Therapeutic role of a vaccine targeting RANKL and TNF-α on collagen-induced arthritis.

Targeting tumor necrosis factor-α (TNF-α) and activator of NF-κB ligand (RANKL) has been proved highly successful in rheumatoid arthritis (RA) models and patients. This raises a possibility whether a single agent simultaneously targeting TNF-α and RANKL provides a potential therapeutic opportunity. This study aimed to design a dual functional vaccine and evaluate its therapeutic effects in RA mice model. Standard molecular biological techniques were used to generate human RANKL-TNF-like core fusion protein (RTFP-2) vaccine. High titers of antibodies against human TNF-α and RANKL were elicited and the RTFP-2 antiserum decreased TNF-α mediated apoptosis of L929 cells to 41% compared with 90% in positive controls. In addition, the antiserum completely abrogated osteoclastogenesis in vitro. Immunization with RTFP-2 also reduced the mortality of TNF-α induced cachexia from 56% to 28%. The RANKL-mediated hypercalcemic effects were significantly attenuated in RTFP-2 vaccinated mice. Furthermore, RTFP-2 vaccine significantly mitigated the incidence and severity of CIA via inhibition of inflammation and bone resorption. Our results showed the RTFP-2 vaccine of dual targets ameliorated the symptoms of CIA mice, suggesting the potential possibility to treat inflammatory bone diseases such as RA.