Although this capability of platelets has been well established, the actual molecular mechanism underlying this function has not been fully demonstrated. Dr. Brendan J. McMorran and his colleagues from the Australian School of Advanced Medicine in Macquarie University, Sydney Australia and the Menzies Research Institute Tasmania University, Hobart, Australia have made a significant contribution to the understanding of the mechanism involved.
From their work, they have shown that platelet factor 4 (PF4) together with the Duffy-antigen receptor (Fy) are necessary for the platelet-mediated eradication of the Plasmodium falciparum parasite. Furthermore, they have shown that upon the binding of platelets to the parasitized red blood cell, PF4 is released and that it is this protein that is responsible for the killing of the parasites residing within the infected red blood cells. In order for PF4 to exert its effect, Fy needs to be present; it is Fy that selectively binds to PF4. It has also been shown that those individuals that have a genetic anomaly that undermines the expression of Fy are devoid of the protection against the parasite provided by platelets.
These findings help to elucidate the role that platelets play in the defense against parasitic infections. Uncovering the underlying mechanism for such a defense may prove to be invaluable in combating malaria - a disease that has a devastating impact on a significant portion of the world’s population.