Histological assessment
Mice were sacrificed on day 56 post first CII immunization, and both hind limbs were removed. After fixation and decalcification, the joints were cut into sections and stained with hematoxylin and eosin. Quantification of histological changes was carried out by two independent and blinded observers and a histological score was assigned to each joint based on the degree of inflammation and erosion, as described previously18,19.