0000000000048483
AUTHOR
W Mannhardt
RELEVANCE OF MESENCHYMAL THYMUS CELLS (MC) FOR ACCEPTANCE OF ALLOGENEIC MATURE THYMUS GRAFTS AND INDUCTION OF ALLOTOLERANCE IN NUDE MICE
Allogeneic thymus (aTh) from an adult immunocompetent donor cannot be transplanted successfully in thymusless nude mice even if the graft is irradiated. The graft is destroyed for unknown reasons and no immunocompetence is achieved in the host. Two approaches were established to achieve acceptance of aTh. In experiment 1, mature aTh was transplanted in nude mice, after specific tolerance to the recipient was induced in the donor during the neonatal period. This resulted in acceptance of the aTh, immunological reconstitution and tolerance to the donor's and recipient's MHC-haplotype as proved by skin-grafts and MLC. In experiment 2, neonatal thymus was grafted into allogeneic nude mice and r…
PROMOTION OF INTRATHYMIC T-CELL DEVELOPMENT BY MHC-Ia-POSITIVE THYMIC MACROPHAGES (Ia + Mø)
The generation of the peripheral T-cell pool is attributed to maturation and differentiation events occurring within the thymus. Three thymic compartments, thymic epithelial cells, thymic hormons and thymic Mo are considered to contribute to the intrathymic T-cell development. While, as we have shown earlier, murine as well as human MHC-Ia-negative-Mo (Ia−Mo) regulate thymocyte (TH) differentiation via suppressive effects (Thymus,6:295,1984) and MHC-Ia+-Mo are involved in intrathymic tolerance induction (Pediatr Res,15:800, 1984), now the contribution of Ia+Mo to intrathymic lymphopoiesis was investigated. An isolation method yielding cell suspensions highly enriched for Ia+ thymic Mo was p…
TRANSPLANTATION AND IN VITRO ANALYSIS OF SOYBEAN-AGGLUTININ SEPARATED MOUSE SPLEEN CELLS
In human bone marrow allotransplantation, an in vitro method using soybean agglutinin(SBA) for enrichment of stem cells and depletion of mature T cells in the graft has been described (Reisner et al.;Lancet 2:1320,1980).To define the quality of the method,mouse spleen cells (C3H, C57/B6,BALB/c)containing about 30% of mature T cells were separated by SBA.The composition and functional capacity of the cell fraction known to contain the stem cells were characterized in vitro after each of two SBA-separation steps.In addition, the ability of the cell fraction to reconstitute successfully allogeneic irradiated (900R) mice was investigated. Only the two step SBA-separation procedure yielded satis…