Anti-DNAM-1 monoclonal antibody does not protect from the development of collagen-induced arthritis at histological assessment. (a) Collagen antibodies levels detected by Elisa in mice injected with anti-DNAM-1 antibody, control IgG antibody and PBS. A standard curve was created for each assay by including serial dilutions of a reference sample obtained from the pooled sera of all immunized mice on each plate. The reference sample was arbitrarily assigned an antibody concentration of 1 AU/mL. Antibody concentrations for each serum sample were obtained by reference to this standard curve and were expressed in relative titer to this reference sample. Collagen antibodies levels are similar in the three groups, confirming the immunization with collagen. (b) Examples of knee sections stained by hematoxylin-eosin revealing inflammatory infiltrates (arrow) but no erosions in the three groups, i.e. treated with anti-DNAM-1 monoclonal antibody, treated with control IgG antibody and injected with PBS. Bar: 100μm. (c) Inflammatory score at histological assessment had a no significant trend to be lower in mice injected with anti-DNAM-1 as compared to those treated with control IgG and PBS. Values are the median ± IQR.