Intestinal autophagy activity is essential for host defense against Salmonella typhimurium infection in Caenorhabditis elega

Salmonella typhimurium infects both intestinal epithelial cells and macrophages. Autophagy is a lysosomal
degradation pathway that is present in all eukaryotes. Autophagy has been reported to limit the
Salmonella replication in Caenorhabditis elegans and in mammals. However, it is unknown whether intestinal
autophagy activity plays a role in host defense against Salmonella infection in C. elegans. In this
study, we inhibited the autophagy gene bec-1 in different C. elegans tissues and examined the survival
of these animals following Salmonella infection. Here we show that inhibition of the bec-1 gene in the
intestine but not in other tissues confers susceptibility to Salmonella infection, which is consistent with
recent studies in mice showing that autophagy is involved in clearance of Salmonella in the intestinal epithelial
cells. Therefore, the intestinal autophagy activity is essential for host defense against Salmonella
infection from C. elegans to mice, perhaps also in humans.