B cells and autoimmune liver diseases.

Autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) are the three major autoimmune diseases affecting the liver. They are all characterized by the presence of a variety of autoantibodies, some of which are found in all three diseases, whereas others are restricted to one or two of them or are even specific for the particular disease. In this review we will first provide details of the serological features of these three autoimmune diseases that target the liver. In addition, we will highlight the possible pathogenic roles of autoreactive B cells, focusing on their immunological functions as autoantibody producing cells and as antigen-presenting cells for T cell priming. As well, we will describe the contribution of toll-like receptor (TLR) signaling to the activation of autoimmune B cells and the putative role of defects in regulatory T cell function in the development of autoimmune liver diseases.