Induction of tolerance to histocompatibility antigens of an organ dono
r would eliminate the need for long-term administration of nonspecific
immunosuppressive drugs associated with an increased risk of infectio
n and malignancies. Recently, we established a murine model in which r
ecipient mice were treated with a single dose of anti-CD3, anti-CD4, l
ow dose of total body irradiation (TBI) and allogeneic bone marrow cel
ls. Our results clearly demonstrate that stable multilineage mixed chi
merism, immunocompetence and permanent donor-specific skin graft toler
ance across full major histocompatibility (MHC) barriers can be succes
sfully achieved in this way.:The observations that the preparative reg
imen and skin transplantation can be performed on the same day, and th
at a significant reduction in irradiation dose is sufficient in haploi
dentical donor-recipient combinations (MHC-sharing effect), bring our
protocol closer to clinical use.