Mice deficient for DNAM-1 are not protected from collagen-induced arthritis at histological assessment. (a) Collagen antibodies levels detected by Elisa. 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 were similar in dnam1+/+ and dnam1−/− mice, confirming the immunization with collagen in all mice. (b) Example of a knee section stained by hematoxylin-eosin revealing inflammatory infiltrates (arrow) but no erosions in a dnam1+/+ mouse. Example of a tarsus section stained by hematoxylin-eosin revealing inflammatory infiltrates (arrow) but no erosions in a dnam1−/− mouse. Bar: 100μm. (c) Inflammatory score at histological assessment was not significantly different in dnam1+/+ mice and dnam1−/− mice. 7 dnam1+/+ mice and 5 dnam1−/− mice were used. Values are the median ± IQR.