Anti-IL-23p19 therapy inhibits the adoptive transfer of syngeneic graft-versus-host disease

Syngeneic graft-versus-host disease (SGVHD), a chronic inflammatory disease, develops following irradiation, syngeneic bone marrow transplantation (BMT) and treatment with the immunosuppressive agent cyclosporine A (CsA). We have shown that T_H1 and T_H17 cytokine responses are increased during the development of SGVHD. The current study was designed to further investigate the involvement of T_H17 immunity in SGVHD-associated colitis. IL-23 is a T_H17 cytokine responsible for maintaining the effector functions of T_H17 cells. The administration of anti-mouse IL-23p19 was shown to significantly reduce the clinical symptoms of primary and secondary SGVHD-associated colitis resulting in a significant reduction in both T_H1 and T_H17 associated cytokine expression. These results demonstrate that the T_H17-associated cytokine, IL-23, may prove to be a beneficial therapeutic target in the treatment of chronic colon inflammation.