Need For Immunosuppression Research Articles

An investigation of functionalized chitosan and alginate multilayer conformal nanocoating on mouse beta cell spheroids as a model for pancreatic islet transplantation

Multilayer conformal coatings have been shown to provide a nanoscale barrier between cells and their environment with adequate stability, while regulating the diffusion of nutrition and waste across the cell membrane. The coating method aims to minimize capsule thickness and implant volume while reducing the need for immunosuppressive drugs, making it a promising approach for islet cell encapsulation in clinical islet transplantation for the treatment of Type 1 diabetes. This study introduces an immunoprotective nanocoating obtained through electrostatic interaction between quaternized phosphocholine-chitosan (PC-QCH) and tetrahydropyran triazole phenyl-alginate (TZ-AL) onto mouse β-cell spheroids. First, successful synthesis of the proposed polyelectrolytes was confirmed with physico-chemical characterization. A coating with an average thickness of 540 nm was obtained with self-assembly of 4-bilayers of PC-QCH/TZ-AL onto MIN6 β-cell spheroids. Surface coating of spheroids did not affect cell viability, metabolic activity, or insulin secretion, when compared to non-coated spheroids. The exposure of the polyelectrolytes to THP-1 monocyte-derived macrophages lead to a reduced level of TNF-α secretion and exposure of coated spheroids to RAW264.7 macrophages showed a decreasing trend in the secretion of TNF-α and IL-6. In addition, coated spheroids were able to establish normoglycemia when implanted into diabetic NOD-SCID mice, demonstrating in vivo biocompatibility and cellular function. These results demonstrate the ability of the PC-QCH/TZ-AL conformal coating to mitigate pro-inflammatory responses from macrophages, and thus can be a promising candidate towards nanoencapsulation for cell-based therapy, particularly in type 1 diabetes, where the insulin secreting β-cells are subjected to inflammation and immune cell attack.

Sickle cell disease: combination new therapies vs. CRISPR-Cas9 potential and challenges - review article.

In 2022, sickle cell disease (SCD) continues to affect the lives of millions of people, being one of the most frequently inherited blood disorders worldwide. Recently, several new therapies have been FDA approved for the treatment of SCD. The complexity of the pathophysiology of sickling has given opportunity to the evolution of several modalities of therapies. Nonetheless, the potential for complementary targeting of HbS polymerization, vasocclusion, and other inflammatory pathways remains controversial. None of these drugs can be considered a single curative line of treatment. With the advancement of CRISPR/Cas9 technology, autologous transplant of gene-edited hematopoietic stem cells could possibly provide a cure for most patients with SCD. The advantage of this approach over the conventional stem cell transplantation is that it decreases the need for immuno-suppressive drugs and the risk of graft-versus-host disease. In addition, recent technological advances can reduce the off-target effects, but long-term monitoring is needed to ensure the reliability of these methods in the clinical setting. This review explores the efficacy and safety of combination therapies and contrasting this alternative with the challenges that exist with sickle cell gene therapy using CRISPR.

OC-009 SYNGENEIC VERSUS ALLOGENEIC NON-VASCULARIZED RECTUS FASCIA TRANSPLANTATION IN A RABBIT MODEL WITHOUT IMMUNOSUPPRESSION: SHORT TERM OUTCOME

Abstract Background and aim Transplantation (Tx) of non-vascularized rectus fascia (NVRF) is a valid option in solid organ transplant recipients to avoid open abdomen after Tx. To extrapolate this technique for non-Tx patients, we investigated in a preclinical rabbit model the feasibility of transplanting NVRF in a syngeneic (Syn) versus allogeneic (Allo) strain without using immunosuppression (IS). Short-term outcome was evaluated after 4 weeks. Material and methods A validated rabbit model of NVRF Tx was used comparing 6 Syn New Zealand White (NZW) rabbits versus 6 Allo Mixed breed to NZW Tx without IS. Animals were macroscopically analyzed at harvesting after 4 weeks for graft integration, herniation, adhesions, seroma, hematoma, and surgical site infections. Histological and immunohistochemical analysis was performed to assess inflammatory cell reaction and neovascularization. Mechanical testing was performed to assess the thickness, stiffness and strength. Results Results showed similar sufficient macroscopic ingrowth of the NVRF in both groups. At the histological level, cell infiltration suggested a clearing reaction more than a rejection-based inflammation, which was more pronounced in the Allo group. No significant differences were seen concerning mechanical properties. Conclusions In a validated rabbit model of NVRF Tx, we showed that Tx was possible in an Allo strain without the need for IS, resulting in satisfying short term inflammatory and mechanical outcomes. Longer-term experiments are needed to evaluate the effect of graft integration and possible hernia development.

Clinical predictors for a complicated course of disease in an inception cohort of patients with ulcerative colitis: results from the prospective, observational EPICOL study

PurposeThe clinical course of ulcerative colitis (UC) is highly heterogeneous, with 20 to 30% of patients experiencing chronic disease activity requiring immunosuppressive or biologic therapies. The aim of this study was to identify predictors for a complicated disease course in an inception cohort of patients with UC.MethodsEPICOL was a prospective, observational, inception cohort (UC diagnosis, ≤ 6 months) study in 311 patients with UC who were naive to immunosuppressants (IS)/biologics. A complicated course of disease was defined as the need for IS and/or biologic treatment (here therapy with a TNF-α antagonist) and/or UC-related hospitalisation. Patients were followed up for 24 months.ResultsOf the 307 out of 311 participants (4 patients did not meet the inclusion criteria “confirmed diagnosis of active UC within the last 6 months” (n = 2) and “immunosuppressive-naïve” (n = 2), analysis population), 209 (68.1%) versus 98 (31.9%) had an uncomplicated versus a complicated disease course, respectively. In a multivariate regression analysis, prior use of corticosteroids and prior anaemia were associated with a significantly increased risk for a complicated disease course (2.3- and 1.9-fold increase, respectively; p < 0.001 and p = 0.002). Based on these parameters, a risk model for patient stratification was developed.ConclusionOur study identifies anaemia and an early need for corticosteroids as predictors for a complicated course of disease in an inception cohort of patients with UC. By determining these parameters in routine clinical practice, our results may support the identification of patients who might benefit from early escalation of therapy.

Disease severity and response to treatment in Iranian patients with myasthenia gravis.

Myasthenia gravis (MG) is a potentially fatal neuromuscular disorder if left untreated. In this study, we tried to address the possible demographic, clinical, and laboratory determinants of severity and outcome in Iranian MG patients over a follow-up period of more than 5years. Demographic and diagnostic data (age, age of onset, antibody status, thymus pathology, and duration of the disease) of the patients with MG were extracted. Maximal disease severity and post-intervention status were assessed according to the recommendations of the task force of the Myasthenia Gravis Foundation of America. In our series of 146 patients, MG was more severe in older, anti-muscle specific tyrosine kinase (MuSK) positive, and thymomatous patients. Seropositivity to the MuSK antibody and the presence of thymoma determined the need for immunosuppressive drugs. However, the number of patients requiring more than one immunosuppressive was not significantly different among various subtypes. The overall outcome was favorable in the majority of patients, despite differences in the disease course and severity. In contrary to the previous reports, anti-MuSK positive patients in our series did not need a more vigorous treatment regimen comparing other serologic subtypes of MG.

Uterus transplant update: innovative fertility solutions and the widening horizons of bioengineering.

Uterus transplantation (UTx) aimed at restoring fertility for women suffering from uterine factor infertility has been making significant strides over the past years, leading to the first successful outcome of live birth in 2014. Nonetheless, the ethical issues raised by such a procreative option are uniquely complex and multifaceted. UTx presents unique features, and the most significant risks it entails are the multiple surgeries required and the need for immunosuppressive drugs to prevent organ rejection. Post-transplantation immunosuppressive therapy, rejection monitoring, and immune tolerance are all crucial aspects That affect UTx outcomes and ensuing pregnancy success rates. In time, an alternative tool might become clinically available that could solve all those issues: tissue engineering relying on a combination of cells, biomaterials, and growth factors that harness the body's innate ability to regenerate and repair reproductive organs. Mastering such techniques could lead in the medium-long term to the creation of a bioengineered uterus for the purpose of transplantation, based on scaffolds derived from decellularized organs or tissues that can be recellularized by several types of autologous somatic/stem cells, in particular for uterine tissue engineering.

Recent Advances in the Generation of β-Cells from Induced Pluripotent Stem Cells as a Potential Cure for Diabetes Mellitus.

Diabetes mellitus (DM) is a group of metabolic disorders characterized by high blood glucose levels due to insufficient insulin secretion, insulin action, or both. The present-day solution to diabetes mellitus includes regular administration of insulin, which brings about many medical complications in diabetic patients. Although islet transplantation from cadaveric subjects was proposed to be a permanent cure, the increased risk of infections, the need for immunosuppressive drugs, and their unavailability had restricted its use. To overcome this, the generation of renewable and transplantable β-cells derived from autologous induced pluripotent stem cells (iPSCs) has gained enormous interest as a potential therapeutic strategy to treat diabetes mellitus permanently. To date, extensive research has been undertaken to derive transplantable insulin-producing β-cells (iβ-cells) from iPSCs in vitro by recapitulating the in vivo developmental process of the pancreas. This in vivo developmental process relies on transcription factors, signaling molecules, growth factors, and culture microenvironment. This review highlights the various factors facilitating the generation of mature β-cells from iPSCs. Moreover, this review also describes the generation of pancreatic progenitors and β-cells from diabetic patient-specific iPSCs, exploring the potential of the diabetes disease model and drug discovery. In addition, the applications of genome editing strategies have also been discussed to achieve patient-specific diabetes cell therapy. Last, we have discussed the current challenges and prospects of iPSC-derived β-cells to improve the relative efficacy of the available treatment of diabetes mellitus.

Predictive parameters for the clinical course of Crohn's disease: development of a simple and reliable risk model.

The aim of our study was to identify clinical parameters in recently diagnosed Crohn's disease (CD) patients for prediction of their disease course. EPIC (Early Predictive parameters of Immunosuppressive therapy in Crohn's disease) is a prospective, observational study in 341 patients with a recent CD diagnosis (≤ 6months), and naïve to immunosuppressants (IS) and anti-tumor necrosis factor α (TNF) agents. Patient characteristics were documented up to 2years. In line with national and international guidelines, a complicated disease course was defined as need for immunosuppressants and/or anti-TNF agents, and CD-related hospitalization with or without immunosuppressants and/or anti-TNF agents. A total of 212 CD patients were analyzed of whom 57 (27%) had an uncomplicated disease within 24months, while 155 (73%) had a complicated disease course: need for IS and/or anti-TNF agents (N = 115), CD-related hospitalization with or without IS/anti-TNF agents (N = 40). Identified risk predictors for a complicated disease were as follows: age at onset < 40years (OR 2.3; 95% CI 1.2-4.5), anemia (OR 2.1; 95% CI 1.1-4.2), and treatment with systemic corticosteroids at first flare (OR 2.2; 95% CI 1.1-4.7). These three parameters were used to develop a risk model allowing prediction of the future disease course. Our three-parameter model enables an assessment of each CD patient's risk to develop a complicated disease course. Due to the easy accessibility of these parameters, this model can be utilized in daily clinical care to assist selecting the initial treatment for each individual patient.

The Impact of Withdrawal of Maintenance Immunosuppression and Graft Nephrectomy on HLA Sensitization and Calculated Chance of Future Transplant.

BackgroundThe development of HLA antibodies towards a failing renal allograft is a barrier to retransplantation. This study aimed to compare the formation of HLA donor-specific antibodies (DSA) in patients undergoing graft nephrectomy and in those with a failed graft left in situ who had maintenance immunosuppression (IS) stopped, and assess the relative impact of IS cessation and graft nephrectomy on future relative chance of transplant (R-CoT).MethodsA single-center retrospective study of patients with failed grafts between 2005 and 2015 was performed. Samples were tested for DSA pre-IS wean, post-IS wean, and post-IS cessation. Nephrectomy patients additionally had samples tested for DSA before and after nephrectomy. Calculated reaction frequency (cRF) was determined at each timepoint and entered into the UK Organ Donation and Transplant R-CoT calculator.ResultsForty-one patients were included in the study: 24 with nephrectomy and 17 with a failed graft in situ. Patient demographics and duration of IS wean were similar between groups. There was a higher rate of blood transfusion (54% vs 24%) in nephrectomy patients. In patients whose graft remained in situ, cRF rose from 13% pre-IS wean to 40% post-IS wean and 62% after IS cessation. This equated to a reduction in mean R-CoT from 54% to 46% at 5 years. In patients undergoing nephrectomy mean cRF rose from 31% pre-IS wean to 69% post-IS wean and 89% post-IS cessation. Mean R-CoT fell from 54% to 42% at 5 years.ConclusionsA stepwise increase in cRF with reduced chance of transplant was observed in both groups as IS was withdrawn, with a similar pattern irrespective of graft nephrectomy. Calculated reaction frequency was higher in the nephrectomy group. The risks and benefits of stopping IS need to be carefully considered on an individual basis to maximize chance of future transplant.

Dexamethasone-Induced Myeloid-Derived Suppressor Cells Prolong Allo Cardiac Graft Survival through iNOS- and Glucocorticoid Receptor-Dependent Mechanism

How to induce immune tolerance without long-term need for immunosuppressive drugs has always been a central problem in solid organ transplantation. Modulating immunoregulatory cells represents a potential target to resolve this problem. Myeloid-derived suppressor cells (MDSCs) are novel key immunoregulatory cells in the context of tumor development or transplantation, and can be generated in vitro. However, none of current systems for in vitro differentiation of MDSCs have successfully achieved long-term immune tolerance. Herein, we combined dexamethasone (Dex), which is a classic immune regulatory drug in the clinic, with common MDSCs inducing cytokine granulocyte macrophage colony stimulating factor (GM-CSF) to generate MDSCs in vitro. Addition of Dex into GM-CSF system specifically increased the number of CD11b+ Gr-1int/low MDSCs with an enhanced immunosuppressive function in vitro. Adoptive transfer of these MDSCs significantly prolonged heart allograft survival and also favored the expansion of regulatory T cells in vivo. Mechanistic studies showed that inducible nitric oxide sythase (iNOS) signaling was required for MDSCs in the control of T-cell response and glucocorticoid receptor (GR) signaling played a critical role in the recruitment of transferred MDSCs into allograft through upregulating CXCR2 expression on MDSCs. Blockade of GR signaling with its specific inhibitor or genetic deletion of iNOS reversed the protective effect of Dex-induced MDSCs on allograft rejection. Together, our results indicated that co-application of Dex and GM-CSF may be a new and important strategy for the induction of potent MDSCs to achieve immune tolerance in organ transplantation.

Facilitating Cells: A Journey from Bench to Bedside

The development of safe conditioning protocols has reduced the morbidity and mortality of hematopoietic stem cell transplantation (HSCT), allowing broader application for treatment of a variety of non-malignant conditions including autoimmune diseases, hemoglobinopathies, metabolic disorders etc., as well as inducing tolerance to solid organ transplants. One of the most successful clinical trials using a facilitating cell enhanced HSCT paired with a kidney transplant has effectively induced tolerance in the absence of immunosuppressive drugs, maintaining the function of the transplanted kidney, and reconstituting the immunocompetence of the recipient. This novel protocol eliminates the need for immunosuppressive drugs, the key source of kidney and liver toxicity, increased malignancy, and shortened life span. CD8+ TCR facilitating cells (FC) are a population of tolerogenic cell which promote hematopoietic stem cell engraftment across human leukocyte antigen (HLA) barriers. In this review, we discuss the bench to bedside journey of FC, from discovery in mouse models, characterization of the subpopulations of FC, the mechanisms by which FC induce tolerance and clinical application. As a novel personalized medicine, FC may change the approach to overcoming HLA barriers for both HSCT and solid organ transplant recipients.

The bioartificial pancreas (BAP): Biological, chemical and engineering challenges

The bioartificial pancreas (BAP) represents a viable solution for the treatment of type 1 diabetes (T1D). By encapsulating pancreatic cells in a semipermeable membrane to allow nutrient, insulin and glucose exchange, the side effects produced by islets and whole organ transplantation-related immunosuppressive therapy can be circumvented. Several factors, mainly related to materials properties, capsule morphology and biological environment, play a key role in optimizing BAP systems.The BAP is an extremely complex delivery system for insulin. Despite considerable efforts, in some instances meeting with limited degree of success, a BAP capable of restoring physiological pancreas functions without the need for immunosuppressive drugs and of controlling blood glucose levels especially in large animal models and a few clinical trials, does not exist. The state of the art in terms of materials, fabrication techniques and cell sources, as well as the current status of commercial devices and clinical trials, are described in this overview from an interdisciplinary viewpoint. In addition, challenges to the creation of effective BAP systems are highlighted including future perspectives in terms of component integration from both a biological and an engineering viewpoint.

Novel biomarkers and functional assays to monitor cell-therapy-induced tolerance in organ transplantation.

Cell-based immunotherapy offers a novel approach to minimize the need for immunosuppressive drugs and to promote a state of immunological tolerance to a transplanted organ. We review the most promising biomarkers and functional assays able to identify patients tolerant to their graft. Such a signature of tolerance is essential in the assessment of the efficacy with which trials of cellular therapies promote immunoregulation and minimize graft rejection. A multitude of novel cellular therapies have entered early-phase clinical trials in solid-organ transplant patients. Recent multicentre collaborations have enabled the determination of distinct tolerance profiles for both liver and kidney transplant recipients. These have been shown to be highly predictive of tolerance in certain settings and show utility in identifying patients in whom immunosuppressive drugs can be weaned or discontinued. In order to become a viable treatment option in solid-organ transplantation, the latest large, multicentre clinical trials of cellular therapies must utilize, validate and discover the biomarkers with the capacity to reliably identify a signature of immune tolerance.

Stem Cell-Derived Beta Cells for Treatment of Type 1 Diabetes?

Stem Cell-Derived Beta Cells for Treatment of Type 1 Diabetes?

Identification of microRNAs involved in acute rejection and spontaneous tolerance in murine hepatic allografts.

Graft acceptance without the need for immunosuppressive drugs is the ultimate goal of transplantation therapy. In murine liver transplantation, allografts are accepted across major histocompatibility antigen complex barriers without the use of immunosuppressive drugs and constitute a suitable model for research on immunological rejection and tolerance. MicroRNA (miRNA) has been known to be involved in the immunological responses. In order to identify mRNAs in spontaneous liver allograft tolerance, miRNA expression in hepatic allografts was examined using this transplantation model. According to the graft pathological score and function, miR-146a, 15b, 223, 23a, 27a, 34a and 451 were upregulated compared with the expression observed in the syngeneic grafts. In contrast, miR-101a, 101b and 148a were downregulated. Our results demonstrated the alteration of miRNAs in the allografts and may indicate the role of miRNAs in the induction of tolerance after transplantation. Furthermore, our data suggest that monitoring the graft expression of novel miRNAs may allow clinicians to differentiate between rejection and tolerance. A better understanding of the tolerance inducing mechanism observed in murine hepatic allografts may provide a therapeutic strategy for attenuating allograft rejection.

The Efficacy of an Immunoisolating Membrane System for Islet Xenotransplantation in Minipigs

Developing a device that protects xenogeneic islets to allow treatment and potentially cure of diabetes in large mammals has been a major challenge in the past decade. Using xenogeneic islets for transplantation is required in light of donor shortage and the large number of diabetic patients that qualify for islet transplantation. Until now, however, host immunoreactivity against the xenogeneic graft has been a major drawback for the use of porcine islets. Our study demonstrates the applicability of a novel immunoprotective membrane that allows successful xenotransplantation of rat islets in diabetic minipigs without immunosuppressive therapy. Rat pancreatic islets were encapsulated in highly purified alginate and integrated into a plastic macrochamber covered by a poly-membrane for subcutaneous transplantation. Diabetic Sinclair pigs were transplanted and followed for up to 90 days. We demonstrated a persistent graft function and restoration of normoglycemia without the need for immunosuppressive therapy. This concept could potentially offer an attractive strategy for a more widespread islet replacement therapy that would restore endogenous insulin secretion in diabetic patients without the need for immunosuppressive drugs and may even open up an avenue for safe utilization of xenogeneic islet donors.

How Regenerative Medicine May Contribute to the Achievement of an Immunosuppression-Free State

How Regenerative Medicine May Contribute to the Achievement of an Immunosuppression-Free State

Illuminating Immune Privilege — A Role for Regulatory T Cells in Preventing Rejection

A recent study suggests that regulatory T cells are relevant in reducing the need for immunosuppressive drugs and in overcoming the limitations of a genetic mismatch between donor and recipient in allogeneic hematopoietic-cell transplantation.

Transplant Tolerance

Until recently, immunologic tolerance was thought to imply the specific absence of an immune response. However, it has now become clear that, at least in the field of transplantation, tolerance can also be brought about by a positive immunologic response of a regulatory nature.2 Thus, we currently define transplant tolerance operationally as “the specific absence of a destructive immune response to a transplanted tissue in the absence of immunosuppression.” The key elements of this definition are “specific,” meaning that the recipient must remain fully capable of responding to other antigens; “destructive immune response,” allowing downregulatory immune responses to still be included in the definition; and “absence of immunosuppression,” signifying total elimination of the need for immunosuppressive drugs, thus not to be confused with the recent concept of “prope tolerance” or “drug minimization.”3,4

Stem cell sources to treat diabetes

We review progress towards the goal of utilizing stem cells as a source of engineered pancreatic beta-cells for therapy of diabetes. Protocols for the in vitro differentiation of embryonic stem (ES) cells based on normal developmental cues have generated beta-like cells that produce high levels of insulin, albeit at low efficiency and without full responsiveness to extracellular levels of glucose. Induced pluripotent stem (iPS) cells also can yield insulin-producing cells following similar approaches. An important recent report shows that when transplanted into mice, human ES-derived cells with a phenotype corresponding to pancreatic endoderm matured to yield cells capable of maintaining near-normal regulation of blood sugar [Kroon et al., 2008]. Major hurdles that must be overcome to enable the broad clinical translation of these advances include teratoma formation by ES and iPS cells, and the need for immunosuppressive drugs. Classes of stem cells that can be expanded extensively in culture but do not form teratomas, such as amniotic fluid-derived stem cells and hepatic stem cells, offer possible alternatives for the production of beta-like cells, but further evidence is required to document this potential. Generation of autologous iPS cells should prevent transplant rejection, but may prove prohibitively expensive. Banking strategies to identify small numbers of stem cell lines homozygous for major histocompatibility loci have been proposed to enable beneficial genetic matching that would decrease the need for immunosuppression.