Edinburgh scientists have found a way to "switch on" an immune cell to help people fight a tropical disease.
Snail fever, or bilharzia, causes a chronic illness which impairs growth and brain development in children.
Edinburgh University experts examined the immune system response in mice infected with the parasites from fresh water snails which cause the infection.
They found one cell type was responsible for triggering the body's defence against the invader.
It is hoped that developing medicines, which manipulate the vital dendritic cell could protect millions of people in the future.
About 200 million people in Asia, Africa and South America are thought to be infected with the disease.
Andrew MacDonald, of Edinburgh University, who led the research, said: "Upwards of 200,000 to 300,000 people a year are dying, just in sub-Saharan Africa, from this disease every year.
"Until now, we were unsure which of the many cells found in the immune system were crucial to fighting this parasite.
"We now know that dendritic cells are key to the process.
"If we can manipulate this immune response, we stand a chance of targeting the widespread suffering and chronic illness caused by this infection."
Dr MacDonald, of the university's school of biological sciences, said the dendritic cell is important for recognising the infection and sending out signals to neighbouring cells, "switching them on" to help fight the disease.
He said: "We know we can say that these cells are important, and that's the starting point, but now we need to pinpoint why they're important and that's the harder challenge.
"What is it that these cells do? How do they respond to this infection? What do they produce that then turns on those other neighbouring cells to do their job properly?
"If we can identify a molecule, something that's produced by these dendritic cells, that's critical for switching on the right type of protective response, then obviously we can help protect against these diseases."
The study, published in the Journal of Experimental Medicine, was carried out alongside researchers from the German Cancer Research Centre in Heidelberg.
It was funded by the Medical Research Council and the Wellcome Trust.