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A Plasmodium vivax vaccine candidate displays limited allele polymorphism, which does not restrict recognition by
I S Soares1, J W Barnwell, M U Ferreira
1Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil.
Background:
The 19 kDa C-terminal region of the merozoite surface protein 1 (MSP1(19)) has been suggested as candidate for part of a subunit vaccine against malaria. A major concern in vaccine development is the polymorphism observed in different plasmodial strains. The present study examined the extension and immunological relevance of the allelic polymorphism of the MSP1(19) from Plasmodium vivax, a major human malaria parasite.
Materials And Methods:
We cloned and sequenced 88 gene fragments representing the MSP1(19) from 28 Brazilian isolates of P. vivax. Subsequently, we evaluated the reactivity of rabbit polyclonal antibodies, a monoclonal antibody, and a panel of 80 human sera to bacterial and yeast recombinant proteins representing the two allelic forms of P. vivax MSP1(19) described thus far.
Results:
We observed that DNA sequences encoding MSP1(19) were not as variable as the equivalent region of other species of Plasmodium, being conserved among Brazilian isolates of P. vivax. Also, we found that antibodies are directed mainly to conserved epitopes present in both allelic forms of the protein.
Conclusions:
Our findings suggest that the use of MSP1(19) as part of a subunit vaccine against P. vivax might be greatly facilitated by the limited genetic polymorphism and predominant recognition of conserved epitopes by antibodies.
Insights
The merozoite surface protein 1 (MSP1(19)) from Plasmodium vivax shows limited genetic polymorphism. This conservation, along with antibody recognition of common epitopes, supports its use in malaria subunit vaccines.
Area of Science:
- Malariology
- Immunology
- Vaccine Development
Background:
- The 19 kDa C-terminal region of merozoite surface protein 1 (MSP1(19)) is a potential subunit vaccine candidate against malaria.
- Polymorphism in Plasmodium strains is a significant challenge for vaccine development.
- This study investigates the allelic polymorphism and immunological relevance of MSP1(19) in Plasmodium vivax.
Purpose of the Study:
- To examine the extent and immunological significance of allelic polymorphism in Plasmodium vivax MSP1(19).
- To assess the potential of MSP1(19) as a vaccine component against P. vivax malaria.
Main Methods:
- Cloning and sequencing of 88 gene fragments of MSP1(19) from 28 Brazilian P. vivax isolates.
- Evaluating antibody reactivity (rabbit polyclonal, monoclonal, and human sera) to recombinant allelic forms of P. vivax MSP1(19).
Main Results:
- MSP1(19) sequences from Brazilian P. vivax isolates exhibited limited variability, showing conservation.
- Antibodies primarily targeted conserved epitopes present in both allelic forms of the protein.
Conclusions:
- The limited genetic polymorphism of P. vivax MSP1(19) is advantageous for vaccine development.
- Predominant recognition of conserved epitopes by antibodies further supports the use of MSP1(19) in a subunit vaccine against P. vivax malaria.