During their life cycle, malaria parasites produce vast numbers of successive proliferative stages in their vertebrate hosts, and yet in the field most mosquitoes are free of parasites. Rodrigues et al. report that the immune system of mosquitoes is primed early-on when the malaria parasite (Plasmodium spp.) first crosses the mosquito gut epithelial barrier. A substantial (2- to 3.2-fold) increase in a single type of hemocyte (macrophage-like insect immune cells) is implicated in long-lived antiplasmodial immunity. This work may prove important for malaria control and for understanding immune memory in invertebrates.
J. Rodrigues, F. A. Brayner, L. C. Alves, R. Dixit, C. Barillas-Mury, Hemocyte differentiation mediates innate immune memory in Anopheles gambiae mosquitoes. Science 329, 1353–1355 (2010). [Abstract] [Full Text]