Reversal of Post-Thymectomy Wasting in Mice with Immunocompetent Cells: Influence of Histocompatibility Differences

Abstract

Reversal of post-thymectomy wasting syndrome in conventional C3H/Bi mice was achieved by intraperitoneal injection of 200 × 10 spleen cells from adult syngeneic, hemiallogeneic and allogeneic donors sharing the same H2 histocompatibility locus with the host. When cells from allogeneic donors differing at the H2 locus were used, reversal of wasting did not occur and all the animals died with a graft-versus-host reaction. When neonatally thymectomized F1 hybrids were treated after the onset of the wasting syndrome with spleen cells, only syngeneic cells were effective, while parental or allogeneic cells killed the animals as a result of a graft-versus-host reaction. The reconstituted animals developed ability to reject skin allografts but were tolerant to skin grafts of donor origin, indicating adoptive immunologic restoration and a chimeric state. The chimeric state was demonstrated using chromosome marked donor cells by high numbers of donor type mitosis in the lymphoid organs of the restored animals. These findings warn against use of immunologically competent lymphoid cells differing from the host by major histocompatibility factors and encourage matching of host and donor in efforts to reverse wasting and establish competence in thymic deficiency syndromes.