title: Immunogenicity of a recombinant protein containing the Plasmodium vivax vaccine candidate MSP1(19) and two human CD4+ T-cell epitopes administered to non-human primates (Callithrix jacchus jacchus).
abstract: One of the most promising vaccine candidates against the erythrocytic forms of malaria is the 19 kDa C-terminal region of the merozoite surface protein 1 (MSP1(19)). As part of our studies aimed at the development of a Plasmodium vivax malaria vaccine, we characterized the immunogenic properties of a new bacterial recombinant protein containing the P. vivax MSP1(19) and two helper T-cell epitopes, the synthetic universal pan allelic DR epitope (PADRE) and a new internal MSP1 P. vivax epitope (DYDVVYLKPLAGMYK). We found that the recognition of His6MSP1(19)-DYDVVYLKPLAGMYK-PADRE was as good as the recognition of His6MSP1(19) indicating that the presence of the T-cell epitopes PADRE and DYDVVYLKPLAGMYK did not modify the MSP1(19) epitopes recognized by human IgG. The recombinant protein His6MSP1(19)-DYDVVYLKPLAGMYK-PADRE proved to be highly immunogenic in marmosets (Callithrix jacchus jacchus) when administered in incomplete Freund's adjuvant. However, when administered in other adjuvant formulations such as Quil A, CpG ODN 2006 or MPL/TDM, antibody titers to MSP1(19) were significantly lower. Among these three adjuvants, Quil A proved to be the most efficient one generating antibody titers significantly higher than the others. These results indicated that under the circumstances evaluated, adjuvants were key for the immunogenicity of the recombinant protein His6MSP1(19)-DYDVVYLKPLAGMYK-PADRE.
authors.affiliation: CINTERGEN, Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo-Escola Paulista de Medicina, Rua Botucatu 862, 6th floor, São Paulo, SP 04023-062, Brazil.
authors.forename: Daniela S
authors.initials: DS
authors.lastname: Rosa
authors.forename: Leo K
authors.initials: LK
authors.lastname: Iwai
authors.forename: Fanny
authors.initials: F
authors.lastname: Tzelepis
authors.forename: Daniel Y
authors.initials: DY
authors.lastname: Bargieri
authors.forename: Magda A
authors.initials: MA
authors.lastname: Medeiros
authors.forename: Irene S
authors.initials: IS
authors.lastname: Soares
authors.forename: John
authors.initials: J
authors.lastname: Sidney
authors.forename: Alessandro
authors.initials: A
authors.lastname: Sette
authors.forename: Jorge
authors.initials: J
authors.lastname: Kalil
authors.forename: Luiz Eugênio
authors.initials: LE
authors.lastname: Mello
authors.forename: Edécio
authors.initials: E
authors.lastname: Cunha-Neto
authors.forename: Mauricio M
authors.initials: MM
authors.lastname: Rodrigues
mesh_terms: D000276:Adjuvants, Immunologic; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002144:Callithrix; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D005620:Freund's Adjuvant; D008288:Malaria / Q000276:immunology; D017780:Malaria Vaccines / Q000276:immunology*; D020066:Merozoite Surface Protein 1 / Q000276:immunology*; D051379:Mice; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D010966:Plasmodium vivax / Q000276:immunology*; D062605:Quillaja Saponins; D012503:Saponins / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000913:Antibodies, Protozoan; C408982:CPG-oligonucleotide; D018984:Epitopes, T-Lymphocyte; D017780:Malaria Vaccines; D020066:Merozoite Surface Protein 1; D009838:Oligodeoxyribonucleotides; D062605:Quillaja Saponins; D012503:Saponins; D014614:Vaccines, Synthetic; C046386:Quil A; D005620:Freund's Adjuvant