Last year, thousands of people were killed and more than 13 million sick with malaria caused by the parasite Plasmodium vivax. Vaccines against the disease does not exist, in part because many strains of Plasmodium vivax circulating around the world, making it difficult to develop a vaccine that would protect from all Plasmodium species.
Now, researchers studying a protein necessary for the survival of the parasite, found the two portions of the protein that do not change in the strains. According to scientists at Washington University School of Medicine in St. Louis, antibodies that act against these parts of the protein, to protect against the disease. The results obtained will serve as a basis for a vaccine for P. vivax, the most deadly form of malaria outside Africa.
The study is published online in the Proceedings of the National Academy of Sciences.
"This protein, called the Duffy binding protein - a promising target for the development of a vaccine because the parasite does not cause infection without him - said Neeraj Toll, assistant professor of molecular microbiology and the study's senior author. - Duffy binding protein is highly variable among P. Vivax strains circulating worldwide. Any vaccine must be effective against numerous modifications plasmodium ".
Vivax gets inside human cells by fixing the binding protein to a human protein located on the immature red blood cells. If the parasite is not associated with a human protein - either because they block the binding of the antibody or because the human protein is absent - the parasite can not cause disease. P. Vivax occurs worldwide, but the disease in Africa is relatively small.
Neeraj Toll and his colleagues studied the three antibodies that prevent binding compound and human proteins and identified part of the binding protein, which in turn joined antibodies.
The researchers analyzed the effects of 511 binding proteins from strains around the world and found that the epitopes (antigenic determinant) preserved in 90-95 percent of cases. This means that the vaccine, which is directed to these epitopes must protect from almost all strains of P. Vivax.
"Our study helps to determine what goal we should set to get the universal protection, - the expert explained. - The next step will be the production of vaccines and to study how it works. "
Based on materials medicalxpress.com