Volume 13 Issue 3, May 2020

Salmonella Typhimurium (S. Tm, red) attempts to overcome the intestinal epithelium (wall) to invade systemic body sites (city) with the help of its flagellum. Intestinal epithelial cells (IECs, bricks) and dendritic cells (light blue cells, “police men”) are equipped with NAIP receptors (blue arms) that are able to bind to the flagellum. IECs are highly effective in preventing S. Tm invasion of systemic sites by NAIP-mediated elimination of S. Tm from the intestinal epithelium. S. Tm downregulates its flagellum upon successful invasion (top of the wall) and thereby evades immune cell mediated recognition via NAIP/NLRC4. Illustration by Federico Cecere. For further information please see article in this issue, pages 530-544.