Fig. 6.

IFN-β enhances macrophage efferocytosis during the resolution of inflammation. a–c Peritoneal macrophages were recovered from male Ifnb^+/+ or Ifnb^−/− mice at 48 h PPI and stained with Hoechst 33342 and FITC-phalloidin (a). Fluorescent images of select frames were taken using high-resolution microscopy achieved by 3D confocal (z-stack) scanning with a Nikon A1-R confocal fluorescent microscope. The number of apoptotic PMN nuclei in each macrophage were enumerated (see arrowheads for illustration) using the Nikon NIS-Elements microscope imaging software and average engulfment per macrophage (b) or engulfment according to thresholds (c) were calculated. Representative images (a) and means ± SEM (b, c) for six (Ifnb^+/+) and three (Ifnb^−/−) experiments. d–f Peritoneal macrophages were recovered from male Ifnb^+/+ or Ifnb^−/− mice at 48 h PPI and incubated with CypHer-labeled apoptotic Jurkat cells at a ratio of 1:3. After 4 h, unbound cells were washed and macrophages were stained with Hoechst 33342 and FITC-phalloidin (as illustrated in d). Select images of each staining and merged images are shown (e). The number of engulfed apoptotic cells (AC) in each macrophage (M) were counted and average apoptotic cell uptake (f) and the percentage of efferocytosing macrophages (g) were calculated. h The total numbers of F4/80⁺ peritoneal macrophages was detected by flow cytometry and calculated. Representative images (e) and means ± SEM (f–g) for four (Ifnb^+/+) and five (Ifnb^−/−) independent experiments. *P < 0.05, ***P < 0.005 (Student’s t test). Source data are provided as a Source Data file