Noncanonical autophagy: one small step for LC3, one giant leap for immunity

Abstract

Noncanonical autophagy is utilized by phagocytes to kill and digest extracellular pathogens. This process is initiated at the cell surface by receptors that recruit elements of the autophagy machinery, like LC3, to the phagosome. Also known as LC3-associated phagocytosis, the intersection of autophagy and phagocytosis was initially described as a pathway that limits the proliferation of engulfed pathogens by expediting phagosome maturation. Emerging evidences suggest that this pathway confers previously unsuspected versatility to the immune response as it regulates functions like the interferon pathway, dead cell clearance, and antigen presentation. Here we review recent advances in understanding the functional consequences of linking the autophagy machinery to phagocytosis in innate immunity.