MDL-1 blockade inhibits autoimmune arthritis. (A) C57BL/6 control, Dap12^−/−, and Mdl1^−/− mice were injected with arthrogenic mAbs to induce CAIA. Mean clinical scores (n = 5/group) ± SEM are shown. Result is representative of two studies. * indicates statistical significance. (B) Hind paw mRNA from A was isolated for gene expression analysis. The absolute values of the inflammatory genes are shown in Fig. S7. (C) MDL-1 activation enhanced T cell– and myeloid cell–dependent arthritis. B10RIII mice were immunized with bovine type II collagen emulsified in CFA at day 0 to induce collagen-induced arthritis. Anti–MDL-1 agonist (clone DX163) was given on day 18 of immunization. Statistical significance was determined by analysis of variance (ANOVA). Results are representative of two studies. (D) B10RIII mice (n > 5/group) were given 1.5 mg of Arthrogen to induce CAIA. MDL-1 Ig fusion protein or control proteins were administrated at the time of Arthrogen treatment. * indicates statistical significance (P < 0.001) as determined by ANOVA analysis.