Discovery may signal 'sticky' end for malaria parasite

Researchers in Melbourne, Australia, have found a vital clue to how malaria parasites infect people, paving the way for new malaria treatments.

Mosquito's inject the malaria parasite into humans when they bite. The parasites go on to infect red blood cells, transforming them into sticky sacks containing up to thirty-two new daughter parasites. The hijacked red blood cells stick to blood vessel walls, thereby avoiding being flushed through the spleen and being destroyed by the body's immune system.

Scientists at the Walter and Eliza Hall Institute of Medical Research have revealed key elements in the parasite's "sticky sack" adhesion strategy. They have identified eight new proteins that transport the parasite's major adhesion factor, PfEMP1, to the surface of infected red cells, where it promotes the formation of sticky knobs. They have also shown that removal of just one of these proteins disrupts the ability of the parasite bag to stick to blood vessel walls.

This discovery suggests that a drug that inactivates an essential adhesion protein would be an effective anti-malarial.

All currently available malaria drugs attempt to disrupt the metabolism or biological function of the parasite. Unfortunately, malaria parasites are evolving resistance to such drugs, suggesting that quite a different strategy may be required . The inability of the parasite to prevent its transport to the human spleen would lead to the parasite's natural destruction.

The work by the research team has been supported by the Wellcome Trust, the NHMRC, the Howard Hughes Medical Institute and the National Institutes of Health. The findings were published in the prestigious international journal, Cell.