Immune surveillance of intracellular pathogens via autophagy

Abstract

MHC class II molecules are thought to present peptides derived from extracellular proteins to CD4þ T cells, which are important mediators of adaptive immunity to infections. In contrast, autophagy delivers constitutively cytosolic material for lysosomal degradation and has so far been recognized as an efficient mechanism of innate immunity against bacteria and viruses. Recent studies, however, link these two pathways and suggest that intracellular cytosolic and nuclear antigens are processed for MHC class II presentation after autophagy. © 2005 Nature Publishing Group. All rights reserved.