Figure 5.

Schematic depiction of the interaction between M-ficolin-opsonized A. fumigatus and the innate immune system of the host. M-ficolin interacts with different life stages of A. fumigatus. The M-ficolin ligand on the surface of resting conidia (1) is unknown, however the effects of opsonization may be overlapping with other A. fumigatus life stages. Swollen conidia (2), germlings (3) and hyphae forming stages (4) expose cell wall polysaccharides β-glucan and chitin, which mediates M-ficolin interaction. M-ficolin enhances fungal polysaccharide-mediated pulmonary epithelial IL-8 secretion involved in phagocyte recruitment and enhances complement activation. The complement activation does not result in the formation of membrane attack complexes (MAC). Possible effects of M-ficolin-enhanced activation of phagocyte functions are unknown.