Abstract
In vitro cultures of mouse bone marrow cells, maintained for periods up to 7 wk, were shown to contain cells able to repopulate irradiated hosts with T and B lymphocytes. The lymphocytes were fully functional and there did not appear to be any gross restriction of their receptor repertoire. The cultured cells reconstituted irradiated semiallogenic hosts without evidence of graft-versus-host disease, suggesting that culture of donor marrow might be a useful preliminary to transplantation when tissue matching is incomplete.