JAK2 inhibition in murine systemic lupus erythematosus

Evaluation of: Lu LD, Stump KL, Wallace NH et al. Depletion of autoreactive plasma cells and treatment of lupus nephritis in mice using CEP-33779, a novel, orally active, selective inhibitor of JAK2. J. Immunol. 187, 3840-3853 (2011). Systemic lupus erythematosus is a systemic autoimmune disease characterized by the presence of myriad autoantibodies, some with pathogenic potential, and diverse clinical manifestations. Involvement of the kidney is a major cause of morbidity and mortality in human lupus patients and in murine models of the disease. It is hoped that more specific inhibition of crucial disease pathways would improve patient response rates, while reducing the considerable rates of drug-related side effects associated with current therapy. IL-6 has a pivotal regulatory role in the development and maturation of long-lived plasma cells, one of the key cell types driving the lupus disease phenotype as the source for the majority of lupus-related autoreactive antibodies. In this study, Lu et al. target the IL-6 signal transduction pathway using a specific JAK2 inhibitor of the JAK-STAT pathway, CEP-33779. In murine lupus models, they show significant improvement in nephritis, and prolonged survival, in mice treated with CEP-33779. The study presents the promise of a novel pathway for therapeutic intervention in systemic lupus erythematosus using a medication administered orally.