Malaria affects some five to ten percent of the world's population. New drugs to combat malaria are in great demand because the parasites that spread the disease are rapidly becoming resistant to the standard anti-malarial drugs, chloroquine and mefloquine. Although vaccines have been suggested as an alternative to drug therapy for malaria, none has proven effective at countering the disease. One of the keys to developing a successful vaccine lies in finding just the right molecule that can stimulate an immune response against the invading pathogen.
Now, researchers led by Louis Schofield, a Howard Hughes Medical Institute international research scholar at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Australia, have identified a toxin, glycosylphosphatidylinositol (GPI), that contributes to the virulence of malaria in mice, and quite likely in humans. The scientists published their work on GPI in the August 15, 2002, issue of the journal Nature.
"In 1886, it was proposed by Camillo Golgi that malaria produces a toxin that appears to be associated with the intense periodic fevers caused by the infection," said Schofield. "In 1993, we published findings on the properties of GPI, showing that it was a toxin that produces a potent inflammatory response both in cell culture and in mice. That work proposed GPI to be the toxin that Golgi hypothesized more than one hundred years earlier. Our work also led us to believe that GPI constituted an excellent target for a vaccine."