Antibodies to a non-repeat region of Plasmodium falciparum antigen Pf155/RESA in individuals from malaria-endemic areas.
Human antibodies to the repeat regions of the Plasmodium falciparum asexual blood stage antigen Pf155/RESA interfere with parasite growth in vitro, but the significance in this respect of antibodies to non-repetitive epitopes is less clear. In this study the levels of antibodies to a non-repetitive part of Pf155/RESA (residue 199-221) in malaria-exposed individuals were analysed, as was the parasite-inhibitory capacity of such antibodies. Residue 199-221 is of particular interest since it includes a sequence homologous to a cytoadherence-related motif from band 3. Sera from donors in Liberia and Tanzania were analysed for reactivity in ELISA with synthetic peptides together overlapping this part of Pf155/RESA. High antibody reactivity was observed in most of the sera with two peptides including residues 199-211 and 202-214, respectively. Specific antibodies were affinity-purified from selected sera using these peptide sequences and were shown to react with Pf155/RESA by immunofluorescence and Western blotting. The purified antibodies were furthermore shown to inhibit parasite growth in vitro. The results suggest that both repeat and non-repeat epitopes in Pf155/RESA elicit antibodies with potential to protect against malaria infection.
Siddique
A B
AB
Department of Immunology, Stockholm University, Stockholm, Sweden.
Ahlborg
N
N
Warsame
M
M
Perlmann
P
P
Berzins
K
K
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000918:Antibody Specificity; D000953:Antigens, Protozoan / Q000235:genetics; D003429:Cross Reactions; D018604:Epitope Mapping; D006801:Humans; D066298:In Vitro Techniques; D016778:Malaria, Falciparum / Q000276:immunology*; D010455:Peptides / Q000235:genetics / Q000276:immunology; D010963:Plasmodium falciparum / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D010455:Peptides; D015800:Protozoan Proteins; C050256:ring-infected erythrocyte surface antigen (RESA), Plasmodium falciparum