1
|
Annamalai C, Kute V, Sheridan C, Halawa A. Hematopoietic cell-based and non-hematopoietic cell-based strategies for immune tolerance induction in living-donor renal transplantation: A systematic review. Transplant Rev (Orlando) 2023; 37:100792. [PMID: 37709652 DOI: 10.1016/j.trre.2023.100792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/24/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023]
Abstract
INTRODUCTION Despite its use to prevent acute rejection, lifelong immunosuppression can adversely impact long-term patient and graft outcomes. In theory, immunosuppression withdrawal is the ultimate goal of kidney transplantation, and is made possible by the induction of immunological tolerance. The purpose of this paper is to review the safety and efficacy of immune tolerance induction strategies in living-donor kidney transplantation, both chimerism-based and non-chimerism-based. The impact of these strategies on transplant outcomes, including acute rejection, allograft function and survival, cost, and immune monitoring, will also be discussed. MATERIALS AND METHODS Databases such as PubMed, Scopus, and Web of Science, as well as additional online resources such as EBSCO, were exhaustively searched. Adult living-donor kidney transplant recipients who developed chimerism-based tolerance after concurrent bone marrow or hematopoietic stem cell transplantation or those who received non-chimerism-based, non-hematopoietic cell therapy using mesenchymal stromal cells, dendritic cells, or regulatory T cells were studied between 2000 and 2021. Individual sources of evidence were evaluated critically, and the strength of evidence and risk of bias for each outcome of the transplant tolerance study were assessed. RESULTS From 28,173 citations, 245 studies were retrieved after suitable exclusion and duplicate removal. Of these, 22 studies (2 RCTs, 11 cohort studies, 6 case-control studies, and 3 case reports) explicitly related to both interventions (chimerism- and non-chimerism-based immune tolerance) were used in the final review process and were critically appraised. According to the findings, chimerism-based strategies fostered immunotolerance, allowing for the safe withdrawal of immunosuppressive medications. Cell-based therapy, on the other hand, frequently did not induce tolerance except for minimising immunosuppression. As a result, the rejection rates, renal allograft function, and survival rates could not be directly compared between these two groups. While chimerism-based tolerance protocols posed safety concerns due to myelosuppression, including infections and graft-versus-host disease, cell-based strategies lacked these adverse effects and were largely safe. There was a lack of direct comparisons between HLA-identical and HLA-disparate recipients, and the cost implications were not examined in several of the retrieved studies. Most studies reported successful immunosuppressive weaning lasting at least 3 years (ranging up to 11.4 years in some studies), particularly with chimerism-based therapy, while only a few investigators used immune surveillance techniques. The studies reviewed were often limited by selection, classification, ascertainment, performance, and attrition bias. CONCLUSIONS This review demonstrates that chimerism-based hematopoietic strategies induce immune tolerance, and a substantial number of patients are successfully weaned off immunosuppression. Despite the risk of complications associated with myelosuppression. Non-chimerism-based, non-hematopoietic cell protocols, on the other hand, have been proven to facilitate immunosuppression minimization but seldom elicit immunological tolerance. However, the results of this review must be interpreted with caution because of the non-randomised study design, potential confounding, and small sample size of the included studies. Further validation and refinement of tolerogenic protocols in accordance with local practice preferences is also warranted, with an emphasis on patient selection, cost ramifications, and immunological surveillance based on reliable tolerance assays.
Collapse
Affiliation(s)
- Chandrashekar Annamalai
- Postgraduate School of Medicine, Institute of Teaching and Learning, Faculty of Health and Life Sciences, University of Liverpool, UK.
| | - Vivek Kute
- Nephrology and Transplantation, Institute of Kidney Diseases and Research Center and Dr. H L Trivedi Institute of Transplantation Sciences (IKDRC-ITS), Ahmedabad, India
| | - Carl Sheridan
- Department of Eye and Vision Science, Ocular Cell Transplantation, Faculty of Health and Life Sciences, University of Liverpool, UK
| | - Ahmed Halawa
- Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| |
Collapse
|
2
|
Mengrelis K, Muckenhuber M, Wekerle T. Chimerism-based Tolerance Induction in Clinical Transplantation: Its Foundations and Mechanisms. Transplantation 2023; 107:2473-2485. [PMID: 37046378 DOI: 10.1097/tp.0000000000004589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Hematopoietic chimerism remains the most promising strategy to bring transplantation tolerance into clinical routine. The concept of chimerism-based tolerance aims to extend the recipient's mechanisms of self-tolerance (ie, clonal deletion, anergy, and regulation) to include the tolerization of donor antigens that are introduced through the cotransplantation of donor hematopoietic cells. For this to be successful, donor hematopoietic cells need to engraft in the recipient at least temporarily. Three pioneering clinical trials inducing chimerism-based tolerance in kidney transplantation have been published to date. Within this review, we discuss the mechanisms of tolerance that are associated with the specific therapeutic protocols of each trial. Recent data highlight the importance of regulation as a mechanism that maintains tolerance. Insufficient regulatory mechanisms are also a likely explanation for situations of tolerance failure despite persisting donor chimerism. After decades of preclinical development of chimerism protocols, mechanistic data from clinical trials have recently become increasingly important. Better understanding of the required mechanisms for tolerance to be induced in humans will be a key to design more reliable and less invasive chimerism protocols in the future.
Collapse
Affiliation(s)
- Konstantinos Mengrelis
- Division of Transplantation, Department of General Surgery, Medical University of Vienna, Vienna, Austria
| | | | | |
Collapse
|
3
|
Abstract
Since it was shown in the early 1950s that it is possible to induce transplantation tolerance in neonates, immune tolerance strategies have been actively pursued. It was found that T cells play a critical role in graft rejection, but can also be major players in mediating transplantation tolerance. Consequently, many experimental systems focused on T cells, often with a complete exclusion of B cells from in vivo animal models. It is now becoming clear that in addition to T cells, B cells can mediate graft rejection and transplantation tolerance. In this issue of the JCI, Khiew et al. investigated the contribution of alloreactive B cells to transplantation tolerance using a mouse cardiac transplantation model. The authors revealed a distinct tolerant B cell phenotype possessing the ability to suppress naive B cells. These data lead to a better understanding of B cell contributions to transplantation tolerance, and may inform the development of future immune tolerance protocols.
Collapse
|
4
|
Oh BC, Furtmüller GJ, Fryer ML, Guo Y, Messner F, Krapf J, Schneeberger S, Cooney DS, Lee WPA, Raimondi G, Brandacher G. Vascularized composite allotransplantation combined with costimulation blockade induces mixed chimerism and reveals intrinsic tolerogenic potential. JCI Insight 2020; 5:128560. [PMID: 32271163 DOI: 10.1172/jci.insight.128560] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 03/04/2020] [Indexed: 12/14/2022] Open
Abstract
Vascularized composite allotransplantation (VCA) has become a valid therapeutic option to restore form and function after devastating tissue loss. However, the need for high-dose multidrug immunosuppression to maintain allograft survival is still hampering more widespread application of VCA. In this study, we investigated the immunoregulatory potential of costimulation blockade (CoB; CTLA4-Ig and anti-CD154 mAb) combined with nonmyeoablative total body irradiation (TBI) to promote allograft survival of VCA in a fully MHC-mismatched mouse model of orthotopic hind limb transplantation. Compared with untreated controls (median survival time [MST] 8 days) and CTLA4-Ig treatment alone (MST 17 days), CoB treatment increased graft survival (MST 82 days), and the addition of nonmyeloablative TBI led to indefinite graft survival (MST > 210 days). Our analysis suggests that VCA-derived BM induced mixed chimerism in animals treated with CoB and TBI + CoB, promoting gradual deletion of alloreactive T cells as the underlying mechanism of long-term allograft survival. Acceptance of donor-matched secondary skin grafts, decreased ex vivo T cell responsiveness, and increased graft-infiltrating Tregs further indicated donor-specific tolerance induced by TBI + CoB. In summary, our data suggest that vascularized BM-containing VCAs are immunologically favorable grafts promoting chimerism induction and long-term allograft survival in the context of CoB.
Collapse
Affiliation(s)
- Byoung Chol Oh
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Georg J Furtmüller
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Madeline L Fryer
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Yinan Guo
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Hand and Microsurgery, Xiangya Hospital, Central South University, Hunan, China
| | - Franka Messner
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Visceral, Transplant and Thoracic Surgery, and
| | - Johanna Krapf
- Department of Plastic and Reconstructive Surgery, Center of Operative Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Damon S Cooney
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - W P Andrew Lee
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Giorgio Raimondi
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Gerald Brandacher
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation Laboratory, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
5
|
Meyer EH, Laport G, Xie BJ, MacDonald K, Heydari K, Sahaf B, Tang SW, Baker J, Armstrong R, Tate K, Tadisco C, Arai S, Johnston L, Lowsky R, Muffly L, Rezvani AR, Shizuru J, Weng WK, Sheehan K, Miklos D, Negrin RS. Transplantation of donor grafts with defined ratio of conventional and regulatory T cells in HLA-matched recipients. JCI Insight 2019; 4:127244. [PMID: 31092732 DOI: 10.1172/jci.insight.127244] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 04/02/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUNDIn preclinical murine and early clinical studies of hematopoietic cell transplantation, engineering of donor grafts with defined ratios of CD4+CD25+FoxP3+ Tregs to conventional T cells (Tcons) results in the prevention of graft-versus-host disease and improved immune reconstitution. The use of highly purified primary graft Tregs for direct cell infusion has potential advantages over impure immunomagnetic selection or culture expansion, but has not been tested clinically. We performed a phase I study of the timed addition of CD34-selected hematopoietic stem cells and Tregs, followed by Tcons for the treatment of patients with high-risk hematological malignancies.METHODSWe present interim evaluation of a single-center open phase I/II study of administration of human leukocyte-matched Tregs and CD34-selected hematopoietic cells, followed by infusion of an equal ratio of Tcons in adult patients undergoing myeloablative hematopoietic stem cell transplantation (HCT) for high-risk or active hematological malignancies. Tregs were purified by immunomagnetic selection and high-speed cell sorting.RESULTSHere we report results for the first 12 patients who received Tregs of between 91% and 96% purity. Greater than grade II GVHD was noted in 2 patients in the first cohort of 5 patients, who received cryopreserved Tregs, but neither acute nor chronic GVHD was noted in the second cohort of 7 patients, who received fresh Tregs and single-agent GVHD prophylaxis. Patients in the second cohort appeared to have normal immune reconstitution compared with patients who underwent transplantation and did not develop GVHD.CONCLUSIONOur study shows that the use of highly purified fresh Tregs is clinically feasible and supports continued investigation of the strategy.TRIAL REGISTRATIONClinicalTrials.gov NCT01660607.FUNDINGNIH NHBLI R01 HL114591 and K08HL119590.
Collapse
Affiliation(s)
- Everett H Meyer
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA.,Cell Therapy Facility, Stanford Health Care, Stanford, California, USA
| | - Ginna Laport
- Tempest Therapeutics, San Francisco, California, USA
| | - Bryan J Xie
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Kate MacDonald
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Kartoosh Heydari
- Cell Therapy Facility, Stanford Health Care, Stanford, California, USA
| | - Bita Sahaf
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Sai-Wen Tang
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Jeanette Baker
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Randall Armstrong
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Keri Tate
- Laboratory for Cell and Gene Medicine, Stanford University, Palo Alto, California, USA
| | - Cynthia Tadisco
- Laboratory for Cell and Gene Medicine, Stanford University, Palo Alto, California, USA
| | - Sally Arai
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Laura Johnston
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Robert Lowsky
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Lori Muffly
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Andrew R Rezvani
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Judith Shizuru
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Wen-Kai Weng
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Kevin Sheehan
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - David Miklos
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| | - Robert S Negrin
- Division of Blood and Marrow Transplantation, Stanford University, Stanford, California, USA
| |
Collapse
|
6
|
Robinson KA, Orent W, Madsen JC, Benichou G. Maintaining T cell tolerance of alloantigens: Lessons from animal studies. Am J Transplant 2018; 18:1843-1856. [PMID: 29939471 PMCID: PMC6352985 DOI: 10.1111/ajt.14984] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 01/25/2023]
Abstract
Achieving host immune tolerance of allogeneic transplants represents the ultimate challenge in clinical transplantation. It has become clear that different cells and mechanisms participate in acquisition versus maintenance of allograft tolerance. Indeed, manipulations which prevent tolerance induction often fail to abrogate tolerance once it has been established. Hence, elucidation of the immunological mechanisms underlying maintenance of T cell tolerance to alloantigens is essential for the development of novel interventions that preserve a robust and long lasting state of allograft tolerance that relies on T cell deletion in addition to intra-graft suppression of inflammatory immune responses. In this review, we discuss some essential elements of the mechanisms involved in the maintenance of naturally occurring or experimentally induced allograft tolerance, including the newly described role of antigen cross-dressing mediated by extracellular vesicles.
Collapse
Affiliation(s)
- Kortney A. Robinson
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
| | - William Orent
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
| | - Joren C. Madsen
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA.,Division of Cardiac Surgery, Department of Surgery,
Massachusetts General Hospital and Harvard Medical School, Boston, MA
| | - Gilles Benichou
- Center for Transplant Sciences, Massachusetts General
Hospital and Harvard Medical School, Boston, MA
| |
Collapse
|
7
|
Sykes M. Immune monitoring of transplant patients in transient mixed chimerism tolerance trials. Hum Immunol 2018; 79:334-342. [PMID: 29289741 PMCID: PMC5924718 DOI: 10.1016/j.humimm.2017.12.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 12/18/2017] [Accepted: 12/21/2017] [Indexed: 12/31/2022]
Abstract
This review focuses on mechanistic studies performed in recipients of non-myeloablative bone marrow transplant regimens developed at Massachusetts General Hospital in HLA-identical and HLA-mismatched haploidentical combinations, initially as a platform for treatment of hematologic malignancies with immunotherapy in the form of donor leukocyte infusions, and later in combination with donor kidney transplantation for the induction of allograft tolerance. In patients with permanent mixed chimerism, central deletion may be a major mechanism of long-term tolerance. In patients in whom donor chimerism is only transient, the kidney itself plays a significant role in maintaining long-term tolerance. A high throughput sequencing approach to identifying and tracking a significant portion of the alloreactive T cell receptor repertoire has demonstrated biological significance in transplant patients and has been useful in pointing to clonal deletion as a long-term tolerance mechanism in recipients of HLA-mismatched combined kidney and bone marrow transplants with only transient chimerism.
Collapse
Affiliation(s)
- Megan Sykes
- Columbia Center for Translational Immunology, Columbia University Medical Center, NY, USA; Department of Medicine, Columbia University Medical Center, NY, USA; Department of Microbiology & Immunology, Columbia University Medical Center, NY, USA; Department of Surgery, Columbia University Medical Center, NY, USA.
| |
Collapse
|
8
|
Agua-Doce A, Caridade M, Oliveira VG, Bergman L, Lafaille MC, Lafaille JJ, Demengeot J, Graca L. Route of Antigen Presentation Can Determine the Selection of Foxp3-Dependent or Foxp3-Independent Dominant Immune Tolerance. THE JOURNAL OF IMMUNOLOGY 2017; 200:101-109. [PMID: 29167234 DOI: 10.4049/jimmunol.1601886] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 10/25/2017] [Indexed: 11/19/2022]
Abstract
It has been shown that dominant tolerance, namely in transplantation, requires Foxp3+ regulatory T cells. Although most tolerance-inducing regimens rely on regulatory T cells, we found that induction of tolerance to proteins in aluminum hydroxide can be achieved in Foxp3-deficient mice using nondepleting anti-CD4 Abs. This type of tolerance is Ag specific, and tolerant mice retain immune competence to respond to unrelated Ags. We demonstrated with chicken OVA-specific TCR-transgenic mice that the same tolerizing protocol (CD4 blockade) and the same target Ag (OVA) achieves Foxp3-dependent transplantation tolerance to OVA-expressing skin grafts, but Foxp3-independent tolerance when the Ag is provided as OVA-aluminum hydroxide. In the latter case, we found that tolerance induction triggered recessive mechanisms leading to elimination of effector cells and, simultaneously, a dominant mechanism associated with the emergence of an anergic and regulatory CTLA-4+IL-2lowFoxp3- T cell population, where the tolerance state is IL-10 dependent. Such Foxp3-independent mechanisms can improve the efficacy of tolerance-inducing protocols.
Collapse
Affiliation(s)
- Ana Agua-Doce
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal.,Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; and
| | - Marta Caridade
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal.,Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; and
| | - Vanessa G Oliveira
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal.,Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; and
| | - Lisa Bergman
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; and
| | - Maria C Lafaille
- Department of Pathology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016
| | - Juan J Lafaille
- Department of Pathology, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016
| | | | - Luis Graca
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; .,Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; and
| |
Collapse
|
9
|
Zuber J, Sykes M. Mechanisms of Mixed Chimerism-Based Transplant Tolerance. Trends Immunol 2017; 38:829-843. [PMID: 28826941 PMCID: PMC5669809 DOI: 10.1016/j.it.2017.07.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 06/24/2017] [Accepted: 07/19/2017] [Indexed: 02/06/2023]
Abstract
Immune responses to allografts represent a major barrier in organ transplantation. Immune tolerance to avoid chronic immunosuppression is a critical goal in the field, recently achieved in the clinic by combining bone marrow transplantation (BMT) with kidney transplantation following non-myeloablative conditioning. At high levels of chimerism such protocols can permit central deletional tolerance, but with a significant risk of graft-versus-host (GVH) disease (GVHD). By contrast, transient chimerism-based tolerance is devoid of GVHD risk and appears to initially depend on regulatory T cells (Tregs) followed by gradual, presumably peripheral, clonal deletion of donor-reactive T cells. Here we review recent mechanistic insights into tolerance and the development of more robust and safer protocols for tolerance induction that will be guided by innovative immune monitoring tools.
Collapse
Affiliation(s)
- Julien Zuber
- Service de Transplantation Rénale, Hôpital Necker, Université Paris Descartes, Paris, France; INSERM UMRS_1163, IHU Imagine, Paris, France.
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University, New York, NY 10032, USA; Department of Surgery, Columbia University, New York, NY 10032, USA; Department of Microbiology and Immunology, Columbia University Center, New York, NY 10032, USA.
| |
Collapse
|
10
|
Pilat N, Wekerle T. Combining Treg therapy with mixed chimerism: Getting the best of both worlds. CHIMERISM 2017; 1:26-9. [PMID: 21327149 DOI: 10.4161/chim.1.1.12964] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 07/12/2010] [Indexed: 11/19/2022]
Abstract
Deliberate establishment of donor-specific immunologic tolerance is considered to be the "Holy Grail" in transplantation medicine, but clinical tolerance protocols for routine organ transplantation are still an unmet need. Mixed hematopoietic chimerism is an attractive tolerance strategy with considerable potential. Recent pilot trials provide proof-of-principle that mixed chimerism can induce tolerance in renal transplant recipients. Routine clinical translation, however, is impeded by the side effects of the cytotoxic recipient conditioning necessary for the transient engraftment of HLA-mismatched BM. In murine studies recently published in The American Journal of Transplantation, we demonstrated that the therapeutic application of polyclonal recipient regulatory T cells (Tregs) leads to engraftment of practicable doses of fully allogeneic BM and to donor-specific tolerance without any cytotoxic conditioning, thereby eliminating a major impediment for the clinical translation of the mixed chimerism strategy in the experimental setting. The background and the implications of these findings are discussed.
Collapse
Affiliation(s)
- Nina Pilat
- Division of Transplantation; Department of Surgery; Vienna General Hospital; Medical University of Vienna; Vienna, Austria
| | | |
Collapse
|
11
|
Yolcu ES, Shirwan H, Askenasy N. Mechanisms of Tolerance Induction by Hematopoietic Chimerism: The Immune Perspective. Stem Cells Transl Med 2017; 6:700-712. [PMID: 28186688 PMCID: PMC5442770 DOI: 10.1002/sctm.16-0358] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/02/2016] [Accepted: 10/10/2016] [Indexed: 01/05/2023] Open
Abstract
Hematopoietic chimerism is one of the effective approaches to induce tolerance to donor‐derived tissue and organ grafts without administration of life‐long immunosuppressive therapy. Although experimental efforts to develop such regimens have been ongoing for decades, substantial cumulative toxicity of combined hematopoietic and tissue transplants precludes wide clinical implementation. Tolerance is an active immunological process that includes both peripheral and central mechanisms of mutual education of coresident donor and host immune systems. The major stages include sequential suppression of early alloreactivity, establishment of hematopoietic chimerism and suppressor cells that sustain the state of tolerance, with significant mechanistic and temporal overlap along the tolerization process. Efforts to devise less toxic transplant strategies by reduction of preparatory conditioning focus on modulation rather than deletion of residual host immunity and early reinstitution of regulatory subsets at the central and peripheral levels. Stem Cells Translational Medicine2017;6:700–712
Collapse
Affiliation(s)
- Esma S Yolcu
- Institute for Cellular Therapeutics and Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Haval Shirwan
- Institute for Cellular Therapeutics and Department of Microbiology and Immunology, University of Louisville, Louisville, Kentucky, USA
| | - Nadir Askenasy
- Frankel Laboratory of Experimental Bone Marrow Transplantation, Petach Tikva, Israel
| |
Collapse
|
12
|
Li Z, Xu X, Feng X, Murphy PM. The Macrophage-depleting Agent Clodronate Promotes Durable Hematopoietic Chimerism and Donor-specific Skin Allograft Tolerance in Mice. Sci Rep 2016; 6:22143. [PMID: 26917238 PMCID: PMC4768260 DOI: 10.1038/srep22143] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/08/2016] [Indexed: 11/19/2022] Open
Abstract
Hematopoietic chimerism is known to promote donor-specific organ allograft tolerance; however, clinical translation has been impeded by the requirement for toxic immunosuppression and large doses of donor bone marrow (BM) cells. Here, we investigated in mice whether durable chimerism might be enhanced by pre-treatment of the recipient with liposomal clodronate, a macrophage depleting agent, with the goal of vacating BM niches for preferential reoccupation by donor hematopoietic stem cells (HSC). We found that liposomal clodronate pretreatment of C57BL/6 mice permitted establishment of durable hematopoietic chimerism when the mice were given a low dose of donor BM cells and transient immunosuppression. Moreover, clodronate pre-treatment increased durable donor-specific BALB/c skin allograft tolerance. These results provide proof-of-principle that clodronate is effective at sparing the number of donor BM cells required to achieve durable hematopoietic chimerism and donor-specific skin allograft tolerance and justify further development of a tolerance protocol based on this principle.
Collapse
Affiliation(s)
- Zhanzhuo Li
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD, USA
| | - Xin Xu
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD, USA
| | - Xingmin Feng
- Hematology Branch, National Heart, Lung and Blood Institute (NHLBI), National Institutes of Health, Bethesda, MD, USA
| | - Philip M Murphy
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
13
|
Use of hematopoietic cell transplants to achieve tolerance in patients with solid organ transplants. Blood 2016; 127:1539-43. [PMID: 26796362 DOI: 10.1182/blood-2015-12-685107] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/12/2016] [Indexed: 12/21/2022] Open
Abstract
The goals of tolerance in patients with solid organ transplants are to eliminate the lifelong need for immunosuppressive (IS) drugs and to prevent graft loss due to rejection or drug toxicity. Tolerance with complete withdrawal of IS drugs has been achieved in recipients of HLA-matched and mismatched living donor kidney transplants in 3 medical centers using hematopoietic cell transplants to establish mixed or complete chimerism.
Collapse
|
14
|
Application of allogeneic bone marrow cells in view of residual alloreactivity: sirolimus but not cyclosporine evolves tolerogenic properties. PLoS One 2015; 10:e0119950. [PMID: 25836261 PMCID: PMC4383565 DOI: 10.1371/journal.pone.0119950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 01/23/2015] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Application of bone marrow cells (BMC) is a promising strategy for tolerance induction, but usually requires strong depletion of the host immune system. This study evaluates the ability of immunosuppressants to evolve tolerogenic properties of BMC in view of residual alloreactivity. METHODS The rat model used a major histocompatibility complex (MHC) class II disparate bone marrow transplantation (BMT) setting (LEW.1AR1 (RT1auu) → LEW.1AR2 (RT1aau)). Heart grafts (LEW.1WR1 (RT1uua)) were disparate for the complete MHC to recipients and for MHC class I to BMC donors. Limited conditioning was performed by total body irradiation of 6 Gy. Cyclosporine (CsA) or Sirolimus (Srl) were administered for 14 or 28 days. Transplantation of heart grafts (HTx) was performed at day 16 or at day 100 after BMT. Chimerism and changes in the T cell pool were detected by flow cytometry. RESULTS Mixed chimeras accepted HTx indefinitely, although the composition of the regenerated T cell pool was not changed to a basically donor MHC class II haplotype. Non-chimeric animals rejected HTx spontaneously. BMC recipients, who received HTx during T cell recovery at day 16, accepted HTx only after pre-treatment with Srl, although chimerism was lost. CsA pre-treatment led to accelerated HTx rejection as did isolated application of BMC. CONCLUSION Srl evolves tolerogenic properties of allogeneic BMC to achieve indefinite acceptance of partly MHC disparate HTx despite residual alloreactivity and in particular loss of chimerism.
Collapse
|
15
|
Mechanistic and therapeutic role of regulatory T cells in tolerance through mixed chimerism. Curr Opin Organ Transplant 2014; 15:725-30. [PMID: 20881493 DOI: 10.1097/mot.0b013e3283401755] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE OF REVIEW Although substantial advances in transplantation medicine have improved short-term graft survival, long-term outcome after organ transplantation is unsatisfactory. The induction of donor-specific tolerance as a potential solution remains an unmet need. Mixed chimerism established through transplantation of donor bone marrow is an appealing tolerance strategy, but widespread clinical application is prevented by the toxicity of recipient conditioning, which is required for achieving bone marrow engraftment. Clonal deletion - both central and peripheral - has long been recognized as a cardinal mechanism in experimental mixed chimerism models. RECENT FINDINGS Several recent studies have delineated the importance of nondeletional, regulatory mechanisms for the induction of tolerance through mixed chimerism. Moreover, the therapeutic application of recipient regulatory T cells (Tregs) has been combined with the transplantation of donor bone marrow. Such a 'Treg-chimerism' protocol leads to engraftment of conventional doses of fully allogeneic bone marrow and to donor-specific tolerance without the need for any cytotoxic conditioning. SUMMARY Regulatory mechanisms play a major role in mixed chimerism protocols. Treg therapy is exceptionally effective in achieving bone marrow engraftment without cytotoxic recipient treatment, thereby eliminating a major toxic factor preventing widespread application of the mixed chimerism strategy.
Collapse
|
16
|
Minimization of immunosuppression in adult liver transplantation: new strategies and tools. Curr Opin Organ Transplant 2014; 15:685-90. [PMID: 20885324 DOI: 10.1097/mot.0b013e3283402c55] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE OF REVIEW To describe most relevant data regarding strategies to achieve immunosuppression minimization and/or complete withdrawal in liver transplantation and to discuss the development of tolerance biomarkers to predict the success of immunosuppression weaning. RECENT FINDINGS In clinical organ transplantation allograft tolerance has been attained through two different pathways: (1) tolerance or immunosuppression minimization has been attempted by administering induction therapies with or without infusion of donor hematopoietic cells; and (2) the availability of spontaneously tolerant liver and kidney recipients has been exploited to develop biomarkers of allograft tolerance. The use of transcriptional profiling is the most promising approach. Recent publications have identified a gene expression signature in tolerant patients. SUMMARY Current immunosuppressive regimens reduce acute rejection episodes but promote a number of complications that have a negative impact on patient morbidity, mortality and quality of life. In this setting, achievement of tolerance is a major goal. Although there are no reliable markers to identify tolerant patients, recent studies have found that tolerant liver recipients exhibit unique peripheral blood transcriptional patterns. The difference in expression patterns is related to the immune response and could constitute the basis of a future diagnostic test of tolerance.
Collapse
|
17
|
Direct and indirect antigen presentation lead to deletion of donor-specific T cells after in utero hematopoietic cell transplantation in mice. Blood 2013; 121:4595-602. [PMID: 23610372 DOI: 10.1182/blood-2012-10-463174] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
In utero hematopoietic cell transplantation (IUHCTx) is a promising method to induce donor-specific tolerance but the mechanisms of antigen presentation that educate host T cells and the relative importance of deletion vs regulation in this setting are unknown. We studied the roles of direct and indirect antigen presentation (mediated by donor- and host-derived antigen-presenting cells [APCs], respectively) in a mouse model of IUHCTx. We found that IUHCTx leads to precocious maturation of neonatal host dendritic cells (DCs) and that there is early differentiation of donor-derived DCs, even after transplantation of a stem cell source without mature APCs. We next performed allogeneic IUHCTx into donor-specific T-cell receptor transgenic mice and confirmed that both direct and indirect antigen presentation lead to clonal deletion of effector T cells in chimeras. Deletion did not persist when chimerism was lost. Importantly, although the percentage of regulatory T cells (Tregs) after IUHCTx increased, there was no expansion in Treg numbers. In wild-type mice, there was a similar deletion of effector cells without expansion of donor-specific Tregs. Thus, tolerance induction after IUHCTx depends on both direct and indirect antigen presentation and is secondary to thymic deletion, without de novo Treg induction.
Collapse
|
18
|
Tolerance induction strategies in vascularized composite allotransplantation: mixed chimerism and novel developments. Clin Dev Immunol 2012; 2012:863264. [PMID: 23320020 PMCID: PMC3540904 DOI: 10.1155/2012/863264] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 11/06/2012] [Accepted: 12/03/2012] [Indexed: 12/29/2022]
Abstract
Since the start of the clinical vascularized composite allotransplantation (VCA) era over a decade ago this field has witnessed significant developments in both basic and translational research. Transplant tolerance, defined as rejection-free acceptance of transplanted organs or tissues without long-term immunosuppression, holds the potential to revolutionize the field of VCA by removing the need for life-long immunosuppression. While tolerance of organ and vascularized composite transplants may be induced in small animal models by a variety of protocols, only mixed-chimerism-based protocols have successfully bridged the gap to preclinical study and to clinical trial in solid organ transplantation to date. In this paper we review the mixed-chimerism approach to tolerance induction, with specific reference to the field of VCA transplantation, and provide an overview of some novel cellular therapies as potential adjuvants to mixed chimerism in the development of tolerance induction protocols for clinical vascularized composite allotransplantation.
Collapse
|
19
|
Ravindra KV, Xu H, Bozulic LD, Song DD, Ildstad ST. The need for inducing tolerance in vascularized composite allotransplantation. Clin Dev Immunol 2012; 2012:438078. [PMID: 23251216 PMCID: PMC3509522 DOI: 10.1155/2012/438078] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2012] [Accepted: 09/14/2012] [Indexed: 11/24/2022]
Abstract
Successful hand and face transplantation in the last decade has firmly established the field of vascularized composite allotransplantation (VCA). The experience in VCA has thus far been very similar to solid organ transplantation in terms of the morbidity associated with long-term immunosuppression. The unique immunological features of VCA such as split tolerance and resistance to chronic rejection are being investigated. Simultaneously there has been laboratory work studying tolerogenic protocols in animal VCA models. In order to optimize VCA outcomes, translational studies are needed to develop less toxic immunosuppression and possibly achieve donor-specific tolerance. This article reviews the immunology, animal models, mixed chimerism & tolerance induction in VCA and the direction of future research to enable better understanding and wider application of VCA.
Collapse
Affiliation(s)
- Kadiyala V. Ravindra
- Department of Surgery, Duke University Medical Center (DUMC) 3512, Durham, NC 27710, USA
| | - Hong Xu
- Institute for Cellular Therapeutics and Jewish Hospital, University of Louisville, 570 South Preston Street, Suite 404, Louisville, KY 40202-1760, USA
| | - Larry D. Bozulic
- Institute for Cellular Therapeutics and Jewish Hospital, University of Louisville, 570 South Preston Street, Suite 404, Louisville, KY 40202-1760, USA
| | - David D. Song
- Institute for Cellular Therapeutics and Jewish Hospital, University of Louisville, 570 South Preston Street, Suite 404, Louisville, KY 40202-1760, USA
| | - Suzanne T. Ildstad
- Institute for Cellular Therapeutics and Jewish Hospital, University of Louisville, 570 South Preston Street, Suite 404, Louisville, KY 40202-1760, USA
| |
Collapse
|
20
|
Lin JY, Tsai FC, Wallace CG, Huang WC, Wei FC, Liao SK. Optimizing chimerism level through bone marrow transplantation and irradiation to induce long-term tolerance to composite tissue allotransplantation. J Surg Res 2012; 178:487-93. [PMID: 22484382 DOI: 10.1016/j.jss.2012.02.064] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/28/2012] [Accepted: 02/29/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Mixed chimerism with long-term composite tissue allotransplant (CTA) acceptance can be achieved through allogeneic bone marrow transplantation (BMT). The present study investigated the optimal chimerism level by giving different irradiation dosages to recipients to induce tolerance to CTA. METHODS Chimera were prepared using Brown-Norway and Lewis rats with strong major histocompatibility complex incompatibility. The Lewis rats received 5 mg antilymphocyte globulin (day -1 and 10) and 16 mg/kg cyclosporine (day 0-10) and were separated into groups 1, 2, 3, 4, and 5 according to the day -1 irradiation dosage: 0, 200, 400, 600, and 950 cGy, respectively. The Lewis rats were then reconstituted with 100 × 10(6) T-cell-depleted Brown-Norway bone marrow cells (day 0) and received vascularized Brown-Norway-CTA on day 28. Chimerism was assessed monthly by flow cytometry starting on day 28 after BMT. Graft-versus-host disease (GVHD) was assessed clinically and histologically. RESULTS Chimerism, 4 weeks after BMT, averaged 0.2%, 9.2%, 30.7%, 58%, and 99.3% in groups 1 to 5, respectively. GVHD occurred as follows: groups 1 and 2, none; group 3, 1 case of GVHD; group 4, 7 cases of GVHD (of which 3 died); and group 5, 10 cases of GVHD (of which 6 died). The percentage of long-term CTA acceptance was 0%, 0%, 90%, 70%, and 40% in groups 1 to 5, respectively. The percentage of regulatory T cells was significantly lower in high-chimerism (≥ 20%, n = 15) than in low-chimerism (<20%, n = 5) rats that accepted CTA long-term . CONCLUSIONS The chimerism level correlated positively with GVHD occurrence and long-term CTA acceptance but correlated negatively with regulatory T-cell levels. Optimal chimerism for CTA acceptance through pre-CTA BMT and irradiation occurs at 20-50% at day 28 after BMT in the rat model.
Collapse
Affiliation(s)
- Jeng-Yee Lin
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | | | | | | | | | | |
Collapse
|
21
|
Abstract
Regulatory T cells (Tregs) are long-lived cells that suppress immune responses in vivo in a dominant and antigen-specific manner. Therefore, therapeutic application of Tregs to control unwanted immune responses is an active area of investigation. Tregs can confer long-term protection against auto-inflammatory diseases in mouse models. They have also been shown to be effective in suppressing alloimmunity in models of graft-versus-host disease and organ transplantation. Building on extensive research in Treg biology and preclinical testing of therapeutic efficacy over the past decade, we are now at the point of evaluating the safety and efficacy of Treg therapy in humans. This review focuses on developing therapy for transplantation using CD4(+)Foxp3(+) Tregs, with an emphasis on the studies that have informed clinical approaches that aim to maximize the benefits while overcoming the challenges and risks of Treg cell therapy.
Collapse
Affiliation(s)
- Qizhi Tang
- Division of Transplantation, Department of Surgery, University of California San Francisco, San Francisco, CA 94143-0780, USA.
| | | | | |
Collapse
|
22
|
Liu G, Duan K, Ma H, Niu Z, Peng J, Zhao Y. An instructive role of donor macrophages in mixed chimeras in the induction of recipient CD4(+)Foxp3(+) Treg cells. Immunol Cell Biol 2011; 89:827-35. [PMID: 21844881 DOI: 10.1038/icb.2011.65] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The immune regulatory function of macrophages (Møs) in mixed chimeras has not been determined. In the present study, with a multi-lineage B6-to-BALB/c mixed chimeric model, we examined the ability of donor-derived splenic Møs in the induction of regulatory T cells (Treg). B6 splenic Møs from mixed chimeras induced significantly less cell proliferation, more IL-10 and TGF-β, and less IL-2 and IFN-γ productions of CD4(+) T cells from BALB/c mice than naive B6 Møs did, whereas they showed similar stimulatory activity to the third part C3H CD4(+) T cells. Importantly, highly purified donor F4/80(+)CD11c(-) Møs efficiently induced recipient CD4(+)Foxp3(+) Treg cells from CD4(+)CD25(-)Foxp3(-) T cells. Furthermore, donor Møs of mixed chimeras produced more IL-10 and less IFN-γ than those of naive mice when cultured with BALB/c but not the third party C3H CD4(+) T cells. Induction of recipient CD4(+) Treg cells by donor Møs was significantly blocked by anti-IL-10, but not by anti-TGF-β mAb. Therefore, donor Møs have the ability to induce recipient CD4(+)Foxp3(+) Treg cells in a donor antigen-specific manner, at least partially, via an IL-10-dependent pathway. This study for the first time showed that, in mixed allogeneic chimeras, donor Møs could be specifically tolerant to recipients and gained the ability to induce recipient but not the third party Foxp3(+) Treg cells. Whether this approach is involved in transplant immune tolerance needs to be determined.
Collapse
Affiliation(s)
- Guangwei Liu
- Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | | | | | | | | | | |
Collapse
|
23
|
Abstract
Secondary, so-called costimulatory, signals are critically required for the process of T cell activation. Since landmark studies defined that T cells receiving a T cell receptor signal without a costimulatory signal, are tolerized in vitro, the investigation of T cell costimulation has attracted intense interest. Early studies demonstrated that interrupting T cell costimulation allows attenuation of the alloresponse, which is particularly difficult to modulate due to the clone size of alloreactive T cells. The understanding of costimulation has since evolved substantially and now encompasses not only positive signals involved in T cell activation but also negative signals inhibiting T cell activation and promoting T cell tolerance. Costimulation blockade has been used effectively for the induction of tolerance in rodent models of transplantation, but turned out to be less potent in large animals and humans. In this overview we will discuss the evolution of the concept of T cell costimulation, the potential of 'classical' and newly identified costimulation pathways as therapeutic targets for organ transplantation as well as progress towards clinical application of the first costimulation blocking compound.
Collapse
Affiliation(s)
- Nina Pilat
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Austria
| | - Mohamed H. Sayegh
- Brigham and Women's Hospital & Children's Hospital Boston, Harvard Medical School, Boston, USA
| | - Thomas Wekerle
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Austria
| |
Collapse
|
24
|
Bozulic LD, Wen Y, Xu H, Ildstad ST. Evidence that FoxP3+ regulatory T cells may play a role in promoting long-term acceptance of composite tissue allotransplants. Transplantation 2011; 91:908-15. [PMID: 21304439 PMCID: PMC3592205 DOI: 10.1097/tp.0b013e31820fafb4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND FoxP3/CD4/CD25 regulatory T cells (Treg) play an important role in maintaining peripheral tolerance and are potent suppressors of T-cell activation. In this study, we evaluated the role of Treg in peripheral tolerance to composite tissue allografts (CTA). METHODS Mixed allogeneic chimeric rats were prepared by preconditioning recipients with anti-αβ-T-cell receptor monoclonal antibody followed by total body irradiation. Animals received T-cell-depleted August Copenhagen Irish bone marrow cells followed by antilymphocyte serum and FK-506. A modified osteomyocutaneous hindlimb flap composed of bone and all limb tissue components was placed in animals with chimerism greater than or equal to 1% on day 28. Recipients with CTA surviving more than or equal to 6 months were evaluated for Treg. Skin samples from tolerant long-term allogeneic transplanted, syngeneic transplanted, rejected, and naïve animals were immunostained with fluorochrome-conjugated anti-FoxP3 and anti-CD4 monoclonal antibody and visualized under a laser confocal microscope. RESULTS Significant CD4/FoxP3 Treg infiltrates were observed in tolerant donor-allograft skin samples. No graft infiltrating FoxP3 cells were observed in rejector, naïve, or skin from syngeneic CTA. In parallel experiments, mixed leukocyte reaction assays were performed to investigate the suppressor function of Treg cells. Splenocytes from tolerant, rejected, and naïve rats were sorted by flow cytometry for CD4/CD25 T cells. Treg demonstrated similar suppressive levels between the three groups. CONCLUSIONS These data suggest that Treg may play an important role in maintenance of tolerance and promoting graft acceptance in long-term CTA acceptors and may explain the favorable outcomes observed in clinical CTA recipients.
Collapse
Affiliation(s)
- Larry D. Bozulic
- Regenerex, LLC, 333 East Main Street, Suite 400, Louisville, KY 40202
| | - Yujie Wen
- Institute for Cellular Therapeutics, University of Louisville, 570 S. Preston Street, Suite 404, Louisville, KY 40202-1760
| | - Hong Xu
- Institute for Cellular Therapeutics, University of Louisville, 570 S. Preston Street, Suite 404, Louisville, KY 40202-1760
| | - Suzanne T. Ildstad
- Institute for Cellular Therapeutics, University of Louisville, 570 S. Preston Street, Suite 404, Louisville, KY 40202-1760
| |
Collapse
|
25
|
Andreani M, Testi M, Gaziev J, Condello R, Bontadini A, Tazzari PL, Ricci F, De Felice L, Agostini F, Fraboni D, Ferrari G, Battarra M, Troiano M, Sodani P, Lucarelli G. Quantitatively different red cell/nucleated cell chimerism in patients with long-term, persistent hematopoietic mixed chimerism after bone marrow transplantation for thalassemia major or sickle cell disease. Haematologica 2011; 96:128-33. [PMID: 20935000 PMCID: PMC3012776 DOI: 10.3324/haematol.2010.031013] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 09/29/2010] [Accepted: 09/30/2010] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Persistent mixed chimerism represents a state in which recipient and donor cells stably co-exist after hematopoietic stem cell transplantation. However, since in most of the studies reported in literature the engraftment state was observed in the nucleated cells, in this study we determined the donor origin of the mature erythrocytes of patients with persistent mixed chimerism after transplantation for hemoglobinopathies. Results were compared with the engraftment state observed in singly picked out burst-forming unit - erythroid colonies and in the nucleated cells collected from the peripheral blood and from the bone marrow. DESIGN AND METHODS The donor origin of the erythrocytes was determined analyzing differences on the surface antigens of the erythrocyte suspension after incubation with anti-ABO and/or anti-C, -c, -D, -E and -e monoclonal antibodies by a flow cytometer. Analysis of short tandem repeats was used to determine the donor origin of nucleated cells and burst-forming unit - erythroid colonies singly picked out after 14 days of incubation. RESULTS The proportions of donor-derived nucleated cells in four transplanted patients affected by hemoglobinopathies were 71%, 46%, 15% and 25% at day 1364, 1385, 1314 and 932, respectively. Similar results were obtained for the erythroid precursors, analyzing the donor/recipient origin of the burst-forming unit - erythroid colonies. In contrast, on the same days of observation, the proportions of donor-derived erythrocytes in the four patients with persistent mixed chimerism were 100%, 100%, 73% and 90%. Conclusions Our results showed that most of the erythrocytes present in four long-term transplanted patients affected by hemoglobinopathies and characterized by the presence of few donor engrafted nucleated cells were of donor origin. The indication that small proportions of donor engrafted cells might be sufficient for clinical control of the disease in patients affected by hemoglobinopathies is relevant, although the biological mechanisms underlying these observations need further investigation.
Collapse
Affiliation(s)
- Marco Andreani
- Laboratorio di Immunogenetica e Biologia dei Trapianti, Fondazione IME, Policlinico Tor Vergata, Viale Oxford 81, 00133 Rome, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Du JF, Li SY, Yu B, Bai X. Treg-based therapy and mixed chimerism in small intestinal transplantation: Does Treg+BMT equal intestine allograft tolerance? Med Hypotheses 2011; 76:77-8. [DOI: 10.1016/j.mehy.2010.08.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 08/08/2010] [Indexed: 11/16/2022]
|
27
|
|
28
|
Chen JC, Kuo ML, Ou LS, Chang PY, Muench MO, Shen CR, Chang HL, Yu HY, Fu RH. Characterization of tolerance induction through prenatal marrow transplantation: the requirement for a threshold level of chimerism to establish rather than maintain postnatal skin tolerance. Cell Transplant 2010; 19:1609-22. [PMID: 20719075 DOI: 10.3727/096368910x516583] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hematopoietic chimerism resulting from prenatal marrow transplantation does not consistently result in allotolerance for unidentified causes. In a C57BL/6-into-FVB/N murine model, we transplanted T-cell-depleted adult marrow on gestational day 14 to elucidate the immunological significance of chimerism towards postnatal tolerance. Postnatally, chimerism was examined by flow cytometry, and tolerance by skin transplantation and mixed lymphocyte reaction. Regulatory T cells were quantified by FoxP3 expression. Peripheral chimerism linearly related to thymic chimerism, and predicted the degree of graft acceptance with levels >3% at skin placement, yielding consistent skin tolerance. Low- and high-level chimeras had lower intrathymic CD3(high) expression than microchimeras or untransplanted mice. Regardless of the skin tolerance status in mixed chimeras, donor-specific alloreactivity by lymphocytes was suppressed but could be partially restored by exogenous interleukin-2. Recipients that lost peripheral chimerism did not accept donor skin unless prior donor skin had engrafted at sufficient chimerism levels, suggesting that complete tolerance can develop as a consequence of chimerism-related immunosuppression of host lymphocytes and the tolerogenic effects of donor skin. Thus, hematopoietic chimerism exerted immunomodulatory effects on the induction phase of allograft tolerance. Once established, skin tolerance did not fade away along with spontaneous regression of peripheral and tissue chimerism, as well as removal of engrafted donor skin. Neither did it break following in vivo depletion of increased regulatory T cells, and subcutaneous interleukin-2 injection beneath the engrafted donor skin. Those observations indicate that the maintenance of skin tolerance is multifaceted, neither solely dependent upon hematopoietic chimerism and engrafted donor skin nor on the effects of regulatory T cells or clonal anergy. We conclude that hematopoietic chimerism generated by in utero hematopoietic stem cell transplantation is critical to establish rather than maintain postnatal skin tolerance. Therefore, the diminution of hematopoietic chimerism below a threshold level does not nullify an existing tolerance state, but lessens the chance of enabling complete tolerance.
Collapse
Affiliation(s)
- Jeng-Chang Chen
- Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University, 5 Fu-Shin Street, Kweishan, Taoyuan, Taiwan.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Ulusal BG, Ulusal AE, Wei FC, Lin CY. Allograft Mass as a Possible Contributing Factor to the Skin Transplant Outcome. J Surg Res 2010; 161:321-7. [DOI: 10.1016/j.jss.2008.05.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Revised: 05/02/2008] [Accepted: 05/13/2008] [Indexed: 10/21/2022]
|
30
|
Muller YD, Mai G, Morel P, Serre-Beinier V, Gonelle-Gispert C, Yung GP, Ehirchiou D, Wyss JC, Bigenzahn S, Irla M, Heusser C, Golshayan D, Seebach JD, Wekerle T, Bühler LH. Anti-CD154 mAb and rapamycin induce T regulatory cell mediated tolerance in rat-to-mouse islet transplantation. PLoS One 2010; 5:e10352. [PMID: 20436684 PMCID: PMC2859949 DOI: 10.1371/journal.pone.0010352] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Accepted: 03/31/2010] [Indexed: 12/16/2022] Open
Abstract
Background Anti-CD154 (MR1) monoclonal antibody (mAb) and rapamycin (RAPA) treatment both improve survival of rat-to-mouse islet xenograft. The present study investigated the effect of combined RAPA/MR1 treatment on rat-to-mouse islet xenograft survival and analyzed the role of CD4+CD25+Foxp3+ T regulatory cells (Treg) in the induction and maintenance of the ensuing tolerance. Methodology/Principal Findings C57BL/6 mice were treated with MR1/RAPA and received additional monoclonal anti-IL2 mAb or anti CD25 mAb either early (0–28 d) or late (100–128 d) post-transplantation. Treg were characterised in the blood, spleen, draining lymph nodes and within the graft of tolerant and rejecting mice by flow cytometry and immunohistochemistry. Fourteen days of RAPA/MR1 combination therapy allowed indefinite islet graft survival in >80% of the mice. Additional administration of anti-IL-2 mAb or depleting anti-CD25 mAb at the time of transplantation resulted in rejection (100% and 89% respectively), whereas administration at 100 days post transplantation lead to lower rejection rates (25% and 40% respectively). Tolerant mice showed an increase of Treg within the graft and in draining lymph nodes early post transplantation, whereas 100 days post transplantation no significant increase of Treg was observed. Rejecting mice showed a transient increase of Treg in the xenograft and secondary lymphoid organs, which disappeared within 7 days after rejection. Conclusions/Significances These results suggest a critical role for Treg in the induction phase of tolerance early after islet xenotransplantation. These encouraging data support the need of developing further Treg therapy for overcoming the species barrier in xenotransplantation.
Collapse
Affiliation(s)
- Yannick D Muller
- Surgical Research Unit, Department of Surgery, University Hospital Geneva, Geneva, Switzerland.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Pilat N, Baranyi U, Klaus C, Jaeckel E, Mpofu N, Wrba F, Golshayan D, Muehlbacher F, Wekerle T. Treg-therapy allows mixed chimerism and transplantation tolerance without cytoreductive conditioning. Am J Transplant 2010; 10:751-762. [PMID: 20148810 PMCID: PMC2856406 DOI: 10.1111/j.1600-6143.2010.03018.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Revised: 12/01/2009] [Accepted: 12/17/2009] [Indexed: 01/25/2023]
Abstract
Establishment of mixed chimerism through transplantation of allogeneic donor bone marrow (BM) into sufficiently conditioned recipients is an effective experimental approach for the induction of transplantation tolerance. Clinical translation, however, is impeded by the lack of feasible protocols devoid of cytoreductive conditioning (i.e. irradiation and cytotoxic drugs/mAbs). The therapeutic application of regulatory T cells (Tregs) prolongs allograft survival in experimental models, but appears insufficient to induce robust tolerance on its own. We thus investigated whether mixed chimerism and tolerance could be realized without the need for cytoreductive treatment by combining Treg therapy with BM transplantation (BMT). Polyclonal recipient Tregs were cotransplanted with a moderate dose of fully mismatched allogeneic donor BM into recipients conditioned solely with short-course costimulation blockade and rapamycin. This combination treatment led to long-term multilineage chimerism and donor-specific skin graft tolerance. Chimeras also developed humoral and in vitro tolerance. Both deletional and nondeletional mechanisms contributed to maintenance of tolerance. All tested populations of polyclonal Tregs (FoxP3-transduced Tregs, natural Tregs and TGF-beta induced Tregs) were effective in this setting. Thus, Treg therapy achieves mixed chimerism and tolerance without cytoreductive recipient treatment, thereby eliminating a major toxic element impeding clinical translation of this approach.
Collapse
Affiliation(s)
- N Pilat
- Division of Transplantation, Department of Surgery, Medical University of ViennaAustria
| | - U Baranyi
- Division of Transplantation, Department of Surgery, Medical University of ViennaAustria
| | - C Klaus
- Division of Transplantation, Department of Surgery, Medical University of ViennaAustria
| | - E Jaeckel
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School (MHH)Hannover, Germany
| | - N Mpofu
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School (MHH)Hannover, Germany
| | - F Wrba
- Institute of Clinical Pathology, Medical University of ViennaAustria
| | - D Golshayan
- Transplantation Centre and Transplantation Immunopathology Laboratory, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne UniversityLausanne, Switzerland
| | - F Muehlbacher
- Division of Transplantation, Department of Surgery, Medical University of ViennaAustria
| | - T Wekerle
- Division of Transplantation, Department of Surgery, Medical University of ViennaAustria
| |
Collapse
|
32
|
Abstract
Non-self cells can circulate in the body of an individual after any sort of contact with an allogeneic source of cells, thus creating a situation of chimerism that can be transient or prolonged over time. This situation may appear after stem cell transplantation, pregnancy, transfusion or transplantation. Concerning transplantation, many hypotheses have been formulated regarding the existence, persistence and role of these circulating cells in the host. We will review the principal hypotheses that have been formulated for years since the first description of non-self circulating cells in mammals to the utilization of artificially induced chimerism protocols for the achievement of tolerance.
Collapse
Affiliation(s)
- Josep-Maria Pujal
- Translational Research Laboratory, Institut Català d'Oncologia, Hospital Duran i Reynals, Avda Gran Via s/n, Km 2.7, 08907 L'Hospitalet de Llobregat, Barcelona, Spain.
| |
Collapse
|
33
|
Serafini G, Andreani M, Testi M, Battarra M, Bontadini A, Biral E, Fleischhauer K, Marktel S, Lucarelli G, Roncarolo MG, Bacchetta R. Type 1 regulatory T cells are associated with persistent split erythroid/lymphoid chimerism after allogeneic hematopoietic stem cell transplantation for thalassemia. Haematologica 2009; 94:1415-26. [PMID: 19608686 PMCID: PMC2754958 DOI: 10.3324/haematol.2008.003129] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 04/28/2009] [Accepted: 04/29/2009] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Thalassemia major can be cured with allogeneic hematopoietic stem cell transplantation. Persistent mixed chimerism develops in around 10% of transplanted thalassemic patients, but the biological mechanisms underlying this phenomenon are poorly understood. DESIGN AND METHODS The presence of interleukin-10-producing T cells in the peripheral blood of eight patients with persistent mixed chimerism and five with full donor chimerism was investigated. A detailed characterization was then performed, by T-cell cloning, of the effector and regulatory T-cell repertoire of one patient with persistent mixed chimerism, who developed stable split erythroid/lymphoid chimerism after a hematopoietic stem cell transplant from an HLA-matched unrelated donor. RESULTS Higher levels of interleukin-10 were produced by peripheral blood mononuclear cells from patients with persistent mixed chimerism than by the same cells from patients with complete donor chimerism or normal donors. T-cell clones of both host and donor origin could be isolated from the peripheral blood of one, selected patient with persistent mixed chimerism. Together with effector T-cell clones reactive against host or donor alloantigens, regulatory T-cell clones with a cytokine secretion profile typical of type 1 regulatory cells were identified at high frequencies. Type 1 regulatory cell clones, of both donor and host origin, were able to inhibit the function of effector T cells of either donor or host origin in vitro. CONCLUSIONS Overall these results suggest that interleukin-10 and type 1 regulatory cells are associated with persistent mixed chimerism and may play an important role in sustaining long-term tolerance in vivo. These data provide new insights into the mechanisms of peripheral tolerance in chimeric patients and support the use of cellular therapy with regulatory T cells following hematopoietic stem cell transplantation.
Collapse
Affiliation(s)
- Giorgia Serafini
- Mediterranean Institute of Hematology (IME Foundation), Policlinico di Tor Vergata, Rome
- San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), Milan
| | - Marco Andreani
- Mediterranean Institute of Hematology (IME Foundation), Policlinico di Tor Vergata, Rome
| | - Manuela Testi
- Mediterranean Institute of Hematology (IME Foundation), Policlinico di Tor Vergata, Rome
| | - MariaRosa Battarra
- Mediterranean Institute of Hematology (IME Foundation), Policlinico di Tor Vergata, Rome
| | | | - Eika Biral
- Pediatric Immunology and Hematology Unit, San Raffaele Scientific Institute, Milan
- Vita-Salute San Raffaele University, Milan, Italy
| | | | - Sarah Marktel
- Pediatric Immunology and Hematology Unit, San Raffaele Scientific Institute, Milan
| | - Guido Lucarelli
- Mediterranean Institute of Hematology (IME Foundation), Policlinico di Tor Vergata, Rome
| | - Maria Grazia Roncarolo
- San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), Milan
- Vita-Salute San Raffaele University, Milan, Italy
| | - Rosa Bacchetta
- San Raffaele Telethon Institute for Gene Therapy (HSR-TIGET), Milan
- Pediatric Immunology and Hematology Unit, San Raffaele Scientific Institute, Milan
| |
Collapse
|
34
|
Abstract
Although the inhibitory receptor CTLA-4 (CD152) has been implicated in peripheral CD4 T-cell tolerance, its mechanism of action remains poorly defined. We analyzed mechanisms of CD4 cell tolerance in a model of tolerance induction involving establishment of mixed hematopoietic chimerism in recipients of fully MHC-mismatched allogeneic bone marrow cells with anti-CD154 mAb. Animals lacking CD80 and CD86 failed to achieve chimerism. We detected no T cell-intrinsic requirement for CD28 for chimerism induction. However, a CD4 T cell-intrinsic signal through CTLA-4 was shown to be essential within the first 48 hours of exposure to alloantigen for the establishment of tolerance and mixed chimerism. This signal must be provided by a recipient CD80/86(+) non-T-cell population. Donor CD80/86 expression was insufficient to achieve tolerance. Together, our findings demonstrate a surprising role for interactions of CTLA-4 expressed by alloreactive peripheral CD4 T cells with CD80/86 on recipient antigen-presenting cells (APCs) in the induction of early tolerance, suggesting a 3-cell tolerance model involving directly alloreactive CD4 cells, donor antigen-expressing bone marrow cells, and recipient antigen-presenting cells. This tolerance is independent of regulatory T cells and culminates in the deletion of directly alloreactive CD4 T cells.
Collapse
|
35
|
Li Z, Benghiat FS, Charbonnier LM, Kubjak C, Rivas MN, Cobbold SP, Waldmann H, De Wilde V, Petein M, Schuind F, Goldman M, Le Moine A. CD8+ T-Cell depletion and rapamycin synergize with combined coreceptor/stimulation blockade to induce robust limb allograft tolerance in mice. Am J Transplant 2008; 8:2527-36. [PMID: 18853957 DOI: 10.1111/j.1600-6143.2008.02419.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The growing development of composite tissue allografts (CTA) highlights the need for tolerance induction protocols. Herein, we developed a mouse model of heterotopic limb allograft in a stringent strain combination in which potentially tolerogenic strategies were tested taking advantage of donor stem cells in the grafted limb. BALB/c allografts were transplanted into C57BL/6 mice treated with anti-CD154 mAb, nondepleting anti-CD4 combined to either depleting or nondepleting anti-CD8 mAbs. Some groups received additional rapamycin. Both depleting and nondepleting mAb combinations without rapamycin only delayed limb allograft rejection, whereas the addition of rapamycin induced long-term allograft survival in both combinations. Nevertheless, robust donor-specific tolerance, defined by the acceptance of a fresh donor-type skin allograft and simultaneous rejection of third-party grafts, required initial CD8(+) T-cell depletion. Mixed donor-recipient chimerism was observed in lymphoid organs and recipient bone marrow of tolerant but not rejecting animals. Tolerance specificity was confirmed by the inability to produce IL-2, IFN-gamma and TNF-alpha in MLC with donor antigen while significant alloreactivity persisted against third- party alloantigens. Collectively, these results show that robust CTA tolerance and mixed donor-recipient chimerism can be achieved in response to the synergizing combination of rapamycin, transient CD8(+) T-cell depletion and costimulation/coreceptor blockade.
Collapse
Affiliation(s)
- Z Li
- Institute for Medical Immunology, Université Libre de Bruxelles, Bruxelles, Belgium
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Schuchmann M, Meyer RG, Distler E, von Stebut E, Kuball J, Schnürer E, Wölfel T, Theobald M, Konur A, Gregor S, Schreiner O, Huber C, Galle PR, Otto G, Herr W. The programmed death (PD)-1/PD-ligand 1 pathway regulates graft-versus-host-reactive CD8 T cells after liver transplantation. Am J Transplant 2008; 8:2434-44. [PMID: 18925909 DOI: 10.1111/j.1600-6143.2008.02401.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Acute graft-versus-host disease (aGVHD) is a life-threatening complication after solid-organ transplantation, which is mediated by host-reactive donor T cells emigrating from the allograft. We report on two liver transplant recipients who developed an almost complete donor chimerism in peripheral blood and bone marrow-infiltrating T cells during aGVHD. By analyzing these T cells directly ex vivo, we found that they died by apoptosis over time without evidence of rejection by host T cells. The host-versus-donor reactivity was selectively impaired, as anti-third-party and antiviral T cells were still detectable in the host repertoire. These findings support the acquired donor-specific allotolerance concept previously established in animal transplantation studies. We also observed that the resolution of aGVHD was not accompanied by an expansion of circulating immunosuppressive CD4/CD25/FoxP3-positive T cells. In fact, graft-versus-host-reactive T cells were controlled by an alternative negative regulatory pathway, executed by the programmed death (PD)-1 receptor and its ligand PD-L1. We found high PD-1 expression on donor CD4 and CD8 T cells. In addition, blocking PD-L1 on host-derived cells significantly enhanced alloreactivity by CD8 T cells in vitro. We suggest the interference with the PD-1/PD-L1 pathway as a therapeutic strategy to control graft-versus-host-reactive T cells in allograft recipients.
Collapse
Affiliation(s)
- M Schuchmann
- Department of Medicine I, University of Mainz, Langenbeckstr, Mainz, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Fehr T, Haspot F, Mollov J, Chittenden M, Hogan T, Sykes M. Alloreactive CD8 T cell tolerance requires recipient B cells, dendritic cells, and MHC class II. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 181:165-73. [PMID: 18566381 PMCID: PMC2734139 DOI: 10.4049/jimmunol.181.1.165] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Allogeneic bone marrow chimerism induces robust systemic tolerance to donor alloantigens. Achievement of chimerism requires avoidance of marrow rejection by pre-existing CD4 and CD8 T cells, either of which can reject fully MHC-mismatched marrow. Both barriers are overcome with a minimal regimen involving anti-CD154 and low dose (3 Gy) total body irradiation, allowing achievement of mixed chimerism and tolerance in mice. CD4 cells are required to prevent marrow rejection by CD8 cells via a novel pathway, wherein recipient CD4 cells interacting with recipient class II MHC tolerize directly alloreactive CD8 cells. We demonstrate a critical role for recipient MHC class II, B cells, and dendritic cells in a pathway culminating in deletional tolerance of peripheral alloreactive CD8 cells.
Collapse
Affiliation(s)
- Thomas Fehr
- Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02129, USA
| | | | | | | | | | | |
Collapse
|
38
|
Baranyi U, Linhart B, Pilat N, Bagley J, Muehlbacher F, Iacomini J, Valenta R, Wekerle T. Tolerization of a type I allergic immune response through transplantation of genetically modified hematopoietic stem cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:8168-75. [PMID: 18523282 PMCID: PMC2993923 DOI: 10.4049/jimmunol.180.12.8168] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Allergy represents a hypersensitivity disease that affects >25% of the population in industrialized countries. The underlying type I allergic immune reaction occurs in predisposed atopic individuals in response to otherwise harmless Ags (i.e., allergens) and is characterized by the production of allergen-specific IgE, an allergen-specific T cell response, and the release of biologically active mediators such as histamine from mast cells and basophils. Regimens permanently tolerizing an allergic immune response still need to be developed. We therefore retrovirally transduced murine hematopoietic stem cells to express the major grass pollen allergen Phl p 5 on their cell membrane. Transplantation of these genetically modified hematopoietic stem cells led to durable multilineage molecular chimerism and permanent immunological tolerance toward the introduced allergen at the B cell, T cell, and effector cell levels. Notably, Phl p 5-specific serum IgE and IgG remained undetectable, and T cell nonresponsiveness persisted throughout follow-up (40 wk). Besides, mediator release was specifically absent in in vitro and in vivo assays. B cell, T cell, and effector cell responses to an unrelated control allergen (Bet v 1) were unperturbed, demonstrating specificity of this tolerance protocol. We thus describe a novel cell-based strategy for the prevention of allergy.
Collapse
Affiliation(s)
- Ulrike Baranyi
- Div. of Transplantation, Dept. of Surgery, Medical University of Vienna, Austria
| | - Birgit Linhart
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
| | - Nina Pilat
- Div. of Transplantation, Dept. of Surgery, Medical University of Vienna, Austria
| | - Jessamyn Bagley
- Transplantation Research Center, Renal Division, Brigham and Women's Hospital and Children's Hospital, Harvard Medical School, Boston, USA
| | | | - John Iacomini
- Transplantation Research Center, Renal Division, Brigham and Women's Hospital and Children's Hospital, Harvard Medical School, Boston, USA
| | - Rudolf Valenta
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
| | - Thomas Wekerle
- Div. of Transplantation, Dept. of Surgery, Medical University of Vienna, Austria
| |
Collapse
|
39
|
Intragraft gene expression profile associated with the induction of tolerance. BMC Immunol 2008; 9:5. [PMID: 18267024 PMCID: PMC2275216 DOI: 10.1186/1471-2172-9-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2007] [Accepted: 02/11/2008] [Indexed: 11/10/2022] Open
Abstract
Background Xenotransplantation holds the promise of providing an unlimited supply of donor organs for terminal patients with organ failure. Pre-existing natural antibodies to the Galα1,3Galβ1,4GlcNac-R (αGal) carbohydrate xenoantigen, however, bind rapidly to the graft endothelium and initiate hyperacute rejection of wild type pig grafts in humans. Experimental procedures designed to prevent xenoantibody-mediated rejection have been tested in gal knockout mice. These mice produce anti-gal xenoantibodies and are widely used as small animal models for xenotransplantation research. In this model, chimerism for cells expressing the gal carbohydrate can be achieved by transplantation of mixed cells or by transduction of bone marrow cells with viral vectors expressing a functional α1,3 galactosyltransferase gene. Chimerism induces tolerance to heart grafts expressing αGal. The mechanisms by which tolerance is achieved include systemic changes such as clonal deletion and/or anergy. Intragraft changes that occur during the early stages of tolerance induction have not been characterized. Results Cytoprotective genes heme oxygenase-1 (HO-1), Bcl2, and A20 that have been reported to contribute to long-term graft survival in various models of accommodation were not expressed at high levels in tolerant heart grafts. Intragraft gene expression at both early (Day 10) and late (>2 month) time points after heart transplant were examined by real-time PCR and microarray analysis was used to identify changes associated with the induction of tolerance. Intragraft gene expression profiling using microarray analysis demonstrated that genes identified in the functional categories of stress and immunity and signal transduction were significantly up-regulated in early tolerant grafts compared with syngeneic control grafts. Biological process classification showed lower binomial p-values in the categories of "response to biotic stimulus, defense response, and immune response" suggesting that up-regulated genes identified in these grafts promote survival in the presence of an immune response. The expression of the incompatible carbohydrate antigen (αGal) was reduced by 2 months post-transplant when compared with the expression of this gene at Day 10 post-transplant. These results suggest that the gal carbohydrate antigen is downmodulated over time in grafts that demonstrate tolerance. Conclusion Our study suggests that tolerance is associated with intragraft gene expression changes that render the heart resistant to immune-mediated rejection. Genes associated with stress and immunity are up-regulated, however cytoprotective genes HO-1, Bcl2 and A20 were not up-regulated. The expression of the gal carbohydrate, the key target initiating an immune response in this model, is down-regulated in the post-transplant period.
Collapse
|
40
|
Abstract
In 1943, Gibson and Medawar opened the modern era of transplantation research with a paper on the problem of skin allograft rejection. Ten years later Billingham, Brent and Medawar demonstrated that it was possible to induce selective immune acceptance of skin grafts in mice, a state of tolerance. After over six decades, however, the precise mechanism of skin allograft rejection remains still ill-defined. Furthermore, it has not been possible to achieve reliably clinical tolerance allowing the widespread application of skin allotransplantation techniques. The first successful applications of skin allotransplantation have included the hand and face. However, complications from the chronic immunosuppression regimens limit the application of these techniques. Induction of tolerance to skin (and the other tissues in the allograft) would be the most effective way to overcome all these difficulties, but this is yet to be achieved reliably, stimulating some to look for other ways to surmount the current limitations. This paper summarizes alternatives to enlarge the scope of skin allotransplantation techniques, current understanding of mechanisms of skin rejection, and the utility and limitations of animal models used to study skin rejection and tolerance induction. Finally, manipulation strategies to achieve skin tolerance are outlined.
Collapse
Affiliation(s)
- Benjamin M Horner
- Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
| | | | | | | |
Collapse
|
41
|
Abstract
The achievement of immune tolerance, a state of specific unresponsiveness to the donor graft, has the potential to overcome the current major limitations to progress in organ transplantation, namely late graft loss, organ shortage and the toxicities of chronic nonspecific immumnosuppressive therapy. Advances in our understanding of immunological processes, mechanisms of rejection and tolerance have led to encouraging developments in animal models, which are just beginning to be translated into clinical pilot studies. These advances are reviewed here and the appropriate timing for clinical trials is discussed.
Collapse
Affiliation(s)
- M Sykes
- Transplantation Biology Research Center, Bone Marrow Transplantation Section, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02129, USA.
| |
Collapse
|
42
|
Saidman SL. Mixed chimerism approach to induction of transplant tolerance: a review of the Massachusetts General Hospital experience. Transplant Proc 2007; 39:676-7. [PMID: 17445571 DOI: 10.1016/j.transproceed.2007.01.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S L Saidman
- Histocompatibility Lab, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
43
|
Pree I, Pilat N, Wekerle T. Recent Progress in Tolerance Induction through Mixed Chimerism. Int Arch Allergy Immunol 2007; 144:254-66. [PMID: 17596699 DOI: 10.1159/000104740] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Organ transplant recipients require life-long treatment with immunosuppressive drugs. Currently available immunosuppression is associated with substantial morbidity and mortality, and is ineffective in inhibiting chronic rejection and graft loss. Therefore, a permanent state of donor-specific tolerance remains a primary goal for transplantation research. The induction of mixed hematopoietic chimerism is an attractive concept in this regard. Hematopoietic chimerism modulates the immunologic repertoire by extending the mechanisms of self-tolerance to donor-specific allotolerance. Despite recent progress in developing nontoxic bone marrow transplantation protocols for rodents, translation to large animals has remained difficult. Here, we outline the concept of tolerance via mixed chimerism, and review recent progress and remaining challenges in bringing this approach to the clinical setting.
Collapse
Affiliation(s)
- Ines Pree
- Division of Transplantation, Department of Surgery, Vienna General Hospital, Medical University of Vienna, Vienna, Austria
| | | | | |
Collapse
|
44
|
Liu G, Ma H, Jiang L, Peng J, Zhao Y. The immunity of splenic and peritoneal F4/80(+) resident macrophages in mouse mixed allogeneic chimeras. J Mol Med (Berl) 2007; 85:1125-35. [PMID: 17541534 DOI: 10.1007/s00109-007-0215-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2007] [Revised: 03/18/2007] [Accepted: 03/27/2007] [Indexed: 01/08/2023]
Abstract
Mixed allogeneic chimeras are emerging as a prospective approach to induce immune tolerance in clinics. However, the immunological function of macrophages in mixed chimeras has not been evaluated. Using a B6-->BALB/c mixed chimera model, we investigated the phenotype and function of F4/80(+) resident peritoneal exudate macrophage (PEMs) and splenic macrophages (SPMs) in vitro and in vivo. Recipient F4/80(+)PEMs and SPMs in mixed chimeras expressed significantly lower levels of MHC-II, CD54, and CD23 than those in non-chimeric mice before lipopolysaccharide stimulation. Recipient F4/80(+)PEMs and SPMs in mixed chimeras induced normal cell proliferation and delayed-type hypersensitivity of allo-T cells, but they induced more IFN-gamma and IL-2 products and less IL-10 and TGF-beta products of allo-T cells compared with those of non-chimeras. Furthermore, recipient F4/80(+)PEMs and SPMs had significantly higher phagocytotic capacity against chicken red blood cells or allo-T cells than those of controls while they had normal phagocytosis to Escherichia coli. Although some slight but significant alterations of recipient macrophages have been detected, these results provide direct evidences for the efficient immunity of recipient macrophages in mixed allogeneic chimeras. The present study also, for the first time, offered basic information for macrophages maturing in heterogeneous environments.
Collapse
Affiliation(s)
- Guangwei Liu
- Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beisihuan Xi Road 25, Beijing, 100080, China
| | | | | | | | | |
Collapse
|
45
|
Li Z, Benghiat FS, Kubjak C, Schuind F, Goldman M, Le Moine A. Donor T-cell development in host thymus after heterotopic limb transplantation in mice. Transplantation 2007; 83:815-8. [PMID: 17414717 DOI: 10.1097/01.tp.0000255703.02587.df] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We developed a mouse model of heterotopic limb transplantation in which we took advantage of Thy1.1 and Thy1.2 congenic strains to track and characterize donor T cells, to determine the role of recipient's thymus in mixed T-cell chimerism induction as well as transplant immunocompetence. The vascularized Thy1.1 limb graft composed of femur, muscle, and skin (VBT) survived long-term in more than 87.5% of Thy1.2 recipients. Percentages of donor-type Thy1.1 T cells increased from day 30 to 90 in thymus and spleen of recipients. Most peripheral donor T cells displayed a naïve phenotype and a few others were regulatory T cells. Thymectomy prevented peripheral T-cell chimerism. Congenic VBT in immunodeficient RAG mice restored their ability to reject skin allografts. These observations suggest that donor T cells differentiated in host thymus might contribute to maintenance of mixed chimerism after transplantation of tissue composite grafts that include vascularized bone.
Collapse
Affiliation(s)
- Zhanzhuo Li
- Institute for Medical Immunology, Université Libre de Bruxelles, Gosselies, Belgium
| | | | | | | | | | | |
Collapse
|
46
|
Demirkiran A, Bosma BM, Kok A, Baan CC, Metselaar HJ, Ijzermans JNM, Tilanus HW, Kwekkeboom J, van der Laan LJW. Allosuppressive Donor CD4+CD25+ Regulatory T Cells Detach from the Graft and Circulate in Recipients after Liver Transplantation. THE JOURNAL OF IMMUNOLOGY 2007; 178:6066-72. [PMID: 17475831 DOI: 10.4049/jimmunol.178.10.6066] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Organ transplantation (Tx) results in a transfer of donor leukocytes from the graft to the recipient, which can lead to chimerism and may promote tolerance. It remains unclear whether this tolerance involves donor-derived regulatory T cells (Tregs). In this study, we examined the presence and allosuppressive activity of CD4+CD25+Foxp3+ Tregs in perfusates of human liver grafts and monitored the cells presence in the circulation of recipients after liver Tx. Vascular perfusions of 22 liver grafts were performed with University of Wisconsin preservation and albumin solutions. Flow cytometric analysis revealed that perfusate T cells had high LFA-1 integrin expression and had a reversed CD4 to CD8 ratio compared with control blood of healthy individuals. These findings indicate that perfusate cells are of liver origin and not derived from residual donor blood. Further characterization of perfusate mononuclear cells showed an increased proportion of CD4+CD25+CTLA4+ T cells compared with healthy control blood. Increased percentages of Foxp3+ cells, which were negative for CD127, confirmed the enrichment of Tregs in perfusates. In MLR, CD4+CD25+ T cells from perfusates suppressed proliferation and IFN-gamma production of donor and recipient T cells. In vivo within the first weeks after Tx, up to 5% of CD4+CD25+CTLA4+ T cells in recipient blood were derived from the donor liver. In conclusion, a substantial number of donor Tregs detach from the liver graft during perfusion and continue to migrate into the recipient after Tx. These donor Tregs suppress the direct pathway alloresponses and may in vivo contribute to chimerism-associated tolerance early after liver Tx.
Collapse
Affiliation(s)
- Ahmet Demirkiran
- Department of Surgery, Erasmus MC-University Medical Center, Rotterdam, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Van Wijmeersch B, Sprangers B, Rutgeerts O, Lenaerts C, Landuyt W, Waer M, Billiau AD, Dubois B. Allogeneic bone marrow transplantation in models of experimental autoimmune encephalomyelitis: evidence for a graft-versus-autoimmunity effect. Biol Blood Marrow Transplant 2007; 13:627-37. [PMID: 17531772 DOI: 10.1016/j.bbmt.2007.03.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 03/05/2007] [Indexed: 12/29/2022]
Abstract
Autologous hematopoietic stem cell transplantation (HSCT) is being explored in the treatment of severe multiple sclerosis (MS), and is based on the concept of "resetting" the immune system. The use of allogeneic HSCT may offer additional advantages, such as the replacement of the autoreactive immune compartment by healthy allogeneic cells and development of a graft-versus-autoimmunity (GVA) effect. However, in clinical practice, the genetic susceptibility to MS of allogeneic stem cell donors is generally unknown, and GVA may therefore be an important mechanism of action. Experimental autoimmune encephalomyelitis (EAE)-susceptible and -resistant mouse strains were used to determine the roles of genetic susceptibility, level of donor-chimerism, and alloreactivity in the therapeutic potential of syngeneic versus allogeneic bone marrow transplant (BMT) for EAE. After transplantation and EAE induction, animals were evaluated for clinical EAE and ex vivo myelin oligodendrocyte glycoprotein-specific proliferation. Early after BMT, both syngeneic and allogeneic chimeras were protected from EAE development. On the longer term, allogeneic but not syngeneic BMT conferred protection, but this required high-level donor-chimerism from EAE-resistant donors. Importantly, when EAE-susceptible donors were used, robust protection from EAE was obtained when active alloreactivity, induced by donor lymphocyte infusions, was provided. Our findings indicate the requirement of a sufficient level of donor-chimerism from a nonsusceptible donor in the therapeutic effect of allogeneic BMT. Importantly, the data indicate that, independently of genetic susceptibility, active alloreactivity is associated with a GVA effect, thereby providing new evidence to support the potential role of allogeneic BMT in the treatment of MS.
Collapse
Affiliation(s)
- Bart Van Wijmeersch
- Laboratory of Experimental Transplantation, University of Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Linhart B, Bigenzahn S, Hartl A, Lupinek C, Thalhamer J, Valenta R, Wekerle T. Costimulation blockade inhibits allergic sensitization but does not affect established allergy in a murine model of grass pollen allergy. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2007; 178:3924-31. [PMID: 17339493 PMCID: PMC2993922 DOI: 10.4049/jimmunol.178.6.3924] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Type I allergy is characterized by the development of an initial Th2-dependent allergen-specific IgE response, which is boosted upon a subsequent allergen encounter. Although the immediate symptoms of allergy are mainly IgE-mediated, allergen-specific T cell responses contribute to the late phase as well as to the chronic manifestations of allergy. This study investigates the potential of costimulation blockade with CTLA4Ig and an anti-CD154 mAb for modifying the allergic immune response to the major timothy grass pollen allergen Phl p 5 in a mouse model. BALB/c mice were treated with the costimulation blockers at the time of primary sensitization to the Phl p 5 allergen or at the time of a secondary allergen challenge. Costimulation blockade (CTLA4Ig plus anti-CD154 or anti-CD154 alone) at the time of sensitization prevented the development of allergen-specific IgE, IgM, IgG, and IgA responses compared with untreated but sensitized mice. However, costimulation blockade had no influence on established IgE responses in sensitized mice. Immediate-type reactions as analyzed by a rat basophil leukemia cell mediator release assay were only suppressed by early treatment but not by a costimulation blockade after sensitization. CTLA4Ig given alone failed to suppress both the primary and the secondary allergen-specific Ab responses. Allergen-specific T cell activation was suppressed in mice by early as well as by a late costimulation blockade, suggesting that IgE responses in sensitized mice are independent of T cell help. Our results indicate that T cell suppression alone without active immune regulation or a shifting of the Th2/Th1 balance is not sufficient for the treatment of established IgE responses in an allergy.
Collapse
Affiliation(s)
- Birgit Linhart
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
| | - Sinda Bigenzahn
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Austria
| | - Arnulf Hartl
- Dept. of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria
| | - Christian Lupinek
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
| | | | - Rudolf Valenta
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
| | - Thomas Wekerle
- Div. of Immunopathology, Dept. of Pathophysiology, Center of Physiology and Pathophysiology, Medical University of Vienna, Austria
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Austria
| |
Collapse
|
49
|
Pree I, Wekerle T. Inducing mixed chimerism and transplantation tolerance through allogeneic bone marrow transplantation with costimulation blockade. Methods Mol Biol 2007; 380:391-403. [PMID: 17876108 DOI: 10.1007/978-1-59745-395-0_25] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Induction of mixed chimerism (i.e., coexistence of donor and recipient hematopoietic cells) through transplantation of allogeneic donor bone marrow under appropriate host conditioning, is one of the most reliable strategies to induce transplantation tolerance. Robust tolerance is evident in mixed chimeras as they permanently accept donor skin grafts while promptly rejecting third party grafts. Although historically, myeloablative and T-cell depleting regimens have been described, milder protocols involving costimulation blockade have recently been developed. The prototypical murine protocol described in this chapter, involves the use of CTLA4Ig and a monoclonal antibody-specific for CD154 (CD40L) for costimulation blockade, 3 Gy of nonmyeloablative total body irradiation and a conventional number of 20 x 10(6) fully allogeneic bone marrow cells. Flow cytometry is used to determine levels of multilineage hematopoietic chimerism and deletion of donor-reactive CD4+ T cells. Tolerance is assessed in vivo by grafting of donor and third party skin.
Collapse
Affiliation(s)
- Ines Pree
- Division of Transplantation, Department of Surgery, Medical University of Vienna, Austria
| | | |
Collapse
|
50
|
Abstract
Herein, we succinctly review mechanisms underlying self-tolerance and the roles of dendritic leukocytes (DCs) in T-cell tolerance to self and foreign antigens. We also consider the properties of naturally arising and other populations of regulatory T cells (Treg), together with growing evidence that interplay between DCs and Treg cells can sustain antigen-specific tolerance. B-cell tolerance and the role of hematopoietic cell chimerism in the induction and maintenance of tolerance are also discussed, as is the impact of cosignaling pathway manipulation on tolerance induction. This overview also surveys prospects for technological advances in the monitoring and prediction of tolerance and the application of genomic and proteomic analysis. In addition, we consider potential novel therapeutic targets for promotion of tolerance induction.
Collapse
Affiliation(s)
- Giorgio Raimondi
- University of Pittsburgh School of Medicine, Thomas E. Starzl Transplantation Institute, Pittsburgh, PA, USA
| | | | | |
Collapse
|