Bone Marrow Transfusions in Previously Irradiated,Hematologically Normal Syngeneic Mice 1

Abstract

Abstract

Transfusion of syngeneic marrow into normal, nonirradiated recipients results only in minimal proliferation of donor cells. However, irradiated recipients, restored to hematologic normalcy by an initial marrow transfusion, subsequently sustain proliferation which replaces approximately 10% of endogenous marrow after a single transfusion of 4 × 10⁷ marrow cells of the same strain as the host. Cells from histoincompatible donors proliferate only rarely or minimally in the marrows of these irradiated, but hematologically normal recipients without reirradiation. Syngeneic male donor cells proliferate in irradiated and restored female mice, while female donor cells fail to proliferate in the marrow of syngeneic male recipients. A possible explanation is that transfused female cells respond immunologically to the abundant H-Y antigen in the male environment and are eliminated as a result.