Evidence for multiple B- and T-cell epitopes in Plasmodium falciparum liver-stage antigen 3.
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.
Toure-Balde
Aissatou
A
Institut Pasteur de Dakar, Dakar, Senegal.
Perlaza
Blanca-Liliana
BL
Sauzet
Jean-Pierre
JP
Ndiaye
Mouhamadou
M
Aribot
Georgette
G
Tall
Adama
A
Sokhna
Cheikh
C
Rogier
Christophe
C
Corradin
Giampietro
G
Roussilhon
Christian
C
Druilhe
Pierre
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D018985:Epitopes, B-Lymphocyte / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D006801:Humans; D017780:Malaria Vaccines / Q000276:immunology*; D016778:Malaria, Falciparum / Q000276:immunology*; D008875:Middle Aged; D010455:Peptides / Q000276:immunology; D010963:Plasmodium falciparum / Q000276:immunology; D012675:Senegal
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D018985:Epitopes, B-Lymphocyte; D018984:Epitopes, T-Lymphocyte; D017780:Malaria Vaccines; D010455:Peptides; C067302:liver stage-specific antigen, Plasmodium