Mechanisms of tolerance in murine radiation bone marrow chimeras. I. Nonspecific suppression of alloreactivity by spleen cells from early, but not late, chimeras.

摘要: Allogeneic chimeras were prepared using lethally irradiated B6 hosts and untreated marrow from exsanguinated BALB/c donors. For about two months after reconstitution, had very weak antihost cell-mediated lymphocytotoxicity (CML) reactivity little third-party alloreactivity. During this time a cell population capable of suppressing CML against both host alloantigens (i.e., antigen-nonspecific) was demonstrated in chimera spleens by vitro mixing experiments. The putative suppressor cells Thy-1-negative radiation-sensitive. Subsequently, mature showed tolerance strong At point mechanisms could no longer be demonstrated. These data are consistent with clonal elimination hypothesis that they do not provide evidence to indicate maintenance specific immune is mediated an active mechanism.