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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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Miura S, Habibabady ZA, Pollok F, Connolly M, Pratts S, Dandro A, Sorrells L, Karavi K, Phelps C, Eyestone W, Ayares D, Burdorf L, Azimzadeh A, Pierson RN. Effects of human TFPI and CD47 expression and selectin and integrin inhibition during GalTKO.hCD46 pig lung perfusion with human blood. Xenotransplantation 2022; 29:e12725. [PMID: 35234315 PMCID: PMC10207735 DOI: 10.1111/xen.12725] [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: 09/12/2021] [Revised: 10/30/2021] [Accepted: 12/17/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Loss of barrier function when GalTKO.hCD46 porcine lungs are perfused with human blood is associated with coagulation pathway dysregulation, innate immune system activation, and rapid sequestration of human formed blood elements. Here, we evaluate whether genetic expression of human tissue factor pathway inhibitor (hTFPI) and human CD47 (hCD47), alone or with combined selectin and integrin adhesion pathway inhibitors, delays GalTKO.hCD46 porcine lung injury or modulates neutrophil and platelet sequestration. METHODS In a well-established paired ex vivo lung perfusion model, GalTKO.hCD46.hTFPI.hCD47 transgenic porcine lungs (hTFPI.hCD47, n = 7) were compared to GalTKO.hCD46 lungs (reference, n = 5). All lung donor pigs were treated with a thromboxane synthase inhibitor, anti-histamine, and anti-GPIb integrin-blocking Fab, and were pre-treated with Desmopressin. In both genotypes, one lung of each pair was additionally treated with PSGL-1 and GMI-1271 (P- and E-selectin) and IB4 (CD11b/18 integrin) adhesion inhibitors (n = 6 hTFPI.hCD47, n = 3 reference). RESULTS All except for two reference lungs did not fail within 480 min when experiments were electively terminated. Selectin and integrin adhesion inhibitors moderately attenuated initial pulmonary vascular resistance (PVR) elevation in hTFPI.hCD47 lungs. Neutrophil sequestration was significantly delayed during the early time points following reperfusion and terminal platelet activation was attenuated in association with lungs expressing hTFPI.hCD47, but additional adhesion pathway inhibitors did not show further effects with either lung genotype. CONCLUSION Expression of hTFPI.hCD47 on porcine lung may be useful as part of an integrated strategy to prevent neutrophil adhesion and platelet activation that are associated with xenograft injury. Additionally, targeting canonical selectin and integrin adhesion pathways reduced PVR elevation associated with hTFPI.hCD47 expression, but did not significantly attenuate neutrophil or platelet sequestration. We conclude that other adhesive mechanisms mediate the residual sequestration of human formed blood elements to pig endothelium that occurs even in the context of the multiple genetic modifications and drug treatments tested here.
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Habibabady ZA, Sendil S, Ellett F, Pollok F, Elias GF, French BM, Sun W, Braileanu G, Burdorf L, Irimia D, Pierson RN, Azimzadeh AM. Human erythrocyte fragmentation during ex-vivo pig organ perfusion. Xenotransplantation 2022; 29:e12729. [PMID: 35112383 PMCID: PMC8995366 DOI: 10.1111/xen.12729] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/22/2021] [Accepted: 01/10/2022] [Indexed: 01/25/2023]
Abstract
Platelet sequestration is a common process during organ reperfusion after transplantation. However, instead of lower platelet counts, when using traditional hemocytometers and light microscopy, we observed physiologically implausible platelet counts in the course of ex-vivo lung and liver xenograft organ perfusion studies. We employed conventional flow cytometry (FC) and imaging FC (AMINS ImageStream X) to investigate the findings and found platelet-sized fragments in the circulation that are mainly derived from red blood cell membranes. We speculate that this erythrocyte fragmentation contributes to anemia during in-vivo organ xenotransplant.
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Burdorf L, Laird CT, Harris DG, Connolly MR, Habibabady Z, Redding E, O’Neill NA, Cimeno A, Parsell D, Phelps C, Ayares D, Azimzadeh AM, Pierson RN. Pig-to-baboon lung xenotransplantation: Extended survival with targeted genetic modifications and pharmacologic treatments. Am J Transplant 2022; 22:28-45. [PMID: 34424601 PMCID: PMC10292947 DOI: 10.1111/ajt.16809] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 08/05/2021] [Accepted: 08/05/2021] [Indexed: 01/25/2023]
Abstract
Galactosyl transferase knock-out pig lungs fail rapidly in baboons. Based on previously identified lung xenograft injury mechanisms, additional expression of human complement and coagulation pathway regulatory proteins, anti-inflammatory enzymes and self-recognition receptors, and knock-down of the β4Gal xenoantigen were tested in various combinations. Transient life-supporting GalTKO.hCD46 lung function was consistently observed in association with either hEPCR (n = 15), hTBM (n = 4), or hEPCR.hTFPI (n = 11), but the loss of vascular barrier function in the xenograft and systemic inflammation in the recipient typically occurred within 24 h. Co-expression of hEPCR and hTBM (n = 11) and additionally blocking multiple pro-inflammatory innate and adaptive immune mechanisms was more consistently associated with survival >1 day, with one recipient surviving for 31 days. Combining targeted genetic modifications to the lung xenograft with selective innate and adaptive immune suppression enables prolonged initial life-supporting lung function and extends lung xenograft recipient survival, and illustrates residual barriers and candidate treatment strategies that may enable the clinical application of other organ xenografts.
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Funamoto M, Pierson RN, Nguyen JH, D'Alessandro DA. Surgical and logistical concerns for ex vivo–based perfusion strategies for “donation after circulatory death” multiorgan recovery. JTCVS Tech 2021; 11:49-56. [PMID: 35169736 PMCID: PMC8828966 DOI: 10.1016/j.xjtc.2021.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 11/04/2021] [Indexed: 12/02/2022] Open
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Connolly MR, Kuravi K, Burdorf L, Sorrells L, Morrill B, Cimeno A, Vaught T, Dandro A, Sendil S, Habibabady ZA, Monahan J, Li T, LaMattina J, Eyestone W, Ayares D, Phelps C, Azimzadeh AM, Pierson RN. Humanized von Willebrand factor reduces platelet sequestration in ex vivo and in vivo xenotransplant models. Xenotransplantation 2021; 28:e12712. [PMID: 34657336 PMCID: PMC10266522 DOI: 10.1111/xen.12712] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/05/2021] [Accepted: 09/07/2021] [Indexed: 01/14/2023]
Abstract
The transplantation of organs across species offers the potential to solve the shortage of human organs. While activation of human platelets by human von Willebrand factor (vWF) requires vWF activation by shear stress, contact between human platelets and porcine vWF (pvWF) leads to spontaneous platelet adhesion and activation. This non-physiologic interaction may contribute to the thrombocytopenia and coagulation pathway dysregulation often associated with xenotransplantation of pig organs in nonhuman primates. Pigs genetically modified to decrease antibody and complement-dependent rejection (GTKO.hCD46) were engineered to express humanized pvWF (h*pvWF) by replacing a pvWF gene region that encodes the glycoprotein Ib-binding site with human cDNA orthologs. This modification corrected for non-physiologic human platelet aggregation on exposure to pig plasma, while preserving in vitro platelet activation by collagen. Organs from pigs with h*pvWF demonstrated reduced platelet sequestration during lung (p ≤ .01) and liver (p ≤ .038 within 4 h) perfusion ex vivo with human blood and after pig-to-baboon lung transplantation (p ≤ .007). Residual platelet sequestration and activation were not prevented by the blockade of canonical platelet adhesion pathways. The h*pvWF modification prevents physiologically inappropriate activation of human or baboon platelets by porcine vWF, addressing one cause of the thrombocytopenia and platelet activation observed with xenotransplantation.
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Cozzi E, Schneeberger S, Bellini MI, Berglund E, Böhmig G, Fowler K, Hoogduijn M, Jochmans I, Marckmann G, Marson L, Neuberger J, Oberbauer R, Pierson RN, Reichart B, Scobie L, White C, Naesens M. Organ transplants of the future: planning for innovations including xenotransplantation. Transpl Int 2021; 34:2006-2018. [PMID: 34459040 DOI: 10.1111/tri.14031] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/10/2021] [Accepted: 08/24/2021] [Indexed: 12/15/2022]
Abstract
The future clinical application of animal-to-human transplantation (xenotransplantation) is of importance to society as a whole. Favourable preclinical data relevant to cell, tissue and solid organ xenotransplants have been obtained from many animal models utilizing genetic engineering and protocols of pathogen-free husbandry. Findings have reached a tipping point, and xenotransplantation of solid organs is approaching clinical evaluation, the process of which now requires close deliberation. Such discussions include considering when there is sufficient evidence from preclinical animal studies to start first-in-human xenotransplantation trials. The present article is based on evidence and opinions formulated by members of the European Society for Organ Transplantation who are involved in the Transplantation Learning Journey project. The article includes a brief overview of preclinical concepts and biology of solid organ xenotransplantation, discusses the selection of candidates for first-in-human studies and considers requirements for study design and conduct. In addition, the paper emphasizes the need for a regulatory framework for xenotransplantation of solid organs and the essential requirement for input from public and patient stakeholders.
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Patel PM, Connolly MR, Coe TM, Calhoun A, Pollok F, Markmann JF, Burdorf L, Azimzadeh A, Madsen JC, Pierson RN. Minimizing Ischemia Reperfusion Injury in Xenotransplantation. Front Immunol 2021; 12:681504. [PMID: 34566955 PMCID: PMC8458821 DOI: 10.3389/fimmu.2021.681504] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 08/12/2021] [Indexed: 12/21/2022] Open
Abstract
The recent dramatic advances in preventing "initial xenograft dysfunction" in pig-to-non-human primate heart transplantation achieved by minimizing ischemia suggests that ischemia reperfusion injury (IRI) plays an important role in cardiac xenotransplantation. Here we review the molecular, cellular, and immune mechanisms that characterize IRI and associated "primary graft dysfunction" in allotransplantation and consider how they correspond with "xeno-associated" injury mechanisms. Based on this analysis, we describe potential genetic modifications as well as novel technical strategies that may minimize IRI for heart and other organ xenografts and which could facilitate safe and effective clinical xenotransplantation.
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D'Alessandro D, Pierson RN. Commentary: A long road back to the beginning. J Thorac Cardiovasc Surg 2021; 164:569-570. [PMID: 34509295 PMCID: PMC10176788 DOI: 10.1016/j.jtcvs.2021.08.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 07/29/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022]
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Pierson RN, Hawthorne WJ. Agnès Marie Azimzadeh, Ph.D – “In Memoriam”. Xenotransplantation 2021. [DOI: 10.1111/xen.12689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Pierson RN, Fishman JA, Lewis GD, D'Alessandro DA, Connolly MR, Burdorf L, Madsen JC, Azimzadeh AM. Progress Toward Cardiac Xenotransplantation. Circulation 2020; 142:1389-1398. [PMID: 33017208 DOI: 10.1161/circulationaha.120.048186] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Consistent survival of life-supporting pig heart xenograft recipients beyond 90 days was recently reported using genetically modified pigs and a clinically applicable drug treatment regimen. If this remarkable achievement proves reproducible, published benchmarks for clinical translation of cardiac xenografts appear to be within reach. Key mechanistic insights are summarized here that informed recent pig design and therapeutic choices, which together appear likely to enable early clinical translation.
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Pierson RN, Burdorf L, Madsen JC, Lewis GD, D’Alessandro DA. Pig-to-human heart transplantation: Who goes first? Am J Transplant 2020; 20:2669-2674. [PMID: 32301262 PMCID: PMC9448330 DOI: 10.1111/ajt.15916] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 01/25/2023]
Abstract
Cardiac xenotransplantation has recently taken an important step towards clinical reality. In anticipation of the "first-in-human" heart xenotransplantation trial, we propose a set of patient characteristics that define potential candidates. Our premise is that, to be ethically justified, the risks posed by current state-of-the-art options must outweigh the anticipated risks of a pioneering xenotransplant procedure. Suitable candidates include patients who are at high immunologic risk because of sensitization to alloantigens, including those who have exhibited early onset or accelerated cardiac allograft vasculopathy. In addition, patients should be considered (1) for whom mechanical circulatory support would be prohibitively risky due to a hypercoagulable state, a contraindication to anticoagulation, or restrictive physiology; (2) with severe biventricular dysfunction predicting unsuccessful univentricular left heart support; and (3) adults with complex congenital heart disease. In conclusion, because the published preclinical benchmark for clinical translation of heart xenotransplantation appears within reach, carefully and deliberately defining appropriate trial participants is timely as the basis for ethical clinical trial design.
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Naito N, Funamoto M, Pierson RN, D'Alessandro DA. First clinical use of a novel hypothermic storage system for a long-distance donor heart procurement. J Thorac Cardiovasc Surg 2019; 159:e121-e123. [PMID: 31420150 DOI: 10.1016/j.jtcvs.2019.05.085] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 05/22/2019] [Accepted: 05/31/2019] [Indexed: 11/17/2022]
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Hawthorne WJ, Cowan PJ, Bühler LH, Yi S, Bottino R, Pierson RN, Ahn C, Azimzadeh A, Cozzi E, Gianello P, Lakey JRT, Luo M, Miyagawa S, Mohiuddin MM, Park CG, Schuurman HJ, Scobie L, Sykes M, Tector J, Tönjes RR, Wolf E, Nuñez JR, Wang W. Third WHO Global Consultation on Regulatory Requirements for Xenotransplantation Clinical Trials, Changsha, Hunan, China December 12-14, 2018: "The 2018 Changsha Communiqué" The 10-Year Anniversary of The International Consultation on Xenotransplantation. Xenotransplantation 2019; 26:e12513. [PMID: 30980428 DOI: 10.1111/xen.12513] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hawthorne WJ, Cowan PJ, Bühler LH, Yi S, Bottino R, Pierson RN, Ahn C, Azimzadeh A, Cozzi E, Gianello P, Lakey JRT, Luo M, Miyagawa S, Mohiuddin MM, Park C, Schuurman H, Scobie L, Sykes M, Tector J, Tönjes RR, Wolf E, Nuñez JR, Wang W. Cover Image, Volume 26, Issue 2. Xenotransplantation 2019. [DOI: 10.1111/xen.12520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kotler DP, Wang J, Pierson RN. Studies of Body Composition in Patients with the Acquired Immunodeficiency Syndrome. Food Nutr Bull 2018. [DOI: 10.1177/156482658901100120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Burdorf L, Harris D, Dahi S, Laird C, Zhang T, Ali F, Shah A, Thompson M, Braileanu G, Cheng X, Sievert E, Schwartz E, Sendil S, Parsell DM, Redding E, Phelps CJ, Ayares DL, Azimzadeh AM, Pierson RN. Thromboxane and histamine mediate PVR elevation during xenogeneic pig lung perfusion with human blood. Xenotransplantation 2018; 26:e12458. [PMID: 30175863 DOI: 10.1111/xen.12458] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/29/2018] [Accepted: 07/20/2018] [Indexed: 01/18/2023]
Abstract
BACKGROUND Elevated pulmonary vascular resistance (PVR), platelet adhesion, coagulation activation, and inflammation are prominent features of xenolung rejection. Here, we evaluate the role of thromboxane and histamine on PVR, and their contribution to other lung xenograft injury mechanisms. METHODS GalTKO.hCD46 single pig lungs were perfused ex vivo with fresh heparinized human blood: lungs were either treated with 1-Benzylimidazole (1-BIA) combined with histamine receptor blocker famotidine (n = 4) or diphenhydramine (n = 6), 1-BIA alone (n = 6) or were left untreated (n = 9). RESULTS Six of the nine control experiments (GalTKO.hCD46 untreated), "survived" until elective termination at 4 hours. Without treatment, initial PVR elevation within the first 30 minutes resolved partially over the following hour, and increased progressively during the final 2 hours of perfusion. In contrast, 1-BIA, alone or in addition to either antihistamine treatment, was associated with low stable PVR. Combined treatments significantly lowered the airway pressure when compared to untreated reference. Although platelet and neutrophil sequestration and coagulation cascade activation were not consistently altered by any intervention, increased terminal wet/dry weight ratio in untreated lungs was significantly blunted by combined treatments. CONCLUSION Combined thromboxane and histamine pathway blockade prevents PVR elevation and significantly inhibits loss of vascular barrier function when GalTKO.hCD46 lungs are perfused with human blood. Platelet activation and platelet and neutrophil sequestration persist in all groups despite efficient complement regulation, and appear to occur independent of thromboxane and histamine antagonism. Our work identifies thromboxane and histamine as key mediators of xenolung injury and defines those pathways as therapeutic targets to achieve successful xenolung transplantation.
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Loeb KL, Radnitz C, Keller KL, Schwartz MB, Zucker N, Marcus S, Pierson RN, Shannon M, DeLaurentis D. The Application of Optimal Defaults to Improve Elementary School Lunch Selections: Proof of Concept. THE JOURNAL OF SCHOOL HEALTH 2018; 88:265-271. [PMID: 29498061 DOI: 10.1111/josh.12611] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 01/14/2017] [Accepted: 12/14/2017] [Indexed: 06/08/2023]
Abstract
BACKGROUND In this study, we applied behavioral economics to optimize elementary school lunch choices via parent-driven decisions. Specifically, this experiment tested an optimal defaults paradigm, examining whether strategically manipulating the health value of a default menu could be co-opted to improve school-based lunch selections. METHODS The design was a randomized comparison of optimal versus suboptimal (standard) default lunch menus for all first-graders in a school district for a period of 1 week. We hypothesized that making the default lunch option healthier, while providing parents the opportunity to access and choose from the standard school menu for their child, would yield more frequent selection of healthier items than when the default option was suboptimal. RESULTS Overall, 127 (93%) first-grade children's families participated. Among those families randomized to receive the nutritionally optimized default menu, all but one remained with these options; of those parents randomized to the standard menu (suboptimal default), all parents remained with these options (Χ2 = 123.06, df = 1, p < .001). CONCLUSIONS The mere positioning of choices, without restricting options, significantly affected which menu items the children received during the test period. Results are proof of concept for a strategy to increase health-promoting school lunch content, procedures, and policies.
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French BM, Sendil S, Sepuru KM, Ranek J, Burdorf L, Harris D, Redding E, Cheng X, Laird C, Zhao Y, Cerel B, Rajarathnam K, Pierson RN, Azimzadeh AM. Interleukin-8 mediates neutrophil-endothelial interactions in pig-to-human xenogeneic models. Xenotransplantation 2018; 25:e12385. [PMID: 29427404 PMCID: PMC5899681 DOI: 10.1111/xen.12385] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 12/21/2017] [Accepted: 01/09/2018] [Indexed: 01/13/2023]
Abstract
BACKGROUND Human neutrophils are sequestered by pig lung xenografts within minutes during ex vivo perfusion. This phenomenon is not prevented by pig genetic modifications that remove xeno-antigens or added human regulatory molecules intended to down-regulate activation of complement and coagulation pathways. This study investigated whether recipient and donor interleukin-8 (IL-8), a chemokine known to attract and activate neutrophils during inflammation, is elaborated in the context of xenogeneic injury, and whether human or pig IL-8 promote the adhesion of human neutrophils in in vitro xenograft models. METHODS Plasma levels of pig, human or non-human primate (NHP) IL-8 from ex vivo pig lung perfusion experiments (n = 10) and in vivo pig-to-baboon lung transplantation in baboons (n = 22) were analysed by ELISA or Luminex. Human neutrophils stimulated with human or pig IL-8 were analysed for CD11b expression, CD18 activation, oxidative burst and adhesion to resting or TNF-activated endothelial cells (EC) evaluated under static and flow (Bioflux) conditions. For some experiments, human neutrophils were incubated with Reparixin (IL-8/CXCL8 receptor blocker) and then analysed as in the in vitro experiments mentioned above. RESULTS Plasma levels of pig IL-8 (~6113 pg/mL) increased more than human (~1235 pg/mL) between one and four hours after initiation of ex vivo lung perfusion. However, pig IL-8 levels remained consistently low (<60 pg/mL) and NHP IL-8 plasma levels increased by ~2000 pg/mL after four hours in a pig-to-baboon lung xenotransplantation. In vitro, human neutrophils' CD11b expression, CD18 activation and oxidative burst all increased in a dose-dependent manner following exposure to either pig or human IL-8, which also were associated with increased adhesion to EC in both static and flow conditions. Reparixin inhibited human neutrophil activation by both pig and human IL-8 in a dose-dependent fashion. At 0.1 mg/mL, Reparixin inhibited the adhesion of IL-8-activated human neutrophils to pAECs by 84 ± 2.5%. CONCLUSIONS Pig IL-8 increased in an ex vivo model of pig-to-human lung xenotransplantation but is not detected in vivo, whereas human or NHP IL-8 is elevated to a similar degree in both models. Both pig and human IL-8 activate human neutrophils and increase their adhesion to pig aortic ECs, a process significantly inhibited by the addition of Reparixin to human neutrophils. This work implicates IL-8, whether of pig or human origin, as a possible factor mediating in lung xenograft inflammation and injury and supports the evaluation of therapeutic targeting of this pathway in the context of xenotransplantation.
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Laird CT, Hassanein W, O'Neill NA, French BM, Cheng X, Fogler WE, Magnani JL, Parsell D, Cimeno A, Phelps CJ, Ayares D, Burdorf L, Azimzadeh AM, Pierson RN. P- and E-selectin receptor antagonism prevents human leukocyte adhesion to activated porcine endothelial monolayers and attenuates porcine endothelial damage. Xenotransplantation 2018; 25:e12381. [PMID: 29359469 DOI: 10.1111/xen.12381] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/24/2017] [Accepted: 01/02/2018] [Indexed: 01/05/2023]
Abstract
BACKGROUND Alongside the need to develop more effective and less toxic immunosuppression, the shortage of human organs available for organ transplantation is one of the major hurdles facing the field. Research into xenotransplantation, as an alternative source of organs, has unveiled formidable challenges. Porcine lungs perfused with human blood rapidly sequester the majority of circulating neutrophils and platelets, which leads to inflammation and organ failure within hours, and is not significantly attenuated by genetic modifications to the pig targeted to diminish antibody binding and complement and coagulation cascade activation. METHODS Here, we model the interaction of freshly isolated human leukocytes with xenotransplanted vasculature under physiologic flow conditions using microfluidic channels coated with porcine endothelial cells. Both isolated human neutrophils and whole human blood were perfused over transgenic pig aortic endothelial cells that had been activated with rhTNF-α or rhIL-4 using the BioFlux system. Novel compounds GMI-1271 and rPSGL1.Fc were tested as E- and P- selectin antagonists, respectively. Cellular adhesion and rolling events were tracked using FIJI (imageJ). RESULTS Porcine endothelium activated with either rhTNF-α or rhIL-4 expressed high amounts of selectins, to which isolated human neutrophils readily rolled and tethered. Both E-and P-selectin antagonism significantly reduced the number of neutrophils rolling and rolling distance in a dose-dependent manner, with near total inhibition at higher doses (P < .001). Similarly, with whole human blood, selectin blocking compounds exhibited dose-dependent inhibition of prevalent leukocyte adhesion and severe endothelial injury (Untreated: 394 ± 97 PMNs/hpf, 57 ± 6% loss EC; GMI1271+rPSGL1.Fc: 23 ± 9 PMNs/hpf, 8 ± 6% loss EC P < .01). CONCLUSIONS Selectin blockade may be useful as part of an integrated strategy to prevent neutrophil-mediated organ xenograft injury, especially during the early time points following reperfusion.
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Cooper DKC, Cowan P, Fishman JA, Hering BJ, Mohiuddin MM, Pierson RN, Sachs DH, Schuurman HJ, Dennis JU, Tönjes RR. Joint FDA‐IXA Symposium, September 20, 2017. Xenotransplantation 2017; 24. [PMID: 29193342 DOI: 10.1111/xen.12365] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Abstract
PURPOSE OF REVIEW This article reviews recent progress in the field of lung xenotransplantation, including mechanisms of xenograft injury, and the influence of mechanism-directed genetic modifications and other interventions that may soon enable therapeutic use of pig lungs in humans. RECENT FINDINGS An extensive series of lung xenotransplantation experiments demonstrates that multiple genetic modifications targeting known xenogeneic lung injury mechanisms are associated with incremental improvements in lung survival or function. Addition of human complement (hCD46, hCD55), coagulation (hEPCR, hTBM, hTFPI, hCD39), or anti-inflammatory pathway regulatory genes (HO-1, HLA-E), and GalT and Neu5Gc gene knockout has each demonstrated protective effects on lung survival or function. In addition, drug treatments targeting key inflammatory and clotting pathways have been shown to attenuate residual mechanisms of lung injury. Work with other pig organs in primate models show that regimens based on costimulatory pathway blocking antibodies prolong xenograft function for months to years, suggesting that once initial lung inflammation mechanisms are fully controlled, clinically useful application of pig lung xenografts may soon be feasible. SUMMARY Genetic modification of pigs coupled with drugs targeting complement activation, coagulation, and inflammation have significantly increased duration of pig lung function in ex-vivo human blood perfusion models, and life-supporting lung xenograft survival in vivo.
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Cimeno A, French BM, Powell JM, Phelps C, Ayares D, O'Neill NA, Laird CT, Pierson RN, Azimzadeh AM, Barth RN, LaMattina JC. Synthetic liver function is detectable in transgenic porcine livers perfused with human blood. Xenotransplantation 2017; 25. [PMID: 29067741 DOI: 10.1111/xen.12361] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/21/2017] [Accepted: 09/26/2017] [Indexed: 12/27/2022]
Abstract
In addition to immune barriers, molecular incompatibilities between species are predicted to limit pig liver survival in primate xenotransplantation models. Assessment and measurement of synthetic function of genetically modified porcine livers after ex vivo perfusion with human blood have not previously been described. Eight porcine livers from α1,3-galactosyl transferase knockout and human membrane cofactor (GalTKO.hCD46), six livers from GalTKO.hCD46 and N-glycolylneuraminic acid knockout (GalTKO.hCD46.Neu5GcKO), and six livers from GalTKO.hCD46 with humanized decay-accelerating factor (hCD55), endothelial protein C receptor (hEPCR), tissue factor pathway inhibitor (hTFPI), and integrin-associated protein (hCD47) (GalTKO.hCD46.hCD55.hEPCR.hTFPI.hCD47) pigs were perfused with human blood under physiologic conditions. Timed blood samples were tested for liver enzymes and for pig-specific albumin production via Western blot. Porcine albumin levels increased with time in all experiments. By densitometry, GalTKO.hCD46.Neu5GcKO livers had the highest albumin levels, measured both as total produced, and when controlled for perfusion duration, compared to GalTKO.hCD46 (P = .068) and GalTKO.hCD46.hCD55.hEPCR.hTFPI.hCD47 livers (P = .04). Porcine livers perfused with human blood demonstrated the synthetic ability to produce albumin in all cases. GalTKO.hCD46.Neu5GcKO pig livers demonstrated the most robust albumin production. This suggests that the Neu5GcKO phenotype provides a protective effect on the graft due to decreased human antibody recognition and graft injury.
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