Transplantation of antibody-forming cells in lethally irradiated mice.

A comprehensive study of the relative contribution of normal versus presensitized bone marrow or spleen tissue to the antibody-forming mechanisms of lethally irradiated mice was made. Bone marrow cells transplanted into the irradiated animals showed definite antibody-forming potential when marrow was obtained from presensitized donors but lacked this capacity if normal, nonsensitized donors were used. In contrast, both normal and presensitized spleen cells transplanted into the irradiated host were able to initiate an immune response to the test antigen. The marked efficiency of the spleen over the bone marrow was indicated by the ability of 12 × 106 presensitized spleen cells to produce agglutinins in amounts comparable to that observed in normal mice undergoing a secondary type of response. Different presensitization procedures of the donors also revealed differences in the efficiency of the transplanted hematopoietic cells to produce antibody in the irradiated host. The increased antibody-forming potential of both bone marrow and spleen cells from presensitized donors was demonstrated in two in vivo biologic tests: a) there was a relative decrease in the ability of marrow and spleen cells from presensitized donors to protect lethally irradiated isologous mice; and b) in a homologous transfer of cells, marrow and spleen cells from donors sensitized to the homologous recipient showed a detrimental effect when transplanted into lethally irradiated homologous mice.