The role of 'eat-me' signals and autophagy cargo receptors in innate immunity

Selective autophagy is an important effector mechanism of cell autonomous immunity, in particular against invasive bacterial species. Anti-bacterial autophagy is activated by rupture of bacteria-containing vacuoles and exposure of bacteria to the cytosol. The autophagy cargo receptors p62, NDP52 and Optineurin detect incoming bacteria that have become associated with specific 'eat-me' signals such as Galectin-8 and poly-ubiquitin and feed them into the autophagy pathway via interactions with phagophore-associated ATG8-like proteins. Here we review recent progress in the field regarding the origin of bacteria-associated 'eat-me' signals, the specific roles of individual cargo receptors and how disrupting cargo receptor function may be important for bacterial evasion of autophagy.