Summary
It is known that the preirradication injection of rat bone marrow cell suspensions into mice accompanying protection against radiation death. Since it has been reported by Billingham et al. that the antigenic stimuli for rejection of skin homografts in mice are confined to nuclear fractions and further that transplantation immunity to skin homografts cannot be transferred with specific sera, it was of interest in the present context to ascertain whether or not the antigens for rat bone marrow rejection by mice, similarly, were confined to the nuclear fractions. The passive transfer of transplantation immunity to rat marrow heterografts in irradiated mice was also studied with various antisera.
The results of the present study indicate that rat erythrocytes (non-nucleated cells) and rat leukocytes (nucleated cells) both contain antigens that can, when injected into mice prior to lethal irradiation, induce a state of transplantation immunity. Under appropriate conditions transplantation immunity can be passively transferred to irradiated mice by means of specific rat erythrocyte or rat leukocyte antisera.
It is suggested that in the heterologous system studied here, there may be a multiplicity of antigens (of non-nuclear as well as of nuclear origin) any one of which might elicit effective transplantation immunity.
