Published September 2018
The STIAS Research Centre, nestled within the backdrop of the Cape Winelands of Stellenbosch, became the stage for the joining of researchers from three different continents. In line with the ideology of the international emphasis of the IRTG2290 program, scientists from Germany, South Africa, and Australia shared an experience in discussing progress towards understanding and controlling Plasmodium during a two day symposium.
The interconnection of research topics half a world over highlighted different perspectives of the same story. For example, the work of Jacky Snoep of Stellenbosch University focuses on modeling the metabolism of glucose in blood stage P. falciparum infection as a biomarker for disease severity. The conclusions drawn from this work were that a hypoglycemic state was negatively associated with survival outcome. In a way, this could indicate that Plasmodium responds to glucose levels of the host – either by reacting or influencing. Meanwhile, the group of Maria Mota works on nutrient sensing of the Plasmodium parasite in rodent malaria, which considers both stages of infection. In a 2017 Nature paper by Liliana Mancio-Silva of the Mota group, they explored the effects of caloric restriction on parasitemia and discovered that mice experiencing caloric restriction exhibited lower parasitemia compared to their non- caloric restricted counter parts. At first sight, it appears these two bodies of work may be at odds with one another. How can one group conclude that a hypoglycemic state predicts worse host survival chances, while the other group states that caloric restriction, and thus lower glucose levels, leads to lower parasitemia? However, they may not be contradictory at all. On one hand it may indicate the necessity for metabolic models to include information on the starting nutrient status of the host, or maybe it needs input on nutrient status during the liver stage of infection. On the other hand, it may be a highlight in the differences between rodent and human models of Plasmodium infection.
A large percentage of the South African based researchers focus their attention on drug discovery from a chemistry based background. This goes hand in hand with the cell biology that is often found within the IRTG cohort. The study of Francois Korbmacher on membrane transport proteins, Merryn Fraser on the mechanisms of membrane asymmetry, and Ayman Hemasa on the requirements of riboflavin all open up potential avenues for drug targeting and discovery. The work of these students would align nicely with that of John Woodland, who utilized fluorescent derivatives of a drug, in this case chloroquine, in order to ascertain interaction with its theorized targets. The cell biology would determine function and importance while the biochemical proteomic work would confirm interaction and mechanism.
All of the work within the IRTG, both on the Australian and German side, focuses on the Plasmodium parasite within the vertebrate host which is why I found the work presented by Lizette Koekemoer to be of particular interest. Her research focuses on vector control within South Africa. They take a hands on approach to eliminating the mosquito vector responsible for transmitting malaria, and this involves maintaining mosquito quarantine facilities that allow for study of the vector. Since these facilities are located within a malaria endemic region, it is of critical importance to adhere to strict safety protocols in order to prevent accidental release. This is in contrast to the protocols at the HU which are less stringent. Because the Molecular Parasitology mosquito breeding facility is based in a non-endemic location, accidental release of an individual uninfected, mature mosquitos does not pose a public safety risk. This highlights the importance of location when undertaking vector research.
Overall, the work presented during the Malaria Symposium, while sometimes straying from our areas of expertise, provided an appropriate complement to our work in the IRTG which helps round out our foundational knowledge as novice malaria researchers.
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