MDL-1 blockade inhibits bone erosion and inflammation. (A) Hind paws from mice in Fig. 3D were harvested on day 11 and prepared for MicroCT analysis. Images show high resolution three-dimensional rendering of MicroCT scans. MDL-1 Ig-fusion protein (antagonist)–treated mice show no sign of cortical bone destruction, whereas the agonist MDL-1 antibody (clone: DX163) treated mice show greater bone destruction than control IgG1-treated mice. Results are representative of three separate experiments. (B) Quantification of bone integrity indicates increased bone loss in anti–MDL-1 agonist-treated mice. Comparable regions of interest (ROI) consisting of three metatarsal joints from each mouse were selected for analysis. Bone volume (BV), bone mass (BM), bone mineral density (BMD = BM/BV mg/cm³), and mean cortical thickness (mm) were quantified from MicroCT scans using GE MicroView software v2.2. Student’s t test was used to determine significance where ***, P < 0.001; **, P < 0.01; *, P < 0.05. (C) ELISA quantification of Serum TRAP 5b and RANKL. Day 20 serum levels of TRAP5b and RANKL from individual mice are shown. TRAP5b levels from day 11 also show similar results. * indicates P < 0.05 by Student’s t test analysis.