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Updated: Jun 17, 2026
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Methods to Investigate the Regulatory Role of Small RNAs and Ribosomal Occupancy of Plasmodium falciparum
Published on: December 4, 2015
Plasmodium falciparum var gene expression is modified by host immunity
George M Warimwe1, Thomas M Keane, Gregory Fegan
1Kenya Medical Research Institute-Wellcome Trust Research Programme, 80108 Kilifi, Kenya.
Summary
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) variants expressed by "cys2" var genes are linked to severe malaria in children. These PfEMP1 variants are associated with lower host immunity, suggesting a parasite adaptation strategy.
Area of Science:
- Malariology
- Immunology
- Genetics
Background:
- Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates host-parasite interactions.
- PfEMP1s are encoded by diverse var genes, with ~60 copies per genome.
- Severe malaria predominantly affects children in endemic areas.
Purpose of the Study:
- To investigate the association between var gene expression and malaria severity in children.
- To determine if specific PfEMP1 variants correlate with host immune responses.
- To test the hypothesis that virulent PfEMP1 variants are more susceptible to host immunity.
Main Methods:
- Study of 217 Kenyan children with malaria.
- Analysis of var gene expression, specifically focusing on "cys2" variants.
- Assessment of host antibody responses to parasite-infected erythrocyte surface antigens.
Main Results:
- Expression of "cys2" var genes was significantly associated with severe malaria.
- Parasites from young children and those with severe malaria showed higher "cys2" expression.
- "Cys2" gene expression correlated with a weaker antibody response in hosts.
- Genomic "cys2" var genes represent a minor fraction of the total var repertoire.
Conclusions:
- The "cys2" var gene group may encode PfEMP1 variants that contribute to severe malaria pathogenesis.
- Parasite var gene repertoire organization may balance virulence with immune evasion.
- This suggests a mechanism for Plasmodium falciparum adaptation to developing host immunity.
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