National scientific medical meeting 1995 abstracts

Abstract

Little is known about hepatic T lymphocyte subpopulations in the human liver. The aim of this study was to document the various subpopulations present in the liver and compare them to peripheral T lymphocytes in the same patients. Normal hepatic tissue was obained at time of transplant from five patients, and a single cell suspension of lymphocytes were prepared by standard methods. Ceils were stained with monoclonal antibodies specific for CD8ct and CD8B chains, CD4, CD8, CD3, o~BTCR, and ySTCR, and analyzed by two and three colour flow cytometry. Of the hepatic CD3+ cells, 71% were CD8+ and 25% were CD4+, with a CD4/CD8 ratio of 1:3 in contrast to the peripheral CD4/CD8 ratio of 2:1.18% of the hepatic CD3+ cells expressed ySTCR. Significantly, CD8~ct accounted for 27% [mean] of the total hepatic CD8+ population. Conclusion: There is now evidence that the adult human gut can support extrathymic T cell differentation. A significant population of hepatic CD8txct cells would suggest that the liver is also a site of extrathymic differentiation, which may have important implications for the understanding of autoimmunity and graft tolerance.