title: CD154 blockade and donor-specific transfusions in DLA-identical marrow transplantation in dogs conditioned with 1-Gy total body irradiation.
abstract: Stable mixed donor/host chimerism has been reliably established in dogs given a sublethal dose (2 Gy) of total body irradiation (TBI) before and immunosuppression with mycophenolate mofetil (MMF) or rapamycin combined with cyclosporine (CSP) after marrow transplantation from dog leukocyte antigen (DLA)-identical littermates (hematopoietic cell transplantation [HCT]). When TBI was reduced to 1 Gy, only transient engraftment was observed. Here we investigated whether stable engraftment after 1-Gy TBI could be accomplished by reducing host-versus-donor immune responsiveness through preceding CD154 blockade and infusion of donor peripheral blood mononuclear cells (PBMCs). We found that the anti-human CD154 antibody, 5c8, cross-reacted with canine lymphocytes and blocked alloimmune responses in vitro. Based on pharmacokinetic studies, 6 dogs received a single intravenous injection of 5 mg/kg anti-CD154 antibody (on day -5), followed 1 day later by donor PBMCs. On day 0, the dogs were given 1 Gy of TBI and underwent DLA-identical marrow grafts. Postgraft immunosuppression consisted of MMF and CSP. All 6 dogs demonstrated initial engraftment; 3 dogs sustained the engraftment for >26 weeks, whereas 3 dogs rejected their grafts, after 9, 22, and 24 weeks, and survived with autologous recovery. Graft survival was significantly improved over that in 11 historical controls conditioned with 1-Gy TBI and given either MMF or rapamycin with CSP after HCT, all of which rejected their grafts between 3 and 12 weeks (P = .03). Preceding donor PBMC infusion and CD154 blockade improved survival of DLA-identical marrow grafts after 1-Gy TBI.
authors.affiliation: Transplantation Biology Program, Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
authors.forename: Christoph
authors.initials: C
authors.lastname: Jochum
authors.forename: Mechthild
authors.initials: M
authors.lastname: Beste
authors.forename: Eustacia
authors.initials: E
authors.lastname: Zellmer
authors.forename: Scott S
authors.initials: SS
authors.lastname: Graves
authors.forename: Rainer
authors.initials: R
authors.lastname: Storb
mesh_terms: D000818:Animals; D000961:Antilymphocyte Serum / Q000627:therapeutic use*; D016026:Bone Marrow Transplantation / Q000379:methods*; D023201:CD40 Ligand / Q000276:immunology*; D004195:Disease Models, Animal; D004285:Dogs; D004307:Dose-Response Relationship, Radiation; D006085:Graft Survival / Q000276:immunology*; D007165:Immunosuppression Therapy / Q000379:methods; D017708:Leukocyte Transfusion; D035781:Siblings; D018183:Transplantation Chimera / Q000097:blood / Q000276:immunology; D019172:Transplantation Conditioning / Q000379:methods*; D014916:Whole-Body Irradiation / Q000379:methods*
chemical_list: D000961:Antilymphocyte Serum; D023201:CD40 Ligand