Аннотация:The deletion induced by an antigenic peptide in vivo results in accumulation in liver of mature T lymphocytes characterized by a lower expression of T-cell receptors and coreceptor molecules on their surface, which leads to apoptosis of these cells. It has been shown that in mice immunized with the allogeneic tumor cells having different MHC class I molecule, the fraction of functional effector cytotoxic T lymphocytes (CTL) specific toward molecule H-2Kb is two to four times higher in the liver mononuclear population than in spleen. Analysis of liver mononuclears at this stage using a fluorescent-activated cell sorter (FACS) reveals a double amount of CD8+ cells along with a lower content of CD4+ and CD3+CD4-CD8-. In both organs two months after immunization, long-lived memory cells were found which were capable of antigen-specific proliferation in vitro in response to the priming alloantigen presented on the surface of stimulators either killed by heating at 45°C or subjected to heat shock. FACS analysis of these populations using antibodies to CD3, CD4, CD8, TCR α/β, and CD44 did not reveal any essential differences in the populations of naive T lymphocytes (not preactivated with specific antigen) and those primed with alloantigen. Thus, at different times after allogeneic immunization in vivo, effector CTL are accumulated in liver, and they can be detected either by functional or by phenotypic features. At the same time, the long-lived memory cells that can be revealed by functional features are also accumulated in liver. These facts point to the direct involvement of liver in the allogeneic immune reaction in vivo. A model is proposed according to which liver is the organ selecting memory T cells with the high-affinity T cell receptors.