Back to article: Maintaining phagosome integrity during fungal infection: do or die?
FIGURE 1: Lysosome Fusion Maintains Phagosome Integrity during Fungal Infection. (A) Phagosomes expand their surface area by insertion of lysosomes. As C. albicans initiates filamentation inside the mature phagosome, luminal Ca2+ is released, leading to recruitment and insertion of lysosomes. This preserves phagosome integrity while restricting fungal growth. (B) The second wave of lysosome insertion can be inhibited by applying the Ca2+ chelator BAPTA. Preventing cytosolic Ca2+ transients during intraphagosomal growth leads to early phagosome rupture, NLRP3 inflammasome activation, and subsequent macrophage cell death. Actin polymerizes at the site where the hypha protrudes through the plasma membrane, possibly re-sealing the macrophage membrane and preventing leakage of cytosolic content.