Bone marrow and lymph node cells in the rejection of skin allografts in mice.

In mice whose bone marrow and lymphoid tissue had been destroyed by irradiation, skin allograft rejection with all the typical histological features could be brought about by injection of marrow cells alone. Lymph node cells alone failed to permit rejection or to induce cellular infiltration of the graft site. However, the addition of lymph node cells accelerated the graft rejection induced by injection of marrow cells. It is suggested that as in delayed hypersensitivity and enhanced cellular immunity, the bone marrow is the source of effector cells and that these may be instructed to function by lymphoid cells.