Maturation process of pathogen-containing phagosomes. Diagram outlining the differences between endosome progression to lysosome (center), maturation of a phagosome harboring a live pathogen, for example, M. tuberculosis H37rv (left) and a phagosome harboring a dead pathogen (right). The fusion processes of phagosomes containing live/dead pathogens with compartments of the endosomal pathway are indicated by bold arrows. The traced arrows indicate inhibition of the fusion events between the phagosome harboring the live pathogen and the endocytic compartment. The diagram also illustrates the importance of two components of the cell’s cytoskeleton in phagosome maturation. Actin is recruited to the phagocytic cup and might nucleate on the phagosome membrane during the maturation process. The microtubules, to which endocytic vesicles and phagosomes are thought to bind during the maturation process, are also represented. EE: early endossome; MVB: multivesicular bodies; LE: late endosome; LY: lysosome. Diagram adapted from [71].
