Malaria parasite `goes bananas before sex`

Last Updated: Wednesday, February 15, 2012 - 11:28

Melbourne: Scientists claim to have solved a 130-year-old mystery by revealing that the malaria parasite adopts a banana shape before sexual reproduction to sneak into spleen, a finding which may pave the way for vaccines against the disease which kills 600,000 people each year globally.

A team at the University of Melbourne says its finding about how the malaria parasite (Plasmodium falciparum) changes into a banana shape before sexual reproduction may explain how the parasite evades the human immune system, thus providing a potential target for vaccine or drug development.

Dr Matthew Dixon, who led the team, said the research finally cracked the 130-year-old puzzle, revealing how the most deadly of human malaria parasites, Plasmodium falciparum, performs its shape-shifting.

"In 1880, the banana or crescent shape of the malaria parasite was first seen in the blood of a patient. Using a 3D microscope technique, we reveal that malaria uses a scaffold of special proteins to form a banana shape before sexual reproduction," Dr Dixon said in a release by the university.

"As the malaria parasite can only reproduce in its `banana form`, if we can target these scaffold proteins in a vaccine or drug, we may be able to stop it reproducing and prevent malaria transmission entirely," he added.

The team says that when in its banana shape, the malaria parasite is passed from a human host to a mosquito where it reproduces in the mosquito gut.
The research found that specific proteins form scaffolds, called microtubules, which lie underneath the parasite surface and elongate it into the sexual stage banana shapem according to the `Journal of Cell Science`.

The research suggests that when the parasites are ready for sexual reproduction, they adopt the banana shape so that they can fit through the tiny sinusoidal slits in the spleen.

This enables them to avoid the host`s mechanical filtering and immune surveillance mechanisms and to survive in the circulation long enough to be picked up by a mosquito and transmitted to the next victim, say the scientists.

The banana shape was revealed in greater detail than ever before by using high-end imaging techniques -- 3D Structured Illumination Microscopy and Cryo Electron Microscopy.

PTI



First Published: Wednesday, February 15, 2012 - 11:28

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