Mycophenolate Mofetil Protects Septic Mice via the Dual Inhibition of Inflammatory Cytokines and PD-1.

Due to the imbalance between hyper-inflammation and hypo-inflammation, which are characterized by excessive cytokine productions and programmed death 1 (PD-1) upregulation, respectively, sepsis remains a highly lethal inflammatory syndrome with limited effective therapies. Mycophenolate mofetil (MMF), an immunosuppressant, has been reported to attenuate various inflammatory diseases. However, the role of MMF in sepsis therapy remains to be elucidated. C57BL-6J mice underwent cecal ligation and puncture (CLP) and were treated either with or without MMF. Survival rate and organ injuries were compared. Cytokine levels, bacteria clearance, apoptosis of spleen and peritoneal macrophages, and PD-1 expression were assessed. At the beginning of CLP, 60 mg/kg MMF administered by gavage significantly protected septic mice, which was evidenced by improved survival and attenuated organ injuries, decreased cytokines, lower bacterial loads, and alleviated immune cell apoptosis. In addition, immune cells in the MMF mice showed lower PD-1 expression and improved immune response to pathogeny stimuli. MMF protects septic mice via the dual inhibition of cytokine releasing and PD-1 expression.