Cellular adhesion and phagocytosis of three agents by WT and βc-null macrophages. (A) Alveolar macrophage adhesion (average cell number per area, derived as shown in Materials and Methods) with incubation in IgG2b isotype control antibody (IC5), chelator EDTA, 2F8 (MoAb to mMSR), or combination of EDTA plus 2F8. (B) Alveolar macrophage endocytosis of colloidal carbon in presence or absence of EDTA or 2F8. (C) Phagocytosis of latex beads. (D) Phagocytosis of opsonized sheep RBCs. Mean results of 2 to 4 wells, incubated at 37°C. No significant phagocytosis was observed in duplicate assays performed at 4°C. Error bars represent SD. One of three similar experiments.