Transplantation of embryonic haemopoietic stem cells without prior recipient X-irradiation.

Allogeneic day 7 mouse embryonic cells can colonize the haemopoietic system of normal, non-irradiated recipient mice. Donor embryonic cells are disaggregated and injected intravenously resulting in colonization in 40% of recipients, as shown by the presence of electrophoretic markers, characteristic of the donor cells. Donor type haemoglobin (Hb) and donor type glucose phosphate isomerase (GPI) demonstrates the presence of donor type erythrocytes and lymphocytes respectively. Repeat grafts in recipients not showing donor makers did not result in colonization. Recipient type haemopoiesis was dominant in all types of recipient. Skin grafts of allogenic donor type skin onto successfully grafted embryonic cell recipients did not survive. Allogeneic donor embryonic cells therefore survive in recipients where adult skin allografts do not. Donor embryonic cells, homozygous for T6 marker chromosomes, were used to assess the site of colonization of intravenously grafted cells. Donor chromosomes were seen in recipient liver and bone marrow at low levels. This distribution of donor cells persists for up to 64 d post-graft.