Scientists discover how molecules work together to kill P. falciparum

Australian scientists recently found a clue as to why malaria is a particular problem in sub-Saharan Africa.

The same scientists from Macquarie University uncovered two molecules located in human platelets that work in conjunction to kill the malaria parasite. The discovery could help in the development of new treatments for the mosquito-borne illness, according to

In a study published in the journal Science, the researchers explain how platelet factor 4 and the Duffy antigen receptor work together to kill Plasmodium falciparum, the malarial parasite responsible for 650,000 deaths annually, mostly in sub-Saharan Africa.

Experts say the role of platelets in malaria resistance has yet to be fully explored.

The Macquarie University study shows how PF4 penetrates red and kills blood cells infected by the malaria parasite. It can only do so, however, when the Duffy antigen receptor is present.

"The Duffy antigen is a docking site that appears to allow PF4 to get to the parasite," Brendan McMorran of Macquarie University and the lead author of the study, said, reports. "We don't know how PF4 kills the parasite, but it kills them quite effectively. PF4 is known to interfere with membrane functions in other microbes like bacteria, so we think a similar mechanism may work with the malaria parasite."

In Africa, the Duffy receptor is absent in most populations, making them more susceptible to malaria caused by P. falciparum. McMorran suggests that the lack of the receptor may have been an advantage at some point.

McMorran said the malaria parasite P. vivax can only invade cells if they express the Duffy receptor, adding that P. vivax is not common in Africa.

"It may be that thousands of years ago to be Duffy-negative was an advantage," McMorran said, reports.