The malaria parasite wreaks havoc in the body, in part by activating receptors that normally detect the presence of microbes and initiate innate immune responses. By interfering with these 'Toll-like' receptors in a mouse model of cerebral malaria, the worst symptoms of the disease can be prevented, say Ricardo Gazzinelli at the University of Massachusetts Medical School in Worcester and his team.

By activating Toll-like receptors, the malaria parasite triggers the excessive release of inflammatory immune molecules called cytokines. The researchers used a small molecule to block Toll-like-receptor activation in mice after they had been infected with malaria. The inhibitor vastly improved the animals' survival and decreased the prevalence of cerebral malaria symptoms such as seizures, even though it did not decrease the number of parasites. The strategy might help to cut malaria mortality in the absence of a preventive vaccine, the authors say.

Proc. Natl Acad. Sci. USA doi:10.1073/pnas.1015406108 (2011)