Purging of Bone Marrow with Imunomagnetic Beads: Studies with Neuroblastoma as a Model System

摘要

Selective purging of cell populations from marrow may be necessary to remove alloreactive cells (for allogeneic transplantation) or malignant cells (for autologous transplantation). A number of materials and methods for selective removal of cells from marrow have been reported, including monoclonal antibodies and complement, lectin agglutination, immunotoxins, cytotoxic drugs, and physical separation by equilibrium centrifugation. Recently, a novel approach to physical separation has been reported in which monoclonal antibodies are used to attach magnetic microspheres, or magnetic colloid, to the target cells, which are then removed by magnets. We have established a model system to study methods for purging bone marrow. Neuroblastoma offers several unique properties that make it ideal for study as a model system. Especially attractive are the intracellular and extracellular intigens of neuroblastoma, which are not found in normal marrow, permitting sensitive detection of residual cells after purging. Furthermore, the improvement in survival seen in neuroblastoma patients treated with intensive therapy and marow transplant should promote an increase in the use of this type of therapy for patients with widespread disease. Use of autologous marrow in treating such patients will require purging of tumor cells from the marrow. The model system we have devised involves seeding a known number of premarked neuroblastoma cells into normal bone marrow.