Transplantation of hematopoietic and lymphoid cells in mice.

CBA mice were exposed to a supralethal dose of whole body X-irradiation and recieved transplants of graded, small doses of bone marrow, fetal liver, or fetal liver plus fetal thymus cells obtained from H-2 matched C58 or H-2 mismatched A donors. Survival at 20 days was used to evaluate the ability of the transplants to restore hematopoiesis following the acute radiation injury. In the higher dose ranges of 6 X 10(7) and 1.2 X 10(8) cells/kg body weight, the fetal cells were as effective as adult bone marrow in both the matched and mismatched strain combinations. Survival at 100 days was used to evaluate the severity of chronic graft-versus-host disease produced by each of the transplants. In the higher dose ranges, cells from fetal donors promoted higher long-term survival rates than did comparable doses of bone marrow cells in both the matched and mismatched strain combinations. In some experimental groups, the addition of fetal thymus cells to fetal liver cells resulted in higher short-term and long-term survival rates than did fetal liver alone, but this was inconsistent and generally fell short of statistical significance. The most important finding was that cells from mismatched unrelated fetal donors (using a cell dose per kilogram body weight comparable to the number of fetal liver and thymus cells which would be obtainable from one human fetus at 14 weeks of embryonation) promoted higher long-term survival rates than did bone marrow transplants from matched unrelated donors.