1
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Kioulaphides S, García AJ. Encapsulation and immune protection for type 1 diabetes cell therapy. Adv Drug Deliv Rev 2024; 207:115205. [PMID: 38360355 PMCID: PMC10948298 DOI: 10.1016/j.addr.2024.115205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/20/2024] [Accepted: 02/07/2024] [Indexed: 02/17/2024]
Abstract
Type 1 Diabetes (T1D) involves the autoimmune destruction of insulin-producing β-cells in the pancreas. Exogenous insulin injections are the current therapy but are user-dependent and cannot fully recapitulate physiological insulin secretion dynamics. Since the emergence of allogeneic cell therapy for T1D, the Edmonton Protocol has been the most promising immunosuppression protocol for cadaveric islet transplantation, but the lack of donor islets, poor cell engraftment, and required chronic immunosuppression have limited its application as a therapy for T1D. Encapsulation in biomaterials on the nano-, micro-, and macro-scale offers the potential to integrate islets with the host and protect them from immune responses. This method can be applied to different cell types, including cadaveric, porcine, and stem cell-derived islets, mitigating the issue of a lack of donor cells. This review covers progress in the efforts to integrate insulin-producing cells from multiple sources to T1D patients as a form of cell therapy.
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Affiliation(s)
- Sophia Kioulaphides
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University School of Medicine, Atlanta, GA 30332, USA
| | - Andrés J García
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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2
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Naqvi RA, Naqvi AR, Singh A, Priyadarshini M, Balamurugan AN, Layden BT. The future treatment for type 1 diabetes: Pig islet- or stem cell-derived β cells? Front Endocrinol (Lausanne) 2023; 13:1001041. [PMID: 36686451 PMCID: PMC9849241 DOI: 10.3389/fendo.2022.1001041] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 12/07/2022] [Indexed: 01/06/2023] Open
Abstract
Replacement of β cells is only a curative approach for type 1 diabetes (T1D) patients to avoid the threat of iatrogenic hypoglycemia. In this pursuit, islet allotransplantation under Edmonton's protocol emerged as a medical miracle to attain hypoglycemia-free insulin independence in T1D. Shortage of allo-islet donors and post-transplantation (post-tx) islet loss are still unmet hurdles for the widespread application of this therapeutic regimen. The long-term survival and effective insulin independence in preclinical studies have strongly suggested pig islets to cure overt hyperglycemia. Importantly, CRISPR-Cas9 technology is pursuing to develop "humanized" pig islets that could overcome the lifelong immunosuppression drug regimen. Lately, induced pluripotent stem cell (iPSC)-derived β cell approaches are also gaining momentum and may hold promise to yield a significant supply of insulin-producing cells. Theoretically, personalized β cells derived from a patient's iPSCs is one exciting approach, but β cell-specific immunity in T1D recipients would still be a challenge. In this context, encapsulation studies on both pig islet as well as iPSC-β cells were found promising and rendered long-term survival in mice. Oxygen tension and blood vessel growth within the capsules are a few of the hurdles that need to be addressed. In conclusion, challenges associated with both procedures, xenotransplantation (of pig-derived islets) and stem cell transplantation, are required to be cautiously resolved before their clinical application.
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Affiliation(s)
- Raza Ali Naqvi
- Department of Periodontics, College of Dentistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Afsar Raza Naqvi
- Department of Periodontics, College of Dentistry, University of Illinois at Chicago, Chicago, IL, United States
| | - Amar Singh
- Department of Surgery, University of Minnesota, Minneapolis, MN, United States
| | - Medha Priyadarshini
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
| | - Appakalai N. Balamurugan
- Center for Clinical and Translational Research, Nationwide Children’s Hospital, Columbus, OH, United States
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Brian T. Layden
- Department of Medicine, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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3
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Graham ML, Ramachandran S, Singh A, Moore MEG, Flanagan EB, Azimzadeh A, Burlak C, Mueller KR, Martins K, Anazawa T, Balamurugan AN, Bansal-Pakala P, Murtaugh MP, O’Brien TD, Papas KK, Spizzo T, Schuurman HJ, Hancock WW, Hering BJ. Clinically available immunosuppression averts rejection but not systemic inflammation after porcine islet xenotransplant in cynomolgus macaques. Am J Transplant 2022; 22:745-760. [PMID: 34704345 PMCID: PMC9832996 DOI: 10.1111/ajt.16876] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 09/30/2021] [Accepted: 10/19/2021] [Indexed: 01/25/2023]
Abstract
A safe, efficacious, and clinically applicable immunosuppressive regimen is necessary for islet xenotransplantation to become a viable treatment option for diabetes. We performed intraportal transplants of wild-type adult porcine islets in 25 streptozotocin-diabetic cynomolgus monkeys. Islet engraftment was good in 21, partial in 3, and poor in 1 recipient. Median xenograft survival was 25 days with rapamycin and CTLA4Ig immunosuppression. Adding basiliximab induction and maintenance tacrolimus to the base regimen significantly extended median graft survival to 147 days (p < .0001), with three animals maintaining insulin-free xenograft survival for 265, 282, and 288 days. We demonstrate that this regimen suppresses non-Gal anti-pig antibody responses, circulating effector memory T cell expansion, effector function, and infiltration of the graft. However, a chronic systemic inflammatory state manifested in the majority of recipients with long-term graft survival indicated by increased neutrophil to lymphocyte ratio, IL-6, MCP-1, CD40, and CRP expression. This suggests that this immunosuppression regimen fails to regulate innate immunity and resulting inflammation is significantly associated with increased incidence and severity of adverse events making this regimen unacceptable for translation. Additional studies are needed to optimize a maintenance regimen for regulating the innate inflammatory response.
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Affiliation(s)
- Melanie L. Graham
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | | | - Amar Singh
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | - Meghan E. G. Moore
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN
| | - E. Brian Flanagan
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | - Agnes Azimzadeh
- Department of Surgery, University of Maryland, Baltimore, MD
| | - Christopher Burlak
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | - Kate R. Mueller
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | - Kyra Martins
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN
| | - Takayuki Anazawa
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | | | - Pratima Bansal-Pakala
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | - Michael P. Murtaugh
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN
| | - Timothy D. O’Brien
- Department of Veterinary Population Medicine, University of Minnesota, St. Paul, MN
| | - Klearchos K. Papas
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
| | | | - Henk-J. Schuurman
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN,Spring Point Project, Minneapolis, MN
| | - Wayne W. Hancock
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Bernhard. J. Hering
- Schulze Diabetes Institute, Department of Surgery, University of Minnesota, Minneapolis, MN
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Li Y, Frei AW, Yang EY, Labrada-Miravet I, Sun C, Rong Y, Samojlik MM, Bayer AL, Stabler CL. In vitro platform establishes antigen-specific CD8 + T cell cytotoxicity to encapsulated cells via indirect antigen recognition. Biomaterials 2020; 256:120182. [PMID: 32599358 DOI: 10.1016/j.biomaterials.2020.120182] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 06/04/2020] [Accepted: 06/06/2020] [Indexed: 02/07/2023]
Abstract
The curative potential of non-autologous cellular therapy is hindered by the requirement of anti-rejection therapy. Cellular encapsulation within nondegradable biomaterials has the potential to inhibit immune rejection, but the efficacy of this approach in robust preclinical and clinical models remains poor. While the responses of innate immune cells to the encapsulating material have been characterized, little attention has been paid to the contributions of adaptive immunity in encapsulated graft destabilization. Avoiding the limitations of animal models, we established an efficient, antigen-specific in vitro platform capable of delineating direct and indirect host T cell recognition to microencapsulated cellular grafts and evaluated their consequential impacts. Using ovalbumin (OVA) as a model antigen, we determined that alginate microencapsulation abrogates direct CD8+ T cell activation by interrupting donor-host interaction; however, indirect T cell activation, mediated by host antigen presenting cells (APCs) primed with shed donor antigens, still occurs. These activated T cells imparted cytotoxicity on the encapsulated cells, likely via diffusion of cytotoxic solutes. Overall, this platform delivers unique mechanistic insight into the impacts of hydrogel encapsulation on host adaptive immune responses, comprehensively addressing a long-standing hypothesis of the field. Furthermore, it provides an efficient benchtop screening tool for the investigation of new encapsulation methods and/or synergistic immunomodulatory agents.
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Affiliation(s)
- Ying Li
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; Graduate Program in Biomedical Sciences, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Anthony W Frei
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Ethan Y Yang
- Diabetes Research Institute, College of Medicine, University of Miami, Miami, FL, USA
| | - Irayme Labrada-Miravet
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Chuqiao Sun
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Yanan Rong
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Magdalena M Samojlik
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Allison L Bayer
- Diabetes Research Institute, College of Medicine, University of Miami, Miami, FL, USA; Department of Microbiology and Immunology, University of Miami, Miami, FL, USA
| | - Cherie L Stabler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA; Graduate Program in Biomedical Sciences, College of Medicine, University of Florida, Gainesville, FL, USA; University of Florida Diabetes Institute, University of Florida, Gainesville, FL, USA.
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5
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Abstract
A logical cure for type 1 diabetes (T1D) involves replacing the lost insulin-producing cells with new ones, preferably cells from a well-characterized and unlimited source of human insulin-producing cells. This straightforward and simple solution to provide a cure for T1D is immensely attractive but entails at least two inherent and thus far unresolved hurdles: 1) provision of an unlimited source of functional human insulin-producing cells and 2) prevention of rejection without the side effects of systemic immunosuppression. Generation of transplantable insulin-producing cells from human embryonic stem cells or induced pluripotent stem cells is at present close to reality, and we are currently awaiting the first clinical studies. Focus is now directed to foster development of novel means to control the immune system to enable large-scale clinical application. Encapsulation introduces a physical barrier that prevents access of immune cells to the transplanted cells but also hinders blood vessel ingrowth. Therefore, oxygen, nutrient, and hormonal passage over the encapsulation membrane is solely dependent on diffusion over the immune barrier, contributing to delays in glucose sensing and insulin secretion kinetics. This Perspective focuses on the physiological possibilities and limitations of an encapsulation strategy to establish near-normoglycemia in subjects with T1D, assuming that glucose-responsive insulin-producing cells are available for transplantation.
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Affiliation(s)
- Olle Korsgren
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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6
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Current Concepts of Using Pigs as a Source for Beta-Cell Replacement Therapy of Type 1 Diabetes. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40610-016-0039-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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7
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Cooper DKC, Ezzelarab MB, Hara H, Iwase H, Lee W, Wijkstrom M, Bottino R. The pathobiology of pig-to-primate xenotransplantation: a historical review. Xenotransplantation 2016; 23:83-105. [PMID: 26813438 DOI: 10.1111/xen.12219] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 12/22/2015] [Indexed: 12/16/2022]
Abstract
The immunologic barriers to successful xenotransplantation are related to the presence of natural anti-pig antibodies in humans and non-human primates that bind to antigens expressed on the transplanted pig organ (the most important of which is galactose-α1,3-galactose [Gal]), and activate the complement cascade, which results in rapid destruction of the graft, a process known as hyperacute rejection. High levels of elicited anti-pig IgG may develop if the adaptive immune response is not prevented by adequate immunosuppressive therapy, resulting in activation and injury of the vascular endothelium. The transplantation of organs and cells from pigs that do not express the important Gal antigen (α1,3-galactosyltransferase gene-knockout [GTKO] pigs) and express one or more human complement-regulatory proteins (hCRP, e.g., CD46, CD55), when combined with an effective costimulation blockade-based immunosuppressive regimen, prevents early antibody-mediated and cellular rejection. However, low levels of anti-non-Gal antibody and innate immune cells and/or platelets may initiate the development of a thrombotic microangiopathy in the graft that may be associated with a consumptive coagulopathy in the recipient. This pathogenic process is accentuated by the dysregulation of the coagulation-anticoagulation systems between pigs and primates. The expression in GTKO/hCRP pigs of a human coagulation-regulatory protein, for example, thrombomodulin, is increasingly being associated with prolonged pig graft survival in non-human primates. Initial clinical trials of islet and corneal xenotransplantation are already underway, and trials of pig kidney or heart transplantation are anticipated within the next few years.
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Affiliation(s)
- David K C Cooper
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mohamed B Ezzelarab
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hidetaka Hara
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Hayato Iwase
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Whayoung Lee
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Martin Wijkstrom
- The Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rita Bottino
- Institute for Cellular Therapeutics, Allegheny-Singer Research Institute, Pittsburgh, PA, USA
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Song S, Roy S. Progress and challenges in macroencapsulation approaches for type 1 diabetes (T1D) treatment: Cells, biomaterials, and devices. Biotechnol Bioeng 2016; 113:1381-402. [PMID: 26615050 DOI: 10.1002/bit.25895] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/30/2015] [Accepted: 11/24/2015] [Indexed: 12/15/2022]
Abstract
Macroencapsulation technology has been an attractive topic in the field of treatment for Type 1 diabetes due to mechanical stability, versatility, and retrievability of the macro-capsule design. Macro-capsules can be categorized into extravascular and intravascular devices, in which solute transport relies either on diffusion or convection, respectively. Failure of macroencapsulation strategies can be due to limited regenerative capacity of the encased insulin-producing cells, sub-optimal performance of encapsulation biomaterials, insufficient immunoisolation, excessive blood thrombosis for vascular perfusion devices, and inadequate modes of mass transfer to support cell viability and function. However, significant technical advancements have been achieved in macroencapsulation technology, namely reducing diffusion distance for oxygen and nutrients, using pro-angiogenic factors to increase vascularization for islet engraftment, and optimizing membrane permeability and selectivity to prevent immune attacks from host's body. This review presents an overview of existing macroencapsulation devices and discusses the advances based on tissue-engineering approaches that will stimulate future research and development of macroencapsulation technology. Biotechnol. Bioeng. 2016;113: 1381-1402. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Shang Song
- Department of Bioengineering and Therapeutic Sciences, University of California-San Francisco, San Francisco, California 94158
| | - Shuvo Roy
- Department of Bioengineering and Therapeutic Sciences, University of California-San Francisco, San Francisco, California 94158.
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9
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Ludwig B, Ludwig S. Transplantable bioartificial pancreas devices: current status and future prospects. Langenbecks Arch Surg 2015; 400:531-40. [DOI: 10.1007/s00423-015-1314-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 02/08/2023]
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10
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Zhu HT, Yu L, Lyu Y, Wang B. Optimal pig donor selection in islet xenotransplantation: current status and future perspectives. J Zhejiang Univ Sci B 2015; 15:681-91. [PMID: 25091986 DOI: 10.1631/jzus.b1400120] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Islet transplantation is an attractive treatment of type 1 diabetes mellitus. Xenotransplantation, using the pig as a donor, offers the possibility of an unlimited supply of islet grafts. Published studies demonstrated that pig islets could function in diabetic primates for a long time (>6 months). However, pig-islet xenotransplantation must overcome the selection of an optimal pig donor to obtain an adequate supply of islets with high-quality, to reduce xeno-antigenicity of islet and prolong xenograft survival, and to translate experimental findings into clinical application. This review discusses the suitable pig donor for islet xenotransplantation in terms of pig age, strain, structure/function of islet, and genetically modified pig.
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Affiliation(s)
- Hai-tao Zhu
- Department of Hepatobiliary Surgery, the First Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an 710061, China
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11
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Cooper DKC, Satyananda V, Ekser B, van der Windt DJ, Hara H, Ezzelarab MB, Schuurman HJ. Progress in pig-to-non-human primate transplantation models (1998-2013): a comprehensive review of the literature. Xenotransplantation 2014; 21:397-419. [PMID: 25176336 DOI: 10.1111/xen.12127] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 06/03/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The pig-to-non-human primate model is the standard choice for in vivo studies of organ and cell xenotransplantation. In 1998, Lambrigts and his colleagues surveyed the entire world literature and reported all experimental studies in this model. With the increasing number of genetically engineered pigs that have become available during the past few years, this model is being utilized ever more frequently. METHODS We have now reviewed the literature again and have compiled the data we have been able to find for the period January 1, 1998 to December 31, 2013, a period of 16 yr. RESULTS The data are presented for transplants of the heart (heterotopic and orthotopic), kidney, liver, lung, islets, neuronal cells, hepatocytes, corneas, artery patches, and skin. Heart, kidney, and, particularly, islet xenograft survival have increased significantly since 1998. DISCUSSION The reasons for this are briefly discussed. A comment on the limitations of the model has been made, particularly with regard to those that will affect progression of xenotransplantation toward the clinic.
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Affiliation(s)
- David K C Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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12
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Scharp DW, Marchetti P. Encapsulated islets for diabetes therapy: history, current progress, and critical issues requiring solution. Adv Drug Deliv Rev 2014; 67-68:35-73. [PMID: 23916992 DOI: 10.1016/j.addr.2013.07.018] [Citation(s) in RCA: 214] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 07/10/2013] [Accepted: 07/22/2013] [Indexed: 02/07/2023]
Abstract
Insulin therapy became a reality in 1921 dramatically saving lives of people with diabetes, but not protecting them from long-term complications. Clinically successful free islet implants began in 1989 but require life long immunosuppression. Several encapsulated islet approaches have been ongoing for over 30 years without defining a clinically relevant product. Macro-devices encapsulating islet mass in a single device have shown long-term success in large animals but human trials have been limited by critical challenges. Micro-capsules using alginate or similar hydrogels encapsulate individual islets with many hundreds of promising rodent results published, but a low incidence of successful translation to large animal and human results. Reduction of encapsulated islet mass for clinical transplantation is in progress. This review covers the status of both early and current studies including the presentation of corporate efforts involved. It concludes by defining the critical items requiring solution to enable a successful clinical diabetes therapy.
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Zhu HT, Wang WL, Yu L, Wang B. Pig-islet xenotransplantation: recent progress and current perspectives. Front Surg 2014; 1:7. [PMID: 25593932 PMCID: PMC4287008 DOI: 10.3389/fsurg.2014.00007] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/07/2014] [Indexed: 01/23/2023] Open
Abstract
Islet xenotransplantation is one prospective treatment to bridge the gap between available human cells and needs of patients with diabetes. Pig represents an ideal candidate for obtaining such available cells. However, potential clinical application of pig islet still faces obstacles including inadequate yield of high-quality functional islets and xenorejection of the transplants. Adequate amounts of available islets can be obtained by selection of a suitable pathogen-free source herd and the development of isolation and purification method. Several studies demonstrated the feasibility of successful preclinical pig-islet xenotransplantation and provided insights and possible mechanisms of xenogeneic immune recognition and rejection. Particularly promising is the achievement of long-term insulin independence in diabetic models by means of distinct islet products and novel immunotherapeutic strategies. Nonetheless, further efforts are needed to obtain much more safety and efficacy data to translate these findings into clinic.
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Affiliation(s)
- Hai-Tao Zhu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi’an Jiaotong University, Xi’an, China
| | - Wan-Li Wang
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi’an Jiaotong University, Xi’an, China
| | - Liang Yu
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi’an Jiaotong University, Xi’an, China
| | - Bo Wang
- Department of Hepatobiliary Surgery, First Affiliated Hospital, Medical College, Xi’an Jiaotong University, Xi’an, China
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14
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Dufrane D, Gianello P. Macro- or microencapsulation of pig islets to cure type 1 diabetes. World J Gastroenterol 2012; 18:6885-93. [PMID: 23322985 PMCID: PMC3531671 DOI: 10.3748/wjg.v18.i47.6885] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 06/14/2012] [Accepted: 06/28/2012] [Indexed: 02/06/2023] Open
Abstract
Although allogeneic islet transplantation can successfully cure type 1 diabetes, it has limited applicability. For example, organs are in short supply; several human pancreas donors are often needed to treat one diabetic recipient; the intrahepatic site may not be the most appropriate site for islet implantation; and immunosuppressive regimens, which are associated with side effects, are often required to prolong survival of the islet graft. An alternative source of insulin-producing cells would therefore be of major interest. Pigs represent a possible alternative source of beta cells. Grafting of pig islets may appear difficult because of the immunologic species barrier, but pig islets have been shown to function in primates for at least 6 mo with clinically incompatible immunosuppression. Therefore, a bioartificial pancreas made of encapsulated pig islets may resolve issues associated with islet allotransplantation. Although several groups have shown that encapsulated pig islets are functional in small-animal models, less is known about the use of bioartificial pancreases in large-animal models. In this review, we summarize current knowledge of encapsulated pig islets, to determine obstacles to implantation in humans and possible solutions to overcome these obstacles.
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15
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Wang C, Wang H, Ide K, Wang Y, Van Rooijen N, Ohdan H, Yang YG. Human CD47 expression permits survival of porcine cells in immunodeficient mice that express SIRPα capable of binding to human CD47. Cell Transplant 2011; 20:1915-20. [PMID: 21535911 DOI: 10.3727/096368911x566253] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Signal regulatory protein α (SIRPα) is a critical immune inhibitory receptor on macrophages, and its interaction with CD47 prevents autologous phagocytosis. We have previously shown that pig CD47 does not interact with human SIRPα, and that human CD47 expression inhibits phagocytosis of porcine cells by human macrophages in vitro. In this study, we have investigated the potential of human CD47 expression to promote porcine cell survival in vivo. Human CD47-expressing and control porcine B-lymphoma cells were transplanted into T- and B-cell-deficient nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice that express SIRPα capable of interacting with human CD47. Only the human CD47-expressing porcine lymphoma cells survived and were able to form tumors in NOD/SCID mice; however, both the control and human CD47-expressing porcine cells survived in macrophage-depleted NOD/SCID mice. These results indicate that transgenic expression of human CD47 may provide an effective approach to inhibiting macrophage-mediated xenograft rejection in clinical xenotransplantation.
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Affiliation(s)
- Chunfeng Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
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16
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Navarro-Alvarez N, Yang YG. CD47: a new player in phagocytosis and xenograft rejection. Cell Mol Immunol 2011; 8:285-8. [PMID: 21258362 DOI: 10.1038/cmi.2010.83] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Organ transplantation is limited by the availability of human donor organs. The transplantation of organs and tissues from other species (xenotransplantation) would supply an unlimited number of organs and offer many other advantages for which the pig has been identified as the most suitable source. However, the robust immune responses to xenografts remain a major obstacle to clinical application of xenotransplantation. The more vigorous xenograft rejection relative to allograft rejection is largely accounted for by the extensive genetic disparities between the donor and recipient. Xenografts activate host immunity not only by expressing immunogenic xenoantigens that provide the targets for immune recognition and rejection, but also by lacking ligands for the host immune inhibitory receptors. This review is focused on recent findings regarding the role of CD47, a ligand of an immune inhibitory receptor, signal regulatory protein alpha (SIRPα), in phagocytosis and xenograft rejection.
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Affiliation(s)
- Nalu Navarro-Alvarez
- Columbia Center for Translational Immunology, Columbia University Medical Center, New York, USA
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17
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Abstract
Robust immune responses to xenografts remain a major obstacle to clinical translation of xenotransplantation, which could otherwise be a potential solution to the worldwide shortage of organ donors. The more vigorous xenograft rejection relative to allograft rejection is largely accounted for by the extensive genetic disparities between the donor and recipient. Xenografts activate host immunity not only by expressing immunogenic xenoantigens that provide the targets for immune recognition and rejection, but also by lacking ligands for the host immune inhibitory receptors. This review is focused on recent findings regarding the role of CD47, a ligand of an immune inhibitory receptor SIRPalpha, in xenograft rejection and induction of xenotolerance.
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Affiliation(s)
- Yong-Guang Yang
- Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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Cohen S, Tchorsh-Yutsis D, Aronovich A, Tal O, Eventov-Friedman S, Katchman H, Klionsky Y, Shezen E, Reisner Y. Growth enhancement by embryonic fibroblasts upon cotransplantation of noncommitted pig embryonic tissues with fully committed organs. Transplantation 2010; 89:1198-207. [PMID: 20195218 DOI: 10.1097/tp.0b013e3181d720fd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND We recently defined the optimal gestational time windows for the transplantation of several embryonic tissues. We showed that the liver and kidney obtained from E28 pig embryos can grow and differentiate normally after transplantation, whereas 1 week earlier in gestation, these tissues develop into teratoma-like structures or fibrotic mass. In this study, we investigated whether cotransplantation of E28 with E21 tissue could control its tumorogenic potential, or alternatively whether the stem cells derived from the earlier tissue contribute to the growth of the more committed one. METHODS Pig embryonic precursors from E21 and E28 gestational age were transplanted alone or together, into nonobese diabetic/severe combined immunodeficiency mice, and their growth and differentiation was evaluated by immunohistology. In situ analysis, based on sex disparity between the E21 and E28 tissues, was used to identify the tissue source. In some experiments, mouse embryonic fibroblasts (MEF) were cotransplanted with E28 liver, and their effect was evaluated. RESULTS E28 tissues could not abrogate the propensity of the cells within the undifferentiated tissue to form teratoma-like structures. However, E21 kidney or liver tissue markedly enhanced the growth and function of E28 kidney, liver, and heart grafts. Moreover, similar growth enhancement was observed on coimplantation of E28 liver tissue with MEF or on infusion of MEF culture medium, indicating that this enhancement is likely mediated through soluble factors secreted by the fibroblasts. CONCLUSION Our results suggest a novel approach for the enhancement of growth and differentiation of transplanted embryonic tissues by the use of soluble factors secreted by embryonic fibroblasts.
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Affiliation(s)
- Sivan Cohen
- Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
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Rogers SA, Mohanakumar T, Liapis H, Hammerman MR. Engraftment of cells from porcine islets of Langerhans and normalization of glucose tolerance following transplantation of pig pancreatic primordia in nonimmune-suppressed diabetic rats. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 177:854-64. [PMID: 20581052 DOI: 10.2353/ajpath.2010.091193] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Transplantation therapy for human diabetes is limited by the toxicity of immunosuppressive drugs. However, even if toxicity can be minimalized, there will still be a shortage of human donor organs. Xenotransplantation of porcine islets may be a strategy to overcome these supply problems. Xenotransplantation in mesentery of pig pancreatic primordia obtained very early during organogenesis [embryonic day 28 (E28)] can obviate the need for immune suppression in rats or rhesus macaques. Here, in rats transplanted previously with E28 pig pancreatic primordia in the mesentery, we show normalization of glucose tolerance in nonimmune-suppressed streptozotocin-diabetic LEW rats and insulin and porcine proinsulin mRNA-expressing cell engraftment in the kidney following implantation of porcine islets beneath the renal capsule. Donor cell engraftment was confirmed using fluorescent in situ hybridization for the porcine X chromosome and electron microscopy. In contrast, cells from islets did not engraft in the kidney without prior transplantation of E28 pig pancreatic primordia in the mesentery. This is the first report of prolonged engraftment and sustained normalization of glucose tolerance following transplantation of porcine islets in nonimmune-suppressed, immune-competent rodents. The data are consistent with tolerance induction to a cell component of porcine islets induced by previous transplantation of E28 pig pancreatic primordia.
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Affiliation(s)
- Sharon A Rogers
- Renal Division, Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA
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Ekser B, Cooper DKC. Overcoming the barriers to xenotransplantation: prospects for the future. Expert Rev Clin Immunol 2010; 6:219-30. [PMID: 20402385 PMCID: PMC2857338 DOI: 10.1586/eci.09.81] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cross-species transplantation (xenotransplantation) has immense potential to solve the critical need for organs, tissues and cells for clinical transplantation. The increasing availability of genetically engineered pigs is enabling progress to be made in pig-to-nonhuman primate experimental models. Potent pharmacologic immunosuppressive regimens have largely prevented T-cell rejection and a T-cell-dependent elicited antibody response. However, coagulation dysfunction between the pig and primate is proving to be a major problem, and this can result in life-threatening consumptive coagulopathy. This complication is unlikely to be overcome until pigs expressing a human 'antithrombotic' or 'anticoagulant' gene, such as thrombomodulin, tissue factor pathway inhibitor or CD39, become available. Progress in islet xenotransplantation has been more encouraging, and diabetes has been controlled in nonhuman primates for periods in excess of 6 months, although this has usually been achieved using immunosuppressive protocols that might not be clinically applicable. Further advances are required to overcome the remaining barriers.
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Affiliation(s)
- Burcin Ekser
- Thomas E Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA, and Department of Surgery and Organ Transplantation, University of Padua, Padua, Italy
| | - David KC Cooper
- Thomas E Starzl Transplantation Institute, University of Pittsburgh Medical Center, Starzl Biomedical Science Tower, W1543, 200 Lothrop Street, Pittsburgh, PA 15261, USA, Tel.: +1 412 383 6961, Fax: +1 412 624 1172,
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Improving islet transplantation: a road map for a widespread application for the cure of persons with type I diabetes. Curr Opin Organ Transplant 2010; 14:683-7. [PMID: 19779341 DOI: 10.1097/mot.0b013e328332c44c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW The widespread application of replacement therapies for type I diabetes is at present limited by the side-effects of systemic immunosuppression. Results obtained in several animal models show that islet encapsulation can control the rejection process without systemic side-effects. However, results have, in general, been disappointing when transferred to large animal models or to humans. RECENT FINDINGS Growing insights into how cells respond to mechanical forces and surrounding extracellular matrixes indicate that differences in the Young's modulus (the resistance to deformation) between the implanted biomaterial and surrounding tissues induce inflammation and fibrosis. A valid approach would be to select for implantation a tissue having a higher value of the Young's modulus, for example, bone, allowing direct contact with the highly vascularized bone marrow providing nutrient and oxygen support as well as a rapid distribution of released insulin to the systemic circulation. SUMMARY Development of a biochamber with bone-integrating properties will allow initiation of clinical trials with allogeneic human islets, xenogeneic pig islets or insulin-producing cells generated from human embryonic stem cell (hESC)/inducible pluripotent stem cell (iPSC).
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Abstract
PURPOSE OF REVIEW Allogeneic islet transplantation faces difficulties because organ shortage is recurrent; several pancreas donors are often needed to treat one diabetic recipient; and the intrahepatic site of islet implantation may not be the most appropriate one. Another source of insulin-producing cells, therefore, would be of major interest, and pigs represent a possible and serious source for obtaining such cells. RECENT FINDINGS Pig islet grafts may appear difficult because of the species barrier, but recent studies demonstrate that pig islets may function in diabetic primates for at least 6 months. SUMMARY Pig islet xenotransplantation, however, must still overcome the selection of a suitable pig donor to translate preclinical findings into clinical applications. This review summarizes the actual acquired knowledge of pig islet transplantation in primates to select the 'ideal' pig donor.
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Pierson RN, Dorling A, Ayares D, Rees MA, Seebach JD, Fishman JA, Hering BJ, Cooper DKC. Current status of xenotransplantation and prospects for clinical application. Xenotransplantation 2009; 16:263-80. [PMID: 19796067 PMCID: PMC2866107 DOI: 10.1111/j.1399-3089.2009.00534.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Xenotransplantation is one promising approach to bridge the gap between available human cells, tissues, and organs and the needs of patients with diabetes or end-stage organ failure. Based on recent progress using genetically modified source pigs, improving results with conventional and experimental immunosuppression, and expanded understanding of residual physiologic hurdles, xenotransplantation appears likely to be evaluated in clinical trials in the near future for some select applications. This review offers a comprehensive overview of known mechanisms of xenograft injury, a contemporary assessment of preclinical progress and residual barriers, and our opinions regarding where breakthroughs are likely to occur.
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Affiliation(s)
- Richard N Pierson
- Division of Cardiac Surgery, Department of Surgery, University of Maryland, Baltimore VAMC, Baltimore, MD 21201, USA.
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Abstract
PURPOSE OF REVIEW Expectations are high on cellular therapy. Being fundamental to elucidate organogenesis, it is unlikely that embryonic stem cells will be used for clinical purposes. Postembryonic stage, developing cells are, therefore, the front-runner for regenerative medicine. In addition to autologous cells, both allogeneic and xenogeneic cells are hypothetical candidates to treat specific diseases. This review summarizes the current knowledge on immunological and functional aspects of xeno(allo)-cellular transplantation for cardiomyopathy, diabetes, liver failure, neural diseases, and bone regeneration. RECENT FINDINGS Xenocellular transplantation is promising for tissue repair in immunologically privileged sites such as the central nervous system or nonvascularized tissues in which no or moderate immunosuppression is required. In vascularized organs, major immune responses are present when cells are transplanted without additional conditioning. Positive results from encapsulation methods that protect cells from the immune system should further stimulate preclinical research. Also, conditioning immunosuppression could be used to circumvent the initial immune response. Transgenic pigs cells are probably the best xenogeneic substitute for human application, although basic research on innate and noninnate immunity toward pig cells is still required. SUMMARY In several fields of medicine, cellular xenotransplantation is slowly emerging as a potential therapeutic tool.
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Hering BJ, Walawalkar N. Pig-to-nonhuman primate islet xenotransplantation. Transpl Immunol 2009; 21:81-6. [PMID: 19427901 DOI: 10.1016/j.trim.2009.05.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 05/01/2009] [Accepted: 05/05/2009] [Indexed: 02/07/2023]
Abstract
Type 1 diabetes continues to present a therapeutic challenge. The restoration of normoglycemia and insulin independence in immunosuppressed type 1 diabetic recipients of human islet allografts has highlighted the potential of cell-based diabetes therapy. The unlimited and on-demand availability of pig islets from healthy, young, living, designated pathogen-free, and potentially genetically modified donors presents unique opportunities for improving the availability and outcomes of islet replacement therapies in diabetes. One of the fundamental prerequisites for initiating clinical research is a favorable benefit-over-harm determination in the stringent preclinical transplant model in nonhuman primates. To date, xenotransplants of pig islet cell therapy products have been reported by 15 institutions in 181 NHPs, including xenotransplants in 72 non-diabetic and 109 diabetic recipients. These studies have demonstrated the feasibility of successful preclinical islet xenotransplantation and have provided insights into the critical events operative in the immune recognition and destruction of islet xenografts in nonhuman primates. Particularly promising is the recent achievement of prolonged insulin independence in this model by means of several distinct islet xenotransplantation products, implantation sites, and immunotherapeutic strategies. Further progress appears likely and the development of suitable source pigs will position the scientific community to translate these findings safely to the clinic.
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Affiliation(s)
- Bernhard J Hering
- Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN 55455, USA.
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Cozzi E, Bosio E, Seveso M, Rubello D, Ancona E. Xenotransplantation as a model of integrated, multidisciplinary research. Organogenesis 2009; 5:288-96. [PMID: 19568350 PMCID: PMC2659370 DOI: 10.4161/org.7578] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 11/19/2008] [Indexed: 11/19/2022] Open
Abstract
Xenotransplantation was proposed a long time ago as a possible solution to the world-wide shortage of human organs. For years, researchers in this field have almost exclusively directed their efforts towards combating the immunological barrier that precluded long-term xenograft survival. Studies have been conducted in both small and large animal models and the most relevant results have been obtained in pre-clincal studies, specifically those utilising the pig-to-nonhuman primate combination. In this context, a better understanding of the immunological mechanisms underlying the rejection of a xenograft have allowed the identification of specific targets of intervention that have resulted in considerable improvements in survival of porcine organs or cells in nonhuman primates. However it has also become apparent that if xenotransplantation has to enter the clinical arena, a multidisciplinary approach will be needed to comprehensively tackle the different issues related to the use of a xenograft to cure human disease.In this regard, the safety, ethics and regulatory aspects of xenotransplantation are currently being aggressively addressed to enable the initiation of xenotransplantation with a favourable risk/benefit ratio.
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Affiliation(s)
- Emanuele Cozzi
- Direzione Sanitaria; Padua General Hospital; Padua, Italy; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua, Italy; CORIT (Consorzio per la Ricerca sul Trapianto d'Organi); Padua, Italy; Department of Nuclear Medicine; PET Centre; S. Maria della Misericordia Hospital; Rovigo, Italy; Clinica Chirurgica III; Padua General Hospital; Padua, Italy
| | - Erika Bosio
- Direzione Sanitaria; Padua General Hospital; Padua, Italy; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua, Italy; CORIT (Consorzio per la Ricerca sul Trapianto d'Organi); Padua, Italy; Department of Nuclear Medicine; PET Centre; S. Maria della Misericordia Hospital; Rovigo, Italy; Clinica Chirurgica III; Padua General Hospital; Padua, Italy
| | - Michela Seveso
- Direzione Sanitaria; Padua General Hospital; Padua, Italy; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua, Italy; CORIT (Consorzio per la Ricerca sul Trapianto d'Organi); Padua, Italy; Department of Nuclear Medicine; PET Centre; S. Maria della Misericordia Hospital; Rovigo, Italy; Clinica Chirurgica III; Padua General Hospital; Padua, Italy
| | - Domenico Rubello
- Direzione Sanitaria; Padua General Hospital; Padua, Italy; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua, Italy; CORIT (Consorzio per la Ricerca sul Trapianto d'Organi); Padua, Italy; Department of Nuclear Medicine; PET Centre; S. Maria della Misericordia Hospital; Rovigo, Italy; Clinica Chirurgica III; Padua General Hospital; Padua, Italy
| | - Ermanno Ancona
- Direzione Sanitaria; Padua General Hospital; Padua, Italy; Department of Surgical and Gastroenterological Sciences; University of Padua; Padua, Italy; CORIT (Consorzio per la Ricerca sul Trapianto d'Organi); Padua, Italy; Department of Nuclear Medicine; PET Centre; S. Maria della Misericordia Hospital; Rovigo, Italy; Clinica Chirurgica III; Padua General Hospital; Padua, Italy
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Tonomura N, Shimizu A, Wang S, Yamada K, Tchipashvili V, Weir GC, Yang YG. Pig islet xenograft rejection in a mouse model with an established human immune system. Xenotransplantation 2008; 15:129-35. [PMID: 18447886 DOI: 10.1111/j.1399-3089.2008.00450.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Xenotransplantation from pigs provides a potential solution to the severe shortage of human pancreata, but strong immunological rejection prevents its clinical application. A better understanding of the human immune response to pig islets would help develop effective strategies for preventing graft rejection. METHODS We assessed pig islet rejection by human immune cells in humanized mice with a functional human immune system. Humanized mice were prepared by transplantation of human fetal thymus/liver tissues and CD34(+) fetal liver cells into immunodeficient mice. Islet xenograft survival/rejection was determined by histological analysis of the grafts and measurement of porcine C-peptide in the sera of the recipients. RESULTS In untreated humanized mice, adult pig islets were completely rejected by 4 weeks. These mice showed no detectable porcine C-peptide in the sera, and severe intra-graft infiltration by human T cells, macrophages, and B cells, as well as deposition of human antibodies. Pig islet rejection was prevented by human T-cell depletion prior to islet xenotransplantation. Islet xenografts harvested from T-cell-depleted humanized mice were functional, and showed no human cell infiltration or antibody deposition. CONCLUSIONS Pig islet rejection in humanized mice is largely T-cell-dependent, which is consistent with previous observations in non-human primates. These humanized mice provide a useful model for the study of human xenoimmune responses in vivo.
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Affiliation(s)
- Noriko Tonomura
- Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02129, USA
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28
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Abstract
Allogeneic islet transplantation faces difficulties because (1) organ shortage is recurrent; (2) several pancreas donors are often needed to treat one diabetic recipient; and (3) the intrahepatic site of islet implantation may not be the most appropriate site. Another source of insulin-producing cells, therefore, would be of major interest, and pigs represent a possible and serious source for obtaining such cells. Pig islet grafts may seem difficult because of the species barrier, but recent reports demonstrate that pig islets may function in primates for at least 6 months. Pig islet xenotransplantation, however, must still overcome several hurdles before becoming clinically applicable. The actual consensus is to produce more preclinical data in the pig-to-primate model as a necessary requirement to envisage any pig-to-human transplantation of islets; therefore, a summary of the actual acquired knowledge of pig islet transplantation in primates seemed useful and is summarized in this overview.
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Current cellular innate immune hurdles in pig-to-primate xenotransplantation. Curr Opin Organ Transplant 2008; 13:171-7. [DOI: 10.1097/mot.0b013e3282f88a30] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Cooper DKC, Dorling A, Pierson RN, Rees M, Seebach J, Yazer M, Ohdan H, Awwad M, Ayares D. Alpha1,3-galactosyltransferase gene-knockout pigs for xenotransplantation: where do we go from here? Transplantation 2007; 84:1-7. [PMID: 17627227 DOI: 10.1097/01.tp.0000260427.75804.f2] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The ability to genetically engineer pigs that no longer express the Galalpha1,3Gal (Gal) oligosaccharide has been a significant step toward the clinical applicability of xenotransplantation. Using a chronic immunosuppressive regimen based on costimulatory blockade, hearts from these pigs have survived from 2 to 6 months in baboons. Graft failure was predominantly from the development of a thrombotic microangiopathy. Potential contributing factors include the presence of preformed anti-nonGal antibodies or the development of low levels of elicited antibodies to nonGal antigens, natural killer (NK) cell or macrophage activity, and inherent coagulation dysregulation between pigs and primates. The breeding of pigs transgenic for an "anticoagulant" gene, such as human tissue factor pathway inhibitor, hirudin, or CD39, or lacking the gene for the prothrombinase, fibrinogen-like protein-2, is anticipated to inhibit the change in the endothelium to a procoagulant state that takes place in the pig organ after transplantation. The identification of the targets for anti-nonGal antibodies and/or human macrophages might allow further genetic modification of the pig, and xenogeneic NK cell recognition and activation may be inhibited by the transgenic expression of human leukocyte antigen molecules and/or by blocking the function of activating NK receptors. The ultimate goal of induction of T-cell tolerance may be possible only if these hurdles in the coagulation system and innate immunity can be overcome.
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Affiliation(s)
- David K C Cooper
- The Thomas E. Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
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31
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Bottino R, Balamurugan AN, Smetanka C, Bertera S, He J, Rood PPM, Cooper DKC, Trucco M. Isolation outcome and functional characteristics of young and adult pig pancreatic islets for transplantation studies. Xenotransplantation 2007; 14:74-82. [PMID: 17214707 DOI: 10.1111/j.1399-3089.2006.00374.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Pig islets have been proposed as an alternative to human islets for clinical use, but their use is limited by rejection. The availability of genetically modified pigs devoid of alpha1,3-galactosyltransferase might provide islets more suitable for xenotransplantation. To limit the costs involved in the logistics and health care of pigs for clinical xenotransplantation, we have studied whether younger, rather than older, pigs that are typically preferred can be used as islet donors. METHODS We utilized pancreases from Yorkshire and White Landrace wild-type pigs and alpha1,3-galactosyltransferase gene-knockout pigs of three main different age and size groups: (i) <6 months, (ii) 6 to 12 months, and (iii) >2 yr of age, inclusive of retired breeders. We compared isolation yield and in vitro and in vivo function of islet cells obtained from these groups. RESULTS Islets from adult pigs (>2 yr) offered not only higher islet yields, but retained the ability to preserve intact morphology during the isolation process and culture, in association with high functional properties after transplantation. Following isolation, islet cells from young (<6 m) and young-adult (6 to 12 m) pigs dissociated into small aggregates and single cells, and exhibited inferior functional properties than adult islets both in vitro and in vivo. CONCLUSIONS These data support the conclusion that, in view of the large number of islets needed to maintain normoglycemia after xenotransplantation, organ-source pigs need to reach adult age (>2 yr) before being considered optimal islet donors, in spite of the higher costs involved.
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Affiliation(s)
- Rita Bottino
- Division of Immunogenetics, Department of Pediatrics, Children's Hospital of Pittsburgh, Rangos Research Center, Pittsburgh, PA 15213, USA.
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Wang H, VerHalen J, Madariaga ML, Xiang S, Wang S, Lan P, Oldenborg PA, Sykes M, Yang YG. Attenuation of phagocytosis of xenogeneic cells by manipulating CD47. Blood 2006; 109:836-42. [PMID: 17008545 PMCID: PMC1785095 DOI: 10.1182/blood-2006-04-019794] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Signal regulatory protein alpha (SIRPalpha) is a critical immune inhibitory receptor on macrophages, and its interaction with CD47, a ligand for SIRPalpha, prevents autologous phagocytosis. We hypothesized that interspecies incompatibility of CD47 may contribute to the rejection of xenogeneic cells by macrophages. Here, we show that pig CD47 does not interact with mouse SIPRalpha. Similar to CD47-/- mouse cells, porcine red blood cells (RBCs) failed to induce SIRPalpha tyrosine phosphorylation in mouse macrophages. Blocking SIRPalpha with antimouse SIRPalpha mAb (P84) significantly enhanced the phagocytosis of CD47+/+ mouse cells, but did not affect the engulfment of porcine or CD47-/- mouse cells by mouse macrophages. CD47-deficient mice, whose macrophages do not phagocytose CD47-/- mouse cells, showed markedly delayed clearance of porcine RBCs compared with wild-type mouse recipients. Furthermore, mouse CD47 expression on porcine cells markedly reduced their phagocytosis by mouse macrophages both in vitro and in vivo. These results indicate that interspecies incompatibility of CD47 contributes significantly to phagocytosis of xenogeneic cells by macrophages and suggest that genetic manipulation of donor CD47 to improve its interaction with the recipient SIRPalpha may provide a novel approach to prevent phagocyte-mediated xenograft rejection.
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Affiliation(s)
- Hui Wang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
- Wenzhou Medical College, Wenzhou, China
| | - Jon VerHalen
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Maria Lucia Madariaga
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Shuanglin Xiang
- Beth Israel Deaconess Medical Center of Harvard Medical School, Boston, MA
| | - Shumei Wang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Ping Lan
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Per-Arne Oldenborg
- Department of Integrative Medical Biology, Section for Histology and Cell Biology, Umeå University, Umeå, Sweden
| | - Megan Sykes
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Yong-Guang Yang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA
- Wenzhou Medical College, Wenzhou, China
- Correspondence: Yong-Guang Yang,
Transplantation Biology Research Center, Massachusetts General Hospital, Harvard Medical School, MGH-East, Bldg 149-5102, 13th St, Boston, MA 02129; e-mail:
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Rood PPM, Buhler LH, Bottino R, Trucco M, Cooper DKC. Pig-to-nonhuman primate islet xenotransplantation: a review of current problems. Cell Transplant 2006; 15:89-104. [PMID: 16719044 DOI: 10.3727/000000006783982052] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Islet allotransplantation has been shown to have potential as a treatment for type 1 diabetic patients. Xenotransplantation, using the pig as a donor, offers the possibility of an unlimited number of islets. This comprehensive review focuses on experience obtained in pig-to-nonhuman primate models, particularly with regard to the different types of islets (fetal, neonatal, adult) and isolation procedures used, and the methods to determine islet viability. The advantages and disadvantages of the methods to induce diabetes (pancreatectomy, streptozotocin) are discussed. Experience in pig-to-nonhuman primate islet transplantation studies is reviewed, including discussion of the possible mechanisms of rejection and the immunosuppressive regimens used. The research carried out to date has led to workable animal models to study islet xenotransplantation, but several questions regarding methodology remain unanswered, and details of these practicalities require to be adequately addressed. The encouraging porcine islet survival reported recently provides an indicator for future immunosuppressive regimens.
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Affiliation(s)
- P P M Rood
- Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Hårdstedt M, Finnegan CP, Kirchhof N, Hyland KA, Wijkstrom M, Murtaugh MP, Hering BJ. Post-transplant upregulation of chemokine messenger RNA in non-human primate recipients of intraportal pig islet xenografts. Xenotransplantation 2005; 12:293-302. [PMID: 15943778 DOI: 10.1111/j.1399-3089.2005.00228.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND We have previously shown that pig-to-primate intraportal islet xenografts reverse diabetes, escape hyperacute rejection, and undergo acute cellular rejection in non-immunosuppressed recipients. To gain a better understanding of mechanisms contributing to xenoislet rejection in non-human primates we examined gene expression in livers bearing islet xenografts in the first 72 h after transplantation. METHODS Liver specimens were collected at sacrifice from seven non-immunosuppressed rhesus macaques at 12, 24, 48 and 72 h after intraportal porcine islet transplantation. Following total RNA extraction, mRNA was quantified using SYBR green real-time reverse transcription polymerase chain reaction (RT-PCR) for species-specific immune response genes. Data were analyzed using comparative cycle threshold (Ct) analysis, adjusted for specific primer-efficiencies and normalized to cyclophilin expression. RESULTS Porcine insulin mRNA was detected in all liver samples. Cluster analysis revealed differential gene expression patterns at 12 and 24 h (early) compared with at 48 and 72 h (late) post-transplant. Gene expression patterns were associated with histological findings of predominantly neutrophils and only a few lymphocytes at 12 and 24 h and an increasing number of lymphocytes and macrophages at 48 and 72 h. Transcript levels of CXCR3 and its ligands, interferon-inducible protein 10 (IP-10) and monokine induced by IFN-gamma (Mig), significantly increased between early and late time points together with expression of MIP-1alpha, regulated on activation normal T expressed and secreted protein (RANTES) and MCP-1. CCR5 showed only a marginal, non-significant increase. Fas ligand, perforin and granzyme B transcripts were all elevated at 48 and 72 h post-transplant. CONCLUSIONS Our data suggest that CXCR3, with ligands IP-10 and Mig, is involved in T cell recruitment in acute islet xenograft rejection in non-human primates. Upregulation of RANTES and MIP-1alpha transcripts in the absence of a significant CCR5 increase suggests a possible involvement of other chemokine receptors. MCP-1 expression is associated with T cell and macrophage infiltration. Elevated cytotoxic effector molecule expression (Fas ligand, perforin, granzyme B) indicates T-cell mediated graft destruction by cytotoxic and cytolytic mechanisms within 48 to 72 h after transplantation. These results identify the CXCR3-mediated chemoattractant pathway as an immunosuppressive target in pig-to-primate islet xenotransplantation.
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Affiliation(s)
- Maria Hårdstedt
- Diabetes Institute for Immunology and Transplantation, Department of Surgery, University of Minnesota, Minneapolis MN, USA.
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Gilli UO, Schneider MKJ, Loetscher P, Seebach JD. Human polymorphonuclear neutrophils are recruited by porcine chemokines acting on CXC chemokine receptor 2, and platelet-activating factor. Transplantation 2005; 79:1324-31. [PMID: 15912099 DOI: 10.1097/01.tp.0000155429.44902.44] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Pig-to-human xenotransplantation is hampered by strong humoral and cellular immune responses, including acute vascular rejection (AVR). Infiltration of vascular xenografts by recipient polymorphonuclear neutrophils (PMN) is an early feature of AVR. Since little is known about the initiation of PMN recruitment, the present study investigated whether activated porcine endothelial cells (EC) release factors that induce human PMN recruitment. METHODS Primary and immortalized porcine aortic EC cultures were stimulated with phorbol-myristate acetate/ionomycin, lipopolysaccharide, tumor-necrosis factor-alpha, or interferon-gamma. The interleukin (IL)-8 concentration of porcine EC supernatants was tested by ELISA. Human and porcine PMN were isolated from peripheral blood by Ficoll sedimentation and centrifugation, characterized by morphology and flow cytometry, and analyzed for chemotaxis using Boyden chambers or Transwells. PMN chemokine receptor desensitization was determined by intracellular calcium-flux measurements. RESULTS Porcine EC supernatants contained significant amounts of porcine IL-8 and triggered chemotaxis in both human and porcine PMN. Chemotaxis of porcine, but not human, PMN was inhibited by anti-porcine IL-8 antibodies and recombinant porcine IL-8 induced strong chemotaxis only in porcine PMN. Porcine EC supernatants desensitized human PMN CXC-chemokine receptor (CXCR) 2, but not CXCR1, a receptor for human IL-8. Human PMN chemotaxis induced by porcine EC supernatants was significantly inhibited by blocking CXCR2 and platelet-activating factor (PAF). CONCLUSIONS Both chemokines acting via CXCR2 and PAF are released by porcine EC inducing efficient chemotaxis of human PMN. These mechanisms responsible for the recruitment of human PMN to porcine endothelium during cell-mediated rejection of xenografts represent potential targets for preventive strategies.
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Affiliation(s)
- Urs O Gilli
- Laboratory for Transplantation Immunology, Department for Internal Medicine, University Hospital Zurich, Zurich, Switzerland
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Komoda H, Miyagawa S, Omori T, Takahagi Y, Murakami H, Shigehisa T, Ito T, Matsuda H, Shirakura R. Survival of adult islet grafts from transgenic pigs with N-acetylglucosaminyltransferase-III (GnT-III) in cynomolgus monkeys. Xenotransplantation 2005; 12:209-16. [PMID: 15807771 DOI: 10.1111/j.1399-3089.2005.00206.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Because of a severe shortage of human donor pancreases, pig islets are considered to be an attractive donor source. Our previous in vitro study revealed that adult pig islets have strong non-Galalpha1-3Galbeta1-4GlcNAc-R (alpha-Gal) antigenicity, including the Hanganutziu-Deicher (H-D) antigen, especially in N-linked sugars. In this study, the issue of whether islets from N-acetylglucosaminyltransferase-III (GnT-III) transgenic pigs can prolong their survival in cynomolgus monkeys was examined. METHODS Adult pig islets were isolated from transgenic pigs with GnT-III and wild-type genes. GnT-III enzyme activity in pig islets was measured by high performance liquid chromatography (HPLC). The antigenicity of the islets to human natural antibodies was examined by flow cytometry. Pig islets were transplanted under the kidney capsule of streptozotocin-induced diabetic monkeys. After transplantation, blood samples were obtained and plasma insulin levels were monitored on a daily basis. RESULTS While GnT-III was barely expressed in wild-type islets, it was expressed at high levels in islets from transgenic pigs, and xenoantigenicity was significantly reduced. There was a trend for islets isolated from GnT-III-transgenic pigs to survive longer than those from wild-type pigs in cynomolgus monkeys (wild type: 1, 1, and 3 days; GnT-III: 1, >3, 4 and 5 days). Humoral and histological studies indicated up-regulated anti-pig islet antibodies and a relatively high deposition in islet grafts from wild-type pigs, respectively. CONCLUSION A reduction in xenoantigenicity by GnT-III may have prolonged the survival of porcine islets, suggesting the importance of non-alpha-Gal and non-H-D antigens, as they relate to N-linked sugars in the early rejection of porcine islets in the monkey. This approach may be useful in the clinical xenotransplantation of islets in the future.
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Affiliation(s)
- Hiroshi Komoda
- Division of Organ Transplantation, Department of Regenerative Medicine, Osaka University Graduate School of Medicine, Japan
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Eventov-Friedman S, Katchman H, Shezen E, Aronovich A, Tchorsh D, Dekel B, Freud E, Reisner Y. Embryonic pig liver, pancreas, and lung as a source for transplantation: optimal organogenesis without teratoma depends on distinct time windows. Proc Natl Acad Sci U S A 2005; 102:2928-33. [PMID: 15710886 PMCID: PMC548800 DOI: 10.1073/pnas.0500177102] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Pig embryonic tissues represent an attractive option for organ transplantation. However, the achievement of optimal organogenesis after transplantation, namely, maximal organ growth and function without teratoma development, represents a major challenge. In this study, we determined distinct gestational time windows for the growth of pig embryonic liver, pancreas, and lung precursors. Transplantation of embryonic-tissue precursors at various gestational ages [from E (embryonic day) 21 to E100] revealed a unique pattern of growth and differentiation for each embryonic organ. Maximal liver growth and function were achieved at the earliest teratoma-free gestational age (E28), whereas the growth and functional potential of the pancreas gradually increased toward E42 and E56 followed by a marked decline in insulin-secreting capacity at E80 and E100. Development of mature lung tissue containing essential respiratory system elements was observed at a relatively late gestational age (E56). These findings, showing distinct, optimal gestational time windows for transplantation of embryonic pig liver, pancreas, and lung, might explain, in part, the disappointing results in previous transplantation trials and could help enhance the chances for successful implementation of embryonic pig tissue in the treatment of a wide spectrum of human diseases.
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Chandra AP, Salvaris E, Walters SN, Murray-Segal L, Gock H, Lehnert AM, Wong JKW, Cowan PJ, d'Apice AJF, O'Connell PJ. Fate of alphaGal +/+ pancreatic islet grafts after transplantation into alphaGal knockout mice. Xenotransplantation 2005; 11:323-31. [PMID: 15196126 DOI: 10.1111/j.1399-3089.2004.00138.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Important phylogenetic differences between pig and human tissues prevent xenotransplantation from becoming a clinically feasible option. Humans lack the galactose-alpha1,3-galactose (alphaGal) epitope on endothelial cell surfaces and therefore have preformed anti-alphaGal antibodies. The role of these antibodies in rejection of non-vascular xenografts remains controversial. This study investigated the role of anti-alphaGal antibodies in rejection of non-vascularized alphaGal+/+ grafts in alphaGal -/- mice. METHODS alphaGal +/+ and alphaGal -/- pancreatic islets were transplanted under the renal capsule of streptozotocin-induced diabetic (1) alphaGal -/- mice and (2) alphaGal +/+ mice. alphaGal -/- recepients were immunized with rabbit red blood cell membranes (RRBCs) to produce elevated anti-alphaGal antibody levels. RESULTS Six of the 18 alphaGal -/- mice rejected the alphaGal +/+ grafts within 68 days whereas indefinite graft survival was achieved in the control groups. Animals with surviving islet grafts were challenged with alphaGal +/+ skin grafts. Although all alphaGal +/+ skin grafts were rejected within 58 days, the islet grafts remained intact. This observation correlated with the level of alphaGal expression (which was very low on islets compared to skin) rather than the actual titre of anti-alphaGal antibody. DISCUSSION The results suggest that the level of alphaGal expression plays an important role in graft survival. Therefore, its removal is important in the development of a pig islet donor for future clinical therapy.
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Affiliation(s)
- Abhilash P Chandra
- Centre for Transplant and Renal Research, Westmead Millenium Institute, University of Sydney at Westmead Hospital, Westmead, NSW, Australia
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Cozzi E, Bosio E, Seveso M, Vadori M, Ancona E. Xenotransplantation-current status and future perspectives. Br Med Bull 2005; 75-76:99-114. [PMID: 16723634 DOI: 10.1093/bmb/ldh061] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Research efforts have shed light on the immunological obstacles to long-term survival of pig organs transplanted into primates and allowed the identification of targets for specific immune intervention. Accordingly, the development of genetically engineered animals has overcome the hyperacute rejection barrier, with acute humoral xenograft rejection (AHXR) currently remaining the most important immunological obstacle. At this stage, a better control of the elicited anti-pig humoral immune response and avoidance of coagulation disorders are the two primary research fronts being pursued in order to overcome AHXR. Nonetheless, it is encouraging that porcine xenografts can sustain the life of non-human primates for several months. Proactive research aimed at the development of a safer organ source is also underway. It is anticipated that ongoing research in several fields, including accommodation, tolerance, immune suppression and genetic engineering, will result in further improvements in non-human primate survival. However, until convincing efficacy data and a more favourable risk/benefit ratio can be established in relevant animal models, progression to the clinic should not be viewed as an option.
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Affiliation(s)
- Emanuele Cozzi
- Department of Medical and Surgical Sciences, University of Padua, Clinica Chirurgica III, Via Giustiniani, 2, 35128 Padova, Italy.
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Duvivier-Kali VF, Omer A, Lopez-Avalos MD, O'Neil JJ, Weir GC. Survival of microencapsulated adult pig islets in mice in spite of an antibody response. Am J Transplant 2004; 4:1991-2000. [PMID: 15575901 DOI: 10.1111/j.1600-6143.2004.00628.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The aim of this study was to assess the capacity of simple alginate capsules to protect adult pig islets in a model of xenotransplantation. Adult pig islets were microencapsulated in alginate, with either single alginate coats (SAC) or double alginate coats (DAC), and transplanted into the streptozotocin-induced diabetic B6AF1 mice. Normalization of glucose levels was associated with an improvement of the glucose clearance during intravenous glucose tolerance tests. After explantation, all mice became hyperglycemic, demonstrating the efficacy of the encapsulated pig islets. Explanted capsules were mainly free of fibrotic reaction and encapsulated islets were still functional, responding to glucose stimulation with a 10-fold increase in insulin secretion. However, a significant decrease in the insulin content and insulin responses to glucose was observed for encapsulated islets explanted from hyperglycemic mice. An immune response of both IgG and IgM subtypes was detectable after transplantation. Interestingly, there were more newly formed antibodies in the serum of mice transplanted with SAC capsules than in the serum of mice transplanted with DAC capsules. In conclusion, alginate capsules can prolong the survival of adult pig islets transplanted into diabetic mice for up to 190 days, even in the presence of an antibody response.
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Kirchhof N, Shibata S, Wijkstrom M, Kulick DM, Salerno CT, Clemmings SM, Heremans Y, Galili U, Sutherland DER, Dalmasso AP, Hering BJ. Reversal of diabetes in non-immunosuppressed rhesus macaques by intraportal porcine islet xenografts precedes acute cellular rejection. Xenotransplantation 2004; 11:396-407. [PMID: 15303976 DOI: 10.1111/j.1399-3089.2004.00157.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND The functional response and immunobiology of primarily non-vascularized islet cell xenografts remain poorly defined in non-human primates. METHODS We transplanted 20,000 adult porcine islet equivalents/kg (purified and cultured for 48-h) intraportally into six streptozotocin-diabetic and two non-diabetic rhesus macaques. Two recipients were killed at various intervals post-transplant for histologic examination of livers bearing xenografts. RESULTS Plasma glucose levels in diabetic recipients averaged 94 mg/dl at 12 h, 92 mg/dl at 24 h, 147 mg/dl at 48 h, and 157 mg/dl at 72 h post-transplant. Serum porcine C-peptide was present in eight of eight recipients at 12 h, in five of six at 24 h, in four of four at 48 h, and in one of two at 72 h post-transplant. C3a and SC5b-9 plasma levels increased at 12 h post-transplant and returned to pre-transplant levels by 24 h. IgG, IgM anti-pig and anti-Gal IgG serum antibody levels did not increase post-transplant. Rejection was initiated by IgM and complement deposition on islets. Neutrophils dominated the cellular infiltrate at 12 h; CD4+ and CD8+ T cells were the main infiltrating cells at 24, 48, and 72 h; and macrophages increasingly infiltrated xenografts starting at 24 h post-transplant. Numerous xenoislets were present at all time points; their proportion without intraislet infiltrates decreased from 65% at 24 h to 17% at 72 h post-transplant. CONCLUSIONS Pig-to-primate intraportal islet xenografts reverse diabetes and the majority of intraportally transplanted xenogeneic islets are not subject to hyperacute rejection. They undergo acute cellular rejection mediated by CD4+- and CD8+ T cells and macrophages.
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Affiliation(s)
- Nicole Kirchhof
- Diabetes Institute for Immunology and Transplantation, University of Minnesota, Minneapolis, MN 55455, USA
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Costa C, Bell NK, Stabel TJ, Fodor WL. Use of porcine tumor necrosis factor receptor 1-Ig fusion protein to prolong xenograft survival. Xenotransplantation 2004; 11:491-502. [PMID: 15479458 DOI: 10.1111/j.1399-3089.2004.00169.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Delayed rejection of xenografts is a major hurdle that needs to be addressed to achieve long-term engraftment in the pig-to-primate transplant setting. Both vascular and avascular xenografts are susceptible to a delayed rejection process that comprises humoral and cellular responses. Tumor necrosis factor (TNF) is believed to play a role in this process by promoting cell activation, apoptosis and the recruitment of inflammatory cells. To address this problem, we engineered the donor cell in such a way that it could block both human and porcine TNF. METHODS We produced a recombinant fusion protein containing the extracellular domain of the porcine TNF-Receptor 1 and an IgG Fc moiety (pTNFR1Ig). We first evaluated by flow cytometry the pTNFR1Ig capacity to prevent TNF alpha-induced expression of SLAI, SLAII, VCAM-1, ICAM-1 and E-selectin on the cell surface of porcine aortic endothelial cells (PAEC). The effect on TNF alpha-mediated cell death was also assessed by propidium iodide staining after incubating PAEC with TNF alpha plus cycloheximide for 24 h. PAEC and porcine fibroblasts were subsequently engineered by retroviral infection to express and secrete pTNFR1Ig and their resistance to the TNF alpha effects was tested in vitro. Finally, we transplanted mock-control and pTNFR1Ig-expressing PAEC under the kidney capsule of BALB/c mice in the absence of immunosuppression and examined the degree of rejection at 2 and 3 weeks post-transplantation. RESULTS Treatment with pTNFR1Ig resulted in a very potent blockade of human, porcine and murine TNF alpha activity on porcine cells. It inhibited the upregulation of all cell surface markers of activation tested as well as the TNF alpha-mediated cell death. Moreover, pTNFR1Ig-expressing PAEC showed prolonged engraftment in a pig-to-mouse xenotransplant model. CONCLUSIONS Incorporation of strategies that block TNF may prove useful in the development of xenografts resistant to delayed rejection.
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Affiliation(s)
- C Costa
- Department of Molecular and Preclinical Sciences, Alexion Pharmaceuticals Inc, Cheshire, CT, USA.
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Yang YG. Application of xenogeneic stem cells for induction of transplantation tolerance: present state and future directions. ACTA ACUST UNITED AC 2004; 26:187-200. [PMID: 15378269 DOI: 10.1007/s00281-004-0159-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2004] [Accepted: 04/18/2004] [Indexed: 01/22/2023]
Abstract
Xenotransplantation using pig organs provides a possible solution to the severe shortage of allogeneic organ donors, one of the major limiting factors in clinical transplantation. However, because of the greater antigenic differences that exist between different species than within a species, the immune response to xenografts is much more vigorous than to allografts. Thus, tolerance induction is essential to the success of clinical xenotransplantation. Tolerance induced by mixed hematopoietic chimerism across the MHC barrier is remarkably robust, but its ability to induce tolerance across highly disparate xenogeneic barriers remains poorly studied. None of the current available regimens of host conditioning, which permit hematopoietic stem cell engraftment and chimerism induction in allogeneic or closely related (concordant) xenogeneic combinations, has been demonstrated to be effective in establishing porcine hematopoietic chimerism in a discordant xenogeneic species. Unlike bone marrow transplantation within the same species, the innate immune system and the species specificity of cytokines and adhesion molecules essential to hematopoiesis pose formidable obstacles to the establishment of donor hematopoiesis across discordant xenogeneic barriers. The genetic incompatibility between species may also impede xenograft tolerance induction by mixed chimerism. While we remain far from achieving tolerance in clinical xenotransplantation, recent studies using a transgenic mouse model have proven the principle that mixed hematopoietic chimerism may induce mouse and human T cell tolerance to porcine xenografts. This review article focuses on the barriers to porcine hematopoietic engraftment in highly disparate xenogeneic species and the possible application of mixed hematopoietic chimerism to xenograft tolerance induction.
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Affiliation(s)
- Yong-Guang Yang
- Bone Marrow Transplantation Section, Transplantation Biology Research Center, Massachusetts General Hospital/Harvard Medical School, MGH-East, Building 149, 13th Street, Boston, MA 02129, USA.
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Goto M, Groth CG, Nilsson B, Korsgren O. Intraportal pig islet xenotransplantation into athymic mice as an in vivo model for the study of the instant blood-mediated inflammatory reaction. Xenotransplantation 2004; 11:195-202. [PMID: 14962281 DOI: 10.1046/j.1399-3089.2003.00107.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
One of the main obstacles to successful intraportal islet transplantation is the instant blood-mediated inflammatory reaction (IBMIR) elicited by the isolated islets when exposed to fresh human blood. In the present study, we investigated whether intraportal transplantation of pig islets into diabetic athymic mice could be used as a small animal model to study xenogeneic IBMIR in vivo. Adult porcine islets (APIs) or rat islets were implanted into the portal vein or under the renal subcapsular space of diabetic athymic mice. Graft survival and morphology were evaluated by measuring blood glucose levels and by performing immunohistochemical staining, respectively. Transplantation of rat islets, irrespective of implantation site, cured all diabetic athymic mice. APIs transplanted subcapsularly also cured all diabetic athymic mice, while none of the animals transplanted with an equivalent amount of APIs via the portal vein remained normoglycemic for more than 10 days after transplantation. Immunohistochemical staining on day 7 showed that most of intraportally transplanted APIs were entrapped in clots and infiltrated with CD11b+ leukocytes. Intraportal transplantation of APIs into athymic mice induced IBMIR, thus providing a small animal model for studying xenogeneic IBMIR.
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Affiliation(s)
- Masafumi Goto
- Department of Radiology, Oncology, and Clinical Immunology, Uppsala University Hospital, Uppsala, Sweden.
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Bretzel RG. Pancreatic islet and stem cell transplantation in diabetes mellitus: results and perspectives. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 534:69-96. [PMID: 12903712 DOI: 10.1007/978-1-4615-0063-6_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Affiliation(s)
- Reinhard G Bretzel
- Third Medical Department and Policlinic, University Hospital Giessen, Rodthohl 6, D-35392 Giessen, Germany
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Rijkelijkhuizen JKRA, Haanstra KG, Wubben J, Töns A, Roos A, van Gijlswijk-Janssen DJ, Ringers J, Bouwman E, Jonker M. T-cell-specific immunosuppression results in more than 53 days survival of porcine islets of langerhans in the monkey. Transplantation 2004; 76:1359-68. [PMID: 14627916 DOI: 10.1097/01.tp.0000085290.60182.6b] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Transplantation of islets of Langerhans can restore insulin production in diabetic patients. Because of the shortage of human donor organs, transplantation of porcine islets may be an alternative solution. The present study was aimed at the characterization of rejection mechanisms of porcine islets transplanted into eight nondiabetic monkeys under the kidney capsule. METHODS Cultured adult pig islets were used, which showed no expression of the galactose(alpha1,3)galactose epitope, major histocompatibility complex class II, or CD45, and no binding of antibodies or complement after exposure to monkey serum. Immunosuppression consisted of cyclophosphamide, cyclosporine A (CsA), and steroids (group 1); or antithymocyte globulin, anti-interleukin-2 receptor antibody, CsA, and steroids (group 2). In three animals of group 2, islets were also transplanted in the portal vein. RESULTS Although all monkeys had preformed anti-pig antibodies, no correlation was found between antibody titers and rejection and no deposition of antibodies or complement was observed in the grafts. Group 1 showed islets up to day 11, followed by T-cell infiltration and rejection at approximately day 14. In group 2, two monkeys showed infiltrates consisting predominantly of T cells starting at approximately day 29, whereas two monkeys showed well-preserved islets without infiltration up to day 53. In the livers of the three monkeys that also received islets intraportally and were resectioned on days 21, 33, and 49, no islets could be detected. CONCLUSIONS This study demonstrates that cultured adult pig islets can survive in the monkey for more than 53 days without signs of rejection under standard immunosuppression.
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Omer A, Keegan M, Czismadia E, De Vos P, Van Rooijen N, Bonner-Weir S, Weir GC. Macrophage depletion improves survival of porcine neonatal pancreatic cell clusters contained in alginate macrocapsules transplanted into rats. Xenotransplantation 2003; 10:240-51. [PMID: 12694544 DOI: 10.1034/j.1399-3089.2003.01150.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND Macrophages can accumulate on the surface of empty and islet-containing alginate capsules, leading to loss of functional tissue. In this study, the effect of peritoneal macrophage depletion on the biocompatibility of alginate macrocapsules and function of macroencapsulated porcine neonatal pancreatic cell clusters (NPCCs) was investigated. METHODS Clodronate liposomes were injected into the peritoneal cavities of normoglycemic Lewis rats 5 and 2 days before the transplantation. Empty or NPCC-containing Ca-alginate poly L-lysine (PLL)-coated macrocapsules were transplanted into the peritoneal cavities of rats injected with either clodronate liposomes or saline. On days 7, 14 and 21, samples were evaluated by immunohistochemistry for cellular immune responses on the surface of the macrocapsules and for macrophage populations in omental tissue. To assess the function of macroencapsulated NPCCs, insulin secretory responses to glucose and theophylline were measured after capsule retrieval. RESULTS In saline-injected control groups, all of the empty and NPCC-containing macrocapsules were overgrown with macrophages, this being especially severe on NPCC-containing macrocapsules. In the clodronate liposomes-injected group, the majority of the empty macrocapsules were free of macrophage accumulation and the NPCC-containing macrocapsules were less overgrown than in control animals. Higher insulin responses to glucose and theophylline were observed in NPCCs retrieved from rats injected with clodronate liposomes. CONCLUSION We conclude that depletion of peritoneal macrophages with clodronate liposomes improve the survival of macroencapsulated NPCCs.
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Affiliation(s)
- Abdulkadir Omer
- Section on Islet Transplantation and Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, MA 02215, USA
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Maeda A, Goto M, Zhang J, Bennet W, Groth CG, Korsgren O, Wennberg L. Immunosuppression with FTY720 and cyclosporine A inhibits rejection of adult porcine islet xenografts in rats. Transplantation 2003; 75:1409-14. [PMID: 12717240 DOI: 10.1097/01.tp.0000061770.39569.7f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Our aim was to evaluate the effect of FTY720 in discordant islet xenotransplantation. METHODS Fetal porcine islet-like cell clusters (ICCs) were transplanted into normoglycemic rats that were either left untreated or treated with FTY720 only, with FTY720 plus cyclosporine A (CsA) or with CsA only. Twelve or 24 days after transplantation, graft morphology was evaluated immunohistochemically. Furthermore, adult porcine islets (APIs) were transplanted into diabetic rats immunosuppressed with FTY720 plus CsA. Blood glucose and porcine C-peptide levels were monitored. RESULTS In untreated rats, the ICC xenografts were completely rejected after 12 days. Treatment with CsA had only a marginal effect on the rejection. In animals given FTY720, only the number of infiltrating cells was somewhat reduced. However, at 12 days, no intact ICCs remained. Immunosuppression with FTY720 plus CsA had a marked inhibitory effect on islet xenograft rejection and plentiful morphologically intact ICCs remained. Twelve days after transplantation, only occasional macrophages and T cells could be detected. At 24 days after transplantation, the findings were similar. Furthermore, diabetic rats transplanted with APIs and immunosuppressed with FTY720 plus CsA remained normoglycemic for 53.0+/-15.8 days. In fact, one animal remained normoglycemic for more than 100 days. Serum levels of porcine C-peptide remained at levels similar to those for human C-peptide in healthy individuals. CONCLUSIONS Immunosuppression with FTY720 plus CsA inhibited almost all morphological signs of pig-to-rat islet xenograft rejection for up to 24 days after transplantation. Diabetic rats transplanted with APIs and immunosuppressed with FTY720 plus CsA remained normoglycemic for 53.0+/-15.8 days.
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Affiliation(s)
- A Maeda
- Department of Transplantation Surgery, Karolinska Institute, Huddinge University Hospital, Huddinge, Sweden
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Gores PF, Hayes DH, Copeland MJ, Korbutt GS, Halberstadt C, Kirkpatrick SA, Rajotte RV. Long-term survival of intratesticular porcine islets in nonimmunosuppressed beagles. Transplantation 2003; 75:613-8. [PMID: 12640298 DOI: 10.1097/01.tp.0000052376.89400.8d] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The testis is an immunoprivileged organ, and at 37 degrees C, the intratesticular microenvironment supports the survival of allogeneic islets. The objective of this study was to determine whether the immunoprotection afforded by the intratesticular environment is potent enough to prevent the rejection of xenogeneic porcine islets in a large-animal model. METHODS A bilateral cryptorchid condition was surgically created in sexually mature beagle dogs. Porcine islets were prepared from neonatal pigs by collagenase digestion and 9 days of culture, after which they were injected into each of the cryptorchid testes. Control dogs received liver subcapsular space transplants of porcine islets and autologous islets. After 100 days, the testes and relevant portions of liver were studied immunohistochemically for the presence of islet tissue. RESULTS The testicular interstitial space of all dogs contained abundant islet tissue. No evidence of lymphocytic infiltration or inflammation was observed. In contrast, porcine islets transplanted to the liver subcapsular space do not survive, although autologous islets engraft well in that position. This occurs even though the recipient's serum contains preformed cytotoxic antibodies to porcine islets that persist after transplantation. CONCLUSIONS These results demonstrate that the microenvironment existing within the surgically repositioned intra-abdominal testis supports the survival of xenogeneic tissue. The survival of xenogeneic tissue in the absence of immunosuppression in this large-animal model raises the possibility that xenogeneic porcine islet tissue will also survive in humans if transplanted into a similar environment.
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Affiliation(s)
- Paul F Gores
- Department of Surgery, Carolinas Medical Center, Charlotte, NC, USA.
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