Thymus-Marrow Cell Combinations. Synergism in Antibody Production.∗

Summary Suspensions containing normal thymus, spleen, or marrow cells were injected into irradiated syngeneic mice which were subsequently given antigen. Normal spleen cells produced discrete areas of antibody production in recipient spleens, and the number of areas was proportional to the number of donor cells. Mice receiving both marrow and thymus cells produced more centers of hemolytic activity in their spleens than mice receiving cells of either type alone. Normal and immunized thymus cells produced little or no hemolytic activity, and normal marrow was also inactive.