title: Immunogenic properties of the Plasmodium vivax vaccine candidate MSP1(19) expressed as a secreted non-glycosylated polypeptide from Pichia pastoris.
abstract: The 19 kDa C-terminal region of the merozoite surface protein 1 (MSP1(19)) is one of the most promising vaccine candidates against the erythrocytic forms of malaria. In the present study, a gene encoding the Plasmodium vivax MSP1(19) epitope (PvMSP1(19)) and the Pan-Allelic DR epitope (PADRE) was expressed in the methylotrophic yeast Pichia pastoris. A non-glycosylated form of the recombinant protein rPvMSP1(19)-PADRE was purified from culture supernatants. This recombinant protein maintains its antigenicity, being recognized by a very high percentage (85.6%) of sera from Brazilian individuals naturally exposed to P. vivax. The antibody immune response elicited by rPvMSP1(19)-PADRE was compared in C57BL/6 mice immunized with different adjuvant formulations. After 3 immunizing doses, antibody titres induced in the presence of the adjuvants monophosphoryl lipid A, trehalose dicorynomycolate and cell wall skeleton or alum plus CpG ODN 1826 were as high as titres generated by Complete Freund's Adjuvant. Based on these immunological studies, we concluded that rPvMSP1(19)-PADRE deserves further evaluation in pre-clinical immunizations against P. vivax in non-human primates.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, SP, Brazil. isoares@ecb.epm.br
authors.forename: I S
authors.initials: IS
authors.lastname: Soares
authors.forename: M M
authors.initials: MM
authors.lastname: Rodrigues
mesh_terms: D000276:Adjuvants, Immunologic; D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007111:Immunity, Cellular / Q000276:immunology; D007114:Immunization; D017780:Malaria Vaccines / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D016780:Malaria, Vivax / Q000276:immunology* / Q000517:prevention & control; D020066:Merozoite Surface Protein 1 / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010843:Pichia / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D010966:Plasmodium vivax / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; D017780:Malaria Vaccines; D020066:Merozoite Surface Protein 1; C401223:PADRE 45; D014614:Vaccines, Synthetic