title: Expression of a Chimeric Antigen Receptor Specific for Donor HLA Class I Enhances the Potency of Human Regulatory T Cells in Preventing Human Skin Transplant Rejection.
abstract: Regulatory T cell (Treg) therapy using recipient-derived Tregs expanded ex vivo is currently being investigated clinically by us and others as a means of reducing allograft rejection following organ transplantation. Data from animal models has demonstrated that adoptive transfer of allospecific Tregs offers greater protection from graft rejection compared to polyclonal Tregs. Chimeric antigen receptors (CAR) are clinically translatable synthetic fusion proteins that can redirect the specificity of T cells toward designated antigens. We used CAR technology to redirect human polyclonal Tregs toward donor-MHC class I molecules, which are ubiquitously expressed in allografts. Two novel HLA-A2-specific CARs were engineered: one comprising a CD28-CD3ζ signaling domain (CAR) and one lacking an intracellular signaling domain (ΔCAR). CAR Tregs were specifically activated and significantly more suppressive than polyclonal or ΔCAR Tregs in the presence of HLA-A2, without eliciting cytotoxic activity. Furthermore, CAR and ΔCAR Tregs preferentially transmigrated across HLA-A2-expressing endothelial cell monolayers. In a human skin xenograft transplant model, adoptive transfer of CAR Tregs alleviated the alloimmune-mediated skin injury caused by transferring allogeneic peripheral blood mononuclear cells more effectively than polyclonal Tregs. Our results demonstrated that the use of CAR technology is a clinically applicable refinement of Treg therapy for organ transplantation.
authors.affiliation: MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.|NIHR Biomedical Research Centre, Guy's & St Thomas' NHS Foundation Trust & King's College London, Guy's Hospital, London, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Boardman
authors.affiliation: Centre for Stem Cells & Regenerative Medicine, King's College London, Guy's Hospital, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Philippeos
authors.affiliation: Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, King's College London, St. Thomas' Hospital, London, UK.
authors.forename: G O
authors.initials: GO
authors.lastname: Fruhwirth
authors.affiliation: Department of Clinical Immunology and Allergy, King's College London, King's College Hospital, London, UK.|Division of Asthma, Allergy & Lung Biology, King's College London, Guy's Hospital, London, UK.
authors.forename: M A A
authors.initials: MA
authors.lastname: Ibrahim
authors.affiliation: Centre for Cell Biology & Cutaneous Research, Bart's and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: R F
authors.initials: RF
authors.lastname: Hannen
authors.affiliation: William Harvey Research Institute, Bart's and The London School of Medicine, Queen Mary University of London, London, UK.
authors.forename: D
authors.initials: D
authors.lastname: Cooper
authors.affiliation: William Harvey Research Institute, Bart's and The London School of Medicine, Queen Mary University of London, London, UK.
authors.forename: F M
authors.initials: FM
authors.lastname: Marelli-Berg
authors.affiliation: NIHR Biomedical Research Centre, Guy's & St Thomas' NHS Foundation Trust & King's College London, Guy's Hospital, London, UK.|Centre for Stem Cells & Regenerative Medicine, King's College London, Guy's Hospital, London, UK.
authors.forename: F M
authors.initials: FM
authors.lastname: Watt
authors.affiliation: MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.|NIHR Biomedical Research Centre, Guy's & St Thomas' NHS Foundation Trust & King's College London, Guy's Hospital, London, UK.
authors.forename: R I
authors.initials: RI
authors.lastname: Lechler
authors.affiliation: NIHR Biomedical Research Centre, Guy's & St Thomas' NHS Foundation Trust & King's College London, Guy's Hospital, London, UK.|Department of Clinical Immunology and Allergy, King's College London, King's College Hospital, London, UK.|CAR Mechanics Group, Division of Cancer Studies, King's College London, Guy's Hospital, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Maher
authors.affiliation: MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.|School of Health, Sport and Bioscience, Stratford Campus, University of East London, London, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Smyth
authors.affiliation: MRC Centre for Transplantation, King's College London, Guy's Hospital, London, UK.|NIHR Biomedical Research Centre, Guy's & St Thomas' NHS Foundation Trust & King's College London, Guy's Hospital, London, UK.
authors.forename: G
authors.initials: G
authors.lastname: Lombardi
mesh_terms: D064591:Allografts; D000818:Animals; D006084:Graft Rejection / Q000209:etiology / Q000517:prevention & control*; D006085:Graft Survival / Q000276:immunology; D015789:HLA-A2 Antigen / Q000276:immunology*; D064593:Heterografts; D006801:Humans; D007963:Leukocytes, Mononuclear; D051379:Mice; D008807:Mice, Inbred BALB C; D011946:Receptors, Antigen / Q000276:immunology*; D016038:Skin Transplantation / Q000009:adverse effects*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D023001:Transplantation Tolerance / Q000276:immunology
chemical_list: D015789:HLA-A2 Antigen; D011946:Receptors, Antigen
keywords: T cell biology; alloantigen; animal models: murine; basic (laboratory) research/science; cellular biology; gene therapy; immune regulation; immunosuppression/immune modulation; molecular biology; translational research/science