[Analysis of the murine autologous mixed lymphocyte reaction. II. Role of thymus in maturation of the responder T cells].

Bone marrow chimera mice sharing an identical H-2 K end as the donor were able to respond in an autologous mixed lymphocyte reaction (AMLR). On the other hand, bone marrow chimera made from histoincompatible partners or partners having identical D end of the H-2 were unable to respond. In the secondary responses of the AMLR primed cells from semiallogeneic bone marrow chimera, T cells responded specifically only to the cells which shared identical H-2 haplotypes with the recipient. AMLR primed cells from F1 T cell deprived mice (F1 At X BM mice) transplanted with the thymus grafts were able to respond only to the cells bearing identical H-2 haplotypes with the thymus grafts. It therefore becomes clear that responder cell activity of the AMLR is genetically restricted by the MHC along the pathway of their maturation through the thymus microenvironment. However, an experiment using athymic nude mice suggests the presence of another pathway for being restricted to the stimulator cells, because nude mice which were unable to respond in the AMLR could generate the reaction after thymic grafting from allogeneic donor.