title: Tolerance induction by lentiviral gene therapy with a nonmyeloablative regimen.
abstract: Antibodies (Abs) directed at the Gal alpha1,3Gal beta1,4GlcNAc-R (alphaGal) carbohydrate epitope initiate xenograft rejection. Previously, we have shown that bone marrow transplantation (BMT) with lentivirus-mediated gene transfer of porcine alpha1,3 galactosyltransferase (GalT) is able to induce tolerance to alphaGal-expressing heart grafts following a lethal dose of irradiation. Here we show the first demonstration of permanent survival of alphaGal+ hearts following transplantation with autologous, lentivirus-transduced BM using a nonmyeloablative regimen. Autologous BM from GalT knockout (GalT-/-) mice was transduced with a lentiviral vector expressing porcine GalT and transplanted into sublethally irradiated (3 Gy) GalT-/- mice. Chimerism in the peripheral blood cells (PBCs) remained low but was higher in the BM, especially within the stromal cell population. Mice reconstituted with GalT did not produce anti-alphaGal Abs over time. We immunized these mice with alphaGal-expressing cells and assessed humoral immune responses. Anti-alphaGal xenoantibodies were not produced in mice reconstituted with GalT, but normal Ab responses to other xenoantigens were detected. Mice reconstituted with GalT accepted alphaGal+ heart grafts over 100 days. Transduction with lentiviral vectors results in chimerism at levels sufficient to induce long-term tolerance under nonmyeloablative conditions.
authors.affiliation: Childrens Hospital of Los Angeles, Department of Cardiothoracic Surgery, Los Angeles, CA 90027, USA.
authors.forename: Noboru
authors.initials: N
authors.lastname: Mitsuhashi
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Fischer-Lougheed
authors.forename: Irina
authors.initials: I
authors.lastname: Shulkin
authors.forename: Annette
authors.initials: A
authors.lastname: Kleihauer
authors.forename: Donald B
authors.initials: DB
authors.lastname: Kohn
authors.forename: Kenneth I
authors.initials: KI
authors.lastname: Weinberg
authors.forename: Vaughn A
authors.initials: VA
authors.lastname: Starnes
authors.forename: Mary
authors.initials: M
authors.lastname: Kearns-Jonker
mesh_terms: D000818:Animals; D000917:Antibody Formation; D016026:Bone Marrow Transplantation; D015316:Genetic Therapy / Q000379:methods*; D006085:Graft Survival; D016027:Heart Transplantation / Q000379:methods*; D007108:Immune Tolerance; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D009237:N-Acetyllactosamine Synthase / Q000008:administration & dosage* / Q000235:genetics; D009844:Oligosaccharides / Q000276:immunology; D013552:Swine; D018183:Transplantation Chimera; D019172:Transplantation Conditioning / Q000379:methods*; D014183:Transplantation, Heterologous
chemical_list: C424822:Gal(1-3)Gal(1 -4)GlcNAc(1 -3)Gal(1 -4)Glc(1-0)Cer; D009844:Oligosaccharides; D009237:N-Acetyllactosamine Synthase