Figure 4.

Altered phagocytosis of human senescent neutrophils by BM, but not peritoneal, AnxA1^−/− macrophages in vitro. BM macrophages were obtained following 5 d culture of BM cells obtained from WT and AnxA1^−/− mice in GM-CSF-rich medium. Peritoneal macrophages were prepared following peritoneal lavage of WT and AnxA1^−/− mice. A, B) Human neutrophils were obtained from healthy volunteers; after an overnight culture they were incubated with BM (A) or peritoneal macrophages (B) for 30 min. C, D) Subsequently, MPO staining was conducted to determine the extent of neutrophil phagocytosis. Total (C) and cell surface-associated (D) AnxA1 levels were determined in both resident BM and peritoneal macrophages; values are normalized to respective isotype control. Results are means ± se of 4 animal cell preparations/group. *P < 0.05 vs. respective control group.