Production of Ascaris suum As14 protein and its fusion protein with cholera toxin B subunit in rice seeds.

Plants are attractive vaccine production and oral delivery systems. Cereals are excellent candidate for edible vaccines, which can express and store high levels of proteins for extended periods of time without degradation. In this study, we produced a 14-kDa protective surface antigen of Ascaris suum L3 larvae and its fusion chimera with a mucosal carrier molecule cholera toxin B subunit (CTB) in rice (Oryza sativa L.) under the control of the endosperm-specific glutelin-B promoter. We found that the recombinant protein expression levels reached 1.5 microg per seed, a comparably high amount as compared to previously reported transgenic rice expression experiments. Potentials of transgenic rice plants as a source of oral vaccines against swine roundworm are discussed.