Silencing of Lpd in macrophages disrupts phagocytosis and yields an aberrant F-actin morphology at the phagocytic cup. (A–C) Lpd immunostaining (red) in resting RAW 264.7 macrophages expressing Lpd-shRNA and soluble GFP (green). (B) Lpd immunostaining in control RAW 264.7 macrophages during phagocytosis. (C) Lpd immunostaining in Lpd-silenced RAW 264.7 macrophages (green) during phagocytosis. Asterisks denote sites of particle engagement. Insets are magnifications of the area within the dotted boxes showing Alexa Fluor647–conjugated phalloidin staining (blue) and Lpd staining (red). Similar results were observed in three independent experiments. (D) Representative confocal extended-focus projection of RAW 264.7 macrophages with and without expression of Lpd-shRNA (green) following a 10 min incubation with IgG-opsonized SRBCs. Inside-outside staining was performed to differentiate between internalized/total (red) and non-internalized (blue) SRBCs. (E) Quantification of the phagocytic efficiency in Control-shRNA and Lpd-shRNA RAW 264.7 macrophages. Unpaired t test of individual phagocytic efficiency values n = 95 (Ctrl-shRNA), n = 98 (Lpd-shRNA), across N = 3 independent experiments; data are means ± SEM. ****, P < 0.0001.