title: Antibody-mediated and cellular immune responses induced in naive volunteers by vaccination with long synthetic peptides derived from the Plasmodium vivax circumsporozoite protein.
abstract: Plasmodium vivax circumsporozoite (CS) protein is a leading malaria vaccine candidate. We describe the characterization of specific immune responses induced in 21 malaria-naive volunteers vaccinated with long synthetic peptides derived from the CS protein formulated in Montanide ISA 720. Both antibody- and cell-mediated immune responses were analyzed. Antibodies were predominantly of IgG1 and IgG3 isotypes, recognized parasite proteins on the immunofluorescent antibody test, and partially blocked sporozoite invasion of hepatoma cell lines in vitro. Peripheral blood mononuclear cells from most volunteers (94%) showed IFN-γ production in vitro upon stimulation with both long signal peptide and short peptides containing CD8+ T-cell epitopes. The relatively limited sample size did not allow conclusions about HLA associations with the immune responses observed. In summary, the inherent safety and tolerability together with strong antibody responses, invasion blocking activity, and the IFN-γ production induced by these vaccine candidates warrants further testing in a phase II clinical trial.
authors.affiliation: Instituto de Inmunología, Universidad del Valle, Cali, Colombia. marevalo@inmuno.org
authors.forename: Myriam
authors.initials: M
authors.lastname: Arévalo-Herrera
authors.forename: Liliana
authors.initials: L
authors.lastname: Soto
authors.forename: Blanca Liliana
authors.initials: BL
authors.lastname: Perlaza
authors.forename: Nora
authors.initials: N
authors.lastname: Céspedes
authors.forename: Omaira
authors.initials: O
authors.lastname: Vera
authors.forename: Ana Milena
authors.initials: AM
authors.lastname: Lenis
authors.forename: Anilza
authors.initials: A
authors.lastname: Bonelo
authors.forename: Giampietro
authors.initials: G
authors.lastname: Corradin
authors.forename: Sócrates
authors.initials: S
authors.lastname: Herrera
mesh_terms: D000293:Adolescent; D000328:Adult; D000913:Antibodies, Protozoan / Q000097:blood*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000502:physiology; D017780:Malaria Vaccines / Q000276:immunology*; D016780:Malaria, Vivax / Q000276:immunology / Q000517:prevention & control*; D008297:Male; D010966:Plasmodium vivax / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*; D014611:Vaccination; D055815:Young Adult
chemical_list: D000913:Antibodies, Protozoan; D017780:Malaria Vaccines; D015800:Protozoan Proteins; C041595:circumsporozoite protein, Protozoan