Scientists find a cytokine against auto-immune hepatitis

Jul 5 2006

There are about 400 million patients of hepatitis in the world. Some of them are suffering from autoimmune hepatitis, a disease in which the body's immune system attacks liver cells.

A research team headed by Prof. TIAN Zhigang from the University of Science and Technology of China (USTC) recently discovered that a cytokine, a protein produced by white blood cells that act as chemical messengers between cells, could prevent mice liver from immune-mediated injury. The work, which was published at the recent issue of prestigious journal HEPATOLOGY, is applauded as providing guidance for the treatment of human autoimmune hepatitis.

Con-A-induced hepatitis is considered a good experimental model of human autoimmune hepatitis with characterized by leukocyte activation and infiltration of the liver. Using the model, Prof. Tian and colleagues found that injection of Interleukin-15 (IL-15), an important cytokine, could prevent mice from Con A-induced mortality, elevation of serum transaminase, liver necrosis, and hepatocyte apoptosis.

The researchers discovered that the mechanism for this lies in the fact that IL-15 pretreatment could decrease the NKT-derived IL-4, IL-5, and TNF- production, thereby resulting in less infiltration of eosinophils, which play a critical role in Con A-induced liver injury. Their studies indicate that IL-15 protects against Con A-induced liver injury via an NKT cell-dependent mechanism by reducing their production of IL-4, IL-5, and infiltration of eosinophils. These findings suggest that IL-15 may be of therapeutic relevance in human autoimmune-related hepatitis.