Long-term amelioration of established collagen-induced arthritis achieved with short-term therapy combining anti-CD3 and anti-tumor necrosis factor treatments

Objective The goal of rheumatoid arthritis (RA) treatment is to achieve clinical remission in order to limit structural damage and physical disability. To this end, recent emphasis has been placed on aggressive treatment early in the course of disease with drugs such as antitumor necrosis factor (anti-TNF) agents. As T cells are also thought to play an important role in the initiation of RA, we hypothesized that targeting both TNF and T cells would result in better outcomes. The aim of this study was to examine the efficacy of combined therapy with anti-CD3 and anti-TNF in experimental RA. Methods Two anti-mouse antibodies were developed as surrogate reagents for anti-TNF and anti-CD3 therapies. Collagen-induced arthritis (CIA) was induced in DBA/1 mice, and antibodies were injected intraperitoneally, either alone on in combination, at predetermined subtherapeutic doses. The frequency and number of pathogenic and regulatory CD4+ T cell subsets in the draining lymph nodes were determined in order to investigate the mechanisms of action. Results Strikingly, the combination of the two antibodies demonstrated a potent synergy in established CIA, with long-term inhibition of disease progression and protection from joint destruction. The results did not demonstrate any enhancement of CD25+FoxP3+ regulatory T cells, but a profound depletion of pathogenic T cells from the draining lymph nodes was associated with reduced numbers of T cells in the joints. Conclusion A short course of combination therapy with anti-CD3 and anti-TNF efficiently depletes pathogenic T cells from the draining lymph nodes, reducing the numbers of T cells in the joints and affording long-lasting inhibition of established CIA.