Malaria is the most important tropical disease that kills around 400,000 people worldwide. The majority of deaths occur after infection with Plasmodium falciparum in Africa. This parasite causes the particularly severe infections by infecting red blood cells and the infected red blood cells eventually bind to the walls of blood vessels. The binding leads to a blockage of small blood vessels, oxygen deficiency and activation of the immune system. This can lead to organ failure and also damage to the brain (cerebral malaria).
The activation of the immune system is characterised by an increased concentration of different messenger substances (cytokines) in the blood of malaria patients. In particular, the cells of the blood vessels, the so-called endothelial cells, are a potential source of these cytokines. So far, more than 30 different cytokines have been detected in elevated concentrations in the plasma of malaria patients. It was not known until now whether the release of these messenger substances can only be stimulated by the direct contact of the red blood cells infected with P. falciparum with the endothelial cells or also contact-independently.
The Bruchhaus working group demonstrated that endothelial cells mixed with plasma from malaria patients secrete various cytokines and growth factors. In a parallel study, the team investigated which RNA molecules are produced by endothelial cells when they are exposed to patient plasma. This so-called transcriptome analysis confirmed the results of the increased production of various cytokines described above. The research group was thus able to show that not only the direct binding of infected red blood cells, but also molecules in the plasma of malaria patients influence the endothelial cells of the blood vessels. This not only affects the immunological response, but also other processes such as cell proliferation and the formation of blood vessels.