Researchers from Birkbeck’s Electron Microscopy Laboratory have helped uncover how malarial parasites escape from a host’s red blood cells in order to spread to new host cells. This process is known as egress. The study was published in Proceedings of the National Academy of Sciences.
Malaria invades red blood cells and once inside it multiplies within an internal compartment called a parasitophorous vacuole. The vacuole and the membranes (cytoplasm) of the red blood cell then break down, destroying the cell and enabling the newly multiplied parasites to escape and invade new red blood cells.
Birkbeck PhD student (now postdoc) Vicky Hale, in a Birkbeck team led by Helen Saibil, in collaboration with Mike Blackman at the Crick Institute and Roland Fleck at King’s College London, used a range of advanced electron microscopy and tomography methods to visualise how the red blood cell membrane and parasitophorous vacuole’s structures change just before egress. They discovered that the parasitophorous vacuole membrane becomes leaky before breaking down completely several minutes later. After a further few minutes the cell’s cytoskeleton collapses, rapidly followed by the explosive release of the parasites. Understanding the process of egress may enable scientists to develop ways of stopping the process, which would trap the parasites in the cell and halt the progression of malaria.
Professor Saibil said: “Malaria is the greatest killer in human history. Finding new ways to halt malaria’s progression is vital if we are to reduce the hundreds of thousands of deaths that occur each year due to it. These findings are an important step towards developing new treatments that tackle the disease in different ways to the existing drugs, which mostly focus on stopping the parasite from multiplying within the cell.”
Published: 15 March 2017