Macroautophagy during Innate Immune Activation

Christian Münz

doi:10.3389/fmicb.2011.00072

Abstract

Innate immune activation is initiated by recognition of pathogen associated molecular patterns (PAMPs). Delivery of PAMPs to their respective receptors, regulation of receptor activity, and effector functions downstream from these receptors, which constitute part of the initiated innate immune control, are in part mediated via macroautophagy, an evolutionary conserved pathway for cytoplasmic constituent degradation in lysosomes. In this review these facets of the recently unveiled involvement of macroautophagy in innate immunity will be summarized, and aspects that need additional investigations will be high-lighted. The improved understanding of the capabilities of macroautophagy for immunity suggests that this pathway should be harnessed in immunotherapies against infectious diseases.

Highlights

Autophagy describes a group of at least three evolutionary conserved cellular degradation processes in eukaryotes that deliver cytoplasmic constituents for lysosomal degradation (Mizushima and Klionsky, 2007)
While Atg8/LC3 remains at the inner autophagosomal membrane, Atg4 cleaves it from the outer autophagosomal membrane and the Atg12–Atg5/Atg16L1 is recycled after autophagosome completion
Fusion of the completed autophagosomes with lysosomes and late endosomes is mediated by Atg6/Beclin-1 containing PI3 kinase complexes with UVRAG or Rubicon replacing Atg14L (Liang et al, 2008; Matsunaga et al, 2009; Zhong et al, 2009)

Summary

Christian Münz*

Delivery of PAMPs to their respective receptors, regulation of receptor activity, and effector functions downstream from these receptors, which constitute part of the initiated innate immune control, are in part mediated via macroautophagy, an evolutionary conserved pathway for cytoplasmic constituent degradation in lysosomes. In this review these facets of the recently unveiled involvement of macroautophagy in innate immunity will be summarized, and aspects that need additional investigations will be high-lighted.The improved understanding of the capabilities of macroautophagy for immunity suggests that this pathway should be harnessed in immunotherapies against infectious diseases

Introduction

Enhanced exocytosis

Conclusion