title: A recombinant vaccine based on domain II of Plasmodium vivax Apical Membrane Antigen 1 induces high antibody titres in mice.
abstract: The Apical Membrane Antigen 1 (AMA-1) is considered a promising candidate for development of a malaria vaccine against asexual stages of Plasmodium. We recently identified domain II (DII) of Plasmodium vivax AMA-1 (PvAMA-1) as a highly immunogenic region recognised by IgG antibodies present in many individuals during patent infection with P. vivax. The present study was designed to evaluate the immunogenic properties of a bacterial recombinant protein containing PvAMA-1 DII. To accomplish this, the recombinant protein was administered to mice in the presence of each of the following six adjuvants: Complete/Incomplete Freund's Adjuvant (CFA/IFA), aluminium hydroxide (Alum), Quil A, QS21 saponin, CpG-ODN 1826 and TiterMax. We found that recombinant DII was highly immunogenic in BALB/c mice when administered in the presence of any of the tested adjuvants. Importantly, we show that DII-specific antibodies recognised the native AMA-1 protein expressed on the surface of P. vivax merozoites isolated from the blood of infected patients. These results demonstrate that a recombinant protein containing PvAMA-1 DII is immunogenic when administered in different adjuvant formulations, and indicate that this region of the AMA-1 protein should continue to be evaluated as part of a subunit vaccine against vivax malaria.
authors.affiliation: Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Gentil
authors.forename: Daniel Y
authors.initials: DY
authors.lastname: Bargieri
authors.forename: Juliana A
authors.initials: JA
authors.lastname: Leite
authors.forename: Kátia S
authors.initials: KS
authors.lastname: Françoso
authors.forename: Mariana B M
authors.initials: MB
authors.lastname: Patricio
authors.forename: Noeli M
authors.initials: NM
authors.lastname: Espíndola
authors.forename: Adelaide J
authors.initials: AJ
authors.lastname: Vaz
authors.forename: Clarisa B
authors.initials: CB
authors.lastname: Palatnik-de-Sousa
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Rodrigues
authors.forename: Fabio T M
authors.initials: FT
authors.lastname: Costa
authors.forename: Irene S
authors.initials: IS
authors.lastname: Soares
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000913:Antibodies, Protozoan / Q000097:blood*; D000917:Antibody Formation; D000953:Antigens, Protozoan / Q000276:immunology*; D005260:Female; D017780:Malaria Vaccines / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010966:Plasmodium vivax / Q000276:immunology; D015800:Protozoan Proteins / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D022223:Vaccines, Subunit / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000911:Antibodies, Monoclonal; D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D017780:Malaria Vaccines; D008565:Membrane Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; C090077:apical membrane antigen I, Plasmodium