Adoptive Immunotherapy in Human and Canine Chimeras

Abstract

Bone marrow transplantation is an effective method for treatment of acute and chronic leukemia. Allogeneic transplants are superior to autologous and syngeneic transplants in the prevention of recurrence of leukemia. Unfortunately the occurrence of graftversus-host disease (GVHD) is associated with a high risk of treatment-related complications. Some evidence of a graftversus-leukemia (GVL) reaction separable from a graft-versus-host reaction has been reported [1], but neither the target antigens nor the effector cells have been well defined. Immune reactivity against histocompatibility antigens expressed by hemopoietic progenitor cells and clonogenic leukemia cells may be sufficient for a strong antileukemic effect. We treated patients with hematologic relapse of chronic myelogenous leukemia (CML) after marrow transplantation by transfusion of viable peripheral blood lymphocytes from their marrow donor and interferon-α (IFN-α) [2]. The effect of donor lymphocyte transfusions was further investigated in mixed DLA-identical canine chimeras at various times after transplantation. The aim of the study was the evaluation of an effect on residual hemopoietic cells of the host as compared to the development of GVHD.

Supported by the Wilhelm Sander Foundation.