Malaria devastates humanity: Approximately every 10 seconds, another child dies as a result of a malarial infection. Globally, it is the third biggest killer, and it mostly kills children. The emergence of all-drug-resistant strains of Plasmodium falciparum, the parasite responsible for most human malarial disease, is a frightening new reality that mandates aggressive research to develop new vaccines and drugs, particularly to uncover new targets for therapeutic agents. A major area of current ignorance is the mechanism by which parasites are released from the infected red blood cells within which they multiply.
To learn more about this release process, in their new work the researchers used high-quality microscopy and a "Nan crystal" fluorescent tag that allowed them to follow the behavior of membranes of infected cells during an extended period of time. The authors discovered that many minutes before release, infected cells look irregular, resembling a fried egg, with the parasites bunched together in the center. They found that just prior to release, cells round up and become very symmetric, resembling a flower, with the parasites (present beneath the cell-membrane surface) appearing like the petals.
The researchers showed that at the seemingly explosive event of release itself, cellular membranes fold upon themselves and bubble into small vesicles, allowing the newly born parasites (in this stage they are called merozoites) to infect neighboring red blood cells. Further experiments i
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Contact: Heidi Hardman
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Cell Press
22-Sep-2005