Use of a Drosophila model to dissect a regulatory loop linking dietary restriction, the immune response and the nervous system

2008 senior Scholar Award in aging

We study the way that aging and immunity interact with each other. The only way we have now of extending the lifespan of a healthy person is through diet restriction. We found it interesting that when animals get infected they often become anorexic and this reduces food intake in the same way as does diet restriction. We wondered if these animals are intentionally putting themselves on a restricted diet. We started studying this problem using a model organism, the fruit fly Drosophila melanogaster. Our preliminary work shows that many infections induce anorexia in flies. This anorexia alters the immune response so that the flies become more tolerant of some infections and we suggest that this is why the flies become anorexic ñ they survive infections better. The story is more complicated though; diet restriction makes flies more tolerant of some infections but makes them very sensitive to others. We plan to determine the changes that occur in the immune response during diet restriction and to understand how the flyís brain and immune system cooperate to regulate these responses.