Researchers from the Hebrew University for the first time cracked the mechanism that allows the deadly malaria parasite to trick the immune system and took a significant step towards developing a cure for the disease
More than a million people die every year from the malaria disease caused by different strains of the Plasmodium parasite transmitted to humans by the Anopheles mosquito. However, despite the devastating dimensions of the disease, the world of medicine has yet to find an effective vaccine against the deadly parasite that mainly affects children under the age of 5 and pregnant women. Now, researchers from the Hebrew University have deciphered for the first time how the dangerous strain manages to evade the scrutinizing eyes of the immune system, thus paving the way for the development of a cure for the severe infectious disease.
The deadliest of the five Plasmodium strains is the Plasmodium falciparum strain which causes more than 90% of the deaths associated with malaria. The uniqueness of this species lies in its sophisticated ability to trick the immune system. When the parasite enters the blood system, it multiplies inside the red blood cells and transports its proteins to the surface of the cells, which become sticky, adhere to the blood vessel wall, block them and damage the human body in a destructive way. The immune system that recognizes the proteins as a "foreign factor" reacts by developing antibodies against them and thus fights the disease. However, the species in question has developed a sophisticated genetic system that allows it to trick the immune system - it reveals to the immune system only one version of the protein encoded by one of the sixty genes it possesses. And while the immune system fights against that protein, the parasite switches to another version of the protein that is not recognized by the immune system.
In a study conducted by Dr. Ron Dzikowski and research student Einbar Avraham from the Kovin Center for the Study of Infectious and Tropical Diseases at the Israel-Canada Medical Research Institute of the Hebrew University, for the first time they were able to understand the genetic mechanism that allows the parasite to express only one protein to the immune system and hide the other proteins. While combining research methods from the fields of computer science, life sciences and medicine, the researchers found a unique DNA sequence found in the 60 protein-coding genes of the parasite and showed that the parasite's ability to silence 59 genes, and express only one gene, depends on this sequence. From this it follows that by disrupting the DNA sequence of the protein it will be possible to prevent the parasite from hiding most of its "violent" genes from the immune system.
According to Dr. Dzikovski, "the research results are a breakthrough in understanding the parasite's mechanisms of violence and may lead to the development of new methods that will force the parasite to express the entire range of genes, thus exposing them to the immune system that can recognize them and act against them." This sophisticated parasite knows how to change masks and thus hide his true intentions and abilities, but our discovery will prevent him from continuing this dangerous game."
The research was published this week in the prestigious journal PNAS and was conducted with funding from the National Academy of Sciences and the Einstein Kay Foundation, which supports outstanding research students.
