Response of Mtb to phagocytosis

Mycobacterium tuberculosis (Mtb) encounters a vastly changed environment shortly after being internalized by macrophages. The compartment it resides in, the phagosome, is acidified and devoid of important metal ions and is flooded with reactive oxygen and nitrogen species. Steps will be soon taken by the macrophage to "mature" the phagosome with all kinds of lysosomal digestive enzymes. However, unlike most other bacteria species, Mtb has evolved solutions to each of these threats. As a last resort to a strong immune response, some bacteria will enter a dormant state (de Chastellier 2009, Flannagan et al. 2009). To what extent this is true is still unclear. Upon weakening of the immune defense, Mtb reawakens from its dormant state and starts to multiply inside the phagocyte.

Summary from Reactome (R-HSA-9637690), read 2026-09-23.