Autophagy in Macrophages: Impacting Inflammation and Bacterial Infection

Figure 4

The autophagic response against intracellular pathogens (xenophagy) is shown. Xenophagy is initiated by the recognition of various PAMPs of different bacteria by corresponding TLRs. The invading microorganisms are phagocytized and delivered to autophagosomes. Xenophagy proceeds as either a nonselective or selective uptake of bacteria via signals, autophagic adaptors, and receptors. For the selective uptake, ubiquitinated bacteria are recruited into autophagosomes via sequestosome 1/p62-like receptors proteins. Another means of xenophagy is LC3-associated phagocytosis, which represents the recruitment of LC3 to phagosomes following TLR activation. LC3 recruitment to such phagosomes triggers the fusion with lysosomes. All three different xenophagy pathway ends with lysosomal fusion leading to degradation of the engulfed pathogen.