Innate immune response of Aedes aegypti

Insects are able to protect themselves from invasion by pathogens by a rapi d and potent arsenal of inducible immune peptides. This fast, extremely eff ective response is part of the innate immunity exhibited by all insects and many invertebrates, and shows striking similarities with the innate immune response of vertebrates. In Aedes aegypti invasion of the hemocoel by bact eria elicits the production of defensins, cecropins, a peptide active only against Gram-negative bacteria, and several other peptides that we are now characterizing. However, not all insects utilize the same peptides in the s ame concentrations, which may reflect the pathogens to which they may have been exposed through evolutionary time. These protective measures we see in mosquitoes are the current state of the evolution of a rapid immune respon se that has contributed to the success of insects in inhabiting essentially every niche on earth. The molecules involved in the response of Aedes aegy pti to pathogens, and the potential role of these peptides against eukaryot ic parasites ingested and transmitted by mosquitoes are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.