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Li S, Anwar IJ, Canning AJ, Vo-Dinh T, Kirk AD, Xu H. Xenorecognition and costimulation of porcine endothelium-derived extracellular vesicles in initiating human porcine-specific T cell immune responses. Am J Transplant 2023; 23:904-919. [PMID: 37054891 PMCID: PMC10330644 DOI: 10.1016/j.ajt.2023.04.006] [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: 10/26/2022] [Revised: 04/02/2023] [Accepted: 04/04/2023] [Indexed: 04/15/2023]
Abstract
Porcine vascular endothelial cells (PECs) form a mechanistic centerpiece of xenograft rejection. Here, we determined that resting PECs release swine leukocyte antigen class I (SLA-I) but not swine leukocyte antigen class-II DR (SLA-DR) expressing extracellular vesicles (EVs) and investigated whether these EVs proficiently initiate xenoreactive T cell responses via direct xenorecognition and costimulation. Human T cells acquired SLA-I+ EVs with or without direct contact to PECs, and these EVs colocalized with T cell receptors. Although interferon gamma-activated PECs released SLA-DR+ EVs, the binding of SLA-DR+ EVs to T cells was sparse. Human T cells demonstrated low levels of proliferation without direct contact to PECs, but marked T cell proliferation was induced following exposure to EVs. EV-induced proliferation proceeded independent of monocytes/macrophages, suggesting that EVs delivered both a T cell receptor signal and costimulation. Costimulation blockade targeting B7, CD40L, or CD11a significantly reduced T cell proliferation to PEC-derived EVs. These findings indicate that endothelial-derived EVs can directly initiate T cell-mediated immune responses, and suggest that inhibiting the release of SLA-I EVs from organ xenografts has the potential to modify the xenograft rejection. We propose a secondary-direct pathway for T cell activation via xenoantigen recognition/costimulation by endothelial-derived EVs.
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Affiliation(s)
- Shu Li
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Imran J Anwar
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA
| | - Aidan J Canning
- Department of Biomedical Engineering, Duke University School of Medicine, Durham, North Carolina, USA
| | - Tuan Vo-Dinh
- Department of Biomedical Engineering, Duke University School of Medicine, Durham, North Carolina, USA
| | - Allan D Kirk
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA; Department of Immunology, Duke University School of Medicine, Durham, North Carolina, USA
| | - He Xu
- Department of Surgery, Duke University School of Medicine, Durham, North Carolina, USA.
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Li S, Xu H, Kirk AD. Modulation of Xenogeneic T-cell Proliferation by B7 and mTOR Blockade of T Cells and Porcine Endothelial Cells. Transplantation 2022; 106:950-962. [PMID: 34387242 PMCID: PMC8850983 DOI: 10.1097/tp.0000000000003920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Activation of porcine endothelial cells (PECs) is the mechanistic centerpiece of xenograft rejection. This study sought to characterize the immuno-phenotype of human T cells in response to PECs and to explore the immuno-modulation of B7 and mammalian target of rapamycin blockade of T cells and/or PECs during xeno-responses. METHODS Rapid memory T-cell (TM) responses to PECs were assessed by an intracellular cytokine staining. T-cell proliferation to PEC with or without belatacept or rapamycin was evaluated by a mixed lymphocyte-endothelial cell reaction (MLER). Additionally, rapamycin-pretreated PECs were used in MLER. Cell phenotypes were analyzed by flow cytometry. RESULTS Tumor necrosis factor-α/interferon-γ producers were detected in CD8+ cells stimulated by human endothelium but not PECs. MLER showed proliferation of CD4+ and CD8+ cells with predominantly memory subsets. Purified memory and naive cells proliferated following PEC stimulation with an increased frequency of TM in PEC-stimulated naive cells. Proliferating cells upregulated programmed cell death-1 (PD-1) and CD2 expression. Belatacept partially inhibited T-cell proliferation with reduced CD2 expression and frequency of the CD8+CD2highCD28- subset. Rapamycin dramatically inhibited PEC-induced T-cell proliferation, and rapamycin-preconditioned PECs failed to induce T-cell proliferation. PD-1 blockade did not restore T-cell proliferation to rapamycin-preconditioned PECs. CONCLUSIONS Humans lack rapid TM-mediated responses to PECs but induce T-cell proliferative responses characterized largely as TM with increasing CD2 and PD-1 expression. B7-CD28 and mammalian target of rapamycin blockade of T cells exhibit dramatic inhibitory effects in altering xeno-proliferating cells. Rapamycin alters PEC xeno-immunogenicity leading to inhibition of xeno-specific T-cell proliferation independent of PD-1-PD ligand interaction.
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Affiliation(s)
- Shu Li
- Department of Surgery, Duke University School of Medicine, Durham, NC, USA
| | - He Xu
- Department of Surgery, Duke University School of Medicine, Durham, NC, USA
| | - Allan D. Kirk
- Department of Surgery, Duke University School of Medicine, Durham, NC, USA
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Porcine to Human Heart Transplantation: Is Clinical Application Now Appropriate? J Immunol Res 2017; 2017:2534653. [PMID: 29238731 PMCID: PMC5697125 DOI: 10.1155/2017/2534653] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/08/2017] [Indexed: 11/24/2022] Open
Abstract
Cardiac xenotransplantation (CXTx) is a promising solution to the chronic shortage of donor hearts. Recent advancements in immune suppression have greatly improved the survival of heterotopic CXTx, now extended beyond 2 years, and life-supporting kidney XTx. Advances in donor genetic modification (B4GALNT2 and CMAH mutations) with proven Gal-deficient donors expressing human complement regulatory protein(s) have also accelerated, reducing donor pig organ antigenicity. These advances can now be combined and tested in life-supporting orthotopic preclinical studies in nonhuman primates and immunologically appropriate models confirming their efficacy and safety for a clinical CXTx program. Preclinical studies should also allow for organ rejection to develop xenospecific assays and therapies to reverse rejection. The complexity of future clinical CXTx presents a substantial and unique set of regulatory challenges which must be addressed to avoid delay; however, dependent on these prospective life-supporting preclinical studies in NHPs, it appears that the scientific path forward is well defined and the era of clinical CXTx is approaching.
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Abstract
Despite their small size and anucleate status, platelets have diverse roles in vascular biology. Not only are platelets the cellular mediator of thrombosis, but platelets are also immune cells that initiate and accelerate many vascular inflammatory conditions. Platelets are linked to the pathogenesis of inflammatory diseases such as atherosclerosis, malaria infection, transplant rejection, and rheumatoid arthritis. In some contexts, platelet immune functions are protective, whereas in others platelets contribute to adverse inflammatory outcomes. In this review, we will discuss platelet and platelet-derived mediator interactions with the innate and acquired arms of the immune system and platelet-vessel wall interactions that drive inflammatory disease. There have been many recent publications indicating both important protective and adverse roles for platelets in infectious disease. Because of this new accumulating data, and the fact that infectious disease continues to be a leading cause of death globally, we will also focus on new and emerging concepts related to platelet immune and inflammatory functions in the context of infectious disease.
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Iwase H, Ezzelarab MB, Ekser B, Cooper DKC. The role of platelets in coagulation dysfunction in xenotransplantation, and therapeutic options. Xenotransplantation 2014; 21:201-20. [PMID: 24571124 DOI: 10.1111/xen.12085] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 01/08/2014] [Indexed: 12/11/2022]
Abstract
Xenotransplantation could resolve the increasing discrepancy between the availability of deceased human donor organs and the demand for transplantation. Most advances in this field have resulted from the introduction of genetically engineered pigs, e.g., α1,3-galactosyltransferase gene-knockout (GTKO) pigs transgenic for one or more human complement-regulatory proteins (e.g., CD55, CD46, CD59). Failure of these grafts has not been associated with the classical features of acute humoral xenograft rejection, but with the development of thrombotic microangiopathy in the graft and/or consumptive coagulopathy in the recipient. Although the precise mechanisms of coagulation dysregulation remain unclear, molecular incompatibilities between primate coagulation factors and pig natural anticoagulants exacerbate the thrombotic state within the xenograft vasculature. Platelets play a crucial role in thrombosis and contribute to the coagulation disorder in xenotransplantation. They are therefore important targets if this barrier is to be overcome. Further genetic manipulation of the organ-source pigs, such as pigs that express one or more coagulation-regulatory genes (e.g., thrombomodulin, endothelial protein C receptor, tissue factor pathway inhibitor, CD39), is anticipated to inhibit platelet activation and the generation of thrombus. In addition, adjunctive pharmacologic anti-platelet therapy may be required. The genetic manipulations that are currently being tested are reviewed, as are the potential pharmacologic agents that may prove beneficial.
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Affiliation(s)
- Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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Iwase H, Ekser B, Hara H, Phelps C, Ayares D, Cooper DKC, Ezzelarab MB. Regulation of human platelet aggregation by genetically modified pig endothelial cells and thrombin inhibition. Xenotransplantation 2013; 21:72-83. [PMID: 24188473 DOI: 10.1111/xen.12073] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 10/02/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND Coagulation disorders remain barriers to successful pig-to-primate organ xenotransplantation. In vitro, we investigated the impact of pig genetic modifications on human platelet aggregation in response to pig aortic endothelial cells (pAEC). METHODS In comparison to human (h)AEC and wild-type (WT) pAEC, the expression of human complement- (CD46, CD55) or coagulation (thrombomodulin [TBM], endothelial protein C receptor [EPCR]) -regulatory proteins on pAEC from WT or α1,3-galactosyltransferase gene-knockout (GTKO) pigs was studied by flow cytometry. Using platelet-aggregometry, human whole blood platelet aggregation was evaluated after co-incubation with various AEC. Further, the inhibitory effect on aggregation of heparin, low molecular weight heparin, and hirudin was assessed. RESULTS Heparin, low molecular weight heparin and hirudin almost completely prevented platelet aggregation induced by WT pAEC. The level of expression of human CD46, CD55, TBM and EPCR on pAEC was comparable to that on hAEC. Platelet aggregation induced by all genetically modified pAEC was significantly less (P < 0.05) than that by WT pAEC (which was 54%). GTKO/CD46/TBM pAEC induced the least platelet aggregation (27%)-a reduction of almost 50%-but this remained significantly greater (P < 0.01) than aggregation induced by hAEC (4%). There was significant positive correlation between reduction of aggregation and TBM or EPCR expression on pAEC (r = 0.89 and r = 0.86, respectively; P < 0.05). Platelet aggregation induced by GTKO/CD46/TBM pAEC in the presence of hirudin (1 IU/ml) was comparable to platelet aggregation induced by hAEC. CONCLUSIONS Genetic modification of pAEC is associated with significant reduction of human platelet aggregation in vitro. With concomitant thrombin inhibition, platelet aggregation was comparable to that stimulated by hAEC.
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Affiliation(s)
- Hayato Iwase
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA
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Byrne GW, Azimzadeh AM, Ezzelarab M, Tazelaar HD, Ekser B, Pierson RN, Robson SC, Cooper DKC, McGregor CGA. Histopathologic insights into the mechanism of anti-non-Gal antibody-mediated pig cardiac xenograft rejection. Xenotransplantation 2013; 20:292-307. [PMID: 25098626 PMCID: PMC4126170 DOI: 10.1111/xen.12050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/31/2013] [Indexed: 01/13/2023]
Abstract
The histopathology of cardiac xenograft rejection has evolved over the last 20 yr with the development of new modalities for limiting antibody-mediated injury, advancing regimens for immune suppression, and an ever-widening variety of new donor genetics. These new technologies have helped us progress from what was once an overwhelming anti-Gal-mediated hyperacute rejection to a more protracted anti-Gal-mediated vascular rejection to what is now a more complex manifestation of non-Gal humoral rejection and coagulation dysregulation. This review summarizes the changing histopathology of Gal- and non-Gal-mediated cardiac xenograft rejection and discusses the contributions of immune-mediated injury, species-specific immune-independent factors, transplant and therapeutic procedures, and donor genetics to the overall mechanism(s) of cardiac xenograft rejection.
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Affiliation(s)
- Guerard W Byrne
- Institute of Cardiovascular Science, University College London, London, UK; Department of Surgery, Mayo Clinic, Rochester, MN, USA
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Charafeddine AH, Kim EJ, Maynard DM, Yi H, Weaver TA, Gunay-Aygun M, Russell M, Gahl WA, Kirk AD. Platelet-derived CD154: ultrastructural localization and clinical correlation in organ transplantation. Am J Transplant 2012; 12:3143-51. [PMID: 22947105 PMCID: PMC3484197 DOI: 10.1111/j.1600-6143.2012.04241.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
CD154 is an immunostimulatory ligand for CD40 that markedly influences alloimmunity. Its presence in platelets suggests that its release and subsequent immune effects are driven by trauma and thus could be relevant following organ transplantation. However, the release of platelet derived CD154 and its consequences have not been investigated in a clinical transplant setting. To better characterize the relationship between platelet activation and CD154 release, we investigated CD154 release by platelets obtained from normal individuals, and patients with two genetic defects that influence platelet granule development. Using these unique patient populations and immune-electron microscopy, we confirmed that CD154 was an alpha granule and not a cell surface protein, and thereafter optimized the methods for its in vivo measurement in humans. We then investigated plasma CD154 levels in kidney and liver transplant recipients and found no evidence that CD154 levels fluctuated systemically as a result of kidney or liver transplant procedures. Paradoxically, we found that kidney transplant patients had significantly lower systemic CD154 levels during episodes of rejection. These data suggest that the immune effects of CD154 are likely mediated through local and not systemic mechanisms, and discourage the use of CD154 as a peripheral biomarker in organ transplantation.
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Affiliation(s)
| | - Eugenia J. Kim
- Emory Transplant Center, Emory University, Atlanta, Georgia, 30322
| | - Dawn M. Maynard
- Medical Genetics Branch, National Human Genome Research Institute, 20892
| | | | | | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, 20892
- Intramural Office of Rare Diseases, Office of the Director, National Institutes of Health, Bethesda, Maryland, 20892
| | - Maria Russell
- Emory Transplant Center, Emory University, Atlanta, Georgia, 30322
| | - William A. Gahl
- Medical Genetics Branch, National Human Genome Research Institute, 20892
| | - Allan D. Kirk
- Emory Transplant Center, Emory University, Atlanta, Georgia, 30322
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Ekser B, Lin CC, Long C, Echeverri GJ, Hara H, Ezzelarab M, Bogdanov VY, Stolz DB, Enjyoji K, Robson SC, Ayares D, Dorling A, Cooper DKC, Gridelli B. Potential factors influencing the development of thrombocytopenia and consumptive coagulopathy after genetically modified pig liver xenotransplantation. Transpl Int 2012; 25:882-96. [PMID: 22642260 DOI: 10.1111/j.1432-2277.2012.01506.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Upregulation of tissue factor (TF) expression on activated donor endothelial cells (ECs) triggered by the immune response (IR) has been considered the main initiator of consumptive coagulopathy (CC). In this study, we aimed to identify potential factors in the development of thrombocytopenia and CC after genetically engineered pig liver transplantation in baboons. Baboons received a liver from either an α1,3-galactosyltransferase gene-knockout (GTKO) pig (n = 1) or a GTKO pig transgenic for CD46 (n = 5) with immunosuppressive therapy. TF exposure on recipient platelets and peripheral blood mononuclear cell (PBMCs), activation of donor ECs, platelet and EC microparticles, and the IR were monitored. Profound thrombocytopenia and thrombin formation occurred within minutes of liver reperfusion. Within 2 h, circulating platelets and PBMCs expressed functional TF, with evidence of aggregation in the graft. Porcine ECs were negative for expression of P- and E-selectin, CD106, and TF. The measurable IR was minimal, and the severity and rapidity of thrombocytopenia were not alleviated by prior manipulation of the IR. We suggest that the development of thrombocytopenia/CC may be associated with TF exposure on recipient platelets and PBMCs (but possibly not with activation of donor ECs). Recipient TF appears to initiate thrombocytopenia/CC by a mechanism that may be independent of the IR.
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Affiliation(s)
- Burcin Ekser
- Thomas E. Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
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10
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Sun ZG, Wang Z, Zhu LM, Fang YS, Yu LZ, Xu H. The Interleukin-2 Receptor α Chain (CD25) Plays an Important Role in Regulating Monocyte-Derived CD40 Expression During Anti-Porcine Cellular Responses. Transplant Proc 2012; 44:1139-42. [PMID: 22564647 DOI: 10.1016/j.transproceed.2012.02.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Page A, Srinivasan S, Singh K, Russell M, Hamby K, Deane T, Sen S, Stempora L, Leopardi F, Price AA, Strobert E, Reimann KA, Kirk AD, Larsen CP, Kean LS. CD40 blockade combines with CTLA4Ig and sirolimus to produce mixed chimerism in an MHC-defined rhesus macaque transplant model. Am J Transplant 2012; 12:115-25. [PMID: 21929643 PMCID: PMC3259212 DOI: 10.1111/j.1600-6143.2011.03737.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In murine models, T-cell costimulation blockade of the CD28:B7 and CD154:CD40 pathways synergistically promotes immune tolerance after transplantation. While CD28 blockade has been successfully translated to the clinic, translation of blockade of the CD154:CD40 pathway has been less successful, in large part due to thromboembolic complications associated with anti-CD154 antibodies. Translation of CD40 blockade has also been slow, in part due to the fact that synergy between CD40 blockade and CD28 blockade had not yet been demonstrated in either primate models or humans. Here we show that a novel, nondepleting CD40 monoclonal antibody, 3A8, can combine with combined CTLA4Ig and sirolimus in a well-established primate bone marrow chimerism-induction model. Prolonged engraftment required the presence of all three agents during maintenance therapy, and resulted in graft acceptance for the duration of immunosuppressive treatment, with rejection resulting upon immunosuppression withdrawal. Flow cytometric analysis revealed that upregulation of CD95 expression on both CD4+ and CD8+ T cells correlated with rejection, suggesting that CD95 may be a robust biomarker of graft loss. These results are the first to demonstrate prolonged chimerism in primates treated with CD28/mTOR blockade and nondepletional CD40 blockade, and support further investigation of combined costimulation blockade targeting the CD28 and CD40 pathways.
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Affiliation(s)
- Andrew Page
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Swetha Srinivasan
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Karnail Singh
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Maria Russell
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Kelly Hamby
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Taylor Deane
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Sharon Sen
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Linda Stempora
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Frank Leopardi
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | | | - Elizabeth Strobert
- The Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322
| | | | - Allan D. Kirk
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Christian P. Larsen
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
| | - Leslie S. Kean
- The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
- Aflac Cancer Center and Blood Disorders Service, Department of Pediatrics and The Emory Transplant Center, Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322
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Kirk AD, Morrell C, Baldwin WM. Platelets influence vascularized organ transplants from start to finish. Am J Transplant 2009; 9:14-22. [PMID: 19067663 PMCID: PMC2692406 DOI: 10.1111/j.1600-6143.2008.02473.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This review relates the basic functions of platelets to specific aspects of organ allograft rejection. Platelet activation can occur in the donor or recipient before transplantation as well as during antibody- and cell-mediated rejection. Biopsies taken during organ procurement from cadaver donors have documented that activated platelets are attached to vascular endothelial cells or leukocytes. In addition, many patients waiting for transplants have activated platelets due to the diseases that lead to organ failure or as a result of interventions used to support patients before and during transplantation. The contribution of platelets to hyperacute rejection of both allografts and xenografts is well recognized. Intravascular aggregates of platelets can also be prominent in experimental and clinical transplants that undergo acute antibody or cell-mediated rejection. In acute rejection, platelets can recruit mononuclear cells by secretion of chemokines. After contact, monocytes, macrophages and T cells interact with platelets through receptor/ligand pairs, including P-selectin/PSGL-1 and CD40/CD154. There is a potential for therapy to inhibit platelet mediated immune stimulation, but it is counterbalanced by the need to maintain coagulation in the perioperative period.
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Affiliation(s)
- A. D. Kirk
- Emory Transplant Center, Department of Surgery, Emory University, Atlanta, GA
| | - C.N. Morrell
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - W. M. Baldwin
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD
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13
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Fang Y, Liu Z, Zhu L, Wang P, Wang Y, Xu H. CD4+ T-cell and monocyte interdependence during discordant xenoimmune responses. Transplant Proc 2008; 40:2764-8. [PMID: 18929856 DOI: 10.1016/j.transproceed.2008.07.118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
This study was designed to examine our hypothesis that human monocytes provide missing constimulatory signals to host CD4+ cells during interactions with porcine endothelial cells (PECs). PECs were isolated from the aorta. Human CD4+ T cells and monocytes were purified from peripheral blood mononuclear cells (PBMCs). A xenogeneic mixed lymphocyte-PEC reaction (xMLER) was performed to determine the proliferation of PBMCs or CD4+ cells in response to PEC. Monocyte-PEC cocultures with or without CD4+ cells were followed by analysis using fluorescence-activated cell scanning (FACS). We evaluated the CD4+ cells proliferation induced by PEC-conditioned monocytes with or without costimulation blockade. xMLER demonstrated strong lymphocyte proliferation in response to PECs. However, purified CD4+ cells showed reduced proliferative responses to PECs when compared with PBMCs. FACS analysis found that CD14+ monocytes up-regulated CD40 and CD80 expressions in the presence of CD4+ cells. PEC-activated but not resting monocytes induced CD4+-cell proliferation, which was inhibited by anti-CD154, anti-CD80, or anti-CD86 antibodies. In summary, human monocytes exposed to PECs are conditioned to up-regulate costimulatory molecules upon exposure to T cells. PEC-conditioned monocytes induced T-cell proliferation by indirect presentation. Costimulation blockade inhibited T-cell proliferation induced by PEC-conditioned monocytes. Our findings suggested that monocytes play an important role in indirect xenoantigen presentation, providing costimulation to T cells. This interaction can occur distant from the initial site of xenoantigen, but monocytes remaide void of costimulatory signals until their interaction with T cells.
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Affiliation(s)
- Y Fang
- Department of Transplantation, Jinan City Central Hospital, PR China
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14
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Expression of tissue factor and initiation of clotting by human platelets and monocytes after incubation with porcine endothelial cells. Transplantation 2008; 86:702-9. [PMID: 18791452 DOI: 10.1097/tp.0b013e31818410a3] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Intravascular thrombosis remains a major barrier to successful pig-to-primate xenotransplantation. However, the precise factors initiating thrombosis are unknown. In this study, we investigated the contribution of recipient platelets and monocytes. METHODS Primary pig aortic endothelial cells (PAECs) were incubated with combinations of fresh or heat-inactivated human plasma, platelets, or monocytes, after which they were separated and analyzed individually by flow cytometry for tissue factor (TF) expression and for their ability to clot recalcified normal or factor-VII-deficient plasma. RESULTS Procoagulant porcine TF was induced in PAECs only by fresh human plasma, and not by heat-inactivated plasma, platelets, or monocytes. In contrast, procoagulant human TF was induced on platelets and monocytes after incubation with PAEC, irrespective of whether the plasma was present or not. In addition, human platelets caused the shedding of procoagulant TF-expressing aggregates from PAEC. CONCLUSIONS This work defines a cell-based in vitro assay system to address complex interactions among PAECs, human platelets, and monocytes. The induction of procoagulant TF on PAECs by fresh human plasma was most likely dependent on xenoreactive natural antibody and complement present in fresh human plasma. In contrast, the shedding of procoagulant platelet-PAEC aggregates, induced by human platelets, and the induction of procoagulant TF on human platelets and monocytes by PAEC, occurred independently of these factors. These results suggest that different mechanisms may contribute to the initiation of thrombosis after xenotransplantation, some of which may not be influenced by the further manipulation of the immune response against pig xenografts.
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15
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Erez O, Romero R, Hoppensteadt D, Fareed J, Chaiworapongsa T, Kusanovic JP, Mazaki-Tovi S, Gotsch F, Than NG, Vaisbuch E, Kim CJ, Espinoza J, Mittal P, Hamill N, Nhan-Chang CL, Mazor M, Hassan S. Premature labor: a state of platelet activation? J Perinat Med 2008; 36:377-87. [PMID: 18958919 PMCID: PMC3163447 DOI: 10.1515/jpm.2008.082] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
OBJECTIVE This study was undertaken to determine whether premature labor is associated with changes in the maternal plasma concentration of soluble CD40 ligand (sCD40L), a marker of platelet activation. METHODS A cross-sectional study included patients in the following groups: 1) non-pregnant (n=21); 2) normal pregnancy (n=71); 3) normal pregnancy at term with (n=67) and without labor (n=88); 4) preterm labor (PTL) with intact membranes (n=136) that was divided into the following sub-groups: 4a) PTL who delivered at term (n=49); 4b) PTL without intra-amniotic infection and/or inflammation (IAI) who delivered preterm (n=54); and 4c) PTL with IAI who delivered preterm (n=33). sCD40L concentrations were measured by ELISA. RESULTS The median maternal plasma sCD40L concentration was higher in pregnant than non-pregnant women (P=0.017). Patients with PTL had a higher median maternal plasma sCD40L concentration than women with normal pregnancies, regardless of the presence or absence of IAI and gestational age at delivery (P<0.001 for all comparisons). IAI was not associated with a higher median maternal plasma concentration of sCD40L. CONCLUSIONS Normal pregnancy is a state in which there is a physiologic increase of sCD40L. PTL was associated with an increased median maternal plasma sCD40L concentration that could not be accounted for by IAI. Thus, our findings suggest that platelet activation occurs during an episode of preterm labor.
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Affiliation(s)
- Offer Erez
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Roberto Romero
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
- Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI, United States, 48201
| | - Debra Hoppensteadt
- Department of Obstetrics and Gynecology, Loyola University Medical Center, Maywood, IL, United States, 60153
| | - Jawed Fareed
- Department of Obstetrics and Gynecology, Loyola University Medical Center, Maywood, IL, United States, 60153
| | - Tinnakorn Chaiworapongsa
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Juan Pedro Kusanovic
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Shali Mazaki-Tovi
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Francesca Gotsch
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
| | - Nandor Gabor Than
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
| | - Edi Vaisbuch
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
| | - Chong Jai Kim
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
- Departments of Pathology, Wayne State University, Detroit, MI, United States, 48201
| | - Jimmy Espinoza
- Perinatology Research Branch, NICHD/NIH/DHHS, Bethesda, MD, United States, 20892
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Pooja Mittal
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Neil Hamill
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Chia-Ling Nhan-Chang
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
| | - Moshe Mazor
- Soroka University Medical Center, Ben Gurion University of the Negev, Beer Sheva, Israel
| | - Sonia Hassan
- Departments of Obstetrics and Gynecology, Wayne State University, Detroit, MI, United States, 48201
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Zhen-Wei X, Jian-Le S, Qi Q, Wen-Wei Z, Xue-Hong Z, Zi-Li Z. Heme oxygenase-1 improves the survival of discordant cardiac xenograft through its anti-inflammatory and anti-apoptotic effects. Pediatr Transplant 2007; 11:850-9. [PMID: 17976119 DOI: 10.1111/j.1399-3046.2007.00701.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
HO-1 is a rate-limiting enzyme in hemoglobin metabolism, and exerts anti-inflammatory as well as anti-apoptotic effects. Previous studies have shown that expression of HO-1 can prolong the survival of concordant transplanted organs. However, little is known about the precise effect and mechanism of HO-1 in discordant xenotransplantation. In this study, we investigated the role of HO-1 in discordant cardiac xenotransplantation. First, HUVECs were used to assess the effect of HO-1 on TNF-alpha-induced apoptosis. Results showed that TNF-alpha induced apoptosis of HUVECs in a dose-dependent manner. Moreover, induction of HO-1 by hemin suppressed TNF-alpha-induced apoptosis. However, the anti-apoptotic action of HO-1 was reversed by SnPP. The up-regulation of HO-1 by hemin treatment significantly prolonged the survival time of discordant cardiac xenograft, greatly reduced the swelling and apoptosis of myocardial cells, interstitial edema, lymphocyte infiltration, and thrombus formation in small vessels. Furthermore, HO-1 overexpression significantly attenuated the serum level of xenoantibody IgM, tissue deposition of IgM and complement 3 (C(3)) in endangium. Finally, HO-1 mitigated CD40L transcription in the xenograft and recipient spleen. These results indicate that the up-regulation of HO-1 can improve the survival of discordant cardiac xenograft by inhibiting apoptosis and alleviating inflammation and thrombosis.
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Affiliation(s)
- Xia Zhen-Wei
- Department of Pediatrics, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
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17
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Charniot JC, Bonnefont-Rousselot D, Albertini JP, Zerhouni K, Dever S, Richard I, Nataf P, Pavie A, Monsuez JJ, Delattre J, Artigou JY. Oxidative stress implication in a new ex-vivo cardiac concordant xenotransplantation model. Free Radic Res 2007; 41:911-8. [PMID: 17654048 DOI: 10.1080/10715760701429775] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Xenotransplantation (XT) reveals a growing interest for the treatment of cardiomyopathy. The major barrier is an acute vascular rejection due to an acute humoral rejection. This pathogenesis is a difficult issue and in order to elaborate means for its prevention, we analysed the implication of oxidative stress (OS) on hearts from mini-pigs followed by reperfusion with either autologous or human blood in an attempt to simulate xenotransplantation. About 14 hearts were studied after a Langendorff blood reperfusion: allografts with autologous blood (n = 7) or xenografts with human blood (n = 7). Blood samples were drawn from the coronary sinus to assess ischemia and OS. In xenografts, arrhythmias occurred more frequently (p < 0.01, left ventricular systolic pressure decreased more significantly (p < 0.05), thiobarbituric acid-reactive substances concentrations increased at 30 min (0.7 +/- 0.1 vs. 2.4 +/- 0.3 mmol/l; p < 0.05) while vitamin A levels decreased (p < 0.05). XT was associated with a significant increase in ischemic injury and OS production. OS might play an eminent role in hyperacute humoral rejection.
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Xu H, Zhang X, Mannon RB, Kirk AD. Platelet-derived or soluble CD154 induces vascularized allograft rejection independent of cell-bound CD154. J Clin Invest 2006; 116:769-74. [PMID: 16498500 PMCID: PMC1378189 DOI: 10.1172/jci27155] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 01/03/2006] [Indexed: 02/05/2023] Open
Abstract
CD154 is a cell surface molecule expressed on activated T cells that binds to CD40, an activating molecule on APCs. Its blockade has been shown to prevent allograft rejection, presumably by interrupting interactions between T cells and APCs. It is known that activated human platelets express and shed CD154 and can induce APC activation and other immune processes in vitro. Here we show that platelet-derived CD154 is sufficient to initiate cardiac allograft rejection independent of any cellular source of this molecule. CD154-KO mice reject cardiac allografts after receiving CD154-expressing human platelets or recombinant CD154 (rCD154) trimers. Treatment with the human CD154-specific mAb 5c8 specifically prevents this induced rejection. Soluble trimers, but not platelets, induce rejection when infused temporally remote from the surgical procedure, suggesting that surgically induced platelet activation is required for CD154 release. Allograft rejection can thus be instigated by activated platelets through CD154. These data implicate platelets as a proximal component of acquired alloimmunity, providing insight into the mechanisms of allograft rejection and the physiological response to trauma in general.
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Affiliation(s)
- He Xu
- Transplantation Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, United States Department of Health and Human Services, Bethesda, Maryland 20892, USA
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Galbusera M, Buelli S, Gastoldi S, Macconi D, Angioletti S, Testa C, Remuzzi G, Morigi M. Activation of porcine endothelium in response to xenogeneic serum causes thrombosis independently of platelet activation. Xenotransplantation 2005; 12:110-20. [PMID: 15693841 DOI: 10.1111/j.1399-3089.2005.00203.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Endothelial cell activation and microvascular thrombosis are hallmarks of hyperacute xenograft rejection. However, the molecular determinants of platelet-endothelial interaction and thrombus formation are poorly understood. This study investigated whether: (i) xenogeneic human serum (HS), as a source of xenoreactive antibodies and complement, activates porcine aortic endothelial cells (PAEC) to promote thrombus formation under high shear stress; (ii) the endothelial adhesive proteins vitronectin receptor and P-selectin are involved in the von Willebrand factor (VWF)-platelet interaction during the thrombotic process under flow; (iii) reactive oxygen species (ROS) are activated by complement and served as intracellular signals for adhesive protein up-regulation. METHODS The PAEC were pre-exposed for 90 min in static conditions to medium plus 10, 20, and 50% HS or 20% porcine serum (PS), as control, then cells were perfused at 50 dynes/cm2 in a parallel plate flow chamber with human blood and area occupied by thrombi was measured. The role of complement in HS-induced thrombus formation was assessed by incubating PAEC with 20% HS in the presence of soluble complement receptor type 1 (sCR1) before blood perfusion. The effect of platelet activation was assessed using human blood treated or not with ADP and then flowed over PAEC pre-exposed to 20% HS or 20% PS as control. To identify the endothelial adhesive proteins involved in thrombus formation PAEC treated with 20% HS were then incubated with anti-vitronectin receptor antibody, anti-P-selectin antibody or P-selectin glycoprotein ligand-1 (PSGL-1), the soluble ligand of P-selectin, before the adhesion assay. Confocal microscopy was used to detect changes in endothelial adhesive protein expression. VWF interaction with platelet receptors GPIb and alphaIIbbeta3 was assessed adding aurin tricarboxylic acid (ATA) and anti-alphaIIbbeta3 antibody to blood before perfusion. The ROS involvement in xenogeneic serum-induced thrombus formation was determined studying the intracellular production of hydrogen peroxide (H2O2). The effect of antioxidants and metal chelators on HS-induced thrombus formation was evaluated treating PAEC with pyrrolidine dithiocarbamate (PDTC) or 1,3-dimethyl-2-thiourea (DMTU) before and during incubation with 20% HS followed by blood perfusion. The effect of antioxidants and sCR1 on ROS generation was investigated treating PAEC with PDTC or DMTU before and during incubation with 20% HS. Intracellular ROS generation was measured by fluorescence spectroscopy using the probe dihydrorhodamine 123 (DHR-123). RESULTS Human serum but not PS caused thrombus formation on PAEC under high shear stress. Blockade of complement activation by sCR1 prevented xenogeneic serum-induced thrombus formation. Activated platelets did not promote thrombus formation on resting endothelium, and did not further increase platelet deposition on xenogeneic serum-treated PAEC. Vitronectin receptor and P-selectin were up-regulated on the endothelial surface by HS. Their functional blockade by specific antibodies prevented platelet deposition and thrombus formation. H2O2 production significantly increased when PAEC were exposed to the xenogeneic condition. Antioxidants and sCR1 completely prevented thrombus formation by reducing excessive ROS production and the expression of vitronectin receptor and P-selectin. CONCLUSIONS Xenogeneic complement induces endothelial cell activation and thrombosis which is independent of platelet activation. Complement deposition elicits a rapid generation of ROS that lead to overexpression of endothelial adhesive molecules instrumental for platelet deposition.
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Affiliation(s)
- Miriam Galbusera
- Mario Negri Institute for Pharmacological Research, Via Gavazzeni, Bergamo, Italy
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Crist SA, Elzey BD, Ludwig AT, Griffith TS, Staack JB, Lentz SR, Ratliff TL. Expression of TNF-related apoptosis-inducing ligand (TRAIL) in megakaryocytes and platelets. Exp Hematol 2005; 32:1073-81. [PMID: 15539085 DOI: 10.1016/j.exphem.2004.07.022] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Revised: 07/16/2004] [Accepted: 07/21/2004] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Platelets are known to play an important role in hemostasis, thrombosis, wound healing, and inflammation. Platelet-induced modulation of inflammation and adaptive immune responses are mediated in part through tumor necrosis factor (TNF) family member ligands, including CD154, Fas ligand, and TNFalpha, that are expressed upon platelet activation. The present study investigated whether platelets and megakaryocytes also express TNF-related apoptosis-inducing ligand (TRAIL), another pro-apoptotic member of the TNF superfamily. MATERIALS AND METHODS Immunoprecipitation, enzyme-linked immunosorbent assay, and flow cytometry were used to assess TRAIL protein expression on isolated platelets, in vitro-derived megakaryocytes and premegakaryocyte cell lines. Reverse-transcription polymerase chain reaction and transient transfection of TRAIL promoter/reporter constructs were used to elucidate mechanisms of TRAIL regulation during megakaryocyte differentiation. TRAIL-dependent cytotoxicity assays were performed to determine if platelet-derived TRAIL induces apoptosis of TRAIL sensitive target cells. RESULTS Activated platelets expressed both membrane-bound and soluble TRAIL. TRAIL was also expressed by megakaryocytes, and in vitro studies showed that TRAIL expression was induced upon megakaryocyte differentiation. TRAIL expression was mediated by increased transcriptional activity of the TRAIL promoter, suggesting lineage-specific regulation of TRAIL during megakaryocyte differentiation. Abundant detergent-extractable, full-length TRAIL protein was observed in the lysates of platelets and megakaryocytes, but only low concentrations of TRAIL were released by nondetergent extraction methods. CONCLUSION The data reported herein show that platelets express TRAIL that is synthesized by megakaryocytes and was expressed by activated platelets. While these data expand the spectrum of TNF family proteins expressed in platelets, the function of platelet-derived TRAIL is not known.
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Affiliation(s)
- Scott A Crist
- Department of Urology, The University of Iowa, Iowa City, Iowa 52242-1089, USA
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Saadi S, Takahashi T, Holzknecht RA, Platt JL. Pathways to acute humoral rejection. THE AMERICAN JOURNAL OF PATHOLOGY 2004; 164:1073-80. [PMID: 14982860 PMCID: PMC1614720 DOI: 10.1016/s0002-9440(10)63194-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Acute humoral rejection, also known as acute vascular rejection, is a devastating condition of organ transplants and a major barrier to clinical application of organ xenotransplantation. Although initiation of acute humoral or vascular rejection is generally linked to the action of antibodies and complement on the graft, other factors such as ischemia, platelets, T cells, natural killer cells, and macrophages have also been implicated. Central to any understanding of the pathogenesis of acute humoral rejection, and to developing means of preventing it, is to know whether these factors injure the graft independently or through one or few pathways. We addressed this question by examining early events in a severe model of vascular rejection in which guinea pig hearts transplanted heterotopically into rats treated with cobra venom factor (CVF) develop disease over 72 hours. The early steps in acute vascular rejection were associated with expression of a set of inflammatory genes, which appeared to be controlled by availability of interleukin (IL)-1. Interruption of IL-1 signaling by IL-1 receptor antagonist (IL-1ra) averted expression of these genes and early tissue changes, including coagulation and influx of inflammatory cells. These findings suggest IL-1 plays an important role in initiation of acute humoral rejection.
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Affiliation(s)
- Soheyla Saadi
- Department of Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA
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Acute vascular rejection/delayed xenograft rejection and consumptive coagulopathy in xenotransplantation. Curr Opin Organ Transplant 2003. [DOI: 10.1097/00075200-200303000-00014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Affiliation(s)
- Soheyla Saadi
- Transplantation Biology, Mayo Clinic, Rochester, MN, USA.
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