Cholera toxin has been engineered into rice. - GreenMedInfo Summary
Expression of cholera toxin B subunit in transgenic rice endosperm.
Mol Biotechnol. 2008 Nov;40(3):261-8. Epub 2008 Jul 10. PMID: 18618297
Department of Biochemistry and Food Technology, Budapest University of Technology and Economics, Budapest, Hungary.
The synthetic cholera toxin B subunit (CTB) gene, modified according to the optimized codon usage of plant genes, was introduced into a plant expression vector and expressed under the control of the Bx17 HMW (high molecular weight) wheat endosperm-specific promoter containing an intron of the rice act1. The recombinant vector was transformed into rice plants using a biolistic-mediated transformation method. Stable integration of the synthetic CTB gene into the chromosomal DNA was confirmed by PCR amplification analysis. A high level of CTB (2.1% of total soluble protein) was expressed in the endosperm tissue of the transgenic rice plants. The synthetic CTB produced only in the rice endosperm demonstrated strong affinity for G(M1)-ganglioside, thereby suggesting that the CTB subunits formed an active pentamer. The successful expression of CTB genes in transgenic plants makes it a powerful tool for the development of a plant-derived edible vaccine.