Autophagy and immunity

Abstract

Autophagy is a highly conserved and regulated process in eukaryotic cells by which components of the cytoplasm, such as damaged organelles and foreign pathogens, become enveloped into double-membrane autophagosome vesicles that fuse with the lysosome for degradation. Autophagy has recently been implicated in modulation of both host innate and adaptive immune systems in response to infection. This chapter discusses how the autophagy pathway becomes activated upon bacterial or viral infection, the role of autophagy proteins in regulating innate immune signaling pathways, and the importance of autophagy in antigen presentation. Specifically, this chapter examines how pathogen-encoded virulence factors evade degradation by blocking the induction, nucleation, elongation, or maturation steps in the autophagy pathway. We also discuss how certain pathogens enhance autophagy induction or usurp autophagic machinery for their own replication. A comprehensive understanding of autophagic response to foreign pathogens may enable the discovery of novel antibiotic and antiviral drug targets.