Concentric Fibrosis and Cellular Infiltration Around Bile Ducts Induced by Graft-Versus-Host Reaction in Mice: A Role of CD8⁺ Cells

Abstract

We report in this paper on obvious fibrotic lesions in the liver of mice undergoing specified graft-versus-host reaction (GVHR). B6 CD8⁺ splenocytes were transferred into (bm 12 × bm 1)F₁ mice to induce GVHR. Recipient mice had been thymectomized and administrated with anti-CD8 monoclonal antibody (mAb) to deplete CD8⁺ cells from the hosts. Two weeks after the mAb administration, recipient mice were injected with B6 CD8⁺ cells and sacrificed further two or four weeks later for analyzing hepatic lesions histopathologically. Light microscopic analyses revealed the presence of concentric fibrosis around both small and large duct levels and the infiltration of mononuclear cells into portal areas. Focal necrrosis of hepatocytes was also detected electron-microscopically. These findings suggest that CD8⁺ T lymphocytes might play an important role in the induction of fibrotic lesions in the liver.

Key Words:

• concentric fibrosis
• primary biliary cirrhosis
• CD8⁺ cells
• GVHR