Murine T lymphocytes incapable of producing macrophage inhibitory protein-1 are impaired in causing graft-versus-host disease across a class I but not class II major histocompatibility complex barrier.

The routine use of bone marrow transplantation is limited by the occurrence of acute and chronic graft-versus-host disease (GVHD). Current approaches to decreasing the occurrence of GVHD after allogeneic transplantation use T-cell depletion, use immunosuppressive agents, or block costimulatory molecule function. The role of proteins in the recruitment of alloreactive lymphocytes has not been well characterized. Chemokines are a large family of proteins that mediate recruitment of mononuclear cells in vitro and in vivo. To investigate the role of T-cell production of the chemokine macrophage inhibitory protein-1 (MIP-1) in the occurrence of GVHD, splenocytes either from wild-type or from MIP-1-/- mice were administered to class I (B6.C-H2(bm1)) and class II disparate mice (B6-C-H2(bm12)). The incidence and severity of GVHD was markedly reduced in bm1 mice receiving splenocytes from MIP-1-/- mice as compared with mice receiving wild-type splenocytes. Bm1 mice receiving MIP-1-/- splenocytes had significantly less weight loss and markedly reduced inflammatory responses in the lung and liver than mice receiving C57BL/6 splenocytes. Bm1 mice receiving MIP-1-/- splenocytes had a markedly decreased production of antichromatin autoantibodies and impaired generation of bm1-specific T lymphocytes versus wild-type mice. However, MIP-1-/- splenocytes easily induced GVHD when administered to bm12 mice. This data show that blockade of chemokine production or function may provide a new approach to the prevention or treatment of GVHD but that chemokines that recruit both CD4(+) and CD8(+) lymphocytes may need to be targeted.