Fungal killing by mammalian phagocytic cells

Abstract

Phagocytes are considered the most important effector cells in the immune response against fungal infections. To exert their role, they must recognize the invading fungi, internalise, and kill them within the phagosome. Major advances in the field have elucidated the roles of pattern-recognition receptors in the innate immunity sensing and the importance of reactive oxygen and nitrogen species in intracellular killing of fungi. Surprising exit mechanisms for intracellular pathogens and extracellular traps have also been discovered. These and several other recent breakthroughs in our understanding of the mechanisms used by phagocytes to kill fungal pathogens are reviewed in this work.

Figure 1. Phagocytosis of C. neoformans

Murine macrophage-like J774 cells and C. neoformans labeled with cell-tracer dyes were incubated in the presence of opsonizing antibody. Some fungal cells have already been internalized, while others are only attached to the cell membrane.

Figure 2. Phagocytosis of encapsulated C. neoformans by J774 cells

Murine macrophage-like J774 cells were infected with IgG-opsonized C. neoformans and stained with anti-capsule antibody (red) and cell wall-binding Uvitex 2B (blue).