Chimaerism of immunocompetent cells in allogeneic bone marrow-reconstituted lethally irradiated chickens.

Injection of parental bone marrow cells into 12-day-old lethally irradiated F1 hybrid chickens resulted in chimaerism of donor-type graft-versus-host (GVH)-reactive cells and suppression of antisheep red blood cell antibody response. These manifestations of a chronic graft-versus-host reaction were prevented by pretreatment of the donor marrow with specific anti-T cell globulin. In some chimaeras donor-type GVH-reactive cells developed gradually from T cells precursors of donor origin. Transplantation of spleen and marrow cells from sheep red blood cell-primed F1 hybrid donors into lethally irradiated parental recipients resulted in the loss of memory potential within 1-2 weeks of transfer, whereas donor-type IgG allotype synthesis was preserved. Injection of goat antichicken thymocyte serum to recipients 1 day before reconstitution enabled the antibody response of memory cells at 1-2 weeks, although it failed to prevent their rejection by 8-9 weeeks after transplantation. Split chimaerism of donor-type GVH-reactive cells was demonstrated in chickens which had previously rejected the B cells derived from the same graft.