Researchers discover how the deadly malaria parasite evades the immune system, make progress toward developing a cure

December 3, 2012
Researchers discover how the deadly malaria parasite evades the immune system, progress toward developing a cure
Anopheles mosquito, carrier of the deadly Plasmodium parasite that causes malaria. Credit: Centers for Disease Control and Prevention

(Medical Xpress)—More than a million people die each year of malaria caused by different strains of the Plasmodium parasite transmitted by the Anopheles mosquito. The medical world has yet to find an effective vaccine against the deadly parasite, which mainly affects pregnant women and children under the age of five. By figuring out how the most dangerous strain evades the watchful eye of the immune system, researchers from the Hebrew University of Jerusalem have now paved the way for the development of new approaches to cure this acute infection.

Upon entering the bloodstream, the Plasmodium parasite reproduces in the and transports its proteins to their surface. These cells become sticky and cling to the walls of blood vessels, blocking them and damaging the human body. The immune system typically identifies these proteins as foreign and creates antibodies to fight the disease.

The deadliest of the five Plasmodium strains is Plasmodium falciparum, which causes more than 90% of deaths associated with malaria. This sophisticated strain deceives the immune system by revealing only one protein encoded by one of the sixty genes at its disposal. While the immune system is busy fighting that protein, the parasite switches to another protein not recognized by the immune system, thus avoiding the antibody response and re-establishing infection.

In research conducted at the Department of Microbiology and at the Institute for Medical Research Israel-Canada, and the Kuvin Center for the Study of Infectious and Tropical Diseases at the Hebrew University-Hadassah Medical School, Dr. Ron Dzikowski and research student Inbar Avraham revealed for the first time the that enables a parasite to selectively express one protein while hiding other proteins from the immune system.

By combining bioinformatic and , the researchers identified a unique DNA sequence found in the regulatory regions of the gene family that encode for these surface proteins. They showed that the parasite's ability to express only one gene while hiding the other 59 depends on this sequence. The research suggests that by interfering with the regulatory role of this DNA sequence it would be possible to prevent Plasmodium falciparum from hiding most of its destructive genes from the immune system.

According to Dr. Dzikowski, ''These results are a major breakthrough in understanding the parasite's ability to cause damage. This understanding could lead to strategies for disrupting this ability and giving the immune system an opportunity to clear the infection and overcome the disease. This clever parasite knows how to switch masks to evade an immune attack, but our discovery could lead to new ways to prevent it from continuing this dangerous game.''

The research was published this week in the Proceedings of the National Academy of Sciences.

Explore further: Discovery of key malaria proteins could mean sticky end for parasite

Related Stories

Unveiling malaria's 'invisibility cloak'

January 18, 2012

The discovery by researchers from the Walter and Eliza Hall Institute of a molecule that is key to malaria's 'invisibility cloak' will help to better understand how the parasite causes disease and escapes from the defenses ...

Malaria parasite goes bananas before sex: new study

February 14, 2012

(PhysOrg.com) -- New research from the University of Melbourne shows how the malaria parasite (Plasmodium falciparum) changes into a banana shape before sexual reproduction, a finding that could provide targets for vaccine ...

Improving human immunity to malaria

August 1, 2012

The deadliest form of malaria is caused the protozoan Plasmodium falciparum. During its life-cycle in human blood, the parasite P. falciparum expresses unique proteins on the surface on infected blood cells.

Recommended for you

New method creates endless supply of kidney precursor cells

August 25, 2016

Salk Institute scientists have discovered the holy grail of endless youthfulness—at least when it comes to one type of human kidney precursor cell. Previous attempts to maintain cultures of the so-called nephron progenitor ...

Strict diet combats rare progeria aging disorders

August 25, 2016

Mice with a severe aging disease live three times longer if they eat thirty percent less. Moreover, they age much healthier than mice that eat as much as they want. These are findings of a joint study being published today ...

New avenue for understanding cause of common diseases

August 25, 2016

A ground-breaking Auckland study could lead to discoveries about many common diseases such as diabetes, cancer and dementia. The new finding could also illuminate the broader role of the enigmatic mitochondria in human development.

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.