It has been much debated how the Drosophila immune system can recognize bacterial peptidoglycan that is hidden in Gram negative bacteria. We have shown that bacteria separated from Drosophila S2cells by a semipermeable membrane can upregulate the Imd pathway and made it likely that the shed elicitors are of peptidoglycan nature. I now want to further characterize the structure and origin of the elicitors.
