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Sokolov AV, Lafta MS, Nordberg DOT, Jonsson J, Schiöth HB. Depression proteomic profiling in adolescents with transcriptome analyses in independent cohorts. Front Psychiatry 2024; 15:1372106. [PMID: 38812487 PMCID: PMC11133714 DOI: 10.3389/fpsyt.2024.1372106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/26/2024] [Indexed: 05/31/2024] Open
Abstract
Introduction Depression is a major global burden with unclear pathophysiology and poor treatment outcomes. Diagnosis of depression continues to rely primarily on behavioral rather than biological methods. Investigating tools that might aid in diagnosing and treating early-onset depression is essential for improving the prognosis of the disease course. While there is increasing evidence of possible biomarkers in adult depression, studies investigating this subject in adolescents are lacking. Methods In the current study, we analyzed protein levels in 461 adolescents assessed for depression using the Development and Well-Being Assessment (DAWBA) questionnaire as part of the domestic Psychiatric Health in Adolescent Study conducted in Uppsala, Sweden. We used the Proseek Multiplex Neuro Exploratory panel with Proximity Extension Assay technology provided by Olink Bioscience, followed by transcriptome analyses for the genes corresponding to the significant proteins, using four publicly available cohorts. Results We identified a total of seven proteins showing different levels between DAWBA risk groups at nominal significance, including RBKS, CRADD, ASGR1, HMOX2, PPP3R1, CD63, and PMVK. Transcriptomic analyses for these genes showed nominally significant replication of PPP3R1 in two of four cohorts including whole blood and prefrontal cortex, while ASGR1 and CD63 were replicated in only one cohort. Discussion Our study on adolescent depression revealed protein-level and transcriptomic differences, particularly in PPP3R1, pointing to the involvement of the calcineurin pathway in depression. Our findings regarding PPP3R1 also support the role of the prefrontal cortex in depression and reinforce the significance of investigating prefrontal cortex-related mechanisms in depression.
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Affiliation(s)
| | | | | | | | - Helgi B. Schiöth
- Department of Surgical Sciences, Functional Pharmacology and Neuroscience, Uppsala University, Uppsala, Sweden
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Ghazi M, Saleh A, Abdallah M, El Masri D, El Masri J, El Ayoubi LM, Hawi J, Jurjus A. Barriers toward xenotransplantation in Arab World. Xenotransplantation 2024; 31:e12852. [PMID: 38526015 DOI: 10.1111/xen.12852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/26/2024]
Abstract
Organ transplant is a crucial therapeutic strategy offering a life-saving and transformative medical intervention. It provides an opportunity to improve their quality of life and increase their lifespan. The shortage of organs remains a critical global challenge, leading to a prolonged waiting times for organ receivers, which contributes to an increase in morbidity and mortality rates. Hence, xenotransplantation offered a promising solution to the global shortage of organs through the use of animal organs, leading to an increase in donor availability, reducing waiting times, minimizing organ trafficking, improving genetic engineering advancements, and driving scientific innovation. Even though xenotransplantation has many benefits in the clinical setting, it has many barriers that are hindering its achievements and constraining its occurrence. Some barriers to xenotransplant are general, such as the immunological barrier, while others are specific to certain regions due to local causes. The Arab region exhibits disparities in clinical settings compared to the global context, marked by the huge economic crisis and a shortage of trained healthcare professionals. Considering the huge resources and advancements needed in the field of xenotransplantation, this review aims to explore the specific barriers toward xenotransplantation in the Arab countries, highlighting the challenges to overcome these barriers.
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Affiliation(s)
- Maya Ghazi
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Aalaa Saleh
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Malak Abdallah
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | - Diala El Masri
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
- Faculty of Medicine, University of Balamand, Koura, Lebanon
| | - Jad El Masri
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon
| | | | - Jihad Hawi
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Abdo Jurjus
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
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Ali A, Kemter E, Wolf E. Advances in Organ and Tissue Xenotransplantation. Annu Rev Anim Biosci 2024; 12:369-390. [PMID: 37906838 DOI: 10.1146/annurev-animal-021122-102606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
End-stage organ failure can result from various preexisting conditions and occurs in patients of all ages, and organ transplantation remains its only treatment. In recent years, extensive research has been done to explore the possibility of transplanting animal organs into humans, a process referred to as xenotransplantation. Due to their matching organ sizes and other anatomical and physiological similarities with humans, pigs are the preferred organ donor species. Organ rejection due to host immune response and possible interspecies infectious pathogen transmission have been the biggest hurdles to xenotransplantation's success. Use of genetically engineered pigs as tissue and organ donors for xenotransplantation has helped to address these hurdles. Although several preclinical trials have been conducted in nonhuman primates, some barriers still exist and demand further efforts. This review focuses on the recent advances and remaining challenges in organ and tissue xenotransplantation.
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Affiliation(s)
- Asghar Ali
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Elisabeth Kemter
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
| | - Eckhard Wolf
- Molecular Animal Breeding and Biotechnology, Gene Center and Department of Veterinary Sciences, LMU Munich, Munich, Germany; , ,
- Center for Innovative Medical Models (CiMM), LMU Munich, Oberschleißheim, Germany
- Interfaculty Center for Endocrine and Cardiovascular Disease Network Modelling and Clinical Transfer (ICONLMU), LMU Munich, Munich, Germany
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Burlak C, Wang ZY, Martens G, Estrada J, Reyes L, Novara Gennuso VM, Vianna R, Tector M, Tector AJ. Xenoreactive antibodies in α-granules of human platelets bind pig liver endothelial cells. Xenotransplantation 2023; 30:e12834. [PMID: 37971870 DOI: 10.1111/xen.12834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 09/22/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023]
Abstract
Pig liver xenotransplantation is limited by a thrombocytopenic coagulopathy that occurs immediately following graft reperfusion. In vitro and ex vivo studies from our lab suggested that the thrombocytopenia may be the result of a species incompatibility in platelet glycosylation. Realization that platelet α-granules contain antibodies caused us to reevaluate whether the thrombocytopenia in liver xenotransplantation could occur because IgM and IgG from inside platelet α-granules bound to pig liver sinusoidal endothelial cells (LSECs). Our in vitro analysis of IgM and IgG from inside α-granules showed that platelets do carry xenoreactive antibodies that can bind to known xenoantigens. This study suggests that thrombocytopenia occurring following liver xenotransplantation could occur because of xenoreactive antibodies tethering human platelets to the pig LSEC enabling the platelet to be phagocytosed. These results suggest genetic engineering strategies aimed at reducing xenoantigens on the surface of pig LSEC will be effective in eliminating the thrombocytopenia that limits survival in liver xenotransplantation.
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Affiliation(s)
- Christopher Burlak
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Zheng Yu Wang
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Greg Martens
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jose Estrada
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Luz Reyes
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | | | - Rodrigo Vianna
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | | | - Alfred Joseph Tector
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
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5
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Lee KW, Park SSW, Kim DS, Choi K, Shim J, Kim J, Kim SJ, Park JB. Auxiliary liver xenotransplantation technique in a transgenic pig-to-non-human primate model: A surgical approach to prolong survival. Xenotransplantation 2023; 30:e12814. [PMID: 37493436 DOI: 10.1111/xen.12814] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/20/2023] [Accepted: 07/13/2023] [Indexed: 07/27/2023]
Abstract
Xenotransplantation using pigs' liver offers a potentially alternative method to overcome worldwide donor shortage, or more importantly as a bridge to allotransplantation. However, it has been challenged by profound thrombocytopenia and fatal coagulopathy in non-human primate models. Here we suggest that a left auxiliary technique can be a useful method to achieve extended survival of the xenograft. Fifteen consecutive liver xenotransplants were carried out in a pig-to-cynomolgus model. Right auxiliary technique was implemented in two cases, orthotopic in eight cases, and left auxiliary in five cases. None of the right auxiliary recipients survived after surgery due to hemorrhage during complex dissection between the primate's right lobe and inferior vena cava. Orthotopic recipients survived less than 7 days secondary to profound thrombocytopenia and coagulopathy. Two out of five left auxiliary xenotransplants survived more than 3 weeks without uncontrolled thrombocytopenia or anemia, with one of them surviving 34 days, the longest graft survival reported to date. Left auxiliary xenotransplant is a feasible approach in non-human primate experiments, and the feared risk of thrombocytopenia and coagulopathy can be minimized. This may allow for longer evaluation of the xenograft and help better understand histopathological and immunological changes that occur following liver xenotransplantation.
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Affiliation(s)
- Kyo Won Lee
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Sean S W Park
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Dong Suk Kim
- GenNBio, Pyeongtaek-Si, Gyeonggi-Do, Republic of Korea
| | - Kimyung Choi
- Optipharm Inc., Cheongju-si, Chungcheongbuk-do, Republic of Korea
| | - Joohyun Shim
- Optipharm Inc., Cheongju-si, Chungcheongbuk-do, Republic of Korea
| | - Jihun Kim
- Department of Pathology, Asan Medical Center, Ulsan University Medical School, Seoul, Republic of Korea
| | - Sung Joo Kim
- GenNBio, Pyeongtaek-Si, Gyeonggi-Do, Republic of Korea
| | - Jae Berm Park
- Department of Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Lei T, Chen L, Wang K, Du S, Gonelle-Gispert C, Wang Y, Buhler LH. Genetic engineering of pigs for xenotransplantation to overcome immune rejection and physiological incompatibilities: The first clinical steps. Front Immunol 2022; 13:1031185. [PMID: 36561750 PMCID: PMC9766364 DOI: 10.3389/fimmu.2022.1031185] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022] Open
Abstract
Xenotransplantation has the potential to solve the shortfall of human organ donors. Genetically modified pigs have been considered as potential animal donors for human xenotransplantation and have been widely used in preclinical research. The genetic modifications aim to prevent the major species-specific barriers, which include humoral and cellular immune responses, and physiological incompatibilities such as complement and coagulation dysfunctions. Genetically modified pigs can be created by deleting several pig genes related to the synthesis of various pig specific antigens or by inserting human complement- and coagulation-regulatory transgenes. Finally, in order to reduce the risk of infection, genes related to porcine endogenous retroviruses can be knocked down. In this review, we focus on genetically modified pigs and comprehensively summarize the immunological mechanism of xenograft rejection and recent progress in preclinical and clinical studies. Overall, both genetically engineered pig-based xenografts and technological breakthroughs in the biomedical field provide a promising foundation for pig-to-human xenotransplantation in the future.
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Affiliation(s)
- Tiantian Lei
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Lin Chen
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Kejing Wang
- Department of Pharmacy, Women and Children’s Hospital of Chongqing Medical University, Chongqing Health Center for Women and Children, Chongqing, China
| | - Suya Du
- Department of Clinical Pharmacy, Sichuan Cancer Hospital and Institute, Sichuan Cancer Center, School of Medicine, University of Electronic Science and Technology of China, Sichuan, China
| | - Carmen Gonelle-Gispert
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
| | - Yi Wang
- Department of Critical Care Medicine, Sichuan Academy of Medical Science and Sichuan Provincial People’s Hospital, University of Electronic Science and Technology of China, Chengdu, China,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
| | - Leo H. Buhler
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland,*Correspondence: Carmen Gonelle-Gispert, ; Yi Wang, ; Leo H. Buhler,
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7
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Cimeno A, Kuravi K, Sorrells L, Dandro A, Sendil S, Burdorf L, Parsell DM, Eyestone W, Phelps C, Ayares D, Azimzadeh AM, Pierson RN, Barth RN, LaMattina JC. hEPCR.hTBM.hCD47.hHO-1 with donor clodronate and DDAVP treatment improves perfusion and function of GalTKO.hCD46 porcine livers perfused with human blood. Xenotransplantation 2022; 29:e12731. [PMID: 35166407 PMCID: PMC10249003 DOI: 10.1111/xen.12731] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 07/15/2021] [Accepted: 01/12/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Platelet sequestration, inflammation, and inappropriate coagulation cascade activation are prominent in liver xenotransplant models and are associated with poor outcomes. Here, we evaluate a cassette of six additional genetic modifications to reduce anti-pig antibody binding (α-1,3-galactosyl transferase knockout [GalTKO]) and target coagulation dysregulation (human endothelial protein C receptor [hEPRC] and thrombomodulin [hTBM]), complement pathway regulation (human membrane cofactor protein, hCD46), inflammation heme oxygenase 1 [hHO-1]), and a self-recognition receptor (integrin-associated protein [hCD47]), as well as donor pharmacologic treatments designed to blunt these phenomena. METHODS Livers from GaltKO.hCD46 pigs ("2-gene," n = 3) and GalTKO.hCD46 pigs also transgenic for hEPRC, hTBM, hCD47, and hHO-1 ("6-gene," n = 4) were perfused ex vivo with whole human blood. Six-gene pigs were additionally pretreated with desmopressin (DDAVP) and clodronate liposomes to deplete vWF and kupffer cells, respectively. RESULTS The average perfusion times increased from 304 (±148) min in the 2-gene group to 856 (±61) min in the 6-gene group (p = .010). The average heparin administration was decreased from 8837 U/h in the 2-gene to 1354 U/h in the 6-gene group (p = .047). Platelet sequestration tended to be delayed in the 6-gene group (p = .070), while thromboxane B2 (TXB2, a platelet activation marker) levels were lower over the first hour (p = .044) (401 ± 124 vs. 2048 ± 712 at 60 min). Thrombin production as measured by F1+2 levels tended to be lower in the 6-gene group (p = .058). CONCLUSIONS The combination of the hEPCR.hTBM.hCD47.hHO-1 cassette along with donor pig DDAVP and clodronate liposome pretreatment was associated with prolonged function of xenoperfused livers, reduced coagulation pathway perturbations, and decreased TXB2 elaboration, and reflects significant progress to modulate liver xenograft injury in a pig to human model.
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Affiliation(s)
- Arielle Cimeno
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | - Amy Dandro
- Revivicor, Inc., Blacksburg, Virginia, USA
| | - Selin Sendil
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Dawn M. Parsell
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - Agnes M. Azimzadeh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Richard N. Pierson
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Rolf N. Barth
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - John C. LaMattina
- Department of Surgery, University of Maryland School of Medicine, Baltimore, Maryland, USA
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8
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Lamm V, Ekser B, Vagefi PA, Cooper DK. Bridging to Allotransplantation-Is Pig Liver Xenotransplantation the Best Option? Transplantation 2022; 106:26-36. [PMID: 33653996 PMCID: PMC10124768 DOI: 10.1097/tp.0000000000003722] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In the past 20 y, the number of patients in the United States who died while waiting for a human donor liver totaled >52 000. The median national wait time for patients with acute liver failure and the most urgent liver transplant listing was 7 d in 2018. The need for a clinical "bridge" to allotransplantation is clear. Current options for supporting patients with acute liver failure include artificial liver support devices, extracorporeal liver perfusion, and hepatocyte transplantation, all of which have shown mixed results with regard to survival benefit and are largely experimental. Progress in the transplantation of genetically engineered pig liver grafts in nonhuman primates has grown steadily, with survival of the pig graft extended to almost 1 mo in 2017. Further advances may justify consideration of a pig liver transplant as a clinical bridge to allotransplantation. We provide a brief history of pig liver xenotransplantation, summarize the most recent progress in pig-to-nonhuman primate liver transplantation models, and suggest criteria that may be considered for patient selection for a clinical trial of bridging by genetically engineered pig liver xenotransplantation to liver allotransplantation.
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Affiliation(s)
- Vladimir Lamm
- Division of Gastroenterology, Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Burcin Ekser
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN
| | - Parsia A. Vagefi
- Division of Surgical Transplantation, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - David K.C. Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, AL
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Li P, Walsh JR, Lopez K, Isidan A, Zhang W, Chen AM, Goggins WC, Higgins NG, Liu J, Brutkiewicz RR, Smith LJ, Hara H, Cooper DKC, Ekser B. Genetic engineering of porcine endothelial cell lines for evaluation of human-to-pig xenoreactive immune responses. Sci Rep 2021; 11:13131. [PMID: 34162938 PMCID: PMC8222275 DOI: 10.1038/s41598-021-92543-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 06/08/2021] [Indexed: 01/25/2023] Open
Abstract
Xenotransplantation (cross-species transplantation) using genetically-engineered pig organs offers a potential solution to address persistent organ shortage. Current evaluation of porcine genetic modifications is to monitor the nonhuman primate immune response and survival after pig organ xenotransplantation. This measure is an essential step before clinical xenotransplantation trials, but it is time-consuming, costly, and inefficient with many variables. We developed an efficient approach to quickly examine human-to-pig xeno-immune responses in vitro. A porcine endothelial cell was characterized and immortalized for genetic modification. Five genes including GGTA1, CMAH, β4galNT2, SLA-I α chain, and β2-microglobulin that are responsible for the production of major xenoantigens (αGal, Neu5Gc, Sda, and SLA-I) were sequentially disrupted in immortalized porcine endothelial cells using CRISPR/Cas9 technology. The elimination of αGal, Neu5Gc, Sda, and SLA-I dramatically reduced the antigenicity of the porcine cells, though the cells still retained their ability to provoke human natural killer cell activation. In summary, evaluation of human immune responses to genetically modified porcine cells in vitro provides an efficient method to identify ideal combinations of genetic modifications for improving pig-to-human compatibility, which should accelerate the application of xenotransplantation to humans.
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Affiliation(s)
- Ping Li
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Julia R Walsh
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.,Weldon School of Biomedical Engineering, West Lafayette, IN, USA
| | - Kevin Lopez
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Abdulkadir Isidan
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wenjun Zhang
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Angela M Chen
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William C Goggins
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Jianyun Liu
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Randy R Brutkiewicz
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lester J Smith
- Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.,3D Bioprinting Core, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Hidetaka Hara
- Xenotransplantation Program, Department of Surgery, University of Birmingham at Alabama, Birmingham, AL, USA
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Birmingham at Alabama, Birmingham, AL, USA
| | - Burcin Ekser
- Division of Transplant Surgery, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
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Abstract
Genetically modified animals, especially rodents, are widely used in biomedical research. However, non-rodent models are required for efficient translational medicine and preclinical studies. Owing to the similarity in the physiological traits of pigs and humans, genetically modified pigs may be a valuable resource for biomedical research. Somatic cell nuclear transfer (SCNT) using genetically modified somatic cells has been the primary method for the generation of genetically modified pigs. However, site-specific gene modification in porcine cells is inefficient and requires laborious and time-consuming processes. Recent improvements in gene-editing systems, such as zinc finger nucleases, transcription activator-like effector nucleases, and the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (CRISPR/Cas) system, represent major advances. The efficient introduction of site-specific modifications into cells via gene editors dramatically reduces the effort and time required to generate genetically modified pigs. Furthermore, gene editors enable direct gene modification during embryogenesis, bypassing the SCNT procedure. The application of gene editors has progressively expanded, and a range of strategies is now available for porcine gene engineering. This review provides an overview of approaches for the generation of genetically modified pigs using gene editors, and highlights the current trends, as well as the limitations, of gene editing in pigs.
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Affiliation(s)
- Fuminori Tanihara
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan.,Center for Development of Advanced Medical Technology, Jichi Medical University, Tochigi 329-0498, Japan
| | - Maki Hirata
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
| | - Takeshige Otoi
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770-8513, Japan
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11
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Ali L, Cupido AJ, Rijkers M, Hovingh GK, Holleboom AG, Dallinga-Thie GM, Stroes ES, van den Boogert MA. Common gene variants in ASGR1 gene locus associate with reduced cardiovascular risk in absence of pleiotropic effects. Atherosclerosis 2020; 306:15-21. [DOI: 10.1016/j.atherosclerosis.2020.07.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/19/2020] [Accepted: 07/01/2020] [Indexed: 01/05/2023]
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12
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Evaluation of the CRISPR/Cas9 Genetic Constructs in Efficient Disruption of Porcine Genes for Xenotransplantation Purposes Along with an Assessment of the Off-Target Mutation Formation. Genes (Basel) 2020; 11:genes11060713. [PMID: 32604937 PMCID: PMC7349392 DOI: 10.3390/genes11060713] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 06/17/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022] Open
Abstract
The increasing life expectancy of humans has led to an increase in the number of patients with chronic diseases and organ failure. However, the imbalance between the supply and the demand for human organs is a serious problem in modern transplantology. One of many solutions to overcome this problem is the use of xenotransplantation. The domestic pig (Sus scrofa domestica) is currently considered as the most suitable for human organ procurement. However, there are discrepancies between pigs and humans that lead to the creation of immunological barriers preventing the direct xenograft. The introduction of appropriate modifications to the pig genome to prevent xenograft rejection is crucial in xenotransplantation studies. In this study, porcine GGTA1, CMAH, β4GalNT2, vWF, ASGR1 genes were selected to introduce genetic modifications. The evaluation of three selected gRNAs within each gene was obtained, which enabled the selection of the best site for efficient introduction of changes. Modifications were examined after nucleofection of porcine primary kidney fibroblasts with CRISPR/Cas9 system genetic constructs, followed by the tracking of indels by decomposition (TIDE) analysis. In addition, off-target analysis was carried out for selected best gRNAs using the TIDE tool, which is new in the research conducted so far and shows the utility of this tool in these studies.
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13
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Lu T, Yang B, Wang R, Qin C. Xenotransplantation: Current Status in Preclinical Research. Front Immunol 2020; 10:3060. [PMID: 32038617 PMCID: PMC6989439 DOI: 10.3389/fimmu.2019.03060] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/16/2019] [Indexed: 12/13/2022] Open
Abstract
The increasing life expectancy of humans has led to a growing numbers of patients with chronic diseases and end-stage organ failure. Transplantation is an effective approach for the treatment of end-stage organ failure; however, the imbalance between organ supply and the demand for human organs is a bottleneck for clinical transplantation. Therefore, xenotransplantation might be a promising alternative approach to bridge the gap between the supply and demand of organs, tissues, and cells; however, immunological barriers are limiting factors in clinical xenotransplantation. Thanks to advances in gene-editing tools and immunosuppressive therapy as well as the prolonged xenograft survival time in pig-to-non-human primate models, clinical xenotransplantation has become more viable. In this review, we focus on the evolution and current status of xenotransplantation research, including our current understanding of the immunological mechanisms involved in xenograft rejection, genetically modified pigs used for xenotransplantation, and progress that has been made in developing pig-to-pig-to-non-human primate models. Three main types of rejection can occur after xenotransplantation, which we discuss in detail: (1) hyperacute xenograft rejection, (2) acute humoral xenograft rejection, and (3) acute cellular rejection. Furthermore, in studies on immunological rejection, genetically modified pigs have been generated to bridge cross-species molecular incompatibilities; in the last decade, most advances made in the field of xenotransplantation have resulted from the production of genetically engineered pigs; accordingly, we summarize the genetically modified pigs that are currently available for xenotransplantation. Next, we summarize the longest survival time of solid organs in preclinical models in recent years, including heart, liver, kidney, and lung xenotransplantation. Overall, we conclude that recent achievements and the accumulation of experience in xenotransplantation mean that the first-in-human clinical trial could be possible in the near future. Furthermore, we hope that xenotransplantation and various approaches will be able to collectively solve the problem of human organ shortage.
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Affiliation(s)
- Tianyu Lu
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Bochao Yang
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Ruolin Wang
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
| | - Chuan Qin
- Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.,NHC Key Laboratory of Human Disease Comparative Medicine, The Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical Diseases, Beijing, China
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14
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Zhang X, Li X, Yang Z, Tao K, Wang Q, Dai B, Qu S, Peng W, Zhang H, Cooper DKC, Dou K. A review of pig liver xenotransplantation: Current problems and recent progress. Xenotransplantation 2019; 26:e12497. [PMID: 30767272 DOI: 10.1111/xen.12497] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/01/2019] [Accepted: 01/07/2019] [Indexed: 12/14/2022]
Abstract
Pig liver xenotransplantation appears to be more perplexing when compared to heart or kidney xenotransplantation, even though great progress has been achieved. The relevant molecular mechanisms involved in xenogeneic rejection, including coagulopathy, and particularly thrombocytopenia, are complex, and need to be systematically investigated. The deletion of expression of Gal antigens in the liver graft highlights the injurious impact of nonGal antigens, which continue to induce humoral rejection. Innate immunity, particularly mediated by macrophages and natural killer cells, interplays with inflammation and coagulation disorders. Kupffer cells and liver sinusoidal endothelial cells (LSECs) together mediate leukocyte, erythrocyte, and platelet sequestration and phagocytosis, which can be exacerbated by increased cytokine production, cell desialylation, and interspecies incompatibilities. The coagulation cascade is activated by release of tissue factor which can be dependent or independent of the xenoreactive immune response. Depletion of endothelial anticoagulants and anti-platelet capacity amplify coagulation activation, and interspecies incompatibilities of coagulation-regulatory proteins facilitate dysregulation. LSECs involved in platelet phagocytosis and transcytosis, coupled with hepatocyte-mediated degradation, are responsible for thrombocytopenia. Adaptive immunity could also be problematic in long-term liver graft survival. Currently, relevant evidence and study results of various genetic modifications to the pig donor need to be fully determined, with the aim of identifying the ideal transgene combination for pig liver xenotransplantation. We believe that clinical trials of pig liver xenotransplantation should initially be considered as a bridge to allotransplantation.
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Affiliation(s)
- Xuan Zhang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Xiao Li
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Zhaoxu Yang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Kaishan Tao
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Quancheng Wang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Bin Dai
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Shibin Qu
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Wei Peng
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Hong Zhang
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - David K C Cooper
- Xenotransplantation Program, Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kefeng Dou
- Department of Hepatobiliary Surgery, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
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Abstract
PURPOSE OF REVIEW To review the progress in the field of xenotransplantation with special attention to most recent encouraging findings which will eventually bring xenotransplantation to the clinic in the near future. RECENT FINDINGS Starting from early 2000, with the introduction of galactose-α1,3-galactose (Gal)-knockout pigs, prolonged survival especially in heart and kidney xenotransplantation was recorded. However, remaining antibody barriers to non-Gal antigens continue to be the hurdle to overcome. The production of genetically engineered pigs was difficult requiring prolonged time. However, advances in gene editing, such as zinc finger nucleases, transcription activator-like effector nucleases, and most recently clustered regularly interspaced short palindromic repeats (CRISPR) technology made the production of genetically engineered pigs easier and available to more researchers. Today, the survival of pig-to-nonhuman primate heterotopic heart, kidney, and islet xenotransplantation reached more than 900, more than 400, and more than 600 days, respectively. The availability of multiple-gene pigs (five or six genetic modifications) and/or newer costimulation blockade agents significantly contributed to this success. Now, the field is getting ready for clinical trials with an international consensus. SUMMARY Clinical trials in cellular or solid organ xenotransplantation are getting closer with convincing preclinical data from many centers. The next decade will show us new achievements and additional barriers in clinical xenotransplantation.
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17
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French BM, Sendil S, Pierson RN, Azimzadeh AM. The role of sialic acids in the immune recognition of xenografts. Xenotransplantation 2017; 24. [PMID: 29057592 PMCID: PMC10167934 DOI: 10.1111/xen.12345] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 07/05/2017] [Accepted: 08/14/2017] [Indexed: 12/11/2022]
Abstract
Presentation of sialic acid (Sia) varies among different tissues and organs within each species, and between species. This diversity has biologically important consequences regarding the recognition of cells by "xeno" antibodies (Neu5Gc vs Neu5Ac). Sia also plays a central role in inflammation by influencing binding of the asialoglycoprotein receptor 1 (ASGR-1), Siglec-1 (Sialoadhesin), and cellular interactions mediated by the selectin, integrin, and galectin receptor families. This review will focus on what is known about basic Sia structure and function in association with xenotransplantation, how changes in sialylation may occur in this context (through desialylation or changes in sialyltransferases), and how this fundamental pathway modulates adhesive and cell activation pathways that appear to be particularly crucial to homeostasis and inflammation for xenografts.
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Affiliation(s)
- Beth M French
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Selin Sendil
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Richard N Pierson
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
| | - Agnes M Azimzadeh
- Division of Cardiac Surgery, University of Maryland Baltimore, School of Medicine, and VAMC, Baltimore, MD, USA
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18
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Cowan PJ, Tector AJ. The Resurgence of Xenotransplantation. Am J Transplant 2017; 17:2531-2536. [PMID: 28397351 DOI: 10.1111/ajt.14311] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 03/21/2017] [Accepted: 04/01/2017] [Indexed: 01/25/2023]
Abstract
There has been an upsurge of interest in xenotransplantation in recent years. This resurgence can attributed to a combination of factors. First, there has been a dramatic improvement in efficacy in several preclinical models, with maximum xenograft survival times increasing to 950 days for islets, 945 days for hearts, and 310 days for kidneys. Second, the rapid development of genome editing technology (particularly the advent of clustered regularly interspaced short palindromic repeats/Cas9) has revolutionized the capacity to generate new donor pigs with multiple protective genetic modifications; what once took many years to achieve can now be performed in months, with much greater precision and scope. Third, the specter of porcine endogenous retrovirus (PERV) has receded significantly. There has been no evidence of PERV transmission in clinical trials and preclinical models, and improved screening methods and new options for the treatment or even elimination of PERV are now available. Balancing these positive developments are several remaining challenges, notably the heavy and often clinically inapplicable immunosuppression required to prevent xenograft rejection. Nonetheless, the potential for xenotransplantation as a solution to the shortage of human organs and tissues for transplantation continues to grow.
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Affiliation(s)
- P J Cowan
- Immunology Research Centre, St Vincent's Hospital Melbourne, Victoria, Australia.,Department of Medicine, University of Melbourne, Victoria, Australia
| | - A J Tector
- School of Medicine, University of Alabama, Birmingham, AL
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19
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Cimeno A, Hassanein W, French BM, Powell JM, Burdorf L, Goloubeva O, Cheng X, Parsell DM, Ramsoondar J, Kuravi K, Vaught T, Uluer MC, Redding E, O'Neill N, Laird C, Hershfeld A, Tatarov I, Thomas K, Ayares D, Azimzadeh AM, Pierson RN, Barth RN, LaMattina JC. N-glycolylneuraminic acid knockout reduces erythrocyte sequestration and thromboxane elaboration in an ex vivo pig-to-human xenoperfusion model. Xenotransplantation 2017; 24. [PMID: 28940313 DOI: 10.1111/xen.12339] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 05/31/2017] [Accepted: 07/15/2017] [Indexed: 01/26/2023]
Abstract
BACKGROUND Wild-type pigs express several carbohydrate moieties on their cell surfaces that differ from those expressed by humans. This difference in profile leads to pig tissue cell recognition of human blood cells causing sequestration, in addition to antibody-mediated xenograft injury. One such carbohydrate is N-glycolylneuraminic acid (Neu5Gc), a sialic acid molecule synthesized in pigs but not in humans. Here, we evaluate livers with and without Neu5Gc in an ex vivo liver xeno perfusion model. METHODS Livers from pigs with an α1,3-galactosyl transferase gene knockout (GalTKO) and transgenic for human membrane cofactor (hCD46) with (n = 5) or without (n = 7) an additional Neu5Gc gene knock out (Neu5GcKO) were perfused ex vivo with heparinized whole human blood. A drug regimen consisting of a histamine inhibitor, thromboxane synthase inhibitor, and a murine anti-human GPIb-blocking antibody fragment was given to half of the experiments in each group. RESULTS Liver function tests (AST and ALT) were not significantly different between livers with and without the Neu5GcKO. GalTKO.hCD46.Neu5GcKO livers had less erythrocyte sequestration as evidenced by a higher mean hematocrit over time compared to GalTKO.hCD46 livers (P = .0003). The addition of Neu5GcKO did not ameliorate profound thrombocytopenia seen within the first 15 minutes of perfusion. TXB2 was significantly less with the added drug regimen (P = .006) or the presence of Neu5GcKO (P = .017). CONCLUSIONS The lack of Neu5Gc expression attenuated erythrocyte loss but did not prevent profound early onset thrombocytopenia or platelet activation, although TXB2 levels were decreased in the presence of Neu5GcKO.
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Affiliation(s)
- Arielle Cimeno
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Wessam Hassanein
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Beth M French
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jessica M Powell
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Lars Burdorf
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Olga Goloubeva
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Xiangfei Cheng
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Dawn M Parsell
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | | | | | - Mehmet C Uluer
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Emily Redding
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Natalie O'Neill
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Christopher Laird
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alena Hershfeld
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Ivan Tatarov
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kathryn Thomas
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | | | - Agnes M Azimzadeh
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Richard N Pierson
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Rolf N Barth
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - John C LaMattina
- Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
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20
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Liu Z, Hu W, He T, Dai Y, Hara H, Bottino R, Cooper DKC, Cai Z, Mou L. Pig-to-Primate Islet Xenotransplantation: Past, Present, and Future. Cell Transplant 2017; 26:925-947. [PMID: 28155815 PMCID: PMC5657750 DOI: 10.3727/096368917x694859] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 03/21/2017] [Indexed: 12/17/2022] Open
Abstract
Islet allotransplantation results in increasing success in treating type 1 diabetes, but the shortage of deceased human donor pancreata limits progress. Islet xenotransplantation, using pigs as a source of islets, is a promising approach to overcome this limitation. The greatest obstacle is the primate immune/inflammatory response to the porcine (pig) islets, which may take the form of rapid early graft rejection (the instant blood-mediated inflammatory reaction) or T-cell-mediated rejection. These problems are being resolved by the genetic engineering of the source pigs combined with improved immunosuppressive therapy. The results of pig-to-diabetic nonhuman primate islet xenotransplantation are steadily improving, with insulin independence being achieved for periods >1 year. An alternative approach is to isolate islets within a micro- or macroencapsulation device aimed at protecting them from the human recipient's immune response. Clinical trials using this approach are currently underway. This review focuses on the major aspects of pig-to-primate islet xenotransplantation and its potential for treatment of type 1 diabetes.
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Affiliation(s)
- Zhengzhao Liu
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, P.R. China
| | - Wenbao Hu
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, P.R. China
| | - Tian He
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, P.R. China
| | - Yifan Dai
- Jiangsu Key Laboratory of Xenotransplantation, Nanjing Medical University, Nanjing, Jiangsu, P.R. China
| | - Hidetaka Hara
- Xenotransplantation Program/Department of Surgery, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rita Bottino
- Institute for Cellular Therapeutics, Allegheny-Singer Research Institute, Pittsburgh, PA, USA
| | - David K. C. Cooper
- Xenotransplantation Program/Department of Surgery, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zhiming Cai
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, P.R. China
| | - Lisha Mou
- Shenzhen Xenotransplantation Medical Engineering Research and Development Center, Institute of Translational Medicine, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, P.R. China
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Abstract
Experience with clinical liver xenotransplantation has largely involved the transplantation of livers from nonhuman primates. Experience with pig livers has been scarce. This brief review will be restricted to assessing the potential therapeutic impact of pig liver xenotransplantation in acute liver failure and the remaining barriers that currently do not justify clinical trials. A relatively new surgical technique of heterotopic pig liver xenotransplantation is described that might play a role in bridging a patient with acute liver failure until either the native liver recovers or a suitable liver allograft is obtained. Other topics discussed include the possible mechanisms for the development of the thrombocytopenis that rapidly occurs after pig liver xenotransplantation in a primate, the impact of pig complement on graft injury, the potential infectious risks, and potential physiologic incompatibilities between pig and human. There is cautious optimism that all of these problems can be overcome by judicious genetic manipulation of the pig. If liver graft survival could be achieved in the absence of thrombocytopenia or rejection for a period of even a few days, there may be a role for pig liver transplantation as a bridge to allotransplantation in carefully selected patients.
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23
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Petersen B, Frenzel A, Lucas-Hahn A, Herrmann D, Hassel P, Klein S, Ziegler M, Hadeler KG, Niemann H. Efficient production of biallelic GGTA1 knockout pigs by cytoplasmic microinjection of CRISPR/Cas9 into zygotes. Xenotransplantation 2016; 23:338-46. [PMID: 27610605 DOI: 10.1111/xen.12258] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/01/2016] [Accepted: 08/12/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Xenotransplantation is considered to be a promising solution to the growing demand for suitable donor organs for transplantation. Despite tremendous progress in the generation of pigs with multiple genetic modifications thought to be necessary to overcoming the severe rejection responses after pig-to-non-human primate xenotransplantation, the production of knockout pigs by somatic cell nuclear transfer (SCNT) is still an inefficient process. Producing genetically modified pigs by intracytoplasmic microinjection of porcine zygotes is an alluring alternative. The porcine GGTA1 gene encodes for the α1,3-galactosyltransferase that synthesizes the Gal epitopes on porcine cells which constitute the major antigen in a xenotransplantation setting. GGTA1-KO pigs have successfully been produced by transfecting somatic cells with zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), or CRISPR/Cas targeting GGTA1, followed by SCNT. METHODS Here, we microinjected a CRISPR/Cas9 vector coding for a single-guide RNA (sgRNA) targeting exon 8 of the GGTA1 gene into the cytoplasm of 97 in vivo-derived porcine zygotes and transferred 86 of the microinjected embryos into three hormonally synchronized recipients. Fetuses and piglets were analyzed by flow cytometry for remaining Gal epitopes. DNA was sequenced to detect mutations at the GGTA1 locus. RESULTS Two of the recipients remained pregnant as determined by ultrasound scanning on day 25 of gestation. One pregnancy was terminated on day 26, and six healthy fetuses were recovered. The second pregnancy was allowed to go to term and resulted in the birth of six healthy piglets. Flow cytometry analysis revealed the absence of Gal epitopes in four of six fetuses (66%), indicating a biallelic KO of GGTA1. Additionally, three of the six live-born piglets (50%) did not express Gal epitopes on their cell surface. Two fetuses and two piglets showed a mosaicism with a mixed population of Gal-free and Gal-expressing cells. Only a single piglet did not have any genomic modifications. Genomic sequencing revealed indel formation at the GGTA1 locus ranging from +17 bp to -20 bp. CONCLUSIONS These results demonstrate the efficacy of CRISPR/Cas to generate genetic modifications in pigs by simplified technology, such as intracytoplasmic microinjection into zygotes, which would significantly facilitate the production of genetically modified pigs suitable for xenotransplantation. Importantly, this simplified injection protocol avoids the penetration of the vulnerable pronuclear membrane, and is thus compatible with higher survival rates of microinjected embryos, which in turn facilitates production of genetically modified piglets.
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Affiliation(s)
- Bjoern Petersen
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany.
| | - Antje Frenzel
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Andrea Lucas-Hahn
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Doris Herrmann
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Petra Hassel
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Sabine Klein
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Maren Ziegler
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Klaus-Gerd Hadeler
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany
| | - Heiner Niemann
- Institute of Farm Animal Genetics, Friedrich-Loeffler-Institut, Mariensee, Neustadt, Germany.
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Silencing Porcine CMAH and GGTA1 Genes Significantly Reduces Xenogeneic Consumption of Human Platelets by Porcine Livers. Transplantation 2016; 100:571-6. [PMID: 26906939 DOI: 10.1097/tp.0000000000001071] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND A profound thrombocytopenia limits hepatic xenotransplantation in the pig-to-primate model. Porcine livers also have shown the ability to phagocytose human platelets in the absence of immune-mediated injury. Recently, inactivation of the porcine ASGR1 gene has been shown to decrease this phenomenon. Inactivating GGTA1 and CMAH genes has reduced the antibody-mediated barrier to xenotransplantation; herein, we describe the effect that these modifications have on xenogeneic consumption of human platelets in the absence of immune-mediated graft injury. METHODS Wild type (WT), ASGR1, GGTA1, and GGTA1CMAH knockout pigs were compared for their xenogeneic hepatic consumption of human platelets. An in vitro assay was established to measure the association of human platelets with liver sinusoidal endothelial cells (LSECs) by immunohistochemistry. Perfusion models were used to measure human platelet uptake in livers from WT, ASGR1, GGTA1, and GGTA1 CMAH pigs. RESULTS GGTA1, CMAH LSECs exhibited reduced levels of human platelet binding in vitro when compared with GGTA1 and WT LSECs. In a continuous perfusion model, GGTA1 CMAH livers consumed fewer human platelets than GGTA1 and WT livers. GGTA1 CMAH livers also consumed fewer human platelets than ASGR1 livers in a single-pass model. CONCLUSIONS Silencing the porcine carbohydrate genes necessary to avoid antibody-mediated rejection in a pig-to-human model also reduces the xenogeneic consumption of human platelets by the porcine liver. The combination of these genetic modifications may be an effective strategy to limit the thrombocytopenia associated with pig-to-human hepatic xenotransplantation.
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27
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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: 95] [Impact Index Per Article: 11.9] [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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Butler JR, Skill NJ, Priestman DL, Platt FM, Li P, Estrada JL, Martens GR, Ladowski JM, Tector M, Tector AJ. Silencing the porcine iGb3s gene does not affect Galα3Gal levels or measures of anticipated pig-to-human and pig-to-primate acute rejection. Xenotransplantation 2016; 23:106-16. [PMID: 27106872 DOI: 10.1111/xen.12217] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/12/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND The Galα(1,3)Gal epitope (α-GAL), created by α-1,3-glycosyltransferase-1 (GGTA1), is a major xenoantigen causing hyperacute rejection in pig-to-primate and pig-to-human xenotransplantation. In response, GGTA1 gene-deleted pigs have been generated. However, it is unclear whether there is a residual small amount of α-Gal epitope expressed in GGTA1(-/-) pigs. Isoglobotrihexosylceramide synthase (iGb3s), another member of the glycosyltransferase family, catalyzes the synthesis of isoglobo-series glycosphingolipids with an α-GAL-terminal disaccharide (iGb3), creating the possibility that iGb3s may be a source of α-GAL epitopes in GGTA1(-/-) animals. The objective of this study was to examine the impact of silencing the iGb3s gene (A3GalT2) on pig-to-primate and pig-to-human immune cross-reactivity by creating and comparing GGTA1(-/-) pigs to GGTA1(-/-) - and A3GalT2(-/-) -double-knockout pigs. METHODS We used the CRISPR/Cas 9 system to target the GGTA1 and A3GalT2 genes in pigs. Both GGTA1 and A3GalT2 genes are functionally inactive in humans and baboons. CRISPR-treated cells used directly for somatic cell nuclear transfer produced single- and double-gene-knockout piglets in a single pregnancy. Once grown to maturity, the glycosphingolipid profile (including iGb3) was assayed in renal tissue by normal-phase liquid chromatography. In addition, peripheral blood mononuclear cells (PBMCs) were subjected to (i) comparative cross-match cytotoxicity analysis against human and baboon serum and (ii) IB4 staining for α-GAL/iGb3. RESULTS Silencing of the iGb3s gene significantly modulated the renal glycosphingolipid profile and iGb3 was not detected. Moreover, the human and baboon serum PBMC cytotoxicity and α-GAL/iGb3 staining were unchanged by iGb3s silencing. CONCLUSIONS Our data suggest that iGb3s is not a contributor to antibody-mediated rejection in pig-to-primate or pig-to-human xenotransplantation. Although iGb3s gene silencing significantly changed the renal glycosphingolipid profile, the effect on Galα3Gal levels, antibody binding, and cytotoxic profiles of baboon and human sera on porcine PBMCs was neutral.
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Affiliation(s)
- James R Butler
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nicholas J Skill
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | | | - Ping Li
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jose L Estrada
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Gregory R Martens
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Joseph M Ladowski
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Matthew Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Joseph Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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Cooper DK, Ekser B, Ramsoondar J, Phelps C, Ayares D. The role of genetically engineered pigs in xenotransplantation research. J Pathol 2016; 238:288-99. [PMID: 26365762 PMCID: PMC4689670 DOI: 10.1002/path.4635] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/22/2015] [Accepted: 09/06/2015] [Indexed: 12/12/2022]
Abstract
There is a critical shortage in the number of deceased human organs that become available for the purposes of clinical transplantation. This problem might be resolved by the transplantation of organs from pigs genetically engineered to protect them from the human immune response. The pathobiological barriers to successful pig organ transplantation in primates include activation of the innate and adaptive immune systems, coagulation dysregulation and inflammation. Genetic engineering of the pig as an organ source has increased the survival of the transplanted pig heart, kidney, islet and corneal graft in non-human primates (NHPs) from minutes to months or occasionally years. Genetic engineering may also contribute to any physiological barriers that might be identified, as well as to reducing the risks of transfer of a potentially infectious micro-organism with the organ. There are now an estimated 40 or more genetic alterations that have been carried out in pigs, with some pigs expressing five or six manipulations. With the new technology now available, it will become increasingly common for a pig to express even more genetic manipulations, and these could be tested in the pig-to-NHP models to assess their efficacy and benefit. It is therefore likely that clinical trials of pig kidney, heart and islet transplantation will become feasible in the near future.
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Affiliation(s)
- David K.C. Cooper
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA
| | - Burcin Ekser
- Transplant Division, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN
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Butler JR, Martens GR, Li P, Wang ZY, Estrada JL, Ladowski JM, Tector M, Tector AJ. The fate of human platelets exposed to porcine renal endothelium: a single-pass model of platelet uptake in domestic and genetically modified porcine organs. J Surg Res 2015; 200:698-706. [PMID: 26375504 DOI: 10.1016/j.jss.2015.08.034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 07/13/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Thrombocytopenia may represent a significant challenge to the clinical application of solid-organ xenotransplantation. When studied in a pig-to-primate model, consumptive coagulopathy has challenged renal xenografts. New strategies of genetic manipulation have altered porcine carbohydrate profiles to significantly reduce human antibody binding to pig cells. As this process continues to eliminate immunologic barriers to clinical xenotransplantation, the relationship between human platelets and pig organs must be considered. METHODS Genetically modified pigs that were created by the CRISPR/Cas9 system with α-1,3-galactosyltransferase (GGTA1)(-/-) or GGTA1(-/-) cytidine monophosphate-N-acetylneuraminic acid hydroxylase(-/-) phenotype, as well as domestic pigs, were used in this study. Autologous porcine platelets were isolated from donor animal blood collection, and human platelets were obtained from a blood bank. Platelets were fluorescently labeled and in a single-pass model, human, or autologous platelets were perfused through porcine organs at a constant concentration and controlled temperature. Platelet uptake was measured by sampling venous output and measuring sample florescence against input florescence. In vitro study of the interaction between human platelets and porcine endothelial cells was accomplished by immunohistochemical stain and confocal microscopy. RESULTS Differences between human and autologous platelet loss through the porcine kidney were not significant in any genetic background tested (WT P = 0.15, GGTA1(-/-)P = 0.12, GGTA1(-/-) cytidine monophosphate-N-acetylneuraminic acid hydroxylase(-/-)P = 0.25). The unmodified porcine liver consumed human platelets in a single-pass model of platelet perfusion in fewer than 10 min. WT suprahepatic inferior vena cava fluoresce reached a maximum of 76% of input fluoresce within the human platelet cohort and was significantly lower than the autologous platelet control cohort (P = 0.001). Confocal microscopic analysis did not demonstrate a significant association between human platelets and porcine renal endothelial cells compared with porcine liver endothelial positive controls. CONCLUSIONS Our results suggest that in the absence of immunologic injury, human platelets respond in a variable fashion to organ-specific porcine endothelial surfaces. Human platelets are not removed from circulation by exposure to porcine renal endothelium but are removed by unmodified porcine hepatic endothelium. Kidneys possessing genetic modifications currently relevant to clinical xenotransplantation failed to consume human platelets in an isolated single-pass model. Human platelets did not exhibit significant binding to renal endothelial cells by in vitro assay.
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Affiliation(s)
- James R Butler
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Gregory R Martens
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ping Li
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Zheng-Yu Wang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jose L Estrada
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Joseph M Ladowski
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Matt Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - A Joseph Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana.
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Butler JR, Ladowski JM, Martens GR, Tector M, Tector AJ. Recent advances in genome editing and creation of genetically modified pigs. Int J Surg 2015; 23:217-222. [PMID: 26231992 DOI: 10.1016/j.ijsu.2015.07.684] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 07/08/2015] [Accepted: 07/17/2015] [Indexed: 11/26/2022]
Abstract
The field of xenotransplantation is benefiting greatly from recent advances in genetic engineering. The efficiency and pace with which new model animals are being created has dramatically sped progress towards clinical relevance. Endonuclease-driven genome editing now allows for the efficient generation of targeted genetic alterations. Herein we review the available methods of genetic engineering that have been successfully employed to create genetically modified pigs.
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Affiliation(s)
- James R Butler
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Joseph M Ladowski
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Gregory R Martens
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Matthew Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
| | - A Joseph Tector
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
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Abstract
Dysregulation of coagulation and disordered hemostasis are frequent complications in the pig-to-nonhuman primate preclinical xenotransplantation model. The most extreme manifestations are the systemic development of a life-threatening consumptive coagulopathy, characterized by thrombocytopenia and bleeding, which is balanced at the opposite extreme by local complications of graft loss due to thrombotic microangiopathy. The contributing mechanisms include inflammation, vascular injury, heightened innate, humoral and cellular immune responses, and molecular incompatibilities affecting the regulation of coagulation. There also appear to be organ-specific factors that have been linked to vascular heterogeneity. As examples, liver xenografts rapidly induce thrombocytopenia by sequestering human/primate platelets; renal xenografts cause a broader coagulopathy, linked in some cases to reactivation of porcine CMV, whereas cardiac xenografts often succumb to microvascular thrombosis without associated systemic coagulopathy but with local perturbations in fibrinolysis. Overcoming coagulation dysfunction will require a combination of genetic and pharmacological strategies. Deletion of the xenoantigen αGal, transgenic expression of human complement regulatory proteins, and refinement of immunosuppression to blunt the antibody response have all had some impact, without providing a complete solution. More recently, the addition of approaches specifically targeted at coagulation have produced promising results. As an example, heterotopic cardiac xenografts from donors expressing human thrombomodulin have survived for more than a year in immunosuppressed baboons, with no evidence of thrombotic microangiopathy or coagulopathy.
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Burlak C, Mueller KR, Beaton BP. Xenotransplantation literature update, May-June 2015. Xenotransplantation 2015; 22:325-7. [PMID: 26179327 DOI: 10.1111/xen.12181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 06/26/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Christopher Burlak
- Department of Surgery, Schulze Diabetes Institute, University of Minnesota School of Medicine, Minneapolis, MN, USA
| | - Kate R Mueller
- Department of Surgery, Schulze Diabetes Institute, University of Minnesota School of Medicine, Minneapolis, MN, USA
| | - Benjamin P Beaton
- Division of Animal Sciences, University of Missouri-Columbia, Columbia, MO, USA
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Ekser B, Markmann JF, Tector AJ. Current status of pig liver xenotransplantation. Int J Surg 2015; 23:240-246. [PMID: 26190837 DOI: 10.1016/j.ijsu.2015.06.083] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 06/28/2015] [Indexed: 12/26/2022]
Abstract
The shortage of organs from deceased human donors is a major problem limiting the number of organs transplanted each year and results in the death of thousands of patients on the waiting list. Pigs are currently the preferred species for clinical organ xenotransplantation. Progress in genetically-engineered (GE) pig liver xenotransplantation increased graft and recipient survival from hours with unmodified pig livers to up to 9 days with normal to near-normal liver function. Deletion of genes such as GGTA1 (Gal-knockout pigs) or adding genes such as human complement regulatory proteins (hCD55, hCD46 expressing pigs) enabled hyperacute rejection to be overcome. Although survival up to 9 days was recorded, extended pig graft survival was not achieved due to lethal thrombocytopenia. The current status of GE pig liver xenotransplantation with world experience, potential factors causing thrombocytopenia, new targets on pig endothelial cells, and novel GE pigs with more genes deletion to avoid remaining antibody response, such as beta1,4-N-acetyl galactosaminyl transferase 2 (β4GalNT2), are discussed.
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Affiliation(s)
- Burcin Ekser
- Transplant Division, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - James F Markmann
- Division of Transplantation, Department of Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - A Joseph Tector
- Transplant Division, Department of Surgery, Indiana University School of Medicine, Indianapolis, IN, USA
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