Evidence for Multiple B- and T-Cell Epitopes in Plasmodium falciparum Liver-Stage Antigen 3

• Published in: Infection and Immunity Vol. 77; no. 3; pp. 1189 - 1196
• Main Authors: Toure-Balde, Aissatou, Perlaza, Blanca-Liliana, Sauzet, Jean-Pierre, Ndiaye, Mouhamadou, Aribot, Georgette, Tall, Adama, Sokhna, Cheikh, Rogier, Christophe, Corradin, Giampietro, Roussilhon, Christian, Druilhe, Pierre
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.03.2009; American Society for Microbiology (ASM)
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antibodies, Protozoan - blood; Antibodies, Protozoan - immunology; Antigens, Protozoan - immunology; Biological and medical sciences; Child; Child, Preschool; Epitopes, B-Lymphocyte - immunology; Epitopes, T-Lymphocyte - immunology; Fundamental and applied biological sciences. Psychology; Humans; Life cycle. Host-agent relationship. Pathogenesis; Malaria Vaccines - immunology; Malaria, Falciparum - immunology; Microbial Immunity and Vaccines; Microbiology; Middle Aged; Peptides - immunology; Plasmodium falciparum; Plasmodium falciparum - immunology; Protozoa; Senegal; Senegal; Antigen; Protozoa; Plasmodium falciparum; Apicomplexa; Antigenic determinant; Microbiology; Digestive system; Liver; T-Lymphocyte; B-Lymphocyte; Immunity
• DOI: 10.1128/IAI.00780-07
• ISSN: 0019-9567

Liver-stage antigen 3 (LSA-3) is a new vaccine candidate that can induce protection against Plasmodium falciparum sporozoite challenge. Using a series of long synthetic peptides (LSP) encompassing most of the 210-kDa LSA-3 protein, a study of the antigenicity of this protein was carried out in 203 inhabitants from the villages of Dielmo (n = 143) and Ndiop (n = 60) in Senegal (the level of malaria transmission differs in these two villages). Lymphocyte responses to each individual LSA-3 peptide were recorded, some at high prevalences (up to 43%). Antibodies were also detected to each of the 20 peptides, many at high prevalence (up to 84% of responders), and were directed to both nonrepeat and repeat regions. Immune responses to LSA-3 were detectable even in individuals of less than 5 years of age and increased with age and hence exposure to malaria, although they were not directly related to the level of malaria transmission. Thus, several valuable T- and B-cell epitopes were characterized all along the LSA-3 protein, supporting the antigenicity of this P. falciparum vaccine candidate. Finally, antibodies specific for peptide LSP10 located in a nonrepeat region of LSA-3 were found significantly associated with a lower risk of malaria attack over 1 year of daily clinical follow-up in children between the ages of 7 and 15 years, but not in older individuals.