title: Stem cell mobilization with G-CSF analogs: a rational approach to separate GVHD and GVL?
abstract: The separation of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) remains the "holy grail" of allogeneic stem cell transplantation, and improvements are urgently needed to allow more effective therapy of malignant disease. The use of G-CSF-mobilized peripheral blood as a clinical stem cell source is associated with enhanced GVL effects without amplification of significant acute GVHD. Preclinical studies have demonstrated that G-CSF modulates donor T cell function before transplantation, promoting T(H)2 differentiation and regulatory T cell function. In addition, the expansion of immature antigen-presenting cells (APCs) and plasmacytoid dendritic cells (DCs) favors the maintenance of this pattern of T cell differentiation after transplantation. Although these patterns of T cell differentiation attenuate acute GVHD, they do not have an impact on the cytolytic pathways of the CD8(+) T cells that are critical for effective GVL. Recently, it has been demonstrated that modification of G-CSF, either by pegylation of the native cytokine or conjugation to Flt-3L, results in the expansion and activation of donor iNKT cells, which significantly augment CD8(+) T cell-mediated cytotoxicity and GVL effects after transplantation. Given that these cytokines also enhance the expansion of regulatory T cells and APCs, they further separate GVHD and GVL, offering potential clinical advantages for the transplant recipient.
authors.affiliation: Bone Marrow Transplantation Laboratory, Queensland Institute of Medical Research, 300 Herston Rd, Herston, QLD 4029, Australia.
authors.forename: Edward S
authors.initials: ES
authors.lastname: Morris
authors.forename: Kelli P A
authors.initials: KP
authors.lastname: MacDonald
authors.forename: Geoffrey R
authors.initials: GR
authors.lastname: Hill
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology; D016026:Bone Marrow Transplantation; D006086:Graft vs Host Disease / Q000276:immunology / Q000517:prevention & control*; D020544:Graft vs Leukemia Effect / Q000187:drug effects* / Q000276:immunology; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization / Q000379:methods*; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D051379:Mice; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor