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Microbiome Anomalies in Allogeneic Hematopoietic Cell Transplantation. Annual review of medicine The microbiome is an integrated part of the human body that can modulate a variety of disease processes and affect prognosis, treatment response, complications, and outcomes. The importance of allogeneic hematopoietic cell transplantation in cancer treatment has resulted in extensive investigations on the interaction between the microbiome and this treatment modality. These investigations are beginning to lead to clinical trials of microbiome-targeted interventions. Here we review some of these discoveries and describe strategies being investigated to manipulate the microbiome for favorable outcomes, such as the proper selection and timing of antibiotics, type of diet and route of administration, probiotics, prebiotics, and fecal microbiota transplantation. 10.1146/annurev-med-052918-122440
Obesity induces gut microbiota alterations and augments acute graft-versus-host disease after allogeneic stem cell transplantation. Khuat Lam T,Le Catherine T,Pai Chien-Chun Steven,Shields-Cutler Robin R,Holtan Shernan G,Rashidi Armin,Parker Sarah L,Knights Dan,Luna Jesus I,Dunai Cordelia,Wang Ziming,Sturgill Ian R,Stoffel Kevin M,Merleev Alexander A,More Shyam K,Maverakis Emanual,Raybould Helen E,Chen Mingyi,Canter Robert J,Monjazeb Arta M,Dave Maneesh,Ferrara James L M,Levine John E,Longo Dan L,Abedi Mehrdad,Blazar Bruce R,Murphy William J Science translational medicine The efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is limited by acute and chronic graft-versus-host disease (GVHD). The impact of obesity on allo-HSCT outcomes is poorly understood. Here, we report that obesity had a negative and selective impact on acute gut GVHD after allo-HSCT in mice with diet-induced obesity (DIO). These animals exhibited increased gut permeability, endotoxin translocation across the gut, and radiation-induced gastrointestinal damage after allo-HSCT. After allo-HSCT, both male and female DIO mouse recipients showed increased proinflammatory cytokine production and expression of the GVHD marker ST2 (IL-33R) and MHC class II molecules; they also exhibited decreased survival associated with acute severe gut GVHD. This rapid-onset, obesity-associated gut GVHD depended on donor CD4 T cells and occurred even with a minor MHC mismatch between donor and recipient animals. Retrospective analysis of clinical cohorts receiving allo-HSCT transplants from unrelated donors revealed that recipients with a high body mass index (BMI, >30) had reduced survival and higher serum ST2 concentrations compared with nonobese transplant recipients. Assessment of both DIO mice and allo-HSCT recipients with a high BMI revealed reduced gut microbiota diversity and decreased Clostridiaceae abundance. Prophylactic antibiotic treatment protected DIO mouse recipients from endotoxin translocation across the gut and increased inflammatory cytokine production, as well as gut pathology and mortality, but did not protect against later development of chronic skin GVHD. These results suggest that obesity-induced alterations of the gut microbiota may affect GVHD after allo-HSCT in DIO mice, which could be ameliorated by prophylactic antibiotic treatment. 10.1126/scitranslmed.aay7713
Prolonged survival after lung transplantation in the absence of conventional immunosuppression. Vazirani Jaideep,Snell Gregory I,Westall Glen P The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation 10.1016/j.healun.2020.06.018
Bioengineered Mini Human Livers for Transplantation. Jalan-Sakrikar Nidhi,Navarro-Corcuera Amaia,Huebert Robert C Hepatology (Baltimore, Md.) 10.1002/hep.31528
Localized Immunosuppression With Tannic Acid Encapsulation Delays Islet Allograft and Autoimmune-Mediated Rejection. Diabetes Type 1 diabetes (T1D) is an autoimmune disease of insulin-producing β-cells. Islet transplantation is a promising treatment for T1D, but long-term graft viability and function remain challenging. Oxidative stress plays a key role in the activation of alloreactive and autoreactive immunity toward the engrafted islets. Therefore, targeting these pathways by encapsulating islets with an antioxidant may delay immune-mediated rejection. Utilizing a layer-by-layer approach, we generated nanothin encapsulation materials containing tannic acid (TA), a polyphenolic compound with redox scavenging and anti-inflammatory effects, and poly(N-vinylpyrrolidone) (PVPON), a biocompatible polymer. We hypothesize that transplantation of PVPON/TA-encapsulated allogeneic C57BL/6 islets into diabetic NOD mice will prolong graft function and elicit localized immunosuppression. In the absence of systemic immunosuppression, diabetic recipients containing PVPON/TA-encapsulated islets maintained euglycemia and delayed graft rejection significantly longer than those receiving nonencapsulated islets. Transplantation of PVPON/TA-encapsulated islets was immunomodulatory because gene expression and flow cytometric analysis revealed significantly decreased immune cell infiltration, synthesis of reactive oxygen species, inflammatory chemokines, cytokines, CD8 T-cell effector responses, and concomitant increases in alternatively activated M2 macrophage and dendritic cell phenotypes. Our results provide evidence that reducing oxidative stress following allotransplantation of PVPON/TA-encapsulated islets can elicit localized immunosuppression and potentially delay graft destruction in future human islet transplantation studies. 10.2337/db20-0248
Ruxolitinib protects skin stem cells and maintains skin homeostasis in murine graft-versus-host disease. Takahashi Shuichiro,Hashimoto Daigo,Hayase Eiko,Ogasawara Reiki,Ohigashi Hiroyuki,Ara Takahide,Yokoyama Emi,Ebata Ko,Matsuoka Satomi,Hill Geoffrey R,Sugita Junichi,Onozawa Masahiro,Teshima Takanori Blood Graft-versus-host disease (GVHD) is the major complication after allogeneic stem cell transplantation (SCT). Emerging evidence indicates that GVHD leads to injury of intestinal stem cells. However, it remains to be investigated whether skin stem cells could be targeted in skin GVHD. Lgr5 hair follicle stem cells (HFSCs) contribute to folliculogenesis and have a multipotent capacity to regenerate all epithelial cells in repair. We studied the fate of Lgr5 HFSCs after SCT and explored the novel treatment to protect Lgr5 HFSCs against GVHD using murine models of SCT. We found that GVHD reduced Lgr5 HFSCs in association with impaired hair regeneration and wound healing in the skin after SCT. Topical corticosteroids, a standard of care for a wide range of skin disorders including GVHD, damaged HFSCs and failed to improve skin homeostasis, despite of their anti-inflammatory effects. In contrast, JAK1/2 inhibitor ruxolitinib significantly ameliorated skin GVHD, protected Lgr5 HFSCs, and restored hair regeneration and wound healing after SCT. We, for the first time, found that GVHD targets Lgr5 HFSCs and that topical ruxolitinib represents a novel strategy to protect skin stem cells and maintain skin homeostasis in GVHD. 10.1182/blood-2017-06-792614
Successful transplantation of human hepatic stem cells with restricted localization to liver using hyaluronan grafts. Hepatology (Baltimore, Md.) Cell therapies are potential alternatives to organ transplantation for liver failure or dysfunction but are compromised by inefficient engraftment, cell dispersal to ectopic sites, and emboli formation. Grafting strategies have been devised for transplantation of human hepatic stem cells (hHpSCs) embedded into a mix of soluble signals and extracellular matrix biomaterials (hyaluronans, type III collagen, laminin) found in stem cell niches. The hHpSCs maintain a stable stem cell phenotype under the graft conditions. The grafts were transplanted into the livers of immunocompromised murine hosts with and without carbon tetrachloride treatment to assess the effects of quiescent versus injured liver conditions. Grafted cells remained localized to the livers, resulting in a larger bolus of engrafted cells in the host livers under quiescent conditions and with potential for more rapid expansion under injured liver conditions. By contrast, transplantation by direct injection or via a vascular route resulted in inefficient engraftment and cell dispersal to ectopic sites. Transplantation by grafting is proposed as a preferred strategy for cell therapies for solid organs such as the liver. 10.1002/hep.26065
Therapeutic lymphangiogenesis ameliorates established acute lung allograft rejection. Cui Ye,Liu Kaifeng,Monzon-Medina Maria E,Padera Robert F,Wang Hao,George Gautam,Toprak Demet,Abdelnour Elie,D'Agostino Emmanuel,Goldberg Hilary J,Perrella Mark A,Forteza Rosanna Malbran,Rosas Ivan O,Visner Gary,El-Chemaly Souheil The Journal of clinical investigation Lung transplantation is the only viable option for patients suffering from otherwise incurable end-stage pulmonary diseases such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. Despite aggressive immunosuppression, acute rejection of the lung allograft occurs in over half of transplant recipients, and the factors that promote lung acceptance are poorly understood. The contribution of lymphatic vessels to transplant pathophysiology remains controversial, and data that directly address the exact roles of lymphatic vessels in lung allograft function and survival are limited. Here, we have shown that there is a marked decline in the density of lymphatic vessels, accompanied by accumulation of low-MW hyaluronan (HA) in mouse orthotopic allografts undergoing rejection. We found that stimulation of lymphangiogenesis with VEGF-C156S, a mutant form of VEGF-C with selective VEGFR-3 binding, alleviates an established rejection response and improves clearance of HA from the lung allograft. Longitudinal analysis of transbronchial biopsies from human lung transplant recipients demonstrated an association between resolution of acute lung rejection and decreased HA in the graft tissue. Taken together, these results indicate that lymphatic vessel formation after lung transplantation mediates HA drainage and suggest that treatments to stimulate lymphangiogenesis have promise for improving graft outcomes. 10.1172/JCI79693
Role of TLRs and DAMPs in allograft inflammation and transplant outcomes. Braza Faouzi,Brouard Sophie,Chadban Steve,Goldstein Daniel R Nature reviews. Nephrology Graft inflammation impairs the induction of solid organ transplant tolerance and enhances acute and chronic rejection. Elucidating the mechanisms by which inflammation is induced after organ transplantation could lead to novel therapeutics to improve transplant outcomes. In this Review we describe endogenous substances--damage-associated molecular patterns (DAMPs)--that are released after allograft reperfusion and induce inflammation. We also describe innate immune signalling pathways that are activated after solid organ transplantation, with a focus on Toll-like receptors (TLRs) and their signal adaptor, MYD88. Experimental and clinical studies have yielded a large body of evidence that TLRs and MYD88 are instrumental in initiating allograft inflammation and promoting the development of acute and chronic rejection. Ongoing clinical studies are testing TLR inhibition strategies in solid organ transplantation, although avoiding compromising host defence to pathogens is a key challenge. Further elucidation of the mechanisms by which sterile inflammation is induced, maintained and amplified within the allograft has the potential to lead to novel anti-inflammatory treatments that could improve outcomes for solid organ transplant recipients. 10.1038/nrneph.2016.41
Clinical Outcomes and Complications Associated with Fractional Lasers: A Review of 730 Patients. Cohen Steven R,Goodacre Ashley,Lim Soobin,Johnston Jennifer,Henssler Cory,Jeffers Brian,Saad Ahmad,Leong Tracy Aesthetic plastic surgery BACKGROUND:Fractional lasers were introduced to provide increased safety, while maintaining high efficacy and patient satisfaction. Patients with virtually all Fitzpatrick skin types could be safely treated using a wide spectrum of wavelengths and a broad array of skin conditions, and aging could be addressed. Although safety studies have been reported for ablative CO and erbium lasers, surprisingly few data are available on adverse events and complications associated with fractional lasers. OBJECTIVE:We report the frequency of adverse events, skin improvement and complications in a broad range of skin types using a standardized protocol that can be safely tailored to the patient's presenting complaints by varying the laser wavelength and number of treatments. MATERIALS AND METHODS:The medical records of 730 patients (>90% females, age ranged from 50.5. to 59.9 years.) who had been treated at FACES+ Aesthetic Facility were reviewed. Patients were followed from 1 to 10 months and were reviewed to determine the frequency of complications, as well as their frequency, type, cause, treatment and resolution thereof. Patients were categorized by Fitzpatrick skin type (I-IV) to determine whether skin type was related to the frequency of complications. Improvement in skin condition (wrinkles, nasolabial folds and pigment) was rated by a technician before and after treatment using a Likert scale, 0-5, with 0 being no change and 5 being the most improvement. RESULTS:Seven hundred thirty patients underwent procedures using fractional lasers in our center. Procedures were carried out with 3 different laser wavelengths, depending on the condition(s) treated (wrinkling vs. pigmentation issues, etc.) and the patients' desired length of downtime. The fractional Fraxel 1927-nm laser was used in 224 patients [Fitzpatrick skin type I (2.2%), II (38.4%), III (46.0%), IV (12.5%)]; the fractional Fraxel 1550-nm laser was used in 334 [type I (4.5%), II (31.9%), III (50.0%), IV (13.3%)], and the fractional Fraxel CO laser was used in 172 [type 1 (4.7%), II (49.7%), III (41.5%), IV (4.1%)]. The Fraxel CO laser showed greater improvement in wrinkles and naso-labial fold (p < 0.001). The greatest improvement in pigmentation was seen with the Fraxel 1927-nm laser (p < 0.001). Adverse events and complications occurred in 31 of 730 patients (4.2%). There was no significant difference in the rate of complications among the three treatments (p = 0.26). Complications were generally minor, and all resolved completely with treatment. Complications occurred in 4.0% of patients having the fractional Fraxel 1927-nm laser, 3.3% of patients having the fractional Fraxel 1550 nm and 6.4% of patients having the fractional Fraxel CO laser. Complications included 5 herpes simplex virus breakouts, 13 acne eruptions, 1 abrasion, 1 bacterial infection, 9 dermatitis, 1 drug eruption, 4 prolonged erythema, 1 hyperpigmentation, 1 increased swelling and 1 telangiectasia. There was no significant relationship between Fitzpatrick skin type and incidence of complications (p = 0.37). CONCLUSIONS:Fractional lasers in general have reduced complication rates, while maintaining high degrees of patient satisfaction. Since their inception in early 2004, our clinic has utilized fractional lasers to treat patients from a variety of ethnic backgrounds and diverse skin types with an overall complication rate of 4.2%, all of which resolved. Comprehensive care of patients with facial aging is not limited to surgery alone and should include these types of strategies to appropriately and safely address photo-damage and photo-aging. LEVEL OF EVIDENCE IV:This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 . 10.1007/s00266-016-0767-x
Nephrocytes: a role in immunity. Allison Susan J Nature reviews. Nephrology 10.1038/s41581-019-0221-9
Synthetic lethality between loss of CDK4/6 activity and VHL inactivation. Allison Susan J Nature reviews. Nephrology 10.1038/s41581-019-0225-5
The importance of non-HLA antibodies in transplantation. Zhang Qiuheng,Reed Elaine F Nature reviews. Nephrology The development of post-transplantation antibodies against non-HLA autoantigens is associated with rejection and decreased long-term graft survival. Although our knowledge of non-HLA antibodies is incomplete, compelling experimental and clinical findings demonstrate that antibodies directed against autoantigens such as angiotensin type 1 receptor, perlecan and collagen, contribute to the process of antibody-mediated acute and chronic rejection. The mechanisms that underlie the production of autoantibodies in the setting of organ transplantation is an important area of ongoing investigation. Ischaemia-reperfusion injury, surgical trauma and/or alloimmune responses can result in the release of organ-derived autoantigens (such as soluble antigens, extracellular vesicles or apoptotic bodies) that are presented to B cells in the context of the transplant recipient's antigen presenting cells and stimulate autoantibody production. Type 17 T helper cells orchestrate autoantibody production by supporting the proliferation and maturation of autoreactive B cells within ectopic tertiary lymphoid tissue. Conversely, autoantibody-mediated graft damage can trigger alloimmunity and the development of donor-specific HLA antibodies that can act in synergy to promote allograft rejection. Identification of the immunologic phenotypes of transplant recipients at risk of non-HLA antibody-mediated rejection, and the development of targeted therapies to treat such rejection, are sorely needed to improve both graft and patient survival. 10.1038/nrneph.2016.88
Humanized Mice as Preclinical Models in Transplantation. Safinia N,Becker P D,Vaikunthanathan T,Xiao F,Lechler R,Lombardi G Methods in molecular biology (Clifton, N.J.) Animal models have been instrumental in our understanding of the mechanisms of rejection and the testing of novel treatment options in the context of transplantation. We have now entered an exciting era with research on humanized mice driving advances in translational studies and in our understanding of the function of human cells in response to pathogens and cancer as well as the recognition of human allogeneic tissues in vivo. In this chapter we provide a historical overview of humanized mouse models of transplantation to date, outlining the distinct strains and share our experiences in the study of human transplantation immunology. 10.1007/978-1-4939-3139-2_11
In this issue: new topics in miRNA and transplantation immunology. Bot Adrian,Jiga Lucian P International reviews of immunology 10.1080/08830180902990620
Transplantation recent advances in transplantation immunology. Gluckman Eliane Current opinion in immunology 10.1016/j.coi.2006.07.017
Transplantation immunology: solid organ and bone marrow. The Journal of allergy and clinical immunology Development of the field of organ and tissue transplantation has accelerated remarkably since the human MHC was discovered in 1967. Matching of donor and recipient for MHC antigens has been shown to have a significant positive effect on graft acceptance. The roles of the different components of the immune system involved in the tolerance or rejection of grafts and in graft-versus-host disease have been clarified. These components include antibodies, antigen-presenting cells, helper and cytotoxic T-cell subsets, immune cell-surface molecules, signaling mechanisms, and cytokines. The development of pharmacologic and biological agents that interfere with the alloimmune response has had a crucial role in the success of organ transplantation. Combinations of these agents work synergistically, leading to lower doses of immunosuppressive drugs and reduced toxicity. Reports of significant numbers of successful solid-organ transplantations include those of the kidneys, liver, heart, and lung. The use of bone marrow transplantation for hematologic diseases, particularly hematologic malignancies and primary immunodeficiencies, has become the treatment of choice in many of these conditions. Other sources of hematopoietic stem cells are also being used, and diverse immunosuppressive drug regimens of reduced intensity are being proposed to circumvent the mortality associated with the toxicity of these drugs. Gene therapy to correct inherited diseases by means of infusion of gene-modified autologous hematopoietic stem cells has shown efficacy in 2 forms of severe combined immunodeficiency, providing an alternative to allogeneic tissue transplantation. 10.1016/j.jaci.2009.11.014
Viewing transplantation immunology through today's lens: new models, new imaging, and new insights. Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation 10.1016/j.bbmt.2012.10.020
Transplantation immunology in 2013: New approaches to diagnosis of rejection. Zwang Nicholas A,Turka Laurence A Nature reviews. Nephrology In 2013, a key theme of research in renal transplantation was the diagnosis of rejection. Data from key studies published in the past year highlight aspects of rejection that warrant further investigation and should prompt the consideration of adjunctive tests to complement traditional histological assessment of allograft biopsy samples. 10.1038/nrneph.2013.262
Influence of acute rejection episodes, HLA matching, and donor/recipient phenotype on the development of 'early' transplant-associated coronary artery disease. Hornick P,Smith J,Pomerance A,Mitchell A,Banner N,Rose M,Yacoub M Circulation BACKGROUND:Transplant-associated coronary artery disease (TxCAD) is the manifestation of chronic rejection in the cardiac allograft. Both immunological and nonimmunological factors contribute to its development. Stratification by the time of development of TxCAD has not been considered previously for an extensive transplant series and may provide a means for apportioning relative risk factors appropriately. Specifically, TxCAD that develops early may have a pathogenesis different from TxCAD that develops later; ie, immunological factors play a more significant role in early development of TxCAD compared with later forms of the disease or in recipients where it has not been found. METHODS AND RESULTS:Between 1980 and 1994, 550 heart transplant recipients with postmortem data or yearly angiograms, donor:recipient serological HLA typing, and biopsy data were reviewed. Recipients were divided into four groups: Very Early (<1 year), Early (1-2 years), Late (3-14 years), and None (clear angio >3 years). There was a significant association between the number of histologically proven acute rejection episodes within 3 months and at 1 year and the development of early TxCAD. The number of acute rejection episodes within 3 months and 1 year is also significantly related to freedom of development of TxCAD. There was no significant association between the mean number of mismatches for Class I or Class II antigens, nor could any Class I/II phenotype for recipient or donor be identified that exerted a protective or deleterious effect. A lack of any association or trend with HLA data is demonstrated. CONCLUSIONS:These differences in pathogenesis between early and late TxCAD help define the importance of acute rejection in the etiology of chronic cardiac rejection. Stratification by time of development of TxCAD may provide further insight into defining the relative importance of other risk factors associated with the development of TxCAD. The lack of association with HLA data is discussed.
The immunological barrier to xenotransplantation. Cascalho M,Platt J L Immunity
Towards the identification of biomarkers of transplantation tolerance. Turka Laurence A,Lechler Robert I Nature reviews. Immunology Although transplantation has been a standard medical practice for decades, the marked morbidity from the use of immunosuppressive drugs and poor long-term graft survival remain important limitations in the field. Achieving tolerance to transplanted organs should solve both problems, but has been an elusive goal. Recent advances in the human immunological toolbox have rekindled interest in studying the small number of transplant recipients who become tolerant to their grafts over time. The development of biomarkers of transplantation tolerance holds promise to improve the care of organ allograft recipients, to provide surrogate end points of tolerance induction strategies and to advance our understanding of the human immune response to both self and foreign antigens. 10.1038/nri2568
Face transplant: long-term follow-up and results of a prospective open study. Lantieri Laurent,Grimbert Philippe,Ortonne Nicolas,Suberbielle Caroline,Bories Dominique,Gil-Vernet Salvador,Lemogne Cédric,Bellivier Frank,Lefaucheur Jean Pascal,Schaffer Nathaniel,Martin Fréderic,Meningaud Jean Paul,Wolkenstein Pierre,Hivelin Mikael Lancet (London, England) BACKGROUND:More than 30 face transplantations have been done worldwide since 2005 but no documented long-term follow-up has been reported in the literature. We aimed to answer remaining question about the long-term risks and benefits of face transplant. METHODS:In this single-centre, prospective, open study, we assessed 20 patients presenting with facial defects. Ten patients were selected, and, after three were secondarily excluded, seven were transplanted: two with neurofibromatosis 1, one with a burn, and four with self-inflicted facial gunshot injuries. We report the long-term outcomes of six face allotransplant recipients at an average of 6 years (range 3·4-9 years) after the transplantation. All admissions to hospital except for planned revisions and immunosuppressive follow-up therapy were reported as adverse events (safety endpoint). Predefined immunological, metabolic, surgical, and social integration endpoints were collected prospectively. Patients underwent quantitative health-related quality of life assessments through Short Form 36 health questionnaires. This study was registered with ClinicalTrials.gov, number NCT00527280. FINDINGS:Two of seven patients died: one at 65 days due to transplant destruction with concomitant pseudomonas infection and the second at 3·4 years after transplantation by suicide. The six patients alive at long-term follow-up presented with functional transplants. Safety endpoints were related to infection in the first month, acute rejection from 1 day to 7 years after transplantation, or side-effects of immunosuppressive therapy. Recurrent rejection episodes justified maintenance therapy with high-dose steroids at high levels in all patients at last follow-up, yet none of the patients developed diabetes. Three patients were found to have hypertension with one requiring therapy. All patients had a noticeable reduction in glomerular filtration rate. All recipients and their families accepted their transplant. Improvements in social integration and quality of life were highly variable among the patients and depended on baseline levels and psychiatric comorbidities. INTERPRETATION:These long-term results show the crucial effect of patients' social support and pre-existing psychiatric conditions on the risk-benefit ratio of facial transplantation. Careful preoperative patient selection and long-term postoperative follow-up programmes under strict institutional review board controls should be used for any future grafts of this type. FUNDING:Protocole Hospitalier de Recherche Clinique (PHRC) National. 10.1016/S0140-6736(16)31138-2
Chemokines, chemokine receptors, and allograft rejection. Nelson P J,Krensky A M Immunity
Allogeneic transplantation of iPS cell-derived cardiomyocytes regenerates primate hearts. Shiba Yuji,Gomibuchi Toshihito,Seto Tatsuichiro,Wada Yuko,Ichimura Hajime,Tanaka Yuki,Ogasawara Tatsuki,Okada Kenji,Shiba Naoko,Sakamoto Kengo,Ido Daisuke,Shiina Takashi,Ohkura Masamichi,Nakai Junichi,Uno Narumi,Kazuki Yasuhiro,Oshimura Mitsuo,Minami Itsunari,Ikeda Uichi Nature Induced pluripotent stem cells (iPSCs) constitute a potential source of autologous patient-specific cardiomyocytes for cardiac repair, providing a major benefit over other sources of cells in terms of immune rejection. However, autologous transplantation has substantial challenges related to manufacturing and regulation. Although major histocompatibility complex (MHC)-matched allogeneic transplantation is a promising alternative strategy, few immunological studies have been carried out with iPSCs. Here we describe an allogeneic transplantation model established using the cynomolgus monkey (Macaca fascicularis), the MHC structure of which is identical to that of humans. Fibroblast-derived iPSCs were generated from a MHC haplotype (HT4) homozygous animal and subsequently differentiated into cardiomyocytes (iPSC-CMs). Five HT4 heterozygous monkeys were subjected to myocardial infarction followed by direct intra-myocardial injection of iPSC-CMs. The grafted cardiomyocytes survived for 12 weeks with no evidence of immune rejection in monkeys treated with clinically relevant doses of methylprednisolone and tacrolimus, and showed electrical coupling with host cardiomyocytes as assessed by use of the fluorescent calcium indicator G-CaMP7.09. Additionally, transplantation of the iPSC-CMs improved cardiac contractile function at 4 and 12 weeks after transplantation; however, the incidence of ventricular tachycardia was transiently, but significantly, increased when compared to vehicle-treated controls. Collectively, our data demonstrate that allogeneic iPSC-CM transplantation is sufficient to regenerate the infarcted non-human primate heart; however, further research to control post-transplant arrhythmias is necessary. 10.1038/nature19815
Transplantation: Personalizing induction therapy in kidney transplantation. Aull Meredith J,Suthanthiran Manikkam Nature reviews. Nephrology Induction therapy with rabbit anti-thymocyte globulin is preferable to induction with daclizumab in renal transplant recipients at high immunological risk. These findings provide additional support to the idea that personalized immunosuppressive regimens should be developed in renal transplant recipients. 10.1038/nrneph.2009.164
Chronic rejection. Libby P,Pober J S Immunity
Location, location, location: regional immune mechanisms critically influence rejection. Kirk Allan D Nature medicine 10.1038/nm0602-553
Rabbit-ATG or basiliximab induction for rapid steroid withdrawal after renal transplantation (Harmony): an open-label, multicentre, randomised controlled trial. Thomusch Oliver,Wiesener Michael,Opgenoorth Mirian,Pascher Andreas,Woitas Rainer Peter,Witzke Oliver,Jaenigen Bernd,Rentsch Markus,Wolters Heiner,Rath Thomas,Cingöz Tülay,Benck Urs,Banas Bernhard,Hugo Christian Lancet (London, England) BACKGROUND:Standard practice for immunosuppressive therapy after renal transplantation is quadruple therapy using antibody induction, low-dose tacrolimus, mycophenolate mofetil, and corticosteroids. Long-term steroid intake significantly increases cardiovascular risk factors with negative effects on the outcome, especially post-transplantation diabetes associated with morbidity and mortality. In this trial, we examined the efficacy and safety parameters of rapid steroid withdrawal after induction therapy with either rabbit antithymocyte globulin (rabbit ATG) or basiliximab in immunologically low-risk patients during the first year after kidney transplantation. METHODS:In this open-label, multicentre, randomised controlled trial, we randomly assigned renal transplant recipients in a 1:1:1 ratio to receive either basiliximab induction with low-dose tacrolimus, mycophenolate mofetil, and steroid maintenance therapy (arm A), rapid corticosteroid withdrawal on day 8 (arm B), or rapid corticosteroid withdrawal on day 8 after rabbit ATG (arm C). The study was done in 21 centres across Germany. Only participants aged between 18 and 75 years with a low immunological risk who were scheduled to receive a single-organ renal transplant from either a living donor or a deceased donor were considered for enrolment. Patients receiving a second renal transplant were eligible, provided that the first allograft was not lost due to acute rejection within the first year after transplantation. Donor and recipient had to be ABO compatible. Grafts with pre-transplant existing donor-specific human leukocyte antigen (HLA) antibodies were not eligible and the recipients had to have a panel-reactive antibody concentration of 30% or less. Pregnant women and nursing mothers were excluded from the study. The primary endpoint was the incidence of biopsy-proven acute rejection (BPAR) at 12 months. All analyses were done by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT00724022. FINDINGS:Between Aug 7, 2008, and Nov 30, 2013, 615 patients were randomly assigned to arm A (206), arm B (189), and arm C (192). BPAR rates were not reduced by rabbit ATG (9·9%) compared with either treatment arm A (11·2%) or B (10·6%; A versus C: p=0·75, B versus C p=0·87). As a secondary endpoint, rapid steroid withdrawal reduced post-transplantation diabetes in arm B to 24% and in arm C to 23% compared with 39% in control arm A (A versus B and C: p=0·0004). Patient survival (94·7% in arm A, 97·4% in arm B, and 96·9% in arm C) and censored graft survival (96·1% in arm A, 96·8% in arm B, and 95·8% in arm C) after 12 months were excellent and equivalent in all arms. Safety parameters such as infections or the incidence of post-transplantation malignancies did not differ between the study arms. INTERPRETATION:Rabbit ATG did not show superiority over basiliximab induction for the prevention of BPAR after rapid steroid withdrawal within 1 year after renal transplantation. Nevertheless, rapid steroid withdrawal after induction therapy for patients with a low immunological risk profile can be achieved without loss of efficacy and is advantageous in regard to post-transplantation diabetes incidence. FUNDING:Investigator Initiated Trial; financial support by Astellas Pharma GmbH, Sanofi, and Roche Pharma AG. 10.1016/S0140-6736(16)32187-0
An immunological algorithm to predict risk of high-grade rejection in cardiac transplant recipients. Itescu S,Tung T C,Burke E M,Weinberg A D,Mancini D,Michler R E,Suciu-Foca N M,Rose E A Lancet (London, England) BACKGROUND:Transplant-related coronary-artery disease (TCAD) develops frequently in cardiac-allograft recipients, and limits long-term survival. We examined the relation between this disorder and cumulative frequency of high-grade rejection, and investigated whether concomitant use of three immunological factors at the time of a low-grade endomyocardial biopsy can predict progression to high-grade rejection. METHODS:We investigated the relation between the cumulative annual frequency of high-grade rejection and TCAD in 198 recipients of cardiac transplantation between 1992 and 1996 by means of Kaplan-Meier actuarial life-tables. Endomyocardial biopsy, lymphocyte-growth assays, and anti-HLA antibody measurements were compiled over 12 months in 102 patients during their first post-transplant year. We calculated predictive values for high-grade rejection within 90 days by chi2, Kaplan Meier survival curves, and by multivariable logistic regression analyses. FINDINGS:We found a direct correlation between cumulative annual frequency of rejection and TCAD onset with highest risk in those with more than 0.75 rejections per year (p=0.0002). After a low-grade endomyocardial biopsy (0 or 1A), one or more donor-recipient HLA-DR matches protected against high-grade rejections (p<0.001). Among individuals with one or two DR matches, the negative predictive value for progression from a low-grade biopsy to a high-grade rejection was 87% in the presence of a negative lymphocyte-growth assay. Among individuals with no DR matches, the presence of either a positive lymphocyte-growth assay or IgG anti-major-histocompatibility complex (MHC) class II antibodies was independently associated with high probability of progression to rejection (64% and 66%, respectively, p<0.0005). When both assays were positive, concomitantly with a low-grade endomyocardial biopsy, the positive predictive value for progression to a high-grade rejection was 86% (p<0.0001). For endomyocardial-biopsy grades 1B or 2, a positive lymphocyte-growth assay alone was associated with high-grade rejection in 100% of cases. INTERPRETATION:Use of an algorithm combining three immunological factors at the time of a low-grade endomyocardial biopsy enables prospective stratification of cardiac transplant recipients into risk categories for progression to high-grade rejection. Low-risk individuals require fewer biopsies, moderate-risk individuals require an ongoing schedule of surveillance biopsies, and high-risk individuals require rational organisation of interventional strategies aimed at preventing rejection. Additional predictive factors are needed to identify moderate-risk individuals who will progress to rejection. Ultimately, successful intervention may have an impact on the subsequent complication of TCAD. 10.1016/S0140-6736(98)09475-6
Domesticating the foreign body response: Recent advances and applications. Advanced drug delivery reviews The foreign body response is an immunological process that leads to the rejection of implanted devices and presents a fundamental challenge to their performance, durability, and therapeutic utility. Recent advances in materials development and device design are now providing strategies to overcome this immune-mediated reaction. Here, we briefly review our current mechanistic understanding of the foreign body response and highlight new anti-FBR technologies from this decade that have been applied successfully in biomedical applications relevant to implants, devices, and cell-based therapies. Further development of these important technologies promises to enable new therapies, diagnostics, and revolutionize the management of patient care for many intractable diseases. 10.1016/j.addr.2019.08.010
Facial transplantation: the first 9 years. Khalifian Saami,Brazio Philip S,Mohan Raja,Shaffer Cynthia,Brandacher Gerald,Barth Rolf N,Rodriguez Eduardo D Lancet (London, England) Since the first facial transplantation in 2005, 28 have been done worldwide with encouraging immunological, functional, psychological, and aesthetic outcomes. Unlike solid organ transplantation, which is potentially life-saving, facial transplantation is life-changing. This difference has generated ethical concerns about the exposure of otherwise young and healthy individuals to the sequelae of lifelong, high-dose, multidrug immunosuppression. Nevertheless, advances in immunomodulatory and immunosuppressive protocols, microsurgical techniques, and computer-aided surgical planning have enabled broader clinical application of this procedure to patients. Although episodes of acute skin rejection continue to pose a serious threat to face transplant recipients, all cases have been controlled with conventional immunosuppressive regimens, and no cases of chronic rejection have been reported. 10.1016/S0140-6736(13)62632-X
Widespread immunological functions of mast cells: fact or fiction? Rodewald Hans-Reimer,Feyerabend Thorsten B Immunity Immunological functions of mast cells are currently considered to be much broader than the original role of mast cells in IgE-driven allergic disease. The spectrum of proposed mast cell functions includes areas as diverse as the regulation of innate and adaptive immune responses, protective immunity against viral, microbial, and parasitic pathogens, autoimmunity, tolerance to graft rejection, promotion of or protection from cancer, wound healing, angiogenesis, cardiovascular diseases, diabetes, obesity, and others. The vast majority of in vivo mast cell data have been based on mast cell-deficient Kit mutant mice. However, work in new mouse mutants with unperturbed Kit function, which have a surprisingly normal immune system, has failed to corroborate some key immunological aspects, formerly attributed to mast cells. Here, we consider the implications of these recent developments for the state of the field as well as for future work, aiming at deciphering the physiological functions of mast cells. 10.1016/j.immuni.2012.07.007
Prevention of acute and chronic allograft rejection with CD4+CD25+Foxp3+ regulatory T lymphocytes. Joffre Olivier,Santolaria Thibault,Calise Denis,Al Saati Talal,Hudrisier Denis,Romagnoli Paola,van Meerwijk Joost P M Nature medicine A major challenge in transplantation medicine is controlling the very strong immune responses to foreign antigens that are responsible for graft rejection. Although immunosuppressive drugs efficiently inhibit acute graft rejection, a substantial proportion of patients suffer chronic rejection that ultimately leads to functional loss of the graft. Induction of immunological tolerance to transplants would avoid rejection and the need for lifelong treatment with immunosuppressive drugs. Tolerance to self-antigens is ensured naturally by several mechanisms; one major mechanism depends on the activity of regulatory T lymphocytes. Here we show that in mice treated with clinically acceptable levels of irradiation, regulatory CD4+CD25+Foxp3+ T cells stimulated in vitro with alloantigens induced long-term tolerance to bone marrow and subsequent skin and cardiac allografts. Regulatory T cells specific for directly presented donor antigens prevented only acute rejection, despite hematopoietic chimerism. By contrast, regulatory T cells specific for both directly and indirectly presented alloantigens prevented both acute and chronic rejection. Our findings demonstrate the potential of appropriately stimulated regulatory T cells for future cell-based therapeutic approaches to induce lifelong immunological tolerance to allogeneic transplants. 10.1038/nm1688
HLA in transplantation. Montgomery Robert A,Tatapudi Vasishta S,Leffell Mary S,Zachary Andrea A Nature reviews. Nephrology The human major histocompatibility complex is a family of genes that encodes HLAs, which have a crucial role in defence against foreign pathogens and immune surveillance of tumours. In the context of transplantation, HLA molecules are polymorphic antigens that comprise an immunodominant alloreactive trigger for the immune response, resulting in rejection. Remarkable advances in knowledge and technology in the field of immunogenetics have considerably enhanced the safety of transplantation. However, access to transplantation among individuals who have become sensitized as a result of previous exposure to alloantigens is reduced proportional to the breadth of their sensitization. New approaches for crossing the HLA barrier in transplantation using plasmapheresis, intravenous immunoglobulin and kidney paired donation have been made possible by the relative ease with which even low levels of anti-HLA antibodies can now be detected and tracked. The development of novel protocols for the induction of tolerance and new approaches to immunomodulation was also facilitated by advances in HLA technology. Here, we review the progress made in understanding HLAs that has enabled organ transplantation to become a life-saving endeavour that is accessible even for sensitized patients. We also discuss novel approaches to desensitization, immunomodulation and tolerance induction that have the potential to further improve transplantation access and outcomes. 10.1038/s41581-018-0039-x
Islet transplantation versus insulin therapy in patients with type 1 diabetes with severe hypoglycaemia or poorly controlled glycaemia after kidney transplantation (TRIMECO): a multicentre, randomised controlled trial. Lablanche Sandrine,Vantyghem Marie-Christine,Kessler Laurence,Wojtusciszyn Anne,Borot Sophie,Thivolet Charles,Girerd Sophie,Bosco Domenico,Bosson Jean-Luc,Colin Cyrille,Tetaz Rachel,Logerot Sophie,Kerr-Conte Julie,Renard Eric,Penfornis Alfred,Morelon Emmanuel,Buron Fanny,Skaare Kristina,Grguric Gwen,Camillo-Brault Coralie,Egelhofer Harald,Benomar Kanza,Badet Lionel,Berney Thierry,Pattou François,Benhamou Pierre-Yves, The lancet. Diabetes & endocrinology BACKGROUND:Islet transplantation is indicated for patients with type 1 diabetes with severe hypoglycaemia or after kidney transplantation. We did a randomised trial to assess the efficacy and safety of islet transplantation compared with insulin therapy in these patients. METHODS:In this multicentre, open-label, randomised controlled trial, we randomly assigned (1:1) patients with type 1 diabetes at 15 university hospitals to receive immediate islet transplantation or intensive insulin therapy (followed by delayed islet transplantation). Eligible patients were aged 18-65 years and had severe hypoglycaemia or hypoglycaemia unawareness, or kidney grafts with poor glycaemic control. We used computer-generated randomisation, stratified by centre and type of patient. Islet recipients were scheduled to receive 11 000 islet equivalents per kg bodyweight in one to three infusions. The primary outcome was proportion of patients with a modified β-score (in which an overall score of 0 was not allocated when stimulated C-peptide was negative) of 6 or higher at 6 months after first islet infusion in the immediate transplantation group or 6 months after randomisation in the insulin group. The primary analysis included all patients who received the allocated intervention; safety was assessed in all patients who received islet infusions. This trial is registered with ClinicalTrials.gov, number NCT01148680, and is completed. FINDINGS:Between July 8, 2010, and July 29, 2013, 50 patients were randomly assigned to immediate islet transplantation (n=26) or insulin treatment (n=24), of whom three (one in the immediate islet transplantation group and two in the insulin therapy group) did not receive the allocated intervention. Median follow-up was 184 days (IQR 181-186) in the immediate transplantation group and 185 days (172-201) in the insulin therapy group. At 6 months, 16 (64% [95% CI 43-82]) of 25 patients in the immediate islet transplantation group had a modified β-score of 6 or higher versus none (0% [0-15]) of the 22 patients in the insulin group (p<0·0001). At 12 months after first infusion, bleeding complications had occurred in four (7% [2-18]) of 55 infusions, and a decrease in median glomerular filtration rate from 90·5 mL/min (IQR 76·6-94·0) to 71·8 mL/min (59·0-89·0) was observed in islet recipients who had not previously received a kidney graft and from 63·0 mL/min (55·0-71·0) to 57·0 mL/min (45·5-65·1) in islet recipients who had previously received a kidney graft. INTERPRETATION:For the indications assessed in this study, islet transplantation effectively improves metabolic outcomes. Although studies with longer-term follow-up are needed, islet transplantation seems to be a valid option for patients with severe, unstable type 1 diabetes who are not responding to intensive medical treatments. However, immunosuppression can affect kidney function, necessitating careful selection of patients. FUNDING:Programme Hospitalier de Recherche Clinique grant from the French Government. 10.1016/S2213-8587(18)30078-0
Pancreatic Islet Transplantation in Humans: Recent Progress and Future Directions. Endocrine reviews Pancreatic islet transplantation has become an established approach to β-cell replacement therapy for the treatment of insulin-deficient diabetes. Recent progress in techniques for islet isolation, islet culture, and peritransplant management of the islet transplant recipient has resulted in substantial improvements in metabolic and safety outcomes for patients. For patients requiring total or subtotal pancreatectomy for benign disease of the pancreas, isolation of islets from the diseased pancreas with intrahepatic transplantation of autologous islets can prevent or ameliorate postsurgical diabetes, and for patients previously experiencing painful recurrent acute or chronic pancreatitis, quality of life is substantially improved. For patients with type 1 diabetes or insulin-deficient forms of pancreatogenic (type 3c) diabetes, isolation of islets from a deceased donor pancreas with intrahepatic transplantation of allogeneic islets can ameliorate problematic hypoglycemia, stabilize glycemic lability, and maintain on-target glycemic control, consequently with improved quality of life, and often without the requirement for insulin therapy. Because the metabolic benefits are dependent on the numbers of islets transplanted that survive engraftment, recipients of autoislets are limited to receive the number of islets isolated from their own pancreas, whereas recipients of alloislets may receive islets isolated from more than one donor pancreas. The development of alternative sources of islet cells for transplantation, whether from autologous, allogeneic, or xenogeneic tissues, is an active area of investigation that promises to expand access and indications for islet transplantation in the future treatment of diabetes. 10.1210/er.2018-00154
Macroporous Dual-compartment Hydrogels for Minimally Invasive Transplantation of Primary Human Hepatocytes. Seale Nailah,Ramaswamy Suvasini,Shih Yu-Ru,Verma Inder,Varghese Shyni Transplantation BACKGROUND:Given the shortage of available organs for whole or partial liver transplantation, hepatocyte cell transplantation has long been considered a potential strategy to treat patients suffering from various liver diseases. Some of the earliest approaches that attempted to deliver hepatocytes via portal vein or spleen achieved little success due to poor engraftment. More recent efforts include transplantation of cell sheets or thin hepatocyte-laden synthetic hydrogels. However, these implants must remain sufficiently thin to ensure that nutrients can diffuse into the implant. METHODS:To circumvent these limitations, we investigated the use of a vascularizable dual-compartment hydrogel system for minimally invasive transplantation of primary hepatocytes. The dual-compartment system features a macroporous outer polyethylene glycol diacrylate/hyaluronic acid methacrylate hydrogel compartment for seeding supportive cells and facilitating host cell infiltration and vascularization and a hollow inner core to house the primary human hepatocytes. RESULTS:We show that the subcutaneous implantation of these cell-loaded devices in NOD/SCID mice facilitated vascular formation while supporting viability of the transplanted cells. Furthermore, the presence of human serum albumin in peripheral blood and the immunostaining of excised implants indicated that the hepatocytes maintained function in vivo for at least 1 month, the longest assayed time point. CONCLUSIONS:Cell transplantation devices that assist the anastomosis of grafts with the host can be potentially used as a minimally invasive ectopic liver accessory to augment liver-specific functions as well as potentially treat various pathologies associated with compromised functions of liver, such as hemophilia B or alpha-1 antitrypsin deficiency. 10.1097/TP.0000000000002330