Mosquito immune responses and malaria transmission: lessons from insect model systems and implications for vertebrate innate immunity and vaccine development

The introduction of novel biochemical, genetic, molecular and cell biology tools to the study of insect immunity has generated an information explosio n in recent years. Due to the biodiversity of insects, complementary model systems have been developed. The conceptual framework built based on these systems is used to discuss our current understanding of mosquito immune res ponses and their implications for malaria transmission. The areas of insect and vertebrate innate immunity are merging as new information confirms the remarkable extent of the evolutionary conservation, at a molecular level, in the signaling pathways mediating these responses in such distant species . Our current understanding of the molecular language that allows the verte brate innate immune system to identify parasites, such as malaria, and dire ct the acquired immune system to mount a protective immune response is very limited, Insect vectors of parasitic diseases, such as mosquitoes, could r epresent excellent models to understand the molecular responses of epitheli al cells to parasite invasion. This information could broaden our understan ding of vertebrate responses to parasitic infection and could have extensiv e implications for anti-malarial vaccine development. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.