Malaria vaccine: immunization of mice with a synthetic T cell helper epitope alone leads to protective immunity.
The immunogenicity of the non-repetitive sequences of the Plasmodium berghei circumsporozoite (CS) protein was studied using synthetic peptides. Two CS sequences (residues 20-39 and 57-70) exhibiting T cell helper activity were identified. Immunization of BALB/c mice with a branched peptide containing either the 20-39 or the 57-70 sequence and two repeats (B epitope) in a linear sequence induced high titers of anti-repeat and anti-sporozoite antibodies. Mice immunized with the T-B construct (high antibody titers) or with the 57-70 epitope alone (no serum anti-repeat or anti-peptide antibodies) were protected to a similar degree after challenge with infective sporozoites. No protection was obtained in mice immunized with the 20-39 epitope. These results indicate that BALB/c mice can be protected either by effector T cells or by high levels of anti-repeat antibodies. Thus, in the same strain, a double mechanism of protection can be obtained by a synthetic peptide vaccine.
Migliorini
P
P
Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
Betschart
B
B
Corradin
G
G
D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology*; D007109:Immunity; D008288:Malaria / Q000276:immunology / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008969:Molecular Sequence Data; D010962:Plasmodium berghei / Q000276:immunology*; D015800:Protozoan Proteins / Q000138:chemical synthesis / Q000276:immunology; D016052:Protozoan Vaccines; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
D000939:Epitopes; D015800:Protozoan Proteins; D016052:Protozoan Vaccines