A sticky end for malaria?

10 July 2008

Scientists have found a key mechanism that enables malaria-infected red blood cells to stick to the walls of blood vessels and avoid being destroyed by the body’s immune system.

The research, funded through our Functional Genomics Development Initiative, highlights an important potential new target for antimalarial drugs. When the malaria parasite infects healthy red blood cells, it secretes a ‘glue’, known as PfEMP1, that travels to the surface of the cells, leading to the formation of knobs there. The cells stick to the walls of the blood vessels, which prevents the cells being flushed through the spleen (where the parasites would be destroyed by the body’s immune system) and also restricts blood supply to vital organs.

Now, an international collaboration of scientists has identified eight proteins that transport the Plasmodium falciparum parasite’s ‘glue’ to the surface of the infected red blood cells. Removing just one of these proteins prevents the infected red blood cells from sticking to the walls of the blood vessels.

“Malaria parasites are evolving, making our current treatments increasingly less effective,” says Professor Alister Craig from the Liverpool School of Tropical Medicine, who collaborated on the project. “A drug which prevents disease rather than killing the parasite might be important because it could retain natural inoculation in the patient, limiting damage caused by the parasite and providing protection from further infection.”

Maier AG et al. Exported proteins required for virulence and rigidity of Plasmodium falciparum-infected human erythrocytes. Cell 2008;134(1):48–61.