title: Naturally acquired antibodies to Plasmodium vivax blood-stage vaccine candidates (PvMSP-1₁₉ and PvMSP-3α₃₅₉₋₇₉₈ and their relationship with hematological features in malaria patients from the Brazilian Amazon.
abstract: An important step when designing a vaccine is identifying the antigens that function as targets of naturally acquired antibodies. We investigated specific antibody responses against two Plasmodium vivax vaccine candidates, PvMSP-1₁₉ and PvMSP-3α₃₅₉₋₇₉₈. Moreover, we assessed the relationship between these antibodies and morbidity parameters. PvMSP-1₁₉ was the most immunogenic antigen and the frequency of responders to this protein tended to increase in P. vivax patients with higher parasitemia. For both antigens, IgG antibody responses tended to be lower in patients who had experienced their first bout of malaria. Furthermore, anemic patients presented higher IgG antibody responses to PvMSP-3α₃₅₉₋₇₉₈. Since the humoral response involves a number of antibodies acting simultaneously on different targets, we performed a Principal Component Analysis (PCA). Anemic patients had, on average, higher first principal component scores (IgG1/IgG2/IgG3/IgG4 anti-MSP3α), which were negatively correlated with hemoglobin levels. Since antibodies against PfMSP-3 have been strongly associated with clinical protection, we cannot exclude the possibility of a dual role of PvMSP-3 specific antibodies in both immunity and pathogenesis of vivax malaria. Our results confirm the high immunogenicity of the conserved C terminus of PvMSP-1 and points to the considerable immunogenicity of polymorphic PvMSP-3α₃₅₉₋₇₉₈ during natural infection.
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Brazil.
authors.forename: Luiza Carvalho
authors.initials: LC
authors.lastname: Mourão
authors.forename: Cristiane Guimarães
authors.initials: CG
authors.lastname: Morais
authors.forename: Lilian Lacerda
authors.initials: LL
authors.lastname: Bueno
authors.forename: Maria Carolina
authors.initials: MC
authors.lastname: Jimenez
authors.forename: Irene Silva
authors.initials: IS
authors.lastname: Soares
authors.forename: Cor Jesus
authors.initials: CJ
authors.lastname: Fontes
authors.forename: Marcus Vinícius
authors.initials: MV
authors.lastname: Guimarães Lacerda
authors.forename: Marcos Silva
authors.initials: MS
authors.lastname: Xavier
authors.forename: John W
authors.initials: JW
authors.lastname: Barnwell
authors.forename: Mary R
authors.initials: MR
authors.lastname: Galinski
authors.forename: Erika Martins
authors.initials: EM
authors.lastname: Braga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000913:Antibodies, Protozoan / Q000097:blood*; D000953:Antigens, Protozoan / Q000276:immunology*; D001938:Brazil; D002648:Child; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D017780:Malaria Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016780:Malaria, Vivax / Q000276:immunology*; D008297:Male; D020066:Merozoite Surface Protein 1 / Q000276:immunology*; D008875:Middle Aged; D010966:Plasmodium vivax / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D017780:Malaria Vaccines; D020066:Merozoite Surface Protein 1; D015800:Protozoan Proteins; C089133:merozoite surface protein 3, Plasmodium