Leveraging the Polymorphism of the Merozoite Surface Protein 2 (MSP2) to Engineer Molecular Tools for Predicting Malaria Episodes in a Community

TL;DR

This study explores using genetic diversity in the malaria parasite's MSP2 protein to predict malaria outbreaks and improve community-based surveillance.

Contribution

The study introduces novel MSP2-derived biomarkers for malaria prediction through combined genotyping and serology.

Findings

3D7 strains of PfMSP2 were more common than FC27 in clinical isolates.

MSP2-derived antigens elicited distinct IgG responses in malaria patients and healthy individuals.

Rwandan individuals with weak or strong humoral responses to antigens experienced malaria episodes later.

Abstract

Malaria remains a significant public health challenge, particularly in endemic regions. The extensive genetic diversity of Plasmodium falciparum (Pf) complicates outbreak prediction and transmission control. One of its most polymorphic markers, merozoite surface protein 2 (MSP2), presents a potential target for molecular surveillance. This cross-sectional study, conducted at King Faisal Hospital Rwanda (KFHR) from October 2021 to June 2023, assessed MSP2’s utility in malaria prediction. PfMSP2 was sequenced, and selected amplicons were cloned, expressed in bacteria, and purified. These antigens were tested against sera from malaria patients and geographically diverse healthy individuals, with complementary surveys contextualizing serological findings. Of the 75 processed monoallelic clinical isolates, 3D7 strains predominated over FC27. Three MSP2-derived biomarkers were produced, eliciting significantly low IgG responses in malaria patients and Belgian controls, but a complex pattern emerged in healthy individuals, with significant differences between Rwandan and Cameroonian samples. IgG3 was the predominant subclass in individuals with high IgG responses. Notably, Rwandan individuals with weak humoral responses to the tested antigens but also other with high responses experienced malaria episodes in the subsequent year. These findings highlight MSP2 polymorphism as a valuable tool for malaria surveillance and outbreak prediction. Integrating genotyping and serology could enable precise, community-specific malaria risk assessments, strengthening control strategies.

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