Involvement of Tim-3 in clearance of apoptotic cells in vivo. Mice (n = 4-6 per group) were treated with rIgG, RMT3-23, and/or RMT4-54 (200 μg each per mouse) twice a week for 4 weeks. (A) Apoptotic cells in paraffin-embedded spleen sections from these mice were detected by TdT-mediated dUTP nick-end labeling (TUNEL) method. Nuclei were counterstained with hematoxylin. Representative sections (top panels, ×20 magnification) were shown. Black bars indicate 100 μm. White squares mark the areas shown at a higher magnification (bottom panels, ×80). (B) The number of TUNEL-positive cells was counted in at least 10 randomly chosen follicles, represented as columns (**P < .01). (C) Anti-dsDNA antibody levels in serum were determined by ELISA. P values compared with rIgG are shown. Similar results were obtained in 2 independent experiments.