Mosquitoes are the world's deadliest animals (after humans) and they transmit malaria, which kills about 400,000 people every year. Malaria is caused by a parasite with a complex life cycle. Cutting-edge microscopy tools have now been used to capture malaria parasites in the act of infecting red blood cells. The real-time images were taken with a technique called lattice light-sheet microscopy, and have enabled researchers to learn more about the molecular basis of malaria infections. The findings have been reported in Nature Communications, and they may provide new insights into fighting malaria infections.
"Understanding in better detail exactly how the parasite invades red blood cells may reveal new ways to stop this stage of the parasite life cycle, potentially leading to much-needed new therapies," said study co-author Dr. Kelly Rogers, the head of WEHI's Centre for Dynamic Imaging.
"We used microscopy - specifically a state-of-the-art approach, lattice light-sheet microscopy (LLSM) - to follow the intricate cellular and molecular changes that occur when the malaria parasite invades red blood cells. We captured the first-ever high-resolution, real-time, and dynamic views of the parasite in action."
The work revealed many new details about the parasitic invasion, added study co-author Cindy Evelyn. "The videos we recorded showed the 'push and pull' interactions as the parasite landed on the red blood cell, and then entered the cell in an enclosed chamber - called a vacuole - where it grew and multiplied. There has long been contention in the field about whether the vacuole is derived from the parasite or the host cell. Our research resolved this question, revealing it was created from the red blood cell's membrane," she said.
Most therapies and vaccines for malaria are aimed at disrupting the binding between the malaria parasite and red blood cells.
"By visualizing these processes in more detail, our research may contribute in several ways to the development of new antimalarial therapies. For example, now that we know that the parasite vacuole relies on components of the red blood cell membrane, it might be possible to target these components with medicines to disrupt the parasite life cycle. This host-directed approach could be one way to bypass the malaria parasite's propensity to rapidly develop drug resistance," said Rogers.
"LLSM may also have applications for observing the specific steps of parasite invasion that are blocked by potential new drugs - an area we are now very interested in pursuing."