PTX3-mediated increase of A fumigatus conidia phagocytosis depends on CD11b and is associated to CD11b activation. (A) The phagocytosis assay was performed in the presence of 10% NHS and anti-CD11b (M1/70) or anti-CD11c (3.9) blocking antibodies or control IgGs. Results are mean ± SEM of 3-5 pooled experiments. *P ≤ 0.05; **P < .01; Student paired t test. (B) FACS analysis of activated CD11b associated with the membrane or present in permeabilized cells (membrane and intracellular) on neutrophils after incubation of whole blood with PTX3-opsonized conidia for 15 minutes. The histogram shows 1 of 9 donors analyzed with similar results. (C) Ratio of activated and total CD11b MFI PE/APC in permeabilized cells after incubation for 15 minutes with conidia or PTX3-opsonized conidia (n = 6).