DNAM-1 is involved in rejection of DNAM-1 ligand-expressing RMA tumor cells. (A) CD155-RMA and CD112-RMA were stained with DNAM-1-Fc chimeric protein, which had been incubated with an excess of TX42 mAb (bold line) or control IgG (thin line), and then analyzed by flow cytometry. Staining with control human IgG1 (dotted line) and blocking of the DNAM-1-Fc staining with an excess of TX42 mAb or control IgG was performed to show the inhibitory function of TX42 mAb for DNAM-1 ligand recognition. (B) Splenocytes from mice were stained with FITC-conjugated anti-CD3 and PE-conjugated DX5 and analyzed 7 days after injection with TX42 mAb (200 μg intraperitoneally on day 1 and day 3) by flow cytometry. (C) Groups of 5 C57BL /6 mice were pretreated with control immunoglobulin or anti–DNAM-1 mAb at day -1. The mice were inoculated subcutaneously in the back at day 0 with 1 × 105 mock-transduced RMA tumor cells or Cd155-transduced RMA tumor cells. The skin regions were subjected to histologic analysis with hematoxylin-eosin under light microscopy at day 8. Data are representative of 3 mice in each group. (D) Survival data for 5 mice per group are shown.
