title: Stable long-term mixed chimerism achieved in a canine model of allogeneic in utero hematopoietic cell transplantation.
abstract: Evidence supporting the efficacy of in utero hematopoietic cell transplantation (IUHCT) in a valid large animal model is needed prior to clinical application. The objective of this study was to establish clinically relevant levels of hematopoietic chimerism in a canine model of maternal-to-fetal IUHCT. We first assessed immune and hematopoietic ontogeny relevant to IUHCT in the canine model and identified 40 days' gestation (term 63 days) as a time point at the initiation of thymic selection, and prior to bone marrow hematopoiesis, that might be optimal for IUHCT. We next determined that intravascular administration of donor cells via intracardiac injection was far more efficient and resulted in much higher levels of donor cell engraftment than intraperitoneal injection. By applying these findings, we achieved stable long-term multilineage engraftment in 21 of 24 surviving recipients with an average level of initial chimerism of 11.7% (range 3% to 39%) without conditioning or evidence of graft-versus-host disease. Donor cell chimerism remained stable for up to 2 years and was associated with donor-specific tolerance for renal transplantation. The levels of donor cell chimerism achieved in this study would be therapeutic for many hematopoietic disorders and are supportive of a clinical trial of IUHCT.
authors.affiliation: Center for Fetal Research and.
authors.forename: Jesse D
authors.initials: JD
authors.lastname: Vrecenak
authors.affiliation: Center for Fetal Research and.
authors.forename: Erik G
authors.initials: EG
authors.lastname: Pearson
authors.affiliation: Center for Fetal Research and.
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Santore
authors.affiliation: Center for Fetal Research and.
authors.forename: Carlyn A
authors.initials: CA
authors.lastname: Todorow
authors.affiliation: Center for Fetal Research and.
authors.forename: Haiying
authors.initials: H
authors.lastname: Li
authors.affiliation: Center for Fetal Research and.
authors.forename: Antoneta
authors.initials: A
authors.lastname: Radu
authors.affiliation: Department of Pathology, Children's Hospital of Philadelphia, Philadelphia, PA.
authors.forename: Tricia
authors.initials: T
authors.lastname: Bhatti
authors.affiliation: Center for Fetal Research and.
authors.forename: William H
authors.initials: WH
authors.lastname: Peranteau
authors.affiliation: Center for Fetal Research and.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Johnson
authors.affiliation: Center for Fetal Research and.
authors.forename: Alan W
authors.initials: AW
authors.lastname: Flake
mesh_terms: D064591:Allografts; D000818:Animals; D004285:Dogs; D005260:Female; D005318:Fetal Heart; D046128:Fetal Therapies / Q000379:methods*; D006086:Graft vs Host Disease / Q000517:prevention & control; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D007267:Injections; D007274:Injections, Intraperitoneal; D016030:Kidney Transplantation; D008856:Microscopy, Fluorescence; D023421:Models, Animal; D011247:Pregnancy; D014019:Tissue Donors; D018183:Transplantation Chimera / Q000033:anatomy & histology / Q000276:immunology; D023001:Transplantation Tolerance