Yu J, Langridge W H
Department of Biochemistry and Center for Molecular Biology and Gene Therapy, Loma Linda University, Loma Linda, CA 92350, USA.
Nat Biotechnol. 2001 Jun;19(6):548-52. doi: 10.1038/89297.
Cholera toxin (CT) B and A2 subunit complementary DNAs (cDNAs) were fused to a rotavirus enterotoxin and enterotoxigenic Escherichia coli fimbrial antigen genes and transferred into potato. Immunoblot and enzyme-linked immunosorbent assay (ELISA) results indicated that the fusion antigens were synthesized in transformed tuber tissues and assembled into cholera holotoxin-like structures that retained enterocyte-binding affinity. Orally immunized mice generated detectable levels of serum and intestinal antibodies against the pathogen antigens. Elevated levels of interleukin 2 (IL2) and interferon gamma (INFgamma) detected in immunogen-challenged spleen cells from the immunized mice indicated the presence of a strong Th1 immune response to the three plant-synthesized antigens. This result was supported by flow cytometry analysis of immunized mouse spleen cells that showed a significant increase in CD4+ lymphocyte numbers. Diarrhea symptoms were reduced in severity and duration in passively immunized mouse neonates following rotavirus challenge. The results suggest that food plants can function as vaccines for simultaneous protection against infectious virus and bacterial diseases.
霍乱毒素（CT）B亚基和A2亚基互补DNA（cDNA）与轮状病毒肠毒素及产肠毒素大肠杆菌菌毛抗原基因融合，并转入马铃薯中。免疫印迹和酶联免疫吸附测定（ELISA）结果表明，融合抗原在转化的块茎组织中合成，并组装成具有肠上皮细胞结合亲和力的霍乱全毒素样结构。经口服免疫的小鼠产生了可检测水平的针对病原体抗原的血清抗体和肠道抗体。在经免疫的小鼠中，对免疫原激发的脾细胞检测到白细胞介素2（IL2）和干扰素γ（INFγ）水平升高，表明对三种植物合成抗原存在强烈的Th1免疫反应。对经免疫的小鼠脾细胞进行的流式细胞术分析支持了这一结果，该分析显示CD4 +淋巴细胞数量显著增加。在轮状病毒攻击后，被动免疫的新生小鼠腹泻症状的严重程度和持续时间有所减轻。结果表明，食用植物可作为疫苗，同时预防传染性病毒和细菌性疾病。
