title: Production of the 42-kDa fragment of Plasmodium falciparum merozoite surface protein 1, a leading malaria vaccine antigen, in Arabidopsis thaliana seeds.
abstract: Malaria is widely associated with poverty, and a low-cost vaccine against malaria is highly desirable for implementing comprehensive vaccination programmes in developing countries. Production of malaria antigens in plants is a promising approach, but its development has been hindered by poor expression of the antigens in plant cells. In the present study, we targeted plant seeds as a low-cost vaccine production platform and successfully expressed the Plasmodium falciparum 42-kDa fragment of merozoite surface protein 1 (MSP1₄₂), a leading malaria vaccine candidate, at a high level in transgenic Arabidopsis seeds. We overcame hurdles of transcript and protein instabilities of MSP1₄₂ in plants by synthesizing a plant-optimized MSP1₄₂ cDNA and either targeting the recombinant protein to protein storage vacuoles or fusing it with a stable plant storage protein. An exceptional improvement in MSP1₄₂ expression, from an undetectable level to 5% of total extractable protein, was achieved with these combined strategies. Importantly, the plant-derived MSP1₄₂ maintains its natural antigenicity and can be recognized by immune sera from malaria-infected patients. Our results provide a strong basis for the development of a plant-based, low-cost malaria vaccine.
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
authors.forename: On Sun
authors.initials: OS
authors.lastname: Lau
authors.forename: Danny W-K
authors.initials: DW
authors.lastname: Ng
authors.forename: Wendy W L
authors.initials: WW
authors.lastname: Chan
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Chang
authors.forename: Samuel S M
authors.initials: SS
authors.lastname: Sun
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D017780:Malaria Vaccines / Q000276:immunology*; D020066:Merozoite Surface Protein 1 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000378:metabolism*
chemical_list: D017780:Malaria Vaccines; D020066:Merozoite Surface Protein 1