Graft versus host inhibition: fetal liver and thymus cells to minimize secondary disease.

Long-lived radiation chimeras were produced in mice diflering at the major histocompatibility locus. Survival occurred in lethally irradiated recipients inoculated with allogeneic fetal liver and allogeneic fetal thymus cells in combination. The survival rate was equal or superior to that of mice with transplanted syngeneic fetal, neonatal, or adult hematopoietic cells.