New technique may "tame" malaria

Scientists have invented a new technique to "tame" the malaria parasite by forcing it to depend on an external supply of a vital chemical during its invasion stage.
Ellen Yeh of Stanford University's School of Medicine and Joseph DeRisi of the University of California - San Francisco have essentially created a domesticated strain of Plasmodium – the one-celled parasite that causes malaria – that would no longer cause the disease.
Their findings reveal that the parasite's survival depends on the production of the chemical isopentenyl pyrophosphate. The parasite's IPP supply is typically manufactured in a structure called the apicoplast. The researchers found that during the blood-infecting stage, the parasite can live without its apicoplast, as long as it gets IPP from another source.
Yeh and DeRisi found that if they added antibiotics to the culture medium along with IPP, the apicoplast-lacking parasites could thrive in culture, showing that IPP is the only product the parasites need from its apicoplast during the blood stage. A drug that could knock out the ability of the apicoplast to create IPP could wipe out the parasite without having any effect on human cells' ability to make the important precursor substance.
"This potential pathway for killing parasites without interfering with human cells is the reason the apicoplast has been a major focus for drug development," Yeh said. "Now we have a way to specifically look for drugs that target its function and discover a whole new class of desperately needed anti-malarials."
By inoculating a patient with a version of Plasmodium that has been tamed with antibiotics and IPP, the immune system could potentially be trained to fight off more virulent strains of Plasmodium, according to Yeh.
While Yeh cautions it will be years before the research gets to the clinical stage, she said they are much closer now than they were previously.