Deadly Interfer(on)ence In Malaria

Malaria is a devastating disease that infects more than 250 million people worldwide, and in a  small percentage of individuals, many of whom are children,  the infection can  progress to life-threatening  cerebral malaria. The host response to Plasmodidium falciparum, the parasite that  causes cerebral malaria, is thought to contribute to disease pathogenesis. In order to better  understand this phenomenon, Sharma et al. performed global gene expression profiling and  found that type I interferons, which are cytokines typically associated with antiviral immunity,  were enriched in cells isolated from febrile patients with malaria. Further analysis demonstrat-ed that AT-rich regions of the P. falciparum genome, which number over 6000, induced type I  interferon production by human cells. Surprisingly, none of the known nucleic acid sensors of the host immune system weree required f for p parasite-induced d type I interferon production. This response, however, did depend on STING and TBK1, p proteins known to signal l downstream other DNA sensorss. Because type I interferons can cause immune pathollogy, the role of the STING-TBK1-type I interferon pathway was examined in a mouse model of cerebral malaria. Genetic ablation of  this pathway in mice resulted  in protection  from disease. Whether  this  pathway is also an important driver of cerebral malaria in humans will need to be examined.

SOURCE : SCIENCE MAGAZINE VOL 333