ULBP4 expression on tumor- and EBV-infected B cells. (A) Cell-surface expression of ULBP4 on tumor cells. The indicated tumor cells were stained with unconjugated anti-ULBP4 mAb 8C9 (black line histograms) or control Ig (gray filled histogram) followed by FITC-conjugated goat anti–mouse IgG. Analyses were measured on a FACSCalibur flow cytometer. (B) Immunohistochemistry staining of colonic carcinoma specimen (40×/0.65 NA oil objective lens), ovarian epithelial carcinoma specimens (20×/0.4 NA oil objective lens), and liver carcinoma specimens (40×/0.65 NA oil objective lens). Slides were viewed with a Leica DM3000 microscope. Images were acquired using a Leica DFC420 camera, and were processed with Leica QWin plus version 3.5.0 software. Staining was visualized using diaminobenzidine as the substrate. (C) Surface expression of ULBP4 in B lymphocytes before or after EBV infection. The indicated cells were stained with the anti-ULBP4 mAb 8C9 (black line histograms) or control Ig (gray filled histogram) followed by FITC-conjugated goat anti–mouse IgG. (D) Cytotoxicity of PBMC-Vδ2T cells against EBV-B cells with or without anti-ULBP4 mAb 8C9. Data represent means ± SD (error bars) of 3 independent experiments.