Her2 CAR macrophages trogocytose target SKOV3 cells. (A) Schematic shows the design of the Her2 CAR (right) compared with the native Fc receptor (left). The Her2 CAR contains an extracellular scFv recognizing Her2 and activates phagocytosis via the intracellular signaling domain from the endogenous Fc receptor common gamma chain. (B) Schematic (left) describes the assay quantified in the graph (right). SKOV3 cells dyed with CellTrace Far Red were added in suspension to adherent Her2 CAR GFP or control GFP (GFP-CAAX) bone marrow–derived macrophages (BMDMs). Flow cytometry was used to measure the percent of macrophages (GFP⁺) that internalized cancer cell material (Far Red⁺). (C) Her2 CAR GFP (green) macrophages were visualized interacting with SKOV3 cancer cells (mCh-CAAX; magenta) using time-lapse confocal microscopy. Stills from the images are depicted on the left, and the percent of macrophages engaging in trogocytosis (internalizing part of a cell) or phagocytosis (internalizing a whole cell) is graphed to the right. These stills correspond to Video 1 (top) and Video 2 (bottom). In B and C, data were compared using a two sided Student’s T test. N = 3 experiments, consisting of ≥100 macrophages with independently generated and infected BMDMs. In all graphs, bars represent the mean ± SEM. Data collected on the same day are annotated with the same shape point. * denotes P < 0.05; **** denotes P < 0.0005. Scale bar denotes 20 μm.