Walmsley A M, Alvarez M L, Jin Y, Kirk D D, Lee S M, Pinkhasov J, Rigano M M, Arntzen C J, Mason H S
Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14850, USA.
Plant Cell Rep. 2003 Jun;21(10):1020-6. doi: 10.1007/s00299-003-0619-4. Epub 2003 Apr 11.
Epitopes often require co-delivery with an adjuvant or targeting protein to enable recognition by the immune system. This paper reports the ability of transgenic tomato plants to express a fusion protein consisting of the B subunit of the Escherichia coli heat-labile enterotoxin (LTB) and an immunocontraceptive epitope. The fusion protein was found to assemble into pentamers, as evidenced by its ability to bind to gangliosides, and had an average expression level of 37.8 microg g(-1) in freeze-dried transgenic tissues. Processing of selected transgenic fruit resulted in a 16-fold increase in concentration of the antigen with minimal loss in detectable antigen. The species-specific nature of this epitope was shown by the inability of antibodies raised against non-target species to detect the LTB fusion protein. The immunocontraceptive ability of this vaccine will be tested in future pilot mice studies.
表位通常需要与佐剂或靶向蛋白共同递送，才能被免疫系统识别。本文报道了转基因番茄植株表达由大肠杆菌不耐热肠毒素（LTB）的B亚基和免疫避孕表位组成的融合蛋白的能力。融合蛋白被发现能组装成五聚体，这可通过其与神经节苷脂结合的能力得到证明，并且在冻干的转基因组织中的平均表达水平为37.8微克/克。对选定的转基因果实进行加工后，抗原浓度增加了16倍，而可检测抗原的损失最小。针对非靶标物种产生的抗体无法检测到LTB融合蛋白，这表明了该表位的物种特异性。这种疫苗的免疫避孕能力将在未来的小鼠试点研究中进行测试。
