Analysis of T Lymphocytes Cloned from Rejected Kidney Allograft: High Frequency of Cytotoxic T Cell Precursor

Abstract

A high proportion of CD8 positive cells and inverted CD4/CD8 ratio were found in peripheral blood mononuclear cells and in freshly isolated kidney-graft infiltrating cells in two patients who underwent irreversible acute rejection. Seventy seven T cell clones were generated from the T cell blasts infiltrating rejected kidney allografts. The majority of T cell clones obtained showed CD8 phenotype in accordance to uncloned graft infiltrating cells. All clones (both CD8 and CD4) displayed cytolytic activity evaluated by lectin-dependent cell-mediated cytotoxicity and natural killer (NK) activities. None of the clones presented lymphokine activated killer phenomenon. These data suggest that the graft infiltrate is characterized by T cell clones with cytolytic potential and that these T cell clones may be responsible for the killing of graft cells by a CTL or NK type mechanism.