rascal Sticky. VAR2CSA the protein (with labeled antibodies attached green) helps red blood cells infected with malaria lock on the placenta.
Malaria infects 30 million pregnant women annually, causing anemia and other problems that kill about 0,000 newborns. researchers have now identified a protein that the parasite needs to infect the placenta -. a first step toward a vaccine that could prevent malaria in pregnant women
Most adults who live where malaria is endemic have developed immunity. Exceptions are pregnant with their first or second child; a particular strain of parasite infects red blood cells and causes them to accumulate in the placenta of women, leading to severe malaria, premature births, low birth weight infants and stillbirths.
In 1995, researchers found the first clues as to why these women were vulnerable. In pregnant women, infected red blood cells stick to chondroitin sulfate A (CSA), a sugar molecule made by the placenta. To find out how they stick, Thor Theander parasitology from the University of Copenhagen in Denmark and colleagues studied the genes of the parasite that are transformed in the presence of CSA. They reported in 03 that a gene called VAR2CSA , which encodes a protein that the parasite membrane inserts on the red-blood-cell, the regime when he meets CSA.
To see if the parasite uses its protein to make VAR2CSA infected red blood cells stick to the placenta, the researchers made antibodies against VAR2CSA rabbit, then labeled with a dye. Dye-labeled antibodies VAR2CSA glued to stains on the surface of infected red blood cells that bind to CSA - circumstantial evidence that VAR2CSA was in the right place to do the job. antibodies isolated from the blood of infected pregnant women stuck Dye scored exactly the same places, showing that humans, too, could produce antibodies targeting this protein
Women with fewer antibodies -. and therefore a lower immune response - against VAR2CSA were four times more likely than women with high levels of antibodies to give birth to children seriously underweight, suggesting that they did not fight off the parasite and, the report of the team in the November 1st issue of the Journal of Experimental Medicine . Because VAR2CSA gene is widely conserved among parasite strains, researchers believe a vaccine containing part of the VAR2CSA protein could make an effective vaccine against malaria associated with pregnancy.
"It is final, high quality work that checks the target of a vaccine" against malaria associated with pregnancy, says molecular parasitologist Kirk Deitsch of Weill Medical College of Cornell University in New York. The specific strain vaccine strategy could also work to prevent P. falciparum brain infections, he said, which means that "you can eliminate two of the three leading causes of death by malaria."
Related Sites
Facts on Malaria in Pregnancy Centers for
More information on malaria associated with pregnancy of the World Health Organization Disease Control and Prevention
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