Discovery may aid vaccine design for common form of malaria

January 9, 2014

A form of malaria common in India, Southeast Asia and South America attacks human red blood cells by clamping down on the cells with a pair of proteins, new research at Washington University School of Medicine in St. Louis has revealed.

The study provides details that will help scientists design better vaccines and drug treatments for the strain, Plasmodium vivax.

"More people live at risk of infection by this strain of than any other," said senior author Niraj Tolia, PhD, assistant professor of molecular microbiology and of biochemistry and molecular biophysics. "We now are using what we have learned to create vaccines tailored to stop the infectious process by preventing the parasite from attaching to red blood cells."

The finding appears Jan. 9 in PLOS Pathogens.

The World Health Organization estimates there were more than 200 million malaria cases in 2012. The deadliest form of malaria, Plasmodium falciparum, is most prevalent in Africa. But P. vivax can hide in the liver, re-emerging years later to trigger new infections, and is harder to prevent, diagnose and treat.

Earlier studies had suggested that one P. vivax protein binds to one protein on the surface of red blood cells. Tolia's new study reveals that the binding is a two-step process that involves two copies of a parasite protein coming together like tongs around two copies of a .

"It's a very intricate and chemically strong interaction that was not easily understood before," Tolia said. "We have had hints that other forms of malaria, including the African strain, may be binding in a similar fashion to host cells, but this is one of the first definitive proofs of this kind of attack."

Tolia suspects blocking any of the proteins with drugs or vaccines will stop the infectious process.

"For example, some people have a mutation that eliminates the protein on surfaces that P. vivax binds to, and they tend to be resistant to the parasite," he said. "This is why this strain isn't prevalent in Africa—evolutionary pressure has caused most of the populations there to stop making this protein."

Tolia also found evidence that other people with immunity to P. vivax have developed naturally occurring antibodies that attach to a key part of the parasite's binding protein, preventing infection.

"The parasite protein is very large, and human antibodies bind to it at many different points along its length," Tolia explained. "We have observed that the ones that are most effective so far are the antibodies that bind to the at the region highlighted by our new research."

Explore further: Study finds protein in platelets fight malaria but only for some people

More information: Batchelor JD, Malpede BM, Omattage NS, DeKoster GT, Heinzler-Wildman KA, Tolia NH. Red blood cell invasion by Plasmodium vivax: structural basis for DBP engagement of DARC. PLOS Pathogens, online Jan. 9, 2014.

Related Stories

Study finds protein in platelets fight malaria but only for some people

December 7, 2012
(Medical Xpress)—Researchers in Australia have found that a protein in platelets found naturally in blood has a protective effect against malaria. In their paper published in the journal Science, the team describes how ...

New research finds potential risk for millions in Africa believed resistant to vivax malaria

November 15, 2013
Provocative new research shows that the Plasmodium vivax parasite, responsible for nearly 20 million cases of malaria in 2010, may be "rapidly evolving" to overcome the natural resistance conferred by a blood type found in ...

Vivax malaria may be evolving around natural defense

November 15, 2013
Researchers at Case Western Reserve University and Cleveland Clinic Lerner Research Institute have discovered recent genetic mutations in a parasite that causes over 100 million cases of malaria annually—changes that may ...

What makes the deadliest form of malaria specific to people?

December 2, 2013
Researchers have discovered why the parasite that causes the deadliest form of malaria only infects humans.

Cell surface mutation protects against common type of malaria

December 1, 2011
A mutation on the surface of human red blood cells provides protection against malaria caused by the parasite Plasmodium vivax, research led by Case Western Reserve University School of Medicine shows.

Building a better malaria vaccine: Mixing the right cocktail

December 26, 2013
A safe and effective malaria vaccine is high on the wish list of most people concerned with global health. Results published on December 26 in PLOS Pathogens suggest how a leading vaccine candidate could be vastly improved.

Recommended for you

Want to win at sports? Take a cue from these mighty mice

July 20, 2017
As student athletes hit training fields this summer to gain the competitive edge, a new study shows how the experiences of a tiny mouse can put them on the path to winning.

'Smart' robot technology could give stroke rehab a boost

July 19, 2017
Scientists say they have developed a "smart" robotic harness that might make it easier for people to learn to walk again after a stroke or spinal cord injury.

Engineered liver tissue expands after transplant

July 19, 2017
Many diseases, including cirrhosis and hepatitis, can lead to liver failure. More than 17,000 Americans suffering from these diseases are now waiting for liver transplants, but significantly fewer livers are available.

Lunatic Fringe gene plays key role in the renewable brain

July 19, 2017
The discovery that the brain can generate new cells - about 700 new neurons each day - has triggered investigations to uncover how this process is regulated. Researchers at Baylor College of Medicine and Jan and Dan Duncan ...

New animal models for hepatitis C could pave the way for a vaccine

July 19, 2017
They say that an ounce of prevention is worth a pound of cure. In the case of hepatitis C—a disease that affects nearly 71 million people worldwide, causing cirrhosis and liver cancer if left untreated—it might be worth ...

Omega-3 fatty acids fight inflammation via cannabinoids

July 18, 2017
Chemical compounds called cannabinoids are found in marijuana and also are produced naturally in the body from omega-3 fatty acids. A well-known cannabinoid in marijuana, tetrahydrocannabinol, is responsible for some of its ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.