Levels of S100A10 on thioglycollate-elicited macrophages. Peritoneal macrophages were collected 4 days after injection with 4% thioglycollate. Cell lysates were prepared, and total levels of S100A10 or annexin A2 were examined by Western blotting (A) using actin as a loading control and quantitated (B). (C) Cell-surface proteins of peritoneal macrophages were incubated with Sulfo-NHS-SS-biotin, lysed, and the biotinylated (cell surface) proteins were collected with streptavidin beads and subjected to SDS-PAGE and Western blotting for S100A10, annexin A2, and F4/80 (loading control). (D) Total and cell-surface annexin A2 obtained from WT and S100A10^−/− peritoneal macrophages were compared with proteolyzed recombinant annexin A2. (E) Flow cytometric analysis of cell-surface annexin A2 and F4/80 levels in WT and S100A10^−/− (KO) peritoneal macrophages. (F) Cells were incubated with antiannexin A2 and anti-F4/80 (control) antibodies. Quantification of flow cytometric analysis of cell-surface annexin A2 and F4/80 levels in WT and S100A10^−/− macrophages, calculated using WinMDI v2.9 software (***P < .001).