A SECRETED EFFECTOR PROTEIN OF SALMONELLA-DUBLIN IS TRANSLOCATED INTOEUKARYOTIC CELLS AND MEDIATES INFLAMMATION AND FLUID SECRETION IN INFECTED ILEAL MUCOSA

Enteritis induced by non-typhoid pathogenic Salmonella is characterize d by fluid secretion and inflammatory responses in the infected ileum. The inflammatory response provoked by Salmonella initially consists l argely of a neutrophil (PMN) migration into the intestinal mucosa and the gut lumen. The interactions between Salmonella and intestinal epit helial cells are known to play an essential role in inducing the infla mmatory response. Upon interaction with epithelial cells salmonellae a re able to elicit transepithelial signalling to neutrophils. This sign alling is recognized as a key virulence feature underlying Salmonella- induced enteritis. However, the nature and mechanism of such signallin g has not been clarified to date. Here, we characterize SopB, a novel secreted effector protein of Salmonella dublin, and present data imply ing that SopB is translocated into eukaryotic cells via a sip-dependen t pathway to promote fluid secretion and inflammatory responses in the infected ileum.