Epithelial Nitration by a Peroxidase/NOX5 System Mediates Mosquito Antiplasmodial Immunity

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Science  26 Jan 2012:
DOI: 10.1126/science.1209678


Plasmodium ookinetes traverse midgut epithelial cells before they encounter the complement system in the mosquito hemolymph. We identified a heme peroxidase (HPX2) and NADPH oxidase 5 (NOX5) as critical mediators of midgut epithelial nitration and antiplasmodial immunity that enhance nitric oxide toxicity in Anopheles gambiae. We show that the two immune mechanisms that target ookinetes—epithelial nitration and thioester-containing protein 1 (TEP1)–mediated lysis—work sequentially and propose that epithelial nitration works as an opsonization-like system that promotes activation of the mosquito complement cascade.