Programmed cell death mediated by ced-3 and ced-4 protects Caenorhabditis elegans from Salmonella typhimurium-mediated killing

Programmed cell death (PCD) in mammals has been implicated in several disea se states including cancer, autoimmune disease, and neurodegenerative disea se. In Caenorhabditis elegans, PCD is a normal component of development. We find that Salmonella typhimurium colonization of the C. elegans intestine leads to an increased level of cell death in the worm gonad. S. typhimurium -mediated germ-line cell death is not observed in C. elegans ced-3 and ced- 4 mutants in which developmentally regulated cell death is blocked, and ced -3 and ced-4: mutants are hypersensitive to S. typhimurium-mediated killing . These results suggest that PCD may be involved in the C. elegans defense response to pathogen attack.