Abstract:Objective To establish a DBA/1J mouse model of collagen-induced arthritis (CIA) and to characterize the pathological and immunological changes of the model. Methods Bovine type Ⅱ collagen (CⅡ) was emulsified in complete Freund's adjuvant (CFA), subcutaneously injected at the root of tail of DBA/1J mice for primary immunization, and the injection was repeated 21 days later for secondary immunization. The changes of body weight, degree of joint swelling and other morphological indicators of arthritis were observed and pathological changes in the ankle joints were analyzed. The serum levels of inflammatory cytokines were detected by cytometric bead assay (CBA). Results The body weight of the CIA mice began to decrease 35 days after primary immunization and was continuously lower than that in the control group. 28 days after the primary immunization, their paws began to tern red and swollen, and after 35 days, the thickness of swollen paws of the CIA mice was significantly greater than that in the control group (P < 0.05). The incidence rate of CIA reached 90% on the 62nd day. Pathological examination showed a narrowed articular space, hyperplasia of synovial tissue, inflammatory cell infiltration and varying degrees of cartilaginous damage. Compared with the control group, the serum levels of inflammatory cytokines IL-6, IFN-γ and MCP-1 were significantly increased in the CIA mice (P< 0.05), while the anti-inflammatory cytokine IL-10 was slightly decreased (P> 0.05). Conclusions A collagen-induced arthritis model can be successfully established by subcutaneous injection of bovine collagen type Ⅱ emulsified in complete Freund's adjuvant at the root of tail of DBA/1J mice, and provides a useful experimental tool for further studies of pathogenesis of and drug development for rheumatoid arthritis.