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Xu H, He X. Developments in kidney xenotransplantation. Front Immunol 2024; 14:1242478. [PMID: 38274798 PMCID: PMC10808336 DOI: 10.3389/fimmu.2023.1242478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 12/13/2023] [Indexed: 01/27/2024] Open
Abstract
The search for kidney xenografts that are appropriate for patients with end-stage renal disease has been ongoing since the beginning of the last century. The major cause of xenograft loss is hyperacute and acute rejection, and this has almost been overcome via scientific progress. The success of two pre-clinical trials of α1,3-galactosyltransferase gene-knockout porcine kidneys in brain-dead patients in 2021 triggered research enthusiasm for kidney xenotransplantation. This minireview summarizes key issues from an immunological perspective: the discovery of key xenoantigens, investigations into key co-stimulatory signal inhibition, gene-editing technology, and immune tolerance induction. Further developments in immunology, particularly immunometabolism, might help promote the long-term outcomes of kidney xenografts.
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Affiliation(s)
| | - Xiaozhou He
- Urology Department, Third Affiliated Hospital of Soochow University, Changzhou, China
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2
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Sykes M, Sachs DH. Progress in xenotransplantation: overcoming immune barriers. Nat Rev Nephrol 2022; 18:745-761. [PMID: 36198911 DOI: 10.1038/s41581-022-00624-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2022] [Indexed: 11/09/2022]
Abstract
A major limitation of organ allotransplantation is the insufficient supply of donor organs. Consequently, thousands of patients die every year while waiting for a transplant. Progress in xenotransplantation that has permitted pig organ graft survivals of years in non-human primates has led to renewed excitement about the potential of this approach to alleviate the organ shortage. In 2022, the first pig-to-human heart transplant was performed on a compassionate use basis, and xenotransplantation experiments using pig kidneys in deceased human recipients provided encouraging data. Many advances in xenotransplantation have resulted from improvements in the ability to genetically modify pigs using CRISPR-Cas9 and other methodologies. Gene editing has the capacity to generate pig organs that more closely resemble those of humans and are hence more physiologically compatible and less prone to rejection. Despite such modifications, immune responses to xenografts remain powerful and multi-faceted, involving innate immune components that do not attack allografts. Thus, the induction of innate and adaptive immune tolerance to prevent rejection while preserving the capacity of the immune system to protect the recipient and the graft from infection is desirable to enable clinical xenotransplantation.
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Affiliation(s)
- Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University, New York, NY, USA. .,Department of Surgery, Columbia University, New York, NY, USA. .,Department of Microbiology and Immunology, Columbia University, New York, NY, USA.
| | - David H Sachs
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University, New York, NY, USA. .,Department of Surgery, Columbia University, New York, NY, USA.
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3
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Khosravi-Maharlooei M, Madley R, Borsotti C, Ferreira LMR, Sharp RC, Brehm MA, Greiner DL, Parent AV, Anderson MS, Sykes M, Creusot RJ. Modeling human T1D-associated autoimmune processes. Mol Metab 2022; 56:101417. [PMID: 34902607 PMCID: PMC8739876 DOI: 10.1016/j.molmet.2021.101417] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/19/2021] [Accepted: 12/07/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Type 1 diabetes (T1D) is an autoimmune disease characterized by impaired immune tolerance to β-cell antigens and progressive destruction of insulin-producing β-cells. Animal models have provided valuable insights for understanding the etiology and pathogenesis of this disease, but they fall short of reflecting the extensive heterogeneity of the disease in humans, which is contributed by various combinations of risk gene alleles and unique environmental factors. Collectively, these factors have been used to define subgroups of patients, termed endotypes, with distinct predominating disease characteristics. SCOPE OF REVIEW Here, we review the gaps filled by these models in understanding the intricate involvement and regulation of the immune system in human T1D pathogenesis. We describe the various models developed so far and the scientific questions that have been addressed using them. Finally, we discuss the limitations of these models, primarily ascribed to hosting a human immune system (HIS) in a xenogeneic recipient, and what remains to be done to improve their physiological relevance. MAJOR CONCLUSIONS To understand the role of genetic and environmental factors or evaluate immune-modifying therapies in humans, it is critical to develop and apply models in which human cells can be manipulated and their functions studied under conditions that recapitulate as closely as possible the physiological conditions of the human body. While microphysiological systems and living tissue slices provide some of these conditions, HIS mice enable more extensive analyses using in vivo systems.
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Affiliation(s)
- Mohsen Khosravi-Maharlooei
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Rachel Madley
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Chiara Borsotti
- Department of Health Sciences, Histology laboratory, Università del Piemonte Orientale, Novara, Italy
| | - Leonardo M R Ferreira
- Departments of Microbiology & Immunology, and Regenerative Medicine & Cell Biology, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA
| | - Robert C Sharp
- Department of Pathology, Immunology and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA
| | - Michael A Brehm
- Program in Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Dale L Greiner
- Program in Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA, USA
| | - Audrey V Parent
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Mark S Anderson
- Diabetes Center, University of California San Francisco, San Francisco, CA, USA
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA
| | - Remi J Creusot
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Irving Medical Center, New York, NY, USA.
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Khosravi-Maharlooei M, Li H, Hoelzl M, Zhao G, Ruiz A, Misra A, Li Y, Teteloshvili N, Nauman G, Danzl N, Ding X, Pinker EY, Obradovic A, Yang YG, Iuga A, Creusot RJ, Winchester R, Sykes M. Role of the thymus in spontaneous development of a multi-organ autoimmune disease in human immune system mice. J Autoimmun 2021; 119:102612. [PMID: 33611150 PMCID: PMC8044037 DOI: 10.1016/j.jaut.2021.102612] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 01/13/2023]
Abstract
We evaluated the role of the thymus in development of multi-organ autoimmunity in human immune system (HIS) mice. T cells were essential for disease development and the same T cell clones with varying phenotypes infiltrated multiple tissues. De novo-generated hematopoietic stem cell (HSC)-derived T cells were the major disease drivers, though thymocytes pre-existing in grafted human thymi contributed if not first depleted. HIS mice with a native mouse thymus developed disease earlier than thymectomized mice with a thymocyte-depleted human thymus graft. Defective structure in the native mouse thymus was associated with impaired negative selection of thymocytes expressing a transgenic TCR recognizing a self-antigen. Disease developed without direct recognition of antigens on recipient mouse MHC. While human thymus grafts had normal structure and negative selection, failure to tolerize human T cells recognizing mouse antigens presented on HLA molecules may explain eventual disease development. These new insights have implications for human autoimmunity and suggest methods of avoiding autoimmunity in next-generation HIS mice.
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Affiliation(s)
- Mohsen Khosravi-Maharlooei
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - HaoWei Li
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Markus Hoelzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Guiling Zhao
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Amanda Ruiz
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Aditya Misra
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Yang Li
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Nato Teteloshvili
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Grace Nauman
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Nichole Danzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Xiaolan Ding
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Elisha Y Pinker
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Aleksandar Obradovic
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Yong-Guang Yang
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Alina Iuga
- Department of Pathology, Columbia University Medical Center, Columbia University, New York, NY, 10032, USA
| | - Remi J Creusot
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Robert Winchester
- Department of Pathology, Columbia University Medical Center, Columbia University, New York, NY, 10032, USA,Division of Rheumatology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, New York, NY, 10032, USA,Department of Microbiology & Immunology, Columbia University Medical Center, Columbia University, New York, NY, 10032, USA,Department of Surgery, Columbia University Medical Center, Columbia University, New York, NY, 10032, USA
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Bikhet M, Morsi M, Hara H, Rhodes LA, Carlo WF, Cleveland D, Cooper DK, Iwase H. The immune system in infants: Relevance to xenotransplantation. Pediatr Transplant 2020; 24:e13795. [PMID: 32845539 PMCID: PMC7606572 DOI: 10.1111/petr.13795] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/10/2020] [Accepted: 06/22/2020] [Indexed: 12/17/2022]
Abstract
Despite the improvement in surgical interventions in the treatment of congenital heart disease, many life-threatening lesions (eg, hypoplastic left heart syndrome) ultimately require transplantation. However, there is a great limitation in the availability of deceased human cardiac donors of a suitable size. Hearts from genetically engineered pigs may provide an alternative source. The relatively immature immune system in infants (eg, absence of anti-carbohydrate antibodies, reduced complement activation, reduced innate immune cell activity) should minimize the risk of early antibody-mediated rejection of a pig graft. Additionally, recipient thymectomy, performed almost routinely as a preliminary to orthotopic heart transplantation in this age-group, impairs the T-cell response. Because of the increasing availability of genetically engineered pigs (eg, triple-knockout pigs that do not express any of the three known carbohydrate antigens against which humans have natural antibodies) and the ability to diagnose congenital heart disease during fetal life, cardiac xenotransplantation could be preplanned to be carried out soon after birth. Because of these several advantages, prolonged graft survival and even the induction of tolerance, for example, following donor-specific pig thymus transplantation, are more likely to be achieved in infants than in adults. In this review, we summarize the factors in the infant immune system that would be advantageous in the success of cardiac xenotransplantation in this age-group.
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Affiliation(s)
- Mohamed Bikhet
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Mahmoud Morsi
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Leslie A. Rhodes
- Division of Pediatric Cardiology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Waldemar F. Carlo
- Division of Pediatric Cardiology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - David Cleveland
- Department of Pediatric Cardiovascular Surgery, Children’s Hospital of Alabama, Birmingham, AL, USA
| | - David K.C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, AL, USA
| | - Hayato Iwase
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, AL, USA
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Abstract
PURPOSE OF REVIEW To describe the most recent progress towards tolerance in xenotransplantation. RECENT FINDINGS Mixed chimerism and thymic transplantation have been used to promote tolerance in xenotransplantation models. Intra-bone bone marrow transplantation is a recent advance for mixed chimerism, which promotes longer lasting chimerism and early graft function of subsequent organ transplantation. The hybrid thymus, an advancement to the vascularized thymokidney and vascularized thymic lobe, is being developed to allow for both donor and recipient T-cell selection in the chimeric thymus, encouraging tolerance to self and donor while maintaining appropriate immune function. Regulatory T cells show promise to promote tolerance by suppressing effector T cells and by supporting mixed chimerism. Monoclonal antibodies such as anti-CD2 may promote tolerance through suppression of CD2+ effector and memory T cells whereas Tregs, which express lower numbers of CD2, are relatively spared and might be used to promote tolerance. SUMMARY These findings contribute major advances to tolerance in xenotransplantation. A combination of many of these mechanisms will likely be needed to have long-term tolerance maintained without the use of immunosuppression.
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Affiliation(s)
- Erin M. Duggan
- Columbia Center for Translational Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
- Department of Surgery, Columbia University, New York, NY
| | - Adam Griesemer
- Columbia Center for Translational Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
- Department of Surgery, Columbia University, New York, NY
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Nauman G, Borsotti C, Danzl N, Khosravi-Maharlooei M, Li HW, Chavez E, Stone S, Sykes M. Reduced positive selection of a human TCR in a swine thymus using a humanized mouse model for xenotolerance induction. Xenotransplantation 2020; 27:e12558. [PMID: 31565822 PMCID: PMC7007369 DOI: 10.1111/xen.12558] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/27/2019] [Accepted: 09/13/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Tolerance-inducing approaches to xenotransplantation would be optimal and may be necessary for long-term survival of transplanted pig organs in human patients. The ideal approach would generate donor-specific unresponsiveness to the pig organ without suppressing the patient's normal immune function. Porcine thymus transplantation has shown efficacy in promoting xenotolerance in humanized mice and large animal models. However, murine studies demonstrate that T cells selected in a swine thymus are positively selected only by swine thymic epithelial cells, and therefore, cells expressing human HLA-restricted TCRs may not be selected efficiently in a transplanted pig thymus. This may lead to suboptimal patient immune function. METHODS To assess human thymocyte selection in a pig thymus, we used a TCR transgenic humanized mouse model to study positive selection of cells expressing the MART1 TCR, a well-characterized human HLA-A2-restricted TCR, in a grafted pig thymus. RESULTS Positive selection of T cells expressing the MART1 TCR was inefficient in both a non-selecting human HLA-A2- or swine thymus compared with an HLA-A2+ thymus. Additionally, CD8 MART1 TCRbright T cells were detected in the spleens of mice transplanted with HLA-A2+ thymi but were significantly reduced in the spleens of mice transplanted with swine or HLA-A2- thymi. [Correction added on October 15, 2019, after first online publication: The missing superscript values +, -, and bright have been included in the Results section.] CONCLUSIONS: Positive selection of cells expressing a human-restricted TCR in a transplanted pig thymus is inefficient, suggesting that modifications to improve positive selection of cells expressing human-restricted TCRs in a pig thymus may be necessary to support development of a protective human T-cell pool in future patients.
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Affiliation(s)
- Grace Nauman
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Chiara Borsotti
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Nichole Danzl
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Mohsen Khosravi-Maharlooei
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Hao-Wei Li
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Estefania Chavez
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Samantha Stone
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
| | - Megan Sykes
- Columbia Center for Translational Immunology, Department of Medicine, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Microbiology and Immunology, Columbia University Medical Center, Columbia University, New York, NY, USA
- Department of Surgery, Columbia University Medical Center, Columbia University, New York, NY, USA
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Sekijima M, Sahara H, Shimizu A, Iwanaga T, Murokawa T, Ariyoshi Y, Pomposelli T, Maharlooei MK, Sykes M, Yamada K. Preparation of hybrid porcine thymus containing non-human primate thymic epithelial cells in miniature swine. Xenotransplantation 2019; 26:e12543. [PMID: 31293016 PMCID: PMC6908759 DOI: 10.1111/xen.12543] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 05/26/2019] [Accepted: 06/04/2019] [Indexed: 01/17/2023]
Abstract
BACKGROUND We have achieved greater than a 6-month survival of a life-supporting kidney co-transplanted with a vascularized thymic graft into non-human primates (NHPs). Although we have achieved pig-specific unresponsiveness in vitro, immunosuppression was not able to be fully weaned. Studies in mice and humanized mice suggest that a hybrid pig thymus (Hyb-thy)-containing host thymic epithelial cells (TECs) can optimize intra-thymic selection, achieving xenograft tolerance with improved reconstitution of T-cell function. METHODS We have tested the feasibility of the preparation of a Hyb-thy that contains NHP TECs in the donor thymic grafts. We first prepared the Hyb-thy in the donor pigs 2-3 weeks before xeno-Tx. We performed six cases of Hyb-thy preparation in six juvenile miniature swine. Two pigs received non-manipulated cynomolgus monkey thymic cells that were isolated from an excised atrophic thymus via injection into their thymic lobes (Group 1). The remaining four received thymic cells that were isolated from non-atrophic thymic glands (Groups 2 and 3). Pigs in Group 2 received unmanipulated thymic cells in one thymic lobe, as well as CD2-positive cell-depleted TEC-enriched cells in the contralateral lobe. Pigs in Group 3 received TEC-enriched cells alone. RESULTS All thymus-injected pigs received tacrolimus and rapamycin until endpoint (POD16). We detected cynomolgus monkey TEC networks in pig thymus from Groups 1 and 3, while pigs in Group 2 rejected the thymic cells. We demonstrated the preparation of Hyb-thy in pigs using tacrolimus plus rapamycin therapy. CONCLUSIONS Our results suggest that the enrichment of TEC from the excised NHP thymus facilitated NHP TEC engraftment in pig thymus.
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Affiliation(s)
- Mitsuhiro Sekijima
- Division of Organ Replacement and Xenotransplantation
Surgery, Center for Advanced Biomedical Science and Swine Research, Kagoshima
University, Japan
| | - Hisashi Sahara
- Division of Organ Replacement and Xenotransplantation
Surgery, Center for Advanced Biomedical Science and Swine Research, Kagoshima
University, Japan
- Columbia University Center for Translational Immunology,
Department of Surgery, Columbia University, New York, NY
| | - Akira Shimizu
- Department of Analytic Human Pathology, Nippon Medical
School, Tokyo, Japan
| | - Takehiro Iwanaga
- Division of Organ Replacement and Xenotransplantation
Surgery, Center for Advanced Biomedical Science and Swine Research, Kagoshima
University, Japan
| | - Takahiro Murokawa
- Division of Organ Replacement and Xenotransplantation
Surgery, Center for Advanced Biomedical Science and Swine Research, Kagoshima
University, Japan
| | - Yuichi Ariyoshi
- Division of Organ Replacement and Xenotransplantation
Surgery, Center for Advanced Biomedical Science and Swine Research, Kagoshima
University, Japan
| | - Thomas Pomposelli
- Columbia University Center for Translational Immunology,
Department of Surgery, Columbia University, New York, NY
| | - Mohsen Khosravi Maharlooei
- Columbia University Center for Translational Immunology,
Department of Surgery, Columbia University, New York, NY
| | - Megan Sykes
- Columbia University Center for Translational Immunology,
Department of Surgery, Columbia University, New York, NY
| | - Kazuhiko Yamada
- Columbia University Center for Translational Immunology,
Department of Surgery, Columbia University, New York, NY
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Sykes M. IXA Honorary Member Lecture, 2017: The long and winding road to tolerance. Xenotransplantation 2018; 25:e12419. [PMID: 29913040 DOI: 10.1111/xen.12419] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 05/03/2018] [Indexed: 12/18/2022]
Abstract
The last 15 years or so have seen exciting progress in xenotransplantation, with porcine organ grafts surviving months or even years in non-human primates. These advances reflect the application of new scientific knowledge, improved immunosuppressive agents, and genetic engineering. The field has recently enjoyed a renaissance of interest and hope, largely due to the exponential increase in our capacity to genetically engineer porcine source animals. However, immune responses to xenografts are very powerful and widespread clinical application of xenotransplantation will depend on the ability to suppress these immune responses while preserving the capacity to protect both the recipient and the graft from infectious microorganisms. Our work over the last three decades has aimed to engineer the immune system of the recipient in a manner that achieves specific tolerance to the xenogeneic donor while preserving otherwise normal immune function. Important proofs of principle have been obtained, first in rodents, and later in human immune systems in "humanized mice" and finally in non-human primates, demonstrating the capacity and potential synergy of mixed xenogeneic chimerism and xenogeneic thymic transplantation in tolerizing multiple arms of the immune system. Considering the fact that clinical tolerance has recently been achieved for allografts and the even greater importance of avoiding excessive immunosuppression for xenografts, it is my belief that it is both possible and imperative that we likewise achieve xenograft tolerance. I expect this to be accomplished through the availability of targeted approaches to recipient immune conditioning, understanding of immunological mechanisms of tolerance, advanced knowledge of physiological incompatibilities, and the availability of inbred miniature swine with optimized use of genetic engineering.
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Affiliation(s)
- Megan Sykes
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, NY, USA.,Department of Medicine, Columbia University, New York, NY, USA.,Department of Microbiology & Immunology, Columbia University, New York, NY, USA.,Department of Surgery, Columbia University, New York, NY, USA
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10
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Liu L, He C, Liu J, Lv Z, Wang G, Gao H, Dai Y, Cooper DKC, Cai Z, Mou L. Transplant Tolerance: Current Insights and Strategies for Long-Term Survival of Xenografts. Arch Immunol Ther Exp (Warsz) 2018; 66:355-364. [PMID: 29992337 DOI: 10.1007/s00005-018-0517-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 06/18/2018] [Indexed: 12/20/2022]
Abstract
Xenotransplantation is an attractive solution to the problem of allograft shortage. However, transplants across discordant species barriers are subject to vigorous immunologic and pathobiologic hurdles, some of which might be overcome with the induction of immunologic tolerance. Several strategies have been designed to induce tolerance to a xenograft at both the central (including induction of mixed chimerism and thymic transplantation) and peripheral (including adoptive transfer of regulatory cells and blocking T cell costimulation) levels. Currently, xenograft tolerance has been well-established in rodent models, but these protocols have not yet achieved similar success in nonhuman primates. This review will discuss the major barriers that impede the establishment of immunological tolerance across xenogeneic barriers and the potential solution to these challenges, and provide a perspective on the future of the development of novel tolerance-inducing strategies.
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Affiliation(s)
- Lu Liu
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center' Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen University School of Medicine, Shenzhen University Health Science Center, Shenzhen, 518035, Guangdong, China.,Department of Gastroenterology' Center For Digestive Diseases, People's Hospital of Baoan District, The 8th people's Hospital of Shenzhen, Shenzhen, 518101, Guangdong, China
| | - Chen He
- Department of Ophthalmology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, 518035, Guangdong, China
| | - Jintao Liu
- Department of Gastroenterology' Center For Digestive Diseases, People's Hospital of Baoan District, The 8th people's Hospital of Shenzhen, Shenzhen, 518101, Guangdong, China
| | - Zhiwu Lv
- Department of Gastroenterology' Center For Digestive Diseases, People's Hospital of Baoan District, The 8th people's Hospital of Shenzhen, Shenzhen, 518101, Guangdong, China
| | - Ganlu Wang
- Department of Gastroenterology' Center For Digestive Diseases, People's Hospital of Baoan District, The 8th people's Hospital of Shenzhen, Shenzhen, 518101, Guangdong, China
| | - Hanchao Gao
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center' Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen University School of Medicine, Shenzhen University Health Science Center, Shenzhen, 518035, Guangdong, China
| | - Yifan Dai
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - David K C Cooper
- Xenotransplantation Program/Department of Surgery, The University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Zhiming Cai
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center' Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen University School of Medicine, Shenzhen University Health Science Center, Shenzhen, 518035, Guangdong, China
| | - Lisha Mou
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center' Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen University School of Medicine, Shenzhen University Health Science Center, Shenzhen, 518035, Guangdong, China.
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11
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Abstract
PURPOSE OF REVIEW This review describes recent progress in tolerance-inducing strategies across xenogeneic immunological barriers as well as the potential benefit of a tolerance strategy for islets and kidney xenotransplantation. RECENT FINDINGS Using advanced gene editing technologies, xenotransplantation from multitransgenic alpha-1,3-galactosyltransferase knockout pigs has demonstrated marked prolongation of renal xenograft survival, ranging from days to greater than several months for life-supporting kidneys, and more than 2 years in a heterotopic nonlife-supporting cardiac xenograft model. Continuous administration of multiple immunosuppressive drugs has been required and attempts to taper immunosuppression have been unsuccessful. It appears likely that low levels of T cell dependent antibodies and activation of innate responses are responsible for xenograft loss. Mixed chimerism and thymic transplantation approaches have achieved xenogeneic tolerance in pig-to-mouse models and both have recently been extended to pig-to-baboon models. Encouraging results have been reported, including persistence of macrochimerism, prolonged pig skin graft survival, donor-specific unresponsiveness in vitro and detection of recent T cell emigrants in vivo. SUMMARY Although tolerance induction in vivo has not yet been achieved in pig-to-baboon models, recent results are encouraging that this goal will be attainable through genetic engineering of porcine donors.
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Griesemer A, Yamada K, Sykes M. Xenotransplantation: immunological hurdles and progress toward tolerance. Immunol Rev 2015; 258:241-58. [PMID: 24517437 DOI: 10.1111/imr.12152] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The discrepancy between organ need and organ availability represents one of the major limitations in the field of transplantation. One possible solution to this problem is xenotransplantation. Research in this field has identified several obstacles that have so far prevented the successful development of clinical xenotransplantation protocols. The main immunologic barriers include strong T-cell and B-cell responses to solid organ and cellular xenografts. In addition, components of the innate immune system can mediate xenograft rejection. Here, we review these immunologic and physiologic barriers and describe some of the strategies that we and others have developed to overcome them. We also describe the development of two strategies to induce tolerance across the xenogeneic barrier, namely thymus transplantation and mixed chimerism, from their inception in rodent models through their current progress in preclinical large animal models. We believe that the addition of further beneficial transgenes to Gal knockout swine, combined with new therapies such as Treg administration, will allow for successful clinical application of xenotransplantation.
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Affiliation(s)
- Adam Griesemer
- Columbia Center for Translational Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
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Kalscheuer H, Onoe T, Dahmani A, Li HW, Hölzl M, Yamada K, Sykes M. Xenograft tolerance and immune function of human T cells developing in pig thymus xenografts. THE JOURNAL OF IMMUNOLOGY 2014; 192:3442-50. [PMID: 24591363 DOI: 10.4049/jimmunol.1302886] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Transplantation of xenogeneic thymus tissue allows xenograft tolerance induction in the highly disparate pig-to-mouse model. Fetal swine thymus (SW THY) can support the generation of a diverse human T cell repertoire that is tolerant of the pig in vitro. We demonstrate that SW THY generates all human T cell subsets, including regulatory T cells (Tregs), in similar numbers as fetal human thymus (HU THY) grafts in immunodeficient mice receiving the same human CD34(+) cells. Peripheral T cells are specifically tolerant to the mouse and to the human and porcine donors, with robust responses to nondonor human and pig Ags. Specific tolerance is observed to pig skin grafts sharing the THY donor MHC. SW THY-generated peripheral Tregs show similar function, but include lower percentages of naive-type Tregs compared with HU THY-generated Tregs. Tregs contribute to donor-pig specific tolerance. Peripheral human T cells generated in SW THY exhibit reduced proportions of CD8(+) T cells and reduced lymphopenia-driven proliferation and memory-type conversion, accelerated decay of memory-type cells, and reduced responses to protein Ags. Thus, SW thymus transplantation is a powerful xenotolerance approach for human T cells. However, immune function may be further enhanced by strategies to permit positive selection by autologous HLA molecules.
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Affiliation(s)
- Hannes Kalscheuer
- Transplantation Biology Research Center, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
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Parent AV, Russ HA, Khan IS, LaFlam TN, Metzger TC, Anderson MS, Hebrok M. Generation of functional thymic epithelium from human embryonic stem cells that supports host T cell development. Cell Stem Cell 2013; 13:219-29. [PMID: 23684540 DOI: 10.1016/j.stem.2013.04.004] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Revised: 02/26/2013] [Accepted: 03/29/2013] [Indexed: 12/29/2022]
Abstract
Inducing immune tolerance to prevent rejection is a key step toward successful engraftment of stem-cell-derived tissue in a clinical setting. Using human pluripotent stem cells to generate thymic epithelial cells (TECs) capable of supporting T cell development represents a promising approach to reach this goal; however, progress toward generating functional TECs has been limited. Here, we describe a robust in vitro method to direct differentiation of human embryonic stem cells (hESCs) into thymic epithelial progenitors (TEPs) by precise regulation of TGFβ, BMP4, RA, Wnt, Shh, and FGF signaling. The hESC-derived TEPs further mature into functional TECs that support T cell development upon transplantation into thymus-deficient mice. Importantly, the engrafted TEPs produce T cells capable of in vitro proliferation as well as in vivo immune responses. Thus, hESC-derived TEP grafts may have broad applications for enhancing engraftment in cell-based therapies as well as restoring age- and stress-related thymic decline.
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Affiliation(s)
- Audrey V Parent
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA 94143-0540, USA
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15
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Systemic Human T Cell Developmental Processes in Humanized Mice Cotransplanted With Human Fetal Thymus/Liver Tissue and Hematopoietic Stem Cells. Transplantation 2012; 94:1095-102. [DOI: 10.1097/tp.0b013e318270f392] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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16
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Zhou J, Wang X, Luo G, He W, Cui Y, Tan J, Yang S, Yang J, Sun W, Song H, Xiang F, Yao Z, Liu D, Wu Y, Wu J. Partial Tolerance Induced by Transplantation of Spatially Separated Thymuses: A Cue for T Cell Retolerization in Thymus Grafts. Scand J Immunol 2012; 75:401-8. [DOI: 10.1111/j.1365-3083.2012.02675.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Onoe T, Kalscheuer H, Danzl N, Chittenden M, Zhao G, Yang YG, Sykes M. Human natural regulatory T cell development, suppressive function, and postthymic maturation in a humanized mouse model. THE JOURNAL OF IMMUNOLOGY 2011; 187:3895-903. [PMID: 21876039 DOI: 10.4049/jimmunol.1100394] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
CD4(+) regulatory T cells (Tregs) control adaptive immune responses and promote self-tolerance. Various humanized mouse models have been developed in efforts to reproduce and study a human immune system. However, in models that require T cell differentiation in the recipient murine thymus, only low numbers of T cells populate the peripheral immune systems. T cells are positively selected by mouse MHC and therefore do not function well in an HLA-restricted manner. In contrast, cotransplantation of human fetal thymus/liver and i.v. injection of CD34(+) cells from the same donor achieves multilineage human lymphohematopoietic reconstitution, including dendritic cells and formation of secondary lymphoid organs, in NOD/SCID mice. Strong Ag-specific immune responses and homeostatic expansion of human T cells that are dependent on peripheral human APCs occur. We now demonstrate that FOXP3(+)Helios(+) "natural" Tregs develop normally in human fetal thymic grafts and are present in peripheral blood, spleen, and lymph nodes of these humanized mice. Humanized mice exhibit normal reversal of CD45 isoform expression in association with thymic egress, postthymic "naive" to "activated" phenotypic conversion, and suppressive function. These studies demonstrate the utility of this humanized mouse model for the study of human Treg ontogeny, immunobiology and therapy.
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Affiliation(s)
- Takashi Onoe
- Department of Surgery, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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18
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Duan K, Zhang B, Zhang W, Zhao Y, Qu Y, Sun C, Zhao Y. Efficient peripheral construction of functional human regulatory CD4(+)CD25(high)Foxp3(+) T cells in NOD/SCID mice grafted with fetal human thymus/liver tissues and CD34(+) cells. Transpl Immunol 2011; 25:173-9. [PMID: 21856420 DOI: 10.1016/j.trim.2011.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Revised: 07/27/2011] [Accepted: 08/04/2011] [Indexed: 10/17/2022]
Abstract
Regulatory T cells, especially CD4(+)CD25(+) regulatory T cells are critical regulators of immune tolerance in humans and mice. Mice with humanized immunity have been developed by various transplantation strategies of human tissues or cells related to immunity, which are being extensively applied in biomedical research. However, it is unclear whether human CD4(+)CD25(+) regulatory T cells can normally develop in human thymic grafts and efficiently populate in the periphery in NOD/SCID mouse recipients. In human thymic grafts, high percentage of mature human CD4(+)CD25(high) regulatory T cells was detected. Human CD4(+)CD25(+) regulatory T cells maturing in fetal human thymus grafts could subsequently output to the periphery of NOD/SCID mouse recipients. Importantly, these cells exhibited Foxp3(+)CD45RO(+)CTLA4(+)CD127(-) phenotype, similarly to those in healthy individuals. In addition, human CD4(+)CD25(+) regulatory T cells maturing in human thymic grafts suppressed proliferative response of CD4(+)CD25(-) T cells to allogeneic antigens, though the peripheral CD4(+)CD25(+) regulatory T cells in fetal human thymus-grafted NOD/SCID mice showed somewhat decreased immunosuppressive ability compared with normal CD4(+)CD25(+) regulatory T cells. Thus, this humanized animal model is suitable for examining development and function of human CD4(+)CD25(+) regulatory T cells in vivo.
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Affiliation(s)
- Kaizhong Duan
- Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Schneider MKJ, Seebach JD. Xenotransplantation literature update: November-December, 2008. Xenotransplantation 2009; 16:50-3. [PMID: 19243562 DOI: 10.1111/j.1399-3089.2008.00507.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mårten K J Schneider
- Laboratory for Transplantation Immunology, Department of Internal Medicine, University Hospital Zurich, Zurich, Switzerland
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