Research note: HLA degenerate T-cell epitopes from Plasmodium falciparum liver stage-specific antigen 1 (LSA-1) are highly conserved in isolates from geographically distinct areas.
Considerable effort is directed at the development of a malaria vaccine that elicits antigen-specific T-cell responses against pre-erythrocytic antigens of Plasmodium falciparum. Genetic restriction of host T-cell responses and polymorphism of target epitopes on parasite antigens pose obstacles to the development of such a vaccine. Liver stage-specific antigen-1 (LSA-1) is a prime candidate vaccine antigen and five T-cell epitopes that are degenerately restricted by HLA molecules common in most populations have been identified on LSA-1. To define the extent of polymorphism within these T-cell epitopes, the N-terminal non-repetitive region of the LSA-1 gene from Malaysian P. falciparum field isolates was sequenced and compared with data of isolates from Brazil, Kenya and Papua New Guinea. Three of the T-cell epitopes were completely conserved while the remaining two were highly conserved in the isolates examined. Our findings underscore the potential of including these HLA-degenerate T-cell epitopes of LSA-1 in a subunit vaccine.
Ravichandran
M
M
Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
Doolan
D L
DL
Cox-Singh
J
J
Hoffman
S L
SL
Singh
B
B
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D017124:Conserved Sequence; D018604:Epitope Mapping; D018984:Epitopes, T-Lymphocyte / Q000235:genetics* / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D017780:Malaria Vaccines; D016778:Malaria, Falciparum / Q000276:immunology / Q000469:parasitology; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000276:immunology* / Q000302:isolation & purification; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
D000953:Antigens, Protozoan; D018984:Epitopes, T-Lymphocyte; D006680:HLA Antigens; D017780:Malaria Vaccines; C067302:liver stage-specific antigen, Plasmodium