Transgenic rice expresses an antigenic lipoprotein of Neisseria gonorrhoeae

BACKGROUND: The use of transgenic plants as new antigen-delivery systems for subunit vaccines has been increasingly explored. We herein report progress toward a rice-based vaccine against Neisseria gonorrhoeae. RESULTS: Two expression cassettes, pKrAgnH and pKcAgnH, containing the lipoprotein gene of N. gonorrhoeae (Ag473) under the control of the tobacco Rubisco small subunit (rbcS) promoter or the CaMV 35S promoter, respectively, were constructed and introduced into rice (Oryzy sativa L.) by Agrobacterium-mediated transformation. Eleven independent transgenic lines were regenerated, integration of the Ag473 gene was confirmed by PCR and specific transcripts of the expected molecular size were detected by RT-PCR. Expression of the putative polypeptide encoded by the Ag473 gene was detected by immunoassay with specific antibodies. ELISA and western blot revealed that the Ag473 protein was expressed and accumulated in both leaf and seed tissues of transgenic rice plants. Some transgenic lines expressed Ag473 up to 0.5% of the total soluble protein. Moreover, the immunogenicity of the expressed protein was tested in a mouse model and the results showed that specific antibodies were elicited in mice immunised intraperitoneally with protein extracts from transgenic rice plants. CONCLUSION: This study demonstrates the feasibility of using transgenic rice as a bioreactor for N. gonorrhoeae vaccine development. Copyright © 2008 Society of Chemical Industry