CD43 is selectively shed from murine cells. (A) Flow cytometry analysis of CD43 cell surface expression on murine cell lines using CD43 antibody S11. Cells were stimulated for 3 hours with 10 nM TPA (solid line), vehicle alone (dashed line), and isotype control (dotted line). (B) Flow cytometric analysis of CD43 cell-surface expression on bone marrow–derived mast cells, macrophages, granulocytes, and CD43-deficient mast cells reconstituted with FLAG-CD43. Cells were stimulated for 3 hours with 10 nM TPA (solid line), vehicle alone (dashed line), and isotype control (dotted line). (C) Western blot analysis of FLAG immunoprecipitates from cell lysates (5 × 10⁶ cells/well) and conditioned media of primary mast cells, activated CD8 T cells (spleen), and MC/9 cells infected with FLAG-CD43. Data are representative of at least 2 repeat experiments.