ELife: a new mechanism for Plasmodium to escape the immune system

February 19, 2020 / BIOON / -- according to a recent study published in the Journal of eLife, Plasmodium can identify a molecule produced by immune cells, and then use it to protect itself from damage to the immune system The study, led by scientists in Singapore, reveals a new molecular mechanism by which Plasmodium evades the immune system and paves the way for the development of new antimalarial drugs (image source: www Pixabay Com) as Plasmodium matures in blood cells, they are recognized by the host's immune system However, these parasites have evolved ways to escape immune responses, such as producing sticky molecules on infected red blood cells that stick to tiny blood vessels Wenn Chyau Lee, a sign researcher and the lead author of the paper, explained: "one of the ways for infected red blood cells to escape the recognition of the immune system is to attach directly to uninfected red blood cells and form a flower like structure called" Rose " This phenomenon has been reported previously and is believed to be related to the severity of the disease, but its exact function in malaria progression is not clear " Recent studies have shown that rosette may act as a 'mask' of infected red blood cells and prevent them from being cleared by the immune system In this regard, Lee and the team hope to conduct research and test They first incubated phagocytes with infected blood cells to study rosette formation They found that in the presence of phagocytes, rosette formation increased by 10-40%, suggesting that immune cells triggered the formation of rosettes in cells infected with malaria Next, they tried to study how immune cells stimulate rosette formation by extracting different components of the blood and analyzing the components needed to form roses Using a step-by-step approach, they identified a substance called human insulin growth factor binding protein 7 (IGFBP7) needed for rosette formation In fact, when they only added IGFBP7 without any immune cells, they still stimulated the formation of rosettes Then, the team investigated how Plasmodium perceives IGFBP7 The authors speculate that the perception of IGFBP7 depends on the parasite derived molecular receptors expressed on the surface of infected red blood cells Finally, the scientists studied whether rosette formation triggered by IGFBP7 could prevent the removal of infected cells by macrophages The results showed that in the presence of IGFBP7, rosette formation increased, but the number of infected erythrocytes phagocytized by immune cells decreased "Our work reveals a new immune escape mechanism for malaria," the authors conclude By using this molecule and other substances in the blood, blood cells infected with malaria collect uninfected blood cells to form a rose 'shield' that protects them from the immune system Our results suggest that targeting this mechanism may be an effective way to develop new antimalarial drugs " Source of information: how malaria detects and shields itself from approaching immune cells original source: Winn Chyau Lee et al, plasma infected estrocytes import secret of IGFBP7 to form type II rosettes and escape phagocytosis, eLife (2020) Doi: 10.7554/elife.51546