ABSTRACT
I. INTRODUCTION With the advent of technologies that exploit monoclonal antibodies (mAbs) for the purposes of positive or negative selection of various cell subpopulations, it has become possible to manipulate, or “engineer,” cellular grafts of autolo gous or allogeneic origin for use in a variety of cell-based therapies. Such therapies include autologous or allogeneic stem cell transplantation for treat ment of solid tumor or hematological malignancies (1,2); T-cell depletion for prevention of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (3-5); infusion of cytokine-activated or antigen (Ag)-specific killer cells (6) or tumor-infiltrating lymphocytes (TEL) (7); vaccination with antigen-pulsed dendritic cells (8); donor lymphocyte infusion for treatment of relapsed leukemia (9-13); and purging of malignant cells from autologous
bone marrow or peripheral blood stem cell harvests (14). Many groups also have begun to explore the potential for selective differentiation of CD34+ cells into desired cell lineages, such as dendritic cells for use in vaccination protocols, or neutrophil or platelet precursors for use in protocols designed to decrease the period of neutropenia (15) and thrombocytopenia after bone marrow transplantation in cytoablated recipients.
