Recent developments in experimental bone marrow transplantation.

: Animal models have been a mainstay for the preclinical evaluation of the principles of bone marrow transplantation. In addition to evaluation of the therapeutic effectiveness of bone marrow transplantation in oncologic, hematologic, immunologic, and genetic diseases, experimental animal models provide insights into the immunobiology of bone marrow transplantation, including engraftment kinetics, tolerance, immune reconstitution, and graft-versus-host and graft-versus-tumor reactions. Many recent developments in experimental bone marrow transplantation resulted from not only the discovery of new spontaneously occurring models of human diseases but also the induction of neoplastic diseases, eg, chronic myelogenous leukemia, by transplantation of syngeneic marrow cells into which foreign genes were introduced and expressed. Murine bone marrow transplantation systems are an exemplary format for the study of clinically relevant basic aspects of hematopoiesis, including identification and elucidation of the biology of hematopoietic stem cells. Finally, the application of molecular biologic techniques in animal bone marrow transplantation models provides the preclinical foundations of gene-insertion therapy by transplantation of syngeneic or autologous marrow-derived stem cells into which functional genes were inserted.