We examined the molecular pathogenesis of graft-versus-host disease–associated (GVHD-associated) liver injury in mice, focusing on the role of chemokines. At the second week after cell transfer in the parent-into-F1 model of GVHD, CD8+ T cells — especially donor-derived CD8+ T cells — infiltrated the liver, causing both portal hepatitis and nonsuppurative destructive cholangitis (NSDC). These migrating cells expressed CCR5. Moreover, macrophage inflammatory protein-1α (MIP-1α), one of the ligands for CCR5, was selectively expressed on intralobular bile duct epithelial cells, endothelial cells, and infiltrating macrophages and lymphocytes. Administration of anti-CCR5 antibody dramatically reduced the infiltration of CCR5+CD8+ T lymphocytes into the liver, and consequently protected against liver damage in GVHD. The levels of Fas ligand (FasL) mRNA expression in the liver were also decreased by anti-CCR5 antibody treatment. Anti–MIP-1α antibody treatment also reduced liver injury. These results suggest that MIP-1α–induced migration of CCR5-expressing CD8+ T cells into the portal areas of the liver plays a significant role in causing liver injury in GVHD; thus, CCR5 and its ligand may be the novel target molecules of therapeutic intervention of hepatic GVHD.
Masako Murai, Hiroyuki Yoneyama, Akihisa Harada, Zhang Yi, Christian Vestergaard, Baoyu Guo, Kenji Suzuki, Hitoshi Asakura, Kouji Matsushima