Breakthrough in search for new malaria cure

Scientists find a way to block malaria parasite from making itself at home inside host blood cells; research opens up possibilities of new generation anti-malarial drugs

 
By Aprajita Singh
Last Updated: Saturday 04 July 2015

The parasite is transmitted through mosquitoes (source: Health and Family Welfare Department, Gujarat) Two separate studies published last week announced breakthrough in the search for a cure for malaria. Working independently, the two teams of scientists from Australia and the US were able to block a mechanism used by the malaria parasite for its survival in the human host blood cells.

The parasite, Plasmodium falciparum, modifies the red blood cells in the human body to make them suitable for its habitation. For this it deposits proteins in the red blood cells through a gateway. The researchers have identified a way to block this gateway, which results in the death of the parasite.

The team that authored the first study, a collaboration between researchers from the Burnet Institute, Deakin University School of Medicine and Monash University, Australia, had earlier identified the gateway used for the  export of proteins into the host cell, but did not possess  evidence to show that it was the only such gateway. In this study, they succeeded in blocking the export of parasite proteins into the red blood cell, effectively killing the parasite. “We are now looking to better understand how the gateway is established, which will help with drug development in the future,” said Tania De Koning-Ward, associate professor at Deakin University Medical School.

The second study, authored by a team from Washington University School of Medicine in the US, targeted a protein called HSP101 or the heat-shock protein, so named because this family of proteins is activated when cells are overheated or stressed. They found that disabling HSP101 blocked all the malarial proteins from entering the red blood cells. The scientists think HSP101 readies malarial proteins for secretion through a pore that opens into the red blood cell. This preparation may involve unfolding the proteins into a linear form that allows them to more easily pass through the narrow pore.

Target for drug development

Both teams have expressed hope that these findings may lead to the development of a new generation of anti-malarial drugs that target the cell gateway to cure malaria. “We think this is a very promising target for drug development,” said Daniel Goldberg, MD, PhD, senior author of the study at the Washington University. “We’re a long way from getting a new drug, but in the short term we may look at screening a variety of compounds to see if they have the potential to block HSP101.”

The studies were published in the July 17 issue of Nature magazine.

Drug resistance

Although there are currently treatments available for malaria, there has been an alarming increase in parasite resistance to these drugs. Partial resistance to artemisinin, recommended by WHO as the first-line treatment for uncomplicated malaria, has been seen in several Southeast Asian countries. According to the WHO, since no other treatment works as well as artemisinin-based therapies, if this resistance were to reach India or areas of sub-Saharan Africa, the consequences could be dire.
 

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