title: In vitro methotrexate as a practical approach to selective allodepletion.
abstract: Graft-versus-host disease (GVHD) is a major cause of transplant-related morbidity and mortality in recipients of allogeneic hematopoietic stem cell transplantation. As GVHD is mediated predominantly by alloreactive donor T cells, selective allodepletion from the graft may alleviate GVHD, whereas potentially maintaining other advantages conferred by donor T cells, such as graft survival, antiviral immunity, and graft-versus-leukemia effect. In this study, we evaluated the ability of methotrexate, a clinically approved antimetabolite drug, to deplete alloreactive T cells in HLA-mismatched mixed lymphocyte reactions (MLR). We observed that methotrexate could inhibit the proliferation of alloreactive T cells in primary in vitro MLR. On reexposure of methotrexate-treated cells to the same allostimulus, a significant reduction in the alloreactive immune response was observed, whereas responses to third-party allostimuli and viral antigens were preserved. Thus, our results provide preclinical evidence that in vitro methotrexate treatment results in specific allodepletion and may be used as an effective agent for preventing GVHD.
authors.affiliation: Department of Pathology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390-9072, USA.
authors.forename: Atul
authors.initials: A
authors.lastname: Sathe
authors.forename: Sterling B
authors.initials: SB
authors.lastname: Ortega
authors.forename: Dorothy I
authors.initials: DI
authors.lastname: Mundy
authors.forename: Robert H
authors.initials: RH
authors.lastname: Collins
authors.forename: Nitin J
authors.initials: NJ
authors.lastname: Karandikar
mesh_terms: D000956:Antigens, Viral / Q000276:immunology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D006086:Graft vs Host Disease / Q000517:prevention & control*; D006650:Histocompatibility Testing; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D008212:Lymphocyte Depletion / Q000379:methods*; D008722:Methods; D008727:Methotrexate / Q000494:pharmacology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D000956:Antigens, Viral; D008727:Methotrexate