title: Adipose-derived stromal cells promote allograft tolerance induction.
abstract: Amputations and unsalvageable injuries with devastating tissue loss are common in the combat wounded. Reconstructive transplantation in the civilian setting using vascular composite allotransplants (VCAs) with multiple tissues (skin, muscle, nerve, bone) combined with long-term multidrug immunosuppression has been encouraging. However, skin rejection remains a critical complication. Adipose-derived stromal/stem cells (ASCs) are easily obtained from normal individuals in high numbers, precluding ex vivo expansion. The reparative function and paracrine immunomodulatory capacity of ASCs has gained considerable attention. The present study investigated whether ASCs facilitate long-term skin allograft survival. ASCs were isolated from fresh human subcutaneous adipose lipoaspirate. Full-thickness skin grafts from BALB/c mice were transplanted onto the dorsal flanks of C57BL/6 mice treated with five doses of anti-CD4/CD8 monoclonal antibodies (10 mg/kg) on days 0, +2, +5, +7, and +14 relative to skin grafting. A single nonmyeloablative low dose of busulfan (5 mg/kg) was given on day +5. Seven days after skin transplantation, ASCs (3×10(6)) were infused i.v. with or without donor bone marrow cells (BMCs; 5×10(5)). ASC+BMC coinfusion with minimal conditioning led to stable lymphoid and myeloid macrochimerism, deletion of alloreactive T cells, expansion of regulatory T cells, and long-term allograft survival (>200 days). ASCs constitutively produced high levels of anti-inflammatory/immunoregulatory factors such as prostaglandin E2, indoleamine 2,3-dioxygenase, APO-1/Fas (CD95), and programmed cell death-1 ligand-2. These findings serve as a foundation for developing a translational advanced VCA protocol, embodying both ASCs and low-dose donor BMCs, in nonhuman primates, with the goal of enhancing functional outcomes and eliminating the complications associated with long-term immunosuppression.
authors.affiliation: Regenerative Medicine Department, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA; Department of Medicine and Surgery Center for Stem Cell Research & Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; LaCell, LLC, New Orleans, Louisiana, USA thomas.davis1@med.navy.mil.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Davis
authors.affiliation: Regenerative Medicine Department, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA; Department of Medicine and Surgery Center for Stem Cell Research & Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; LaCell, LLC, New Orleans, Louisiana, USA.
authors.forename: Khairul
authors.initials: K
authors.lastname: Anam
authors.affiliation: Regenerative Medicine Department, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA; Department of Medicine and Surgery Center for Stem Cell Research & Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; LaCell, LLC, New Orleans, Louisiana, USA.
authors.forename: Yelena
authors.initials: Y
authors.lastname: Lazdun
authors.affiliation: Regenerative Medicine Department, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA; Department of Medicine and Surgery Center for Stem Cell Research & Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; LaCell, LLC, New Orleans, Louisiana, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Gimble
authors.affiliation: Regenerative Medicine Department, Operational and Undersea Medicine Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA; Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA; Department of Medicine and Surgery Center for Stem Cell Research & Regenerative Medicine, Tulane University School of Medicine, New Orleans, Louisiana, USA; LaCell, LLC, New Orleans, Louisiana, USA.
authors.forename: Eric A
authors.initials: EA
authors.lastname: Elster
mesh_terms: D000273:Adipose Tissue / Q000166:cytology / Q000276:immunology*; D064591:Allografts; D000818:Animals; D002066:Busulfan / Q000494:pharmacology*; D006801:Humans; D008212:Lymphocyte Depletion; D051379:Mice; D008807:Mice, Inbred BALB C; D019653:Myeloablative Agonists / Q000494:pharmacology*; D016038:Skin Transplantation; D017154:Stromal Cells / Q000166:cytology / Q000276:immunology; D019172:Transplantation Conditioning; D023001:Transplantation Tolerance / Q000187:drug effects*
chemical_list: D019653:Myeloablative Agonists; D002066:Busulfan
keywords: Adipose tissue-derived stromal cells; Allogeneic transplantation; Bone marrow; Chimerism; T regulatory cells; Tolerance induction