CELL-MEDIATED CYTOTOXICITY TOWARD CANINE KIDNEY EPITHELIAL CELLS

Abstract

Cellular cytotoxicity toward kidney cell targets has been studied in a model using in vitro cultured canine kidney cells obtained after perfusion trypsinization of kidneys from one-haplotype-mismatched beagles. To study whether cytotoxic effector cells recognize identical antigens on kidney cells as on phytohemagglu-tinin (PHA)-stimulated lymphoblasts, adsorption studies with different monolayers have been performed. Both leukocyte and kidney cell monolayers reduced cytotoxicity against ⁵¹Cr-labeled PHA-stimulated lymphoblasts very effectively. The average reduction of cytotoxicity was 86% in six consecutive experiments after one adsorption on either one of these two types of target-specific monolayers. Nonspecific monolayers reduced cytotoxicity only for 13%. Specific kidney cell monolayers reduced cytotoxicity against kidney cells almost completely, however leukocyte monolayers reduced cytotoxicity toward kidney cells for only 40%. These results and cold target inhibition data strongly suggest that kidney cells present antigens to which a selective population of cytotoxic T lymphocytes (CTLs) is directed. These CTLs are not cytotoxic for PHA-stimulated lymphoblasts. It is discussed whether the relevant antigens on the kidney cells are organ-specific antigens comparable to the en-dothelial monocyte antigen system as described by Mo-reas and Stastny or that class II antigens are involved in cytotoxicity toward kidney cells.