To investigate the therapeutic effect of gene vaccine encoding chicken collagen type II (CC II) on collagen-induced arthritis (CIA) comprehensively.Three groups (CIA) were given a single intravenous injection of plasmid pcDNA-CCOL2A1 (20 microg/kg, 200 microg/kg, 400 microg/kg) respectively and one group (CIA) was injected 200 microg/kg pcDNA3.1 as a control. The effect of gene vaccine (pcDNA-CCOL2A1) was evaluated according to the arthritis score, radiological and histological examinations.The severity of arthritis of CIA rats which were administered 200 microg/kg pcDNA-CCOL2A1 was significantly reduced from the fifth day. According to the radiological and histological examinations, the articular cartilage as well as subchondral bone trabeculae are similar to those of the normal groups, so the bone and articular cartilage structure were protected after treatment with 200 microg/kg pcDNA-CCOL2A1 with a little synovial hyperplasia. The therapeutic effect of 200 microg/kg pcDNA-CCOL2A1 group has significant difference in comparison with that of the pcDNA3.1 group (P0.05) and the arthritis scores are reduced to about 50% of those in control groups, but 20 microg/kg group and 400 microg/kg group has no therapeutic effect in our observation (P0.05).The new gene vaccine pcDNA-CCOL2A1 has significant therapeutic effect on CIA rats, and the treatment may therefore be an effective strategy for RA patient clinically.
