Figure EV3. Antigen‐specific splenic B cells phagocytose antigens in vivo through a BCR‐driven process also dependent on RhoG.

1. WT B1‐8^hi B cells were incubated in vitro with fluorescent 1 μm beads coated with NIP‐OVA at 0°C for 1 h and subsequently left unstained or stained with an anti‐OVA antibody. B cells with extracellular membrane‐attached beads that are not internalized are positive for the fluorescent beads and the anti‐ova staining (red histogram), while the control without primary antibody is in grey.
2. Phagocytosis of 1 μm fluorescent beads covalently bound to NIP‐OVA by splenic macrophages from WT or Rhog ^−/− B1‐8^hi and WT non‐transgenic mice was assessed after 5 h post‐IP immunization using extracellular staining with an anti‐ovalbumin antibody. The cytometry plot shows staining with the anti‐OVA antibody in the CD11b⁺ F4/80⁺ macrophage population. The graph on the right shows the percentage of phagocytic splenic macrophages in WT and Rhog ^−/− mice. Data represents means and SEM (n = 3). n.s, not significant (unpaired Student's t test).