Effects of supralethal total body irradiation and bone marrow reconstitution upon immunologic memory.

The transplantation of bone marrow from prospectively selected genotypically and pedigree DLA-identical donors into supralethally irradiated littermate and nonlittermate recipients within the Copperstown beagle colony has regularly resulted in the establishment of long-term chimerism, with no evidence of graft-versus-host disease in the recipients. It has been demonstrated that irradiated recipients exhibit significant decreases in their ability to muster primary immunological responses during the first months after reconstitution with bone marrow. Beyond the documented capacity of preirradiation blood transfusions to interfere with subsequent engraftment of allogeneic marrow, however, there have been no systematic studies of the possible effects of irradiation and bone marrow transplantation upon immunologic memory. The present study was designed in order to assess this question in greater detail, with particular regard to the effects of irradiation and bone marrow reconstitution upon host sensitization to skin allografts. The results indicate that, within the experimental limitations described, the state of sensitivity produced by first set skin allograft rejection is not affected significantly by supralethal total body irradiation and reconstitution of the recipient with allogeneic bone marrow.