Thursday, June 7, 2012

Immune system 'circuitry' that kills malaria in mosquitoes identified

Researchers at the Johns Hopkins Malaria Research Institute have, for the first time, determined the function of a series proteins within the mosquito that transduce a signal that enables the mosquito to fight off infection from the parasite that causes malaria in humans. Together, these proteins are known as immune deficiency (Imd) pathway signal transducing factors, are analogous to an electrical circuit. As each factor is switched on or off it triggers or inhibits the next, finally leading to the launch of an immune response against the malaria parasite. 

The study was published June 7 in the journal PLoS Pathogens.

The latest study builds upon earlier work of the research team, in which they found that silencing one gene of this circuit, Caspar, activated Rel2, an Imd pathway transcription factor of the Anopheles gambiae mosquito. The activation of Rel2 turns on the effectors TEP1, APL1 and FBN9 that kill malaria-causing parasites in the mosquito's gut. More significantly, this study discovered the Imd pathway signal transducing factors and effectors that will mediate a successful reduction of parasite infection at their early ookinete stage, as well as in the later oocyst stage when the levels of infection were similar to those found in nature.