CXCL10 and autoimmune diseases.

CXCL10 is a 10 kDa protein, which is categorized functionally as a Th1-chemokine. It binds to the receptor CXCR3 and regulates immune responses through the activation and recruitment of leukocytes, such as, T cells, eosinophils, and monocytes. Recent reports have shown that serum and/or tissue expressions of CXCL10 are increased in various autoimmune diseases like rheumatoid arthritis (RA), systemic lupus rythematosus (SLE), Sjogren syndrome (SS), systemic sclerosis (SSc), and idiopathic inflammatory myopathy (IIM). Moreover, CXCL10 and CXCR3 may have important roles in leukocyte homing to inflamed tissues and in the perpetuation of inflammation, and therefore, tissue damage. Our recent study shows that CXCL10 also has a pathogenic role in bone destruction via receptor activator of NF-kappaB ligand (RANKL) induction in inflamed synovial tissue of RA. In addition to its chemotactic effect, CXCL10 may have pleiotropic functions. Further research on the function of this chemokine and interactions between CXCL10 and other cytokines and chemokines may provide therapeutic targets in various autoimmune diseases.