The first line of defense against infection in all animals is the innate immune response. Innate immunity relies on the broad recognition of non-self characteristics of pathogens and the induction of effector mechanisms that will dispose of the pathogens. The ability to recognize general features of foreign microbes distinguishes it from adaptive immunity, which selects for specific antibodies or receptors to mediate its response. The innate and adaptive immune systems converge in their use of common effector mechanisms, e.g., complement, phagocytosis, and cytolytic factors. The innate immune response may also be important to prime the adaptive immune response for an effective response.

We study innate immunity in the fruit fly Drosophila melanogaster. The advantages of using Drosophila include (1) the ability to use genetics to identify and characterize new mutations, (2) the genomic resources which make it easier to clone the corresponding genes and manipulate them in vivo and (3) the fact that many biological processes are conserved between flies and humans. Our lab has done genetic and molecular screens to identify Drosophila mutants impaired in either their humoral (antimicrobial peptide induction) or cellular immune response to different microbes. We have identified genes from a number of these screens and have gained insight into the molecular mechanisms important for host defense against pathogens. Our long-term goal is to take the information from our studies of Drosophila immunity and use it for the identification and development of promising genetic targets for regulating inflammatory responses or for augmenting host resistance to bacterial infections in humans.