Previous Article | Next Article ![]()
Infect. Immun., 05 1996, 1502-1509, Vol 64, No. 5
GS Hui, C Nikaido, C Hashiro, DC Kaslow and WE Collins
We have shown that conserved B epitopes were immunodominant in animals
hyperimmunized with parasite-purified or recombinant merozoite surface
protein MSP1 of Plasmodium falciparum. Cross-priming studies also suggested
that a conserved T-helper epitope(s) is efficient in inducing the anti-MSP1
antibody response. In this study, we determined whether a similar profile
of immune responses was induced during live P. falciparum infections. Naive
Aotus monkeys were infected by blood-stage challenge with either one of the
two dimorphic MSP1 alleles represented by the FUP and FVO parasites. Sera
collected after parasite clearance were analyzed by enzyme-linked
immunosorbent assays (ELISAs). Monkeys infected with parasites carrying one
allelic form of MSP1 had antibodies that were equally reactive with
homologous or heterologous MSP1s. This preferential recognition of
conserved epitopes of MSP1 was confirmed by competitive binding ELISAs.
Studies with Plasmodium yoelii and P. falciparum show that the C-terminal
19-kDa fragment of MSP1, MSP1(19), is the target of protective immunity.
Thus, monkey sera were assayed for recognition with recombinant MSP1(19)s
expressing variant and conserved B epitopes. Results of direct and
competitive binding ELISAs showed that the anti-MSP1(19) antibodies were
also directed primarily against conserved determinants. The similarities
between vaccine- or infection-induced antibody responses suggest a possible
reciprocal enhancement of the two populations of anti-MSP1 antibodies when
a subunit MSP1 vaccine is introduced into populations living in areas where
malaria is endemic. This together with previous observations that conserved
determinants are important in MSP1-mediated immunity provides an optimistic
outlook that a subunit MSP1 vaccine may be effective and practical for
field applications in malaria-exposed populations.
Copyright © 1996, American Society for Microbiology
Dominance of conserved B-cell epitopes of the Plasmodium falciparum merozoite surface protein, MSP1, in blood-stage infections of naive Aotus monkeys
Department of Tropical Medicine, University of Hawaii, Honolulu, Hawaii 96816, USA. ghui@hawaii.edu
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|