Expression of cholera toxin B subunit in transgenic tomato plants.

Abstract

Cholera toxin, secreted by Vibrio cholerae, consists of A and B subunits. The latter binds to G(M1)-ganglioside receptors as a pentamer (approximately 55 kDa). Tomato plants were transformed with the gene encoding cholera toxin B subunit (ctxB) along with an endoplasmic reticulum retention signal (SEKDEL) under the control of the CaMV 35S promoter via Agrobacterium-mediated transformation. PCR and Southern analysis confirmed the presence of the ctxB gene in transformed tomato plants. Northern analysis showed the presence of the ctxB-specific transcript. Immunoblot assays of the plant-derived protein extract showed the presence of cholera toxin subunit B (CTB) with mobility similar to purified CTB from V. cholerae. Both tomato leaves and fruits expressed CTB at levels up to 0.02 and 0.04% of total soluble protein, respectively. The G(M1)-ELISA showed that the plant-derived CTB bound specifically to G(M1)-ganglioside receptor, suggesting that it retained its native pentameric form. This study forms a basis for exploring the utility of CTB to develop tomato-based edible vaccines against cholera.

• Authors: Dewal Jani, Laxman Singh Meena, Quazi Mohammad Rizwan-ul-Haq, Yogendra Singh, Arun K Sharma, Akhilesh K Tyagi
• Journal: Transgenic research (Transgenic Res) Vol. 11 Issue 5 Pg. 447-54 (Oct 2002) ISSN: 0962-8819 [Print] Netherlands
• PMID: 12437076 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA Primers
• RNA, Messenger
• Receptors, Cell Surface
• ganglioside receptor
• G(M1) Ganglioside
• Cholera Toxin

Topics

• Agrobacterium tumefaciens (genetics)
• Blotting, Northern
• Blotting, Southern
• Blotting, Western
• Cholera Toxin (genetics, metabolism)
• DNA Primers (chemistry)
• Endoplasmic Reticulum (metabolism)
• Enzyme-Linked Immunosorbent Assay
• G(M1) Ganglioside (metabolism)
• Gene Expression Regulation, Plant
• Gene Transfer Techniques
• Genetic Vectors
• Solanum lycopersicum (genetics, metabolism)
• Plant Leaves (chemistry)
• Plants, Genetically Modified
• Plasmids
• Polymerase Chain Reaction
• RNA, Messenger (genetics, metabolism)
• Receptors, Cell Surface (metabolism)