Summary
Groups of sensitized mice were irradiated (870 r) and injected with mouse or rat bone marrow from donors previously sensitized with the other antigen. In other experiments, lethally irradiated mice were injected with isologous bone marrow only, and either the host or the bone marrow donor was sensitized; or neither one was sensitized. Groups from each experiment were given “booster” injections of antigen at various times subsequent to irradiation and bone marrow protection. Anti-sheep-erythrocyte and antihuman-erythrocyte agglutinin titers were determined on all groups periodically after irradiation.
The results were as follows: a) All marrow-treated irradiated mice continued to produce antibodies if sensitized prior to irradiation; b) The isologous bone marrow treated, presensitized mice reacted to a “booster” with a secondary response; the heterologous bone marrow treated mice did not; c) The isologous bone marrow treated mice were capable of a primary response but the heterologous bone marrow treated mice were not.
The results may be interpreted as evidence that: a) The primary response is radiosensitive; antibody production is relatively insensitive; b) The secondary immune response is relatively radioresistant; c) treatment with isologous bone marrow leads to recovery of essentially normal immune response in the “isologous chimera.” In the heterologous chimera, the immune response, is at all times, at a very low level.
