Sustained immunotolerance in multiple sclerosis after stem cell transplant

Current knowledge on multiple sclerosis pathophysiology, disability progression assessment and treatment options, and the role of autologous hematopoietic stem cell transplantation

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that affects nearly 2.8 million people each year. MS distinguishes three main types: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS) and primary progressive MS (PPMS). RRMS is the most common type, with the majority of patients eventually progressing to SPMS, in which neurological development is constant, whereas PPMS is characterized by a progressive course from disease onset. New or additional insights into the role of effector and regulatory cells of the immune and CNS systems, Epstein-Barr virus (EBV) infection, and the microbiome in the pathophysiology of MS have emerged, which may lead to the development of more targeted therapies that can halt or reverse neurodegeneration. Depending on the type and severity of the disease, various disease-modifying therapies (DMTs) are currently used for RRMS/SPMS and PPMS. As a last resort, and especially in highly active RRMS that does not respond to DMTs, autologous hematopoietic stem cell transplantation (AHSCT) is performed and has shown good results in reducing neuroinflammation. Nevertheless, the question of its potential role in preventing disability progression remains open. The aim of this review is to provide a comprehensive update on MS pathophysiology, assessment of MS disability progression and current treatments, and to examine the potential role of AHSCT in preventing disability progression.

The differentiation courses of the Tfh cells: a new perspective on autoimmune disease pathogenesis and treatment

The follicular helper T cells are derived from CD4+T cells, promoting the formation of germinal centers and assisting B cells to produce antibodies. This review describes the differentiation process of Tfh cells from the perspectives of the initiation, maturation, migration, efficacy, and subset classification of Tfh cells, and correlates it with autoimmune disease, to provide information for researchers to fully understand Tfh cells and provide further research ideas to manage immune-related diseases.

Immunological outcomes of autologous hematopoietic stem cell transplantation for multiple sclerosis: a systematic review

Background

Autologous hematopoietic stem cell transplantation (AHSCT) is an extensive procedure that allows for the depletion of the immune system and its restoration from hemopoietic stem cells. The approach has been modified for the treatment of severe immune-mediated illnesses, including multiple sclerosis (MS), after being initially devised for the treatment of hematological malignancies.

Objective

This systematic review aims to determine and consolidate the information on the short-term and long-term immunological effects of AHSCT on the cellular level in MS patients.

Methods

The PubMed, Scopus, and Web of Science servers were used to conduct a systematic search in compliance with the PRISMA guidelines. The results were tabulated and analyzed.

Results

A total of 17 studies (10 clinical trials, 6 cohort studies, and 1 case-control study) were included in the final analysis, and 383 MS patients were analyzed. A significant decline in the cell count of CD4 T cells was reported when compared to the CD8 T cells, B cells, and NK cells. B cell count returned to baseline in 71.4% of the studies at the end of 6 months. The NK cell count was found to be above the baseline in 62.5% of studies.

Conclusion

AHSCT has been proven to be one of the most effective treatment modalities for MS in recent studies. However, debilitating complications due to immunological outcomes of the procedure have led to increased morbidity. Further research into this domain will help boost the success rate and efficacy of AHSCT.

Regulatory T Cells in Multiple Sclerosis Diagnostics-What Do We Know So Far?

BACKGROUND

Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS) through inflammation. MS symptoms become acute if the disease progresses to the relapsing phase.

AIM

This review aimed to evaluate the role played by regulatory T cells (Tregs) in the pathogenesis of MS.

METHODS

This review used scholarly journal articles obtained from PubMed, PsycINFO, and CINAHL with different search parameters such as 'regulatory T cells', 'multiple sclerosis', and 'current knowledge'. The process of searching for articles was limited to those that had publication dates falling between 2010 and 2020.

RESULTS

Tregs play a role in the pathogenesis of MS. This conclusion is supported by animal disease models and environmental factors that can underlie Treg alterations in MS. Despite the knowledge of the role played by Tregs in MS pathogenesis, the specific subsets of Tregs involved in MS development remain incompletely understood.

DISCUSSION

This review provides an essential link between Tregs and MS activity. Targeting Tregs could be an efficient way to establish new treatment methods for MS management.

CONCLUSION

MS is a complex condition affecting many people worldwide. Research has shown that Tregs can influence MS development and progression. More investigations are needed to understand how Tregs affect the pathogenesis of MS.

Potential of Nano-Engineered Stem Cells in the Treatment of Multiple Sclerosis: A Comprehensive Review

Multiple sclerosis (MS) is a chronic and degrading autoimmune disorder mainly targeting the central nervous system, leading to progressive neurodegeneration, demyelination, and axonal damage. Current treatment options for MS are limited in efficacy, generally linked to adverse side effects, and do not offer a cure. Stem cell therapies have emerged as a promising therapeutic strategy for MS, potentially promoting remyelination, exerting immunomodulatory effects and protecting against neurodegeneration. Therefore, this review article focussed on the potential of nano-engineering in stem cells as a therapeutic approach for MS, focusing on the synergistic effects of combining stem cell biology with nanotechnology to stimulate the proliferation of oligodendrocytes (OLs) from neural stem cells and OL precursor cells, by manipulating neural signalling pathways-PDGF, BMP, Wnt, Notch and their essential genes such as Sox, bHLH, Nkx. Here we discuss the pathophysiology of MS, the use of various types of stem cells in MS treatment and their mechanisms of action. In the context of nanotechnology, we present an overview of its applications in the medical and research field and discuss different methods and materials used to nano-engineer stem cells, including surface modification, biomaterials and scaffolds, and nanoparticle-based delivery systems. We further elaborate on nano-engineered stem cell techniques, such as nano script, nano-exosome hybrid, nano-topography and their potentials in MS. The article also highlights enhanced homing, engraftment, and survival of nano-engineered stem cells, targeted and controlled release of therapeutic agents, and immunomodulatory and tissue repair effects with their challenges and limitations. This visual illustration depicts the process of utilizing nano-engineering in stem cells and exosomes for the purpose of delivering more accurate and improved treatments for Multiple Sclerosis (MS). This approach targets specifically the creation of oligodendrocytes, the breakdown of which is the primary pathological factor in MS.

Detailed immunophenotyping of the hematopoietic graft from patients with multiple sclerosis undergoing autologous hematopoietic stem cell transplant

BACKGROUND AIMS

Autologous hematopoietic stem cell transplantation (AHSCT) is a highly effective therapy for relapsing multiple sclerosis. Re-infused stem cells provide "rescue" from the pancytopenia induced by immuno-chemotherapy. To date, no study has analyzed the non-stem cell content of the leukapheresis product (graft) in regards to its influence on disease remission in AHSCT for multiple sclerosis (MS).

METHODS

Detailed immunophenotyping of the stem cell graft was performed in a cohort of highly active patients with MS (n = 22) followed for a median of 6 years' post-AHSCT.

RESULTS

Effector memory populations thought to house pathogenic clones including Th17 cells and central nervous system homing T cells were detected in the graft at similar proportions to pre-AHSCT. There was no association between absolute counts of these populations in the graft and treatment response. Only in responder patients was there evidence of a significant decrease in these putative pro-inflammatory populations by 3 months' post-transplant. Although there was no statistical difference in the number of T regulatory cells (Tregs) in the graft between responders and relapsing patients, the absolute count of Tregs in the graft correlated with circulating Tregs in the first 6 months post-AHSCT in responders alone.

CONCLUSIONS

Our results collectively suggest that the early establishment of immune tolerance post-AHSCT appears to relate to a decrease in putative pathogenic cell populations following reinfusion, and that Treg load in the leukapheresis product is less relevant to treatment response than the early expansion of graft-derived Tregs. It therefore remains unclear whether employment of CD34 selection to manipulate the graft may offer additional benefit in remission rates post-AHSCT for MS. Cellular therapy targeted toward early Treg expansion may provide recourse for long-term remission rates in MS.

Natural killer cells in the central nervous system

Natural killer (NK) cells are essential components of the innate lymphoid cell family that work as both cytotoxic effectors and immune regulators. Accumulating evidence points to interactions between NK cells and the central nervous system (CNS). Here, we review the basic knowledge of NK cell biology and recent advances in their roles in the healthy CNS and pathological conditions, with a focus on normal aging, CNS autoimmune diseases, neurodegenerative diseases, cerebrovascular diseases, and CNS infections. We highlight the crosstalk between NK cells and diverse cell types in the CNS and the potential value of NK cells as novel therapeutic targets for CNS diseases. Video Abstract.

The Use of Stem Cells as a Potential Treatment Method for Selected Neurodegenerative Diseases: Review

Stem cells have been the subject of research for years due to their enormous therapeutic potential. Most neurological diseases such as multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) are incurable or very difficult to treat. Therefore new therapies are sought in which autologous stem cells are used. They are often the patient's only hope for recovery or slowing down the progress of the disease symptoms. The most important conclusions arise after analyzing the literature on the use of stem cells in neurodegenerative diseases. The effectiveness of MSC cell therapy has been confirmed in ALS and HD therapy. MSC cells slow down ALS progression and show early promising signs of efficacy. In HD, they reduced huntingtin (Htt) aggregation and stimulation of endogenous neurogenesis. MS therapy with hematopoietic stem cells (HSCs) inducted significant recalibration of pro-inflammatory and immunoregulatory components of the immune system. iPSC cells allow for accurate PD modeling. They are patient-specific and therefore minimize the risk of immune rejection and, in long-term observation, did not form any tumors in the brain. Extracellular vesicles derived from bone marrow mesenchymal stromal cells (BM-MSC-EVs) and Human adipose-derived stromal/stem cells (hASCs) cells are widely used to treat AD. Due to the reduction of Aβ42 deposits and increasing the survival of neurons, they improve memory and learning abilities. Despite many animal models and clinical trial studies, cell therapy still needs to be refined to increase its effectiveness in the human body.

The Safety and Efficacy of Mesenchymal Stem Cells in the Treatment of Type 2 Diabetes- A Literature Review

INTRODUCTION

Type 2 diabetes (T2D) is the most common type of diabetes, affecting 6.28% of the population worldwide. Over the decades, multiple therapies and drugs have been developed to control T2D, but they are far from a long-term solution. Stem cells are promising as novel regenerative treatments, especially mesenchymal stem cells (MSCs), which are highly versatile in their regenerative and paracrine capabilities and characteristics. This makes them the most commonly used adult stem cells and ideal candidates to treat diabetes.

OBJECTIVE

To assess the safety and efficacy of mesenchymal stem cells (MSCs) in treating Type 2 diabetes (T2D) in humans.

METHODS

Mesenchymal stem cell-based treatments were studied in 262 patients. A total of 6 out of 58 trials fit our inclusion criteria in the last five years.

RESULTS

The treatment of patients with MSCs reduced the dosage of anti-diabetic drugs analyzed over a follow-up period of 12 months. The effective therapy dosage ranged from 1×10⁶ cells/kg to 3.7×10⁶ cells/kg. After treatment, HbAc1 levels were reduced by an average of 32%, and the fasting blood glucose levels were reduced to an average of 45%. The C-peptide levels were decreased by an average of 38% in 2 trials and increased by 36% in 4 trials. No severe adverse events were noted in all trials.

CONCLUSION

This analysis concludes that MSC treatment of type 2 diabetes is safe and effective. A larger sample size is required, and the trials should also study the effect of differentiated MSCs as insulin-producing cells.

[Multiple sclerosis: interventions to halt disease : Which patients can be considered for autologous stem cell transplantation]

BACKGROUND

Autologous hematopoietic stem cell transplantation (aHSCT) for treatment of multiple sclerosis (MS) is gaining increasing prominence in the therapeutic landscape. This review article focuses on describing the evidence and European guidelines for aHSCT so that neurologists in Germany can consider this treatment option for appropriate MS patients. In this context, it must be taken into consideration that in every case a cost transfer must be individually applied for.

AIM

To provide information for neurologists considering aHSCT for patients with MS.

MATERIAL AND METHODS

In this narrative review articles from PubMed were pooled and analyzed.

RESULTS AND DISCUSSION

High quality data from randomized, controlled clinical trials are required to compare the efficacy of aHSCT to the currently available highly effective disease-modifying therapies (DMT) so that reliable conclusions can be drawn regarding the relationship between the risks and benefits of aHSCT in MS; however, the studies discussed in this review provide important points of reference for patient selection and the transplantation protocol. Further advice is available from the European Society for Blood and Marrow Transplantation (EBMT) for experienced centers considering aHSCT. The available data and the European guidelines suggest that patients aged less than 45 years, an expanded disability status scale (EDSS) ≤ 5.5, highly active MS, a disease duration of less than 10 years, an ineffective course of DMT or rapidly progressive MS may be eligible for aHSCT and should be referred to an experienced center for further assessment.

Antibody-mediated cell depletion therapies in multiple sclerosis

Development of disease-modifying therapies including monoclonal antibody (mAb)-based therapeutics for the treatment of multiple sclerosis (MS) has been extremely successful over the past decades. Most of the mAb-based therapies approved for MS deplete immune cell subsets and act through activation of cellular Fc-gamma receptors expressed by cytotoxic lymphocytes and phagocytes, resulting in antibody-dependent cellular cytotoxicity or by initiation of complement-mediated cytotoxicity. The therapeutic goal is to eliminate pathogenic immune cell components and to potentially foster the reconstitution of a new and healthy immune system. Ab-mediated immune cell depletion therapies include the CD52-targeting mAb alemtuzumab, CD20-specific therapeutics, and new Ab-based treatments which are currently being developed and tested in clinical trials. Here, we review recent developments in effector mechanisms and clinical applications of Ab-based cell depletion therapies, compare their immunological and clinical effects with the prototypic immune reconstitution treatment strategy, autologous hematopoietic stem cell transplantation, and discuss their potential to restore immunological tolerance and to achieve durable remission in people with MS.

Adenosinergic axis and immune checkpoint combination therapy in tumor: A new perspective for immunotherapy strategy

There are two figures and one table in this review, the review consists of 5823 words, without the description of figures and table, but including references.

Tumor cells escape anti-tumor immune responses in various ways, including functionally shaping the microenvironment through the secretion of various chemokines and, cytokines. Adenosine is a powerful immunosuppressive metabolite, that is frequently elevated in the extracellular tumor microenvironment (TME). Thus, it has recently been proposed as a novel antitumor immunoassay for targeting adenosine- generating enzymes, such as CD39, CD73, and adenosine receptors. In recent years, the discovery of the immune checkpoints, such as programmed cell death 1(PD-1) and cytotoxic T lymphocyte antigen 4 (CTLA-4), has also greatly changed treatment methods and ideas for malignant tumors. Malignant tumor immunotherapy has been developed from point-to-point therapy targeting immune checkpoints, combining different points of different pathways to create a therapy based on the macroscopic immune regulatory system network. This article reviews the theoretical basis of the adenosine energy axis and immune checkpoint combined therapy for malignant tumors and the latest advances in malignant tumors.

The genealogy, methodology, similarities and differences of immune reconstitution therapies for multiple sclerosis and neuromyelitis optica

Immune reconstitution therapies (IRTs) are a type of short course procedure or pharmaceutical agent within the MS pharmacopeia. They emanate from oncology and induce transient incomplete lympho-ablation with or without myelo-ablation, resulting in potential prolonged immunomodulation. Thus, they provide significant prophylaxis from disease activity without retreatment. Modern IRT for autoimmunity encompasses a heterogeneous group of pulsed lympho- and non-myelo-ablative treatments designed to re-boot the adaptive immune system in a quasi-permanent manner - a re-induction of ontogeny. IRT is the extensive debulking of an auto-aggressive immune system to attempt to reach the Holy Grail of immune tolerance. This incomplete yet significant lympho-ablation induces lymphoproliferation, reduces pathogenic clonal cells, causes thymopoiesis and results in the induction of immune tolerance. Lympho-ablation with immune reconstitution can result in minimal residual autoimmunity. There is a resetting of the immune thermostat - i.e., the immunostat. IRTs have the potential to provide prolonged periods of disease inactivity without retreatment in part through the immunological results of their pulsatile lymphocyte depletion. It is vital to increase our understanding of how IRTs alter a patient's immune response to the antigenic target of the disease so that we can devise newer, more durable and safer forms of such agents. What common features do extant IRTs (i.e., stem cell transplant, alemtuzumab and oral cladribine) have to produce the durable therapeutic response without long term treatment in neuroimmunological diseases such as MS (multiple sclerosis) and NMOSD (neuromyelitis optica spectrum disorders)? Can we learn from these critical features to predict what other maneuvers or agents might effect similar clinical results with equal or greater efficacy and safety?

The current standing of autologous haematopoietic stem cell transplantation for the treatment of multiple sclerosis

Autologous haematopoietic stem cell transplantation (aHSCT) is gaining traction as a valuable treatment option for patients affected by severe multiple sclerosis (MS), particularly the relapsing–remitting form. We describe the current literature in terms of clinical trials, observational and retrospective studies, as well as immune reconstitution following transplantation, with a focus on the conditioning regimens used for transplantation. The evidence base predominantly consists of non-randomised, uncontrolled clinical trials or data from retrospective or observational cohorts, i.e. very few randomised or controlled trials. Most often, intermediate-intensity conditioning regimens are used, with promising results from both myeloablative and lymphoablative strategies, as well as from regimens that are low and high intensity. Efficacy of transplantation, which is likely secondary to immune reconstitution and restored immune tolerance, is, therefore, not clearly dependent on the intensity of the conditioning regimen. However, the conditioning regimen may well influence the immune response to transplantation. Heterogeneity of conditioning regimens among studies hinders synthesis of the articles assessing post-aHSCT immune system changes. Factors associated with better outcomes were lower Kurtzke Expanded Disability Status Scale, relapsing–remitting MS, younger age, and shorter disease duration at baseline, which supports the guidance for patient selection proposed by the European Society for Blood and Marrow Transplantation. Interestingly, promising outcomes were described for patients with secondary progressive MS by some studies, which may be worth taking into account when considering treatment options for patients with active, progressive disease. Of note, a significant proportion of patients develop autoimmune disease following transplantation, with alemtuzumab-containing regimens associated with the highest incidence.