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Schmalkuche K, Rother T, Besli S, Schwinzer R, Blasczyk R, Petersen B, Figueiredo C. Human PD-L1 overexpression decreases xenogeneic human T-cell immune responses towards porcine kidneys. Front Immunol 2024; 15:1279050. [PMID: 38352884 PMCID: PMC10861674 DOI: 10.3389/fimmu.2024.1279050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 01/11/2024] [Indexed: 02/16/2024] Open
Abstract
Xenotransplantation offers a promising alternative to circumvent the lack of donated human organs available for transplantation. Different attempts to improve the survival of xenografts led to the generation of transgenic pigs expressing various combinations of human protective genes or knocked out for specific antigens. Currently, testing the efficiency of porcine organs carrying different genetic modifications in preventing xenogeneic immune responses completely relies on in vitro assays, humanized mouse models, or non-human primate transplantation models. However, these tests are often associated with major concerns due to reproducibility and generation of insufficient data as well as they raise ethical, logistical, and economic issues. In this study, we investigated the feasibility of specifically assessing the strength of human T-cell responses towards the kidneys of wild-type (WT) or transgenic pigs overexpressing human programmed death-1 ligand 1 (hPD-L1) during ex vivo kidney perfusion (EVKP). Human T cells were shown to adhere to the endothelium and transmigrate into WT and hPD-L1 kidneys. However, transcript levels of TNF-a and IFN-y as well as cytotoxic molecules such as granzyme B and perforin secreted by human T cells were significantly decreased in the tissue of hPD-L1 kidneys in comparison to WT kidneys. These results were confirmed via in vitro assays using renal endothelial cells (ECs) isolated from WT and hPD-L1 transgenic pigs. Both CD4+ and CD8+ T cells showed significantly lower proliferation rates after exposure to hPD-L1 porcine renal ECs in comparison to WT ECs. In addition, the secretion of pro-inflammatory cytokines was significantly reduced in cultures using hPD-L1 ECs in comparison to WT ECs. Remarkably, hPD-L1 EC survival was significantly increased in cytotoxic assays. This study demonstrates the feasibility of evaluating the human response of specific immune subsets such as human T cells towards the whole xenograft during EVKP. This may represent a robust strategy to assess the potency of different genetic modifications to prevent xenogeneic immune responses and thereby predict the risk of immune rejection of new genetically engineered xenografts.
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Affiliation(s)
- Katharina Schmalkuche
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
- Transregional Collaborative Research Centre 127, Hannover Medical School, Hannover, Germany
| | - Tamina Rother
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Sevval Besli
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Reinhard Schwinzer
- Transregional Collaborative Research Centre 127, Hannover Medical School, Hannover, Germany
- Transplantation Laboratory, Clinic for General, Visceral and Transplantation-Surgery, Hannover Medical School, Hannover, Germany
| | - Rainer Blasczyk
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
| | - Björn Petersen
- Transregional Collaborative Research Centre 127, Hannover Medical School, Hannover, Germany
- Department of Biotechnology, Institute of Farm Animal Genetics, Friedrich-Loeffler-Institute, Federal Research Institute for Animal Health, Neustadt am Rübenberge, Germany
| | - Constanca Figueiredo
- Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hannover, Germany
- Transregional Collaborative Research Centre 127, Hannover Medical School, Hannover, Germany
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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] [MESH Headings] [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
| | | | - 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
| | - Leo H. Buhler
- Faculty of Science and Medicine, University of Fribourg, Fribourg, Switzerland
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Kaur G, Wright K, Mital P, Hibler T, Miranda JM, Thompson LA, Halley K, Dufour JM. Neonatal Pig Sertoli Cells Survive Xenotransplantation by Creating an Immune Modulatory Environment Involving CD4 and CD8 Regulatory T Cells. Cell Transplant 2021; 29:963689720947102. [PMID: 32841048 PMCID: PMC7564626 DOI: 10.1177/0963689720947102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The acute cell-mediated immune response presents a significant barrier to
xenotransplantation. Immune-privileged Sertoli cells (SC) can prolong the
survival of co-transplanted cells including xenogeneic islets, hepatocytes, and
neurons by protecting them from immune rejection. Additionally, SC survive as
allo- and xenografts without the use of any immunosuppressive drugs suggesting
elucidating the survival mechanism(s) of SC could be used to improve survival of
xenografts. In this study, the survival and immune response generated toward
neonatal pig SC (NPSC) or neonatal pig islets (NPI), nonimmune-privileged
controls, was compared after xenotransplantation into naïve Lewis rats without
immune suppression. The NPSC survived throughout the study, while NPI were
rejected within 9 days. Analysis of the grafts revealed that macrophages and T
cells were the main immune cells infiltrating the NPSC and NPI grafts. Further
characterization of the T cells within the grafts indicated that the NPSC grafts
contained significantly more cluster of differentiation 4 (CD4) and cluster of
differentiation 8 (CD8) regulatory T cells (Tregs) at early time points than the
NPI grafts. Additionally, the presence of increased amounts of interleukin 10
(IL-10) and transforming growth factor (TGF) β and decreased levels of tumor
necrosis factor (TNF) α and apoptosis in the NPSC grafts compared to NPI grafts
suggests the presence of regulatory immune cells in the NPSC grafts. The NPSC
expressed several immunoregulatory factors such as TGFβ, thrombospondin-1
(THBS1), indoleamine-pyrrole 2,3-dioxygenase, and galectin-1, which could
promote the recruitment of these regulatory immune cells to the NPSC grafts. In
contrast, NPI grafts had fewer Tregs and increased apoptosis and inflammation
(increased TNFα, decreased IL-10 and TGFβ) suggestive of cytotoxic immune cells
that contribute to their early rejection. Collectively, our data suggest that a
regulatory graft environment with regulatory immune cells including CD4 and
CD8 Tregs in NPSC grafts could be attributed to the prolonged survival of the
NPSC xenografts.
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Affiliation(s)
- Gurvinder Kaur
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Department of Medical Education, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Kandis Wright
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Payal Mital
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Taylor Hibler
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Jonathan M Miranda
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Lea Ann Thompson
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Katelyn Halley
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Jannette M Dufour
- Department of Cell Biology and Biochemistry, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA.,Department of Medical Education, 12343Texas Tech University Health Sciences Center, Lubbock, TX, USA
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Niu D, Ma X, Yuan T, Niu Y, Xu Y, Sun Z, Ping Y, Li W, Zhang J, Wang T, Church GM. Porcine genome engineering for xenotransplantation. Adv Drug Deliv Rev 2021; 168:229-245. [PMID: 32275950 DOI: 10.1016/j.addr.2020.04.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/28/2020] [Accepted: 04/06/2020] [Indexed: 02/06/2023]
Abstract
The extreme shortage of human donor organs for treatment of patients with end-stage organ failures is well known. Xenotransplantation, which might provide unlimited organ supply, is a most promising strategy to solve this problem. Domestic pigs are regarded as ideal organ-source animals owing to similarity in anatomy, physiology and organ size to humans as well as high reproductive capacity and low maintenance cost. However, several barriers, which include immune rejection, inflammation and coagulative dysfunctions, as well as the cross-species transmission risk of porcine endogenous retrovirus, blocked the pig-to-human xenotransplantation. With the rapid development of genome engineering technologies and the potent immunosuppressive medications in recent years, these barriers could be eliminated through genetic modification of pig genome together with the administration of effective immunosuppressants. A number of candidate genes involved in the regulation of immune response, inflammation and coagulation have been explored to optimize porcine xenograft survival in non-human primate recipients. PERV inactivation in pigs has also been accomplished to firmly address the safety issue in pig-to-human xenotransplantation. Many encouraging preclinical milestones have been achieved with some organs surviving for years. Therefore, the clinical trials of some promising organs, such as islet, kidney and heart, are aimed to be launched in the near future.
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Affiliation(s)
- Dong Niu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P.R. China
| | - Xiang Ma
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australian Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Laboratory for Animal Health Inspection & Internet Technology, College of Animal Science and Technology & College of Veterinary Medicine of Zhejiang A&F University, Hangzhou, P.R. China
| | - Taoyan Yuan
- Institute of Animal Husbandry and Veterinary Science, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310021, China
| | - Yifan Niu
- Nanjing Kgene Genetic Engineering Co., Ltd, Nanjing, Jiangsu 211300, China
| | - Yibin Xu
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhongxin Sun
- Cosmetic & Plastic Surgery Department, Hangzhou First People's Hospital, Hangzhou, Zhejiang 310006, China
| | - Yuan Ping
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Weifen Li
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jufang Zhang
- Cosmetic & Plastic Surgery Department, Hangzhou First People's Hospital, Hangzhou, Zhejiang 310006, China.
| | - Tao Wang
- Nanjing Kgene Genetic Engineering Co., Ltd, Nanjing, Jiangsu 211300, China.
| | - George M Church
- Department of Genetics, Harvard Medical School, Boston, MA 02115, USA; Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, MA 02138, USA.
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Yu XH, Deng WY, Jiang HT, Li T, Wang Y. Kidney xenotransplantation: Recent progress in preclinical research. Clin Chim Acta 2020; 514:15-23. [PMID: 33301767 DOI: 10.1016/j.cca.2020.11.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 11/26/2020] [Accepted: 11/30/2020] [Indexed: 01/23/2023]
Abstract
Kidney transplantation is the most effective treatment for end-stage renal disease, but is limited by the increasing shortage of deceased and living human donor kidneys. Xenotransplantation using pig organs provides the possibility to resolve the issue of organ supply shortage and is regarded as the next great medical revolution. In the past five years, there have been sequential advances toward the prolongation of life-supporting pig kidney xenograft survival in non-human primates, with the longest survival being 499 days. This progress is due to the growing availability of pigs with multi-layered genetic modifications to overcome the pathobiological barriers and the application of a costimulation blockade-based immunosuppressive regimen. These encouraging results bring the hope to initiate the clinical trials of pig kidney transplantation in the near future. In this review, we summarized the latest advances regarding pig kidney xenotransplantation in preclinical models to provide a basis for future investigation and potential clinical translation.
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Affiliation(s)
- Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; The Transplantation Institute of Hainan Medical University, Haikou, Hainan 460106, China
| | - Wen-Yi Deng
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; The Transplantation Institute of Hainan Medical University, Haikou, Hainan 460106, China
| | - Hong-Tao Jiang
- Department of Organ Transplantation, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; The Transplantation Institute of Hainan Medical University, Haikou, Hainan 460106, China
| | - Tao Li
- Department of Organ Transplantation, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; The Transplantation Institute of Hainan Medical University, Haikou, Hainan 460106, China
| | - Yi Wang
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; Department of Organ Transplantation, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China; The Transplantation Institute of Hainan Medical University, Haikou, Hainan 460106, China.
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6
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Pan D, Liu T, Lei T, Zhu H, Wang Y, Deng S. Progress in multiple genetically modified minipigs for xenotransplantation in China. Xenotransplantation 2019; 26:e12492. [PMID: 30775816 DOI: 10.1111/xen.12492] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2019] [Indexed: 12/18/2022]
Abstract
Pig-to-human organ transplantation provides an alternative for critical shortage of human organs worldwide. Genetically modified pigs are promising donors for xenotransplantation as they show many anatomical and physiological similarities to humans. However, immunological rejection including hyperacute rejection (HAR), acute humoral xenograft rejection (AHXR), immune cell-mediated rejection, and other barriers associated with xenotransplantation must be overcome with various strategies for the genetic modification of pigs. In this review, we summarize the outcomes of genetically modified and cloned pigs achieved by Chinese scientists to resolve the above-mentioned problems in xenotransplantation. It is now possible to knockout several porcine genes associated with the expression of sugar residues, antigens for (naturally) existing antibodies in humans, including GGTA1, CMAH, and β4GalNT2, and thereby preventing the antigen-antibody response. Moreover, insertion of human complement- and coagulation-regulatory transgenes, such as CD46, CD55, CD59, and hTBM, can further overcome effects of the humoral immune response and coagulation dysfunction, while expression of regulatory factors of immune responses can inhibit the adaptive immune rejection. Furthermore, transgenic strategies have been developed by Chinese scientists to reduce the potential risk of infections by endogenous porcine retroviruses (PERVs). Breeding of multi-gene low-immunogenicity pigs in China is also presented in this review. Lastly, we will briefly mention the preclinical studies on pig-to-non-human primate xenotransplantation conducted in several centers in China.
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Affiliation(s)
- Dengke Pan
- Organ Transplant and Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of an Transplant Science & Sichuan Provincial People's Hospital, Chengdu, China
| | - Ting Liu
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Tiantian Lei
- School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Huibin Zhu
- Chengdu Clonorgan Biotechnology Co., LTD, Chengdu, China
| | - Yi Wang
- Health Management Center, Sichuan Academy of Medical Science & Sichuan Provincial People's Hospital, Chengdu, China
| | - Shaoping Deng
- Organ Transplant and Clinical Immunology Translational Medicine Key Laboratory of Sichuan Province, Sichuan Academy of an Transplant Science & Sichuan Provincial People's Hospital, Chengdu, China
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Plege-Fleck A, Lieke T, Römermann D, Düvel H, Hundrieser J, Buermann A, Kraus L, Klempnauer J, Schwinzer R. Pig to rat cell transplantation: reduced cellular and antibody responses to xenografts overexpressing PD-L1. Xenotransplantation 2014; 21:533-42. [DOI: 10.1111/xen.12121] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/28/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Annegret Plege-Fleck
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Thorsten Lieke
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Dorothee Römermann
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Heike Düvel
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Joachim Hundrieser
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Anna Buermann
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Lilli Kraus
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Jürgen Klempnauer
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
| | - Reinhard Schwinzer
- Transplant Laboratory; Department of General-, Visceral-, and Transplantation Surgery; Hannover Medical School; Hannover Germany
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Fasler-Kan E, Barteneva NS, Ketterer S, Wunderlich K, Reschner A, Nurzhanova A, Flammer J, Huwyler J, Meyer P. Human cytokines activate JAK-STAT signaling pathway in porcine ocular tissue. Xenotransplantation 2013; 20:469-80. [PMID: 24289470 PMCID: PMC4235432 DOI: 10.1111/xen.12070] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2013] [Accepted: 09/20/2013] [Indexed: 12/15/2022]
Abstract
Background The JAK/STAT (Janus Tyrosine Kinase, Signal Transducers and Activators of Transcription) pathway is associated with cytokine or growth factor receptors and it is critical for growth control, developmental regulation and homeostasis. The use of porcine ocular cells as putative xenotransplants appears theoretically possible. The aim of this study was to investigate the response of various porcine ocular cells in vitro to human cytokines in regard to the activation of JAK-STAT signaling pathways. Methods Porcine lens epithelial cells, pigmented iris epithelial cells and pigmented ciliary body cells were used in this study. These cells were isolated from freshly enucleated porcine eyes by enzymatic digestion. Cultured cells between passages 3–8 were used in all experiments. Electromobility shift assay (EMSA), proliferation assay, immunofluorescence staining and flow cytometry were used to evaluate the JAK-STAT signaling pathway in these cells. Results JAK/STAT signaling pathways could be activated in porcine pigmented epithelial ciliary body cells, in pigmented iris epithelial cells and in lens epithelial cells in response to porcine and human interferons and cytokines. All cells showed very strong STAT1 activation upon stimulation with porcine interferon-gamma. Porcine ocular cells also respond to human cytokines; IFN-alpha induced strong activation of STAT1 in EMSA, flow cytometry and immunofluorescence experiments whereas activation of STAT3 was less strong in EMSA, but strong in flow cytometry and immunofluorescence. Human recombinant IL-6 activated STAT3 and human IL-4 activated STAT6. With the help of immunofluorescence assay and flow cytometry we observed nuclear localization of STAT proteins after activation of porcine ocular cells with cytokines and interferons. Human IFN-α had an inhibitory effect on porcine ocular cells in proliferation assays. Conclusion Our study demonstrated that some types of human cytokines and interferon activate intracellular JAK-STAT signaling pathways in porcine ocular cells. We hypothesize that direct stimulation of the JAK-STAT pathway in porcine cells in response to human cytokines will lead to complications or failure, if pig-to-human ocular tissue xenotransplantation were to be carried out. For successful xenotransplantation among other obstacles there must be new approaches developed to regulate signaling pathways.
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Affiliation(s)
- Elizaveta Fasler-Kan
- Department of Biomedicine, University of Basel and University Hospital Basel, Basel, Switzerland; Institute of Chemistry and Bioanalytics, University of Applied Sciences Northwestern Switzerland, Muttenz, Switzerland
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Abstract
PURPOSE OF REVIEW Immunological barriers still preclude clinical xenotransplantation. The protective role of CD4(+)CD25(+)Foxp3(+) T-regulatory cells (Treg) in allotransplantation is well described and, therefore, could represent a promising therapeutical tool for xenotransplantation. This review addresses the latest findings on Treg in xenotransplantation research. RECENT FINDINGS In vivo, costimulation blockade-based strategies including anti-CD154 monoclonal antibodies (mAbs) in combination with rapamycin or anti-LFA-1 mAb prolonged both concordant and discordant islets xenografts survival in a Treg-dependent manner. In vitro, IL-10 secretion was shown to be critical for the suppression of xenogeneic responses mediated by Treg. Moreover, transgenic expression of inducible costimulator-immunoglobulin or PD-L1 on porcine endothelial cells inhibited human T-cell proliferation in vitro and was associated with the induction of Treg and IL-10 secretion. CXCR3 mediated the recruitment of Treg to pig endothelium. Finally, the recruitment of human Treg was enhanced by the immobilization of human CCL17 on pig endothelium. SUMMARY There is increasing evidence for the potential of CD4(+)CD25(+)Foxp3(+) Treg to protect xenografts. Induction of Treg in recipients and/or recruitment of human Treg to pig endothelium may represent novel strategies to prevent cell-mediated rejection in pig-to-human xenotransplantation.
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Watson CJE, Dark JH. Organ transplantation: historical perspective and current practice. Br J Anaesth 2012; 108 Suppl 1:i29-42. [PMID: 22194428 DOI: 10.1093/bja/aer384] [Citation(s) in RCA: 145] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Over the course of the last century, organ transplantation has overcome major technical limitations to become the success it is today. The breakthroughs include developing techniques for vascular anastomoses, managing the immune response (initially by avoiding it with the use of identical twins and subsequently controlling it with chemical immunosuppressants), and devising preservation solutions that enable prolonged periods of ex vivo storage while preserving function. One challenge that has remained from the outset is to overcome the shortage of suitable donor organs. The results of organ transplantation continue to improve, both as a consequence of the above innovations and the improvements in peri- and postoperative management. This review describes some of the achievements and challenges of organ transplantation.
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Affiliation(s)
- C J E Watson
- University Department of Surgery, NIHR Cambridge Biomedical Research Centre, Addenbrooke's Hospital, Cambridge CB2 0QQ, UK.
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11
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Koshika T, Phelps C, Fang J, Lee SE, Fujita M, Ayares D, Cooper DKC, Hara H. Relative efficiency of porcine and human cytotoxic T-lymphocyte antigen 4 immunoglobulin in inhibiting human CD4+ T-cell responses co-stimulated by porcine and human B7 molecules. Immunology 2012; 134:386-97. [PMID: 22043861 DOI: 10.1111/j.1365-2567.2011.03496.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
α1,3-Galactosyltransferase gene-knockout pigs transgenic for porcine cytotoxic T-lymphocyte antigen 4 immunoglobulin (pCTLA4-Ig) have been produced to reduce T-cell-mediated rejection following xenotransplantation. The level of soluble pCTLA4-Ig in their blood was greatly in excess of the therapeutic level in patients, rendering the pigs immune-incompetent. Soluble pCTLA4-Ig produced by these transgenic pigs was evaluated for binding to porcine and human (h) B7 molecules, and for its inhibitory effect on allogeneic and xenogeneic human T-cell responses. Porcine CTLA4-Ig-expressing peripheral blood mononuclear cells (PBMCs) and aortic endothelial cells (AECs) were evaluated for their direct inhibitory effect on hCD4+ T-cell responses. Soluble pCTLA4-Ig and purified hCTLA4-Ig showed similar binding to pB7 molecules, but pCTLA4-Ig showed significantly less binding to hB7 molecules. The pCTLA4-Ig and hCTLA4-Ig inhibited the response of hCD4+ T cells to pAECs equally, but pCTLA4-Ig was less successful in inhibiting the human allogeneic response. The hCD4+ T-cell response to PBMCs from pCTLA4-Ig pigs was significantly lower than that of non-pCTLA4-Ig pigs. Although pCTLA4-Ig was detected in the cytoplasm of pCTLA4-Ig-expressing pAECs, only a minimal level of soluble pCTLA4-Ig was detected in the supernatant during culture, and pCTLA4-Ig-expressing pAECs did not inhibit the xenogeneic direct human T-cell response. High-level tissue-specific production of pCTLA4-Ig may be required for sufficient immunosuppression for organ or cell (e.g., islets) transplantation.
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Affiliation(s)
- Tadatsura Koshika
- Department of Surgery, Thomas E. Starzl Transplantation Institute, University of Pittsburgh, PA, USA.
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13
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Gock H, Nottle M, Lew AM, d'Apice AJ, Cowan P. Genetic modification of pigs for solid organ xenotransplantation. Transplant Rev (Orlando) 2011; 25:9-20. [DOI: 10.1016/j.trre.2010.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 08/13/2010] [Accepted: 10/01/2010] [Indexed: 10/18/2022]
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Abstract
PURPOSE OF REVIEW Cellular human antipig immune responses are increasingly recognized as an important barrier to successful clinical xenotransplantation. This review addresses the role of monocytes/macrophages, natural killer (NK) cells, and T cells in xenograft rejection. We focus on the receptor-ligand interactions that regulate the responses of these cells to porcine tissues and thus could be targets for immunomodulation. RECENT FINDINGS Activation of human monocytes by pig cells is partly due to the incapacity of porcine ligands to bind to inhibitory receptors such as signal regulatory protein alpha. Porcine UL16-binding protein 1 can functionally interact with human NK group 2D protein, thereby contributing to human NK cell activity. Transgenic pigs overexpressing human leukocyte antigen class E were generated. Cells from these pigs induced diminished NK-cell lysis, suggesting that human leukocyte antigen class E expression compensates for the inability of porcine ligands to bind to the inhibitory CD94/NK group 2A receptor on human NK cells. A new concept for the modulation of antipig T-cell reactivity may result from the finding that porcine antigen-presenting cells that overexpress human negative costimulatory PD ligands also induce diminished responses of human T cells. SUMMARY Disruption of stimulatory receptor-ligand interactions (e.g. by blocking antibodies or 'knockout/down' technologies) combined with transgenic overexpression of inhibitory ligands in porcine cells and tissues could be an effective approach to downregulate human antipig cellular immune responses.
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Current world literature. Curr Opin Organ Transplant 2010; 15:254-61. [PMID: 20351662 DOI: 10.1097/mot.0b013e328337a8db] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pepper AR, Gall C, Mazzuca DM, Melling CWJ, White DJG. Diabetic rats and mice are resistant to porcine and human insulin: flawed experimental models for testing islet xenografts. Xenotransplantation 2010; 16:502-10. [PMID: 20042050 DOI: 10.1111/j.1399-3089.2009.00548.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Islet transplantation is potentially a promising therapy for the restoration of carbohydrate control to diabetic patients. However, the global application of islet transplantation requires a ubiquitous source of beta cells. The xenotransplantation of porcine islets would provide such a source. Success in porcine islet xenografting has been achieved in diabetic primates. However, there are few reports of reversal of diabetes with porcine islet xenografts in rodent models of diabetes, relative to the number of successful rodent experiments performed as allografts. Here we report for the first time the inability of porcine (and human) insulin to control blood glucose levels in diabetic rodents determined by a series of dose escalating studies. METHODS Insulin was administered intravenously to streptozotocin induced diabetic Lewis rats, Balb/c and athymic Balb/c mice (n = 5 per group) at the following doses: Group I "physiological dose" (pd) of 0.16 U/kg for a total dose of 40 mU to a 250 g rat. Group II received 0.64 U/kg (4xpd), group III 1.6 U/kg (10xpd) and group IV 6.4 U/kg (40xpd). Blood glucose levels were monitored in each animal at seven time points: 0 (pre-injection), 10 min, 20 min, 30 min, 45 min, 1 h, 1.5 h, 2 h and 3 h post-injection. Serum insulin levels were also determined. RESULTS Diabetic Lewis rats achieved a maximum reduction in blood glucose from 22.1 +/- 1.8mmol/l to 8.0 +/- 3.1 mmol/l (a 63.7% reduction), 90 minutes post-injection of 6.4 U/kg dose of porcine insulin (40xpd). Human insulin was less effective at reducing blood glucose levels in rats than porcine insulin (P < 0.001). Porcine insulin reduced blood glucose levels in Balb/c mice from a mean of 18.2 +/- 2.1 mmol/l to a hypoglycemic minimum of 1.26 +/- 0.18 mmol/l a reduction of 93.0%, 60 min post-injection of the maximum dose of 6.4 U/kg. Balb/c mice were significantly more responsive to porcine insulin than Lewis rats at doses of 0.64 U/kg (P < 0.001), 1.6 U/kg (P < 0.05) and 6.4 U/kg (P < 0.001). Athymic Balb/c nude mice reached a maximum reduction in blood glucose from 21.6 +/- 1.8 mmol/l to 3.6 +/- 0.9 mmol/l (a 83.4% reduction) 120 min post-injection at a dose of 6.4 U/kg. Overall, athymic Balb/c nude mice were more resistant to porcine insulin than immunocompetent Balb/c mice at doses of 0.64 U/kg (P < 0.001), 1.6 U/kg (P < 0.001) and 6.4 U/kg (P < 0.05). Insulin diluent alone marginally increased blood glucose levels in all animals tested. CONCLUSIONS Our results suggest that restoration of normoglycemia in diabetic rodents is not ideal for testing porcine islets xenografts since the reversals of diabetes in these species requires 20 to 40 times the dose of porcine insulin used in humans.
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Affiliation(s)
- Andrew R Pepper
- Department of Pathology, University of Western Ontario, London, Canada
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Schneider MKJ, Seebach JD. Xenotransplantation literature update: May-October, 2009. Xenotransplantation 2010; 16:555-62. [PMID: 20042055 DOI: 10.1111/j.1399-3089.2009.00561.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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18
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Abstract
In recent years the development of novel immunosuppressive strategies and new lines of engineered pigs have enabled improved xenograft survival in the clinically-relevant pig-to-primate models (especially in islet xenotransplantation). Furthermore, researchers have now developed appropriate biomolecular tools to address rapidly the remaining barriers and render organs from source pigs more "compatible" with man. Efficacy has been the main focus of the research conducted in the last few years. However, other fundamental issues, such as those regarding the physiology, the safety, the ethics and regulatory aspects of xenotransplantation, will need to be addressed satisfactorily prior to proceeding with clinical xenotransplantation trials.
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