Islanders may hold key to malaria vaccine
Scientists may have discovered how to develop a vaccine to beat the killer disease malaria, it was revealed today.
Biologists have found a genetic mutation that provides resistance to the disease in people from Papua New Guinea.
It is hoped that the findings can be adapted to develop a vaccine to the virus, which kills up to two million people a year.
The team of scientists at the University of Edinburgh found that the Papua New Guineans were protected against severe malaria as they lack a sticky protein called complement receptor one (CR1).
In many blood samples from children with severe malaria, the malaria parasite sticks to the surrounding red blood cells.
This phenomenon, known as “rosetting”, is much less common in children with milder forms of the illness.
The Edinburgh team, led by Dr Alex Rowe, decided to investigate the phenomenon more closely with funding from the Wellcome Trust and UK Medical Research Council.
His previous work has shown that the parasite was sticking to a protein on the human red blood cell CR1.
Dr Rowe said: “We reasoned that if rosetting was causing the symptoms of severe disease, then you would expect evolution to select CR1-deficient people whose blood cells rosette less, so we’ve been studying CR1 in individuals from populations most affected by severe malaria.”
The latest results were striking, as almost all the people tested were deficient in CR1.
Researcher Ian Cockburn, who collected the samples in collaboration with the Papua New Guinea Institute of Medical Research, said: “We were amazed to find that 80% to 90% of Papua New Guineans had very low CR1 levels compared to Europeans.
“In fact, some samples had no detectable CR1 at all.”
The group, which published its results in the journal Proceedings of the National Academy of Sciences, went on to determine the genetic basis of CR1 deficiency and to show that the genetic mutations that cause CR1 deficiency protect against severe malaria.
Understanding the basis of natural protection against disease can lead to new treatments.
Dr Rowe said: “The discovery is a bit like sickle cell anaemia, which is another genetic disorder that protects against severe malaria in Africans.
“The key difference with this finding is that we understand how CR1 protein deficiency protects people from severe malaria, and that means we have identified a pathway against which drugs and vaccines can be developed.”
