T-cell epitopes in Pf155/RESA, a major candidate for a Plasmodium falciparum malaria vaccine.
Immunogens included in a subunit vaccine should contain both B- and T-cell-activating sites to ensure anamnestic responses following reinfection after vaccination as well as antibody-independent cellular immunity. The Plasmodium falciparum antigen Pf155/RESA, a major candidate for a vaccine against the asexual blood stages of this malaria parasite, was investigated for T-cell epitopes in its C-terminal amino acid repeat region, a region known to be conserved in different P. falciparum strains. It was found to contain several related sequences that activated T cells from humans primed to P. falciparum by natural exposure, to proliferation, and/or interferon-gamma release in vitro. T cells from approximately half of the donor group investigated responded to the intact protein, and 65% of these responders also responded to short synthetic peptides, probably representing a small number of partly overlapping T-cell epitopes. Thus, sequences from the C terminus of Pf155 may be suitable constituents of a P. falciparum subunit vaccine and also provide a basis for epitope-specific epidemiological studies relating cellular immune responses in vitro to clinical immunity and P. falciparum endemicity.
Kabilan
L
L
Department of Immunology, University of Stockholm, Sweden.
Troye-Blomberg
M
M
Perlmann
H
H
Andersson
G
G
Högh
B
B
Petersen
E
E
Björkman
A
A
Perlmann
P
P
D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D000954:Antigens, Surface / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D003429:Cross Reactions; D004247:DNA / Q000096:biosynthesis; D000939:Epitopes / Q000032:analysis / Q000235:genetics / Q000276:immunology; D006801:Humans; D007111:Immunity, Cellular; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D008288:Malaria / Q000276:immunology / Q000517:prevention & control; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology*; D015800:Protozoan Proteins; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000276:immunology*; D014612:Vaccines
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D000954:Antigens, Surface; D000939:Epitopes; D015800:Protozoan Proteins; D014612:Vaccines; C050256:ring-infected erythrocyte surface antigen (RESA), Plasmodium falciparum; D007371:Interferon-gamma; D004247:DNA