TNT003 prevents phagocytosis of hRBCs exposed to CAD patient plasma samples and NHS. (A) Representative example of the phagocytosis assay run by using a single patient sample. CellTracker Green–labeled hRBCs sensitized in plasma and subsequently exposed to 25% NHS were incubated in the presence of retinoic acid–treated THP-1 cells to induce phagocytosis. hRBCs sensitized in the presence of normal human plasma and subsequently exposed to NHS showed little C3 fragment deposition on the cell surface (red bars, right y-axis) and were minimally taken up by THP-1 cells (black bars, left y-axis), similar to what was observed with CA-sensitized hRBCs not exposed to NHS. In contrast, CA-sensitized hRBCs exposed to NHS exhibited significant C3 fragment deposition on their cell surface and were readily phagocytosed by THP-1 cells. NHS exposure in the presence of an IC IgG2 mAb or an anti-C5 mAb (both 100 μg/mL) did not prevent C3 fragment deposition or RBC phagocytosis. In contrast, TNT003 (100 μg/mL) prevented both C3 fragment deposition and hRBC phagocytosis. (B) Bar graph depicting data generated from 10 different experiments using 5 separate CAD patient samples (2 experiments per patient sample). Data are normalized to control (CAD plasma plus 25% NHS) for both phagocytosis and C3 fragment deposition across all experiments.