Bone marrow and spleen: dissociation of immunologic properties by cortisone.

Bone marrow and spleen cells react differently after treatment with cortisone acetate in vivo. Antibody-forming, hematopoietic, and proliferative responses of spleen cells are reduced, while bone marrow cell responses are not. The stimulation of spleen cells by phytohemagglutinin is abolished, but the response of marrow cells is enhanced. These reactions provide functional markers for the different cells involved in immunologic responses.