The insulin receptor substrate Chico regulates antibacterial immune function in Drosophila.

Background Molecular and genetic studies in model organisms have recently revealed a dynamic interplay between immunity and ageing mechanisms. In the fruit fly Drosophila melanogaster, inhibition of the insulin/insulin-like growth factor signaling pathway prolongs lifespan, and mutations in the insulin receptor substrate Chico extend the survival of mutant flies against certain bacterial pathogens. Here we investigated the immune phenotypes, immune signaling activation and immune function of chico mutant adult flies against the virulent insect pathogen Photorhabdus luminescens as well as to non-pathogenic Escherichia coli bacteria.