Analysis of cytotoxic T lymphocyte response in rejecting allografted canine kidneys

The involvement of cytotoxic T lymphocytes (CTL) in the rejection process of allografted canine kidneys was studied. The frequency of donor-specific (precursor) CTL was determined with a sensitive limiting dilution assay. Longitudinal sampling of peripheral blood and kidney aspiration biopsies were used to obtain information on the CTL response toward the graft. An accurate analysis of CTL kinetics in both kidney and peripheral blood of allografted dogs appeared to be technically possible. During the first days after transplantation precursor CTL (CTLp) frequencies decreased in both blood and kidney. A minimum CTLp frequency of 5-15% of the pretransplant value was reached in the peripheral blood at day 4 after transplantation. The cause of this decrease, which was observed in all 5 allografted dogs is discussed. CTLp frequencies increased after day 4 and showed an exponential rise in the kidney before serum creatinine increased due to loss of kidney function caused by rejection. The data obtained with the quantitative study of CTL show that rejection of a canine kidney allograft is accompanied by a rise in CTL numbers in the kidney. The methodology developed permits extensive functional analysis of cellular processes in allografted organs.