Zürich: Test for malaria protection

Research lead | Licensing opportunity

Parasite glycosylphosphatidylinositol (GPI), a sugar molecule, is an important toxin in malaria disease, and people living in malaria-endemic regions often produce high levels of anti-GPI antibodies. An understanding of the body’s natural response to anti-GPI antibodies is crucial for the development of carbohydrate-based vaccines against the toxin. Now a team at the ETH–Zürich in Switzerland led by Professor Peter Seeberger has produced a test that can identify the presence of these antibodies. The test will be available for licensing.

Tests show that blood samples taken from adults living in areas of Africa where malaria is endemic contain specific antibodies against particular GPIs. While infection is still possible despite the antibodies, the consequences are less serious. The immune system recognises the GPIs as foreign bodies and blocks their toxic impact.

Not living in high-risk areas, Europeans lack the relevant antibodies. As soon as Europeans are infected with malaria, the number of antibodies increases significantly. Subsequently, there is a direct link between the amount of antibodies and protection against the disease.

Faustin Kamena, a postdoc in Seeberger’s lab, has developed a special chip that can, inexpensively and with minute quantities of blood serum and sugar molecules, determine whether someone has formed particular antibodies against various GPIs. To this end, the researchers use the purest possible GPIs. These can be produced synthetically and in large amounts in a laboratory, as the Seeberger team has demonstrated in earlier research.    

The new method involves affixing to glass slides more than 64 pads comprising pinpoint dots. Every little pad consists of several tiny heaps of different GPIs in varying concentrations. When blood serum is then administered to such a pad, possible antibodies specifically bind to certain sugar molecules. Dyes then reveal to which GPIs the antibodies have attached themselves.

Thanks to the information obtained from the chip, scientists can produce the specific sugar molecules that the immune system has to recognise. The findings on natural resistance subsequently acquired are crucial to developing a sugar-based malaria vaccine. This could prove particularly beneficial to children in malaria-infested regions.

Most of the millions of malaria sufferers are children under the age of five, as only adults develop antibodies against the malaria pathogen’s sugars. An infant’s immune system is incapable of recognising and combating the toxic sugar molecules – hence the need for a new, selective vaccine. “This evidence is another important step towards finding a malaria vaccine because we now know which antibodies protect adults,” says Seeberger.