Affiliated Research Centres
New possibilities for malaria vaccines
The cheating ways of the malaria parasite have been exposed by researchers at an OU Affiliated Research Centre, the Kenya Medical Research Institute, opening up new possibilities for developing medicines and vaccines.
Dr George Warimwe and colleagues from the Kenya Medical Research Institute-Wellcome Trust Programme can now explain how the malaria parasite manages to outwit the human body’s defence mechanisms.
In malaria-endemic regions of sub-Saharan Africa, severe life-threatening malaria is a disease of young children. This is because exposure to the Plasmodium falciparum infection leads to a relatively rapid acquisition of immunity to severe malaria. Nevertheless, older children and adults remain susceptible to mild malaria even after many years of exposure to infection. The research provides a potential molecular explanation for this phenomenon by identifying a subset of the parasite antigenic variants called PfEMP1 whose expression is independently associated with infections of young children and those with severe malaria.
The research reveals how parasites isolated from children with severe malaria, as compared to those from children of the same age with non-severe malaria, tend to express higher amounts of a specific subset of PfEMp1 variants. Independently, this same group of molecules is expressed more frequently in parasites from young children and those from children with low levels of anti-PfEMP1 antibodies. They are also encoded as a minority group within the PfEMP1 repertoires of all parasites analysed to date. Thus, they appear to play an important biological role. The research team proposes that young children growing up in malaria endemic areas require immunity to this group of molecules relatively quickly, whilst remaining susceptible to the broader class of other, less pathogenic variants.
The study opens up the possibility for designing a vaccine against severe malaria that mimics an adult’s immune response, making the infections less dangerous.
The research is in collaboration with The University of Oxford and the Wellcome Trust Sanger Institute, Cambridge.
Proceedings of the National Academy of Sciences publication
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