means to deliver antigens to these sites and to stimulate a desired immune response. More recently, plant biotechnology techniques have been used to create plants which contain a gene derived from a human pathogen; the resultant plant tissues will accumulate an antigenic protein encoded by the foreign DNA. In pre-clinical trials, we found that antigenic proteins produced in transgenic plants retained immunogenic properties when purified; if injected into mice the antigen caused production of protein-specific antibodies. Moreover, in some experiments, if the plant tissues were simply fed to mice, a mucosal immune response occurred. The present study was conducted as a proof of principle to determine if humans would also develop a serum and/or mucosal immune response to an antigen delivered in an uncooked foodstuff.
与注射式疫苗接种相比，口服疫苗为更便捷的免疫策略带来了希望，也为在全球实施普及疫苗接种计划提供了更切实可行的手段。口服疫苗通过刺激位于肠道的效应部位（淋巴组织）的免疫系统来发挥作用。基因工程已被用于设计活的和非活的系统，以此作为将抗原递送至这些部位并激发所需免疫反应的一种手段，不过成效各异。最近，植物生物技术技术已被用于培育含有源自人类病原体基因的植物；由此产生的植物组织会积累由外源DNA编码的抗原蛋白。在临床前试验中，我们发现转基因植物产生的抗原蛋白在纯化后仍保留免疫原性；如果将该抗原注射到小鼠体内，会引发蛋白质特异性抗体的产生。此外，在一些实验中，如果将植物组织直接喂给小鼠，会引发黏膜免疫反应。本研究作为一项原理验证进行，以确定人类是否也会对未经烹饪的食物中递送的抗原产生血清和/或黏膜免疫反应。
