Renal allograft rejection: possible involvement of lymphokine-activated killer cells.

Human renal allograft tissue was recovered at transplant nephrectomy from three patients with irreversible loss of graft function. This tissue was disaggregated and separated into two fractions on the basis of particle size. Fraction 1 contained glomeruli and developed a mixed outgrowth containing adherent epithelial and mesangial cells after a limited period of culture. Fraction 2 contained fragments of renal tubules and produced monolayers of tubular epithelial cells during culture. A population of lymphoid cells was observed to grow from the primary disaggregate into medium supplemented with recombinant human interleukin-2 (IL-2). After culture for 5 days these lymphoid cells were predominantly CD3-positive and carried both class II major histocompatibility antigens (MHC) and the CD25 IL-2 receptor. Culture of peripheral blood-derived mononuclear cells with IL-2 caused the generation of lymphokine-activated killer (LAK) cells; these cells were able to lyse both glomerular and tubular cells grown from nephrectomy tissue without showing MHC antigen restriction. The lymphoid cells grown from renal allograft tissue showed a similar lytic potential for both renal cells prepared from the same nephrectomy specimen and from third party renal tissue. It is possible that any LAK cells formed within a renal allograft by the action of IL-2 may contribute to the tissue destruction observed during graft rejection.