Administration of embryonic stem cell-derived thymic epithelial progenitors expressing MOG induces antigen-specific tolerance and ameliorates experimental autoimmune encephalomyelitis

Extracellular vesicles containing miR-181a-5p as a novel therapy for experimental autoimmune encephalomyelitis-induced demyelination

Multiple sclerosis (MS) is an inflammatory demyelinating disorder of the central nervous system. Recent research has revealed that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), containing specific miRNAs, possess immunomodulatory properties and have demonstrated therapeutic potential in the treatment of MS. This study aimed to investigate the role MSC-EVs, containing microRNA-181a-5p (miR-181a-5p) in both experimental autoimmune encephalomyelitis (EAE), an established animal model of MS, and lipopolysaccharide-stimulated BV2 microglia. We evaluated clinical symptoms and inflammatory responses in EAE mice following intrathecal injections of MSC-EVs. MSC-EVs containing miR-181a-5p were co-cultured with microglia to explore their impact on inflammation and cell pyroptosis. We validated the interaction between miR-181a-5p and its downstream regulators and conducted in vivo verification by injecting manipulated EVs containing miR-181a-5p into EAE mice. Our results demonstrated that MSC-EVs, containing miR-181a-5p reduced the clinical symptoms of EAE mice. Furthermore, we observed downregulation of miR-181a-5p in EAE model mice, and its expression was restored after treatment with MSC-EVs, which corresponded to suppressed microglial inflammation and pyroptosis. Additionally, EVs containing miR-181a-5p mitigated spinal cord injury and demyelination in EAE mice. Mechanistically, ubiquitin-specific protease 15 (USP15) exhibited high expression in EAE mice, and miR-181a-5p was specifically targeted and bound to USP15, thereby regulating the RelA/NEK7 axis. In conclusion, MSC-EVs containing miR-181a-5p inhibit microglial inflammation and pyroptosis through the USP15-mediated RelA/NEK7 axis, thus alleviating the clinical symptoms of EAE. These findings present a potential therapeutic approach for the treatment of MS.

BTN2A2-Ig protein inhibits the differentiation of pathogenic Th17 cells and attenuates EAE in mice

Pathogenic Th17 cells play a key role in the pathogenesis of many autoimmune diseases. Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is the commonly used animal model for human MS and is characterized by autoreactive CD4⁺ T cells attacking autoantigens in the CNS and causing myelin sheath damage. Although the recombinant BTN2A2-IgG2aFc (BTN2A2-Ig) fusion protein has been shown to inhibit T cell functions in vitro, it's unclear whether BTN2A2-Ig affects pathogenic Th17 cells and EAE development. We show here that BTN2A2-Ig protein attenuates established EAE, as compared with control Ig protein treatment. This is associated with reduced activation and proliferation of T cells in BTN2A2-Ig-treated EAE mice. Furthermore, BTN2A2-Ig protein inhibits the differentiation of CD4 naïve T cells into pathogenic Th17 cells and reduces the expression levels of Th1/Th17 cytokines and the Th1/Th17 pathway related genes and proteins but increases the expression levels of Th2-related genes and proteins. Our studies not only provide new insights into the mechanisms by which BTN2A2-Ig affects T cells, but also have the potential to provide a new strategy to treat MS and other autoimmune diseases.

Mesenchymal stem cell-derived exosomal microRNA-367–3p alleviates experimental autoimmune encephalomyelitis via inhibition of microglial ferroptosis by targeting EZH2

Multiple sclerosis (MS) is an autoimmune, inflammatory demyelinating disorder of the central nervous system. Accumulating evidence has underscored the therapeutic potential of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSC-Exos) containing bioactive compounds in MS. Herein, the current study sought to characterize the mechanism of BMSC-Exos harboring miR-367-3p both in BV2 microglia by Erastin-induced ferroptosis and in experimental autoimmune encephalomyelitis (EAE), a typical animal model of MS. Exosomes were firstly isolated from BMSCs and identified for further use. BV2 microglia were co-cultured with miR-367-3p-containing BMSC-Exos, followed by an assessment of cell ferroptosis. Mechanistic exploration was furthered by the interaction of miR-367-3p and its downstream regulators. Lastly, BMSC-Exos harboring miR-367-3p were injected into EAE mice for in vivo validation. BMSC-Exos carrying miR-367-3p restrained microglial ferroptosis in vitro. Mechanistically, miR-367-3p could bind to Enhancer of zeste homolog 2 (EZH2) and restrain EZH2 expression, leading to the over-expression of solute carrier family 7 member 11 (SLC7A11). Meanwhile, over-expression of SLC7A11 resulted in Glutathione Peroxidase 4 (GPX4) activation and ferroptosis suppression. Ectopic expression of EZH2 in vitro negated the protective effects of BMSC-Exos. Furthermore, BMSC-Exos containing miR-367-3p relieved the severity of EAE by suppressing ferroptosis and restraining EZH2 expression in vivo. Collectively, our findings suggest that BMSC-Exos carrying miR-367-3p brings about a significant decline in microglia ferroptosis by repressing EZH2 and alleviating the severity of EAE in vivo, suggesting a possible role of miR-367-3p overexpression in the treatment strategy of EAE. AVAILABILITY OF DATA AND MATERIALS: The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Exosomal miR-23b-3p from bone mesenchymal stem cells alleviates experimental autoimmune encephalomyelitis by inhibiting microglial pyroptosis

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system and is marked by inflammation and damage to the myelin sheath surrounding nerve fibers. Recent studies have highlighted the therapeutic value of exosomes (Exos) obtained from bone marrow mesenchymal stem cells (BMSCs) in MS treatment. These BMSC-Exos contain biologically active molecules that show promising results in preclinical evaluations. The aim of this study was to investigate the mechanism of BMSC-Exos containing miR-23b-3p in both LPS-stimulated BV2 microglia and in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. Exos were isolated from BMSCs, and their effects were evaluated in vitro by co-culturing with BV2 microglia. The interaction between miR-23b-3p and its downstream targets was also explored. The efficacy of BMSC-Exos was further verified in vivo by injecting the Exos into EAE mice. The results showed that BMSC-Exos containing miR-23b-3p reduced microglial pyroptosis in vivo by specifically binding to and suppressing the expression of NEK7. In vivo, BMSC-Exos containing miR-23b-3p alleviated the severity of EAE by decreasing microglial inflammation and pyroptosis via the repression of NEK7. These findings provide new insights into the therapeutic potential of BMSC-Exos containing miR-23b-3p for MS.

Dual peptide nanoparticles platform for enhanced antigen-specific immune tolerance for treatment of experimental autoimmune encephalomyelitis

Current therapeutic strategies for autoimmune diseases including multiple sclerosis (MS) are directed toward nonspecific immunosuppression which has severe side effects. The induction of antigen-specific tolerance becomes an ideal therapy for...

ERMAP is a B7 family-related molecule that negatively regulates T cell and macrophage responses

T cell activation and tolerance are tightly regulated by costimulatory and coinhibitory molecules. B7 family members play a crucial role in regulating immune responses. In this study, we identified erythroid membrane-associated protein (ERMAP) as a novel T cell inhibitory molecule. ERMAP shares significant sequence and structural homology with existing B7 family members in its extracellular domain. The ERMAP protein is expressed on the cell surface of resting and activated antigen-presenting cells (APCs) and in some tumor tissues. The putative ERMAP receptor is expressed on activated CD4 and CD8 T cells and macrophages. Both mouse and human ERMAP-IgG2a Fc (ERMAP-Ig) fusion proteins inhibit T cell functions in vitro. Administration of ERMAP-Ig protein ameliorates autoimmune diseases, including experimental autoimmune encephalomyelitis and type 1 diabetes, in mice. Anti-ERMAP antibody enhances macrophage phagocytosis of cancer cells in vitro. Furthermore, administration of an anti-ERMAP antibody inhibits tumor growth in mice likely by blocking the inhibitory effects of ERMAP on T cells and macrophages. Our results suggest that therapeutic interaction with the ERMAP inhibitory pathway may represent a novel strategy for treating patients with autoimmune disease or cancer.

Administration of Amyloid Precursor Protein Gene Deleted Mouse ESC-Derived Thymic Epithelial Progenitors Attenuates Alzheimer's Pathology

Alzheimer's disease (AD) is a devastating neurodegenerative disorder and the most common cause of dementia in older adults. Although amyloid-beta (Aβ) plaque deposition and chronic neuroinflammation in the central nervous system (CNS) contribute to AD pathology, neither Aβ plaque removal nor anti-inflammatory therapy has shown much clinical success, suggesting that the combinational therapies for the disease-causative factors may be needed for amelioration. Recent data also suggest that systemic immunity in AD should be boosted, rather than suppressed, to drive an immune-dependent cascade needed for Aβ clearance and brain repair. Thymic epithelial cells (TECs) not only play a critical role in supporting T cell development but also mediate the deletion of autoreactive T cells by expressing autoantigens. We have reported that embryonic stem cells (ESCs) can be selectively induced to differentiate into thymic epithelial progenitors (TEPs) in vitro that further develop into TECs in vivo to support T cell development. We show here that transplantation of mouse ESC (mESC)-TEPs into AD mice reduced cerebral Aβ plaque load and improved cognitive performance, in correlation with an increased number of T cells, enhanced choroid plexus (CP) gateway activity, and increased number of macrophages in the brain. Furthermore, transplantation of the amyloid precursor protein (APP) gene deleted mESC-TEPs (APP^-/-) results in more effective reduction of AD pathology as compared to wild-type (APP^+/+) mESC-TEPs. This is associated with the generation of Aβ-specific T cells, which leads to an increase of anti-Aβ antibody (Ab)-producing B cells in the spleen and enhanced levels of anti-Aβ antibodies in the serum, as well as an increase of Aβ phagocytosing macrophages in the CNS. Our results suggest that transplantation of APP^-/- human ESC- or induced pluripotent stem cell (iPSC)-derived TEPs may provide a new tool to mitigate AD in patients.

Changes of immune parameters of T lymphocytes and macrophages in EAE mice after BM-MSCs transplantation

Multiple sclerosis (MS) is an autoimmune disease characterized by inflammatory infiltration, demyelination and axonal injury. Mesenchymal stem cells (MSCs) are pluripotent which can not only differentiate into many types of cells, but also have immunomodulatory effects. We show here that the transplantation of bone marrow MSCs (BM-MSCs) prevents the development of experimental autoimmune encephalomyelitis (EAE), the most common animal model of MS. Furthermore, we demonstrate that the immunologic mechanism by which BM-MSC transplantation ameliorates EAE involves inhibiting the proliferation and activation of T cells, reducing the production of inflammatory cytokines, and regulating macrophage responses, especially the macrophage polarization. The findings broaden our understanding about the regulation of T cell and macrophage immune responses by MSC transplantation.

Transplantation of MHC-mismatched mouse embryonic stem cell-derived thymic epithelial progenitors and MHC-matched bone marrow prevents autoimmune diabetes

Background

Type 1 diabetes (T1D) is an autoimmune disease resulting from the destruction of insulin-secreting islet β cells by autoreactive T cells. Non-obese diabetic (NOD) mice are the widely used animal model for human T1D. Autoimmunity in NOD mice is associated with particular major histocompatibility complex (MHC) loci and impaired islet autoantigen expression and/or presentation in the thymus, which results in defects in both central and peripheral tolerance. It has been reported that induction of mixed chimerism with MHC-mismatched, but not MHC-matched donor bone marrow (BM) transplants prevents the development T1D in NOD mice. We have reported that mouse embryonic stem cells (mESCs) can be selectively induced in vitro to generate thymic epithelial progenitors (TEPs) that further develop into thymic epithelial cells (TECs) in vivo to support T cell development.

Methods

To determine whether transplantation of MHC-mismatched mESC-TEPs could prevent the development of insulitis and T1D, NOD mice were conditioned and injected with MHC-mismatched B6 mESC-TEPs and MHC-matched BM from H-2^g7 B6 mice. The mice were monitored for T1D development. The pancreas, spleen, BM, and thymus were then harvested from the mice for evaluation of T1D, insulitis, chimerism levels, and T cells.

Results

Transplantation of MHC-mismatched mESC-TEPs and MHC-matched donor BM prevented insulitis and T1D development in NOD mice. This was associated with higher expression of proinsulin 2, a key islet autoantigen in the mESC-TECs, and an increased number of regulatory T cells.

Conclusions

Our results suggest that embryonic stem cell-derived TEPs may offer a new approach to control T1D.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1347-1) contains supplementary material, which is available to authorized users.

Immune Thymic Profile of the MOG-Induced Experimental Autoimmune Encephalomyelitis Mouse Model

Multiple sclerosis (MS) is a chronic, immune-mediated, demyelinating disease that affects the neurons of the central nervous system. Activated T cells, specific for myelin epitopes, cross the brain barriers, and react against the myelin sheath, leading to demyelination. Since T cells are generated within the thymus, here we explored, in mice, the alterations occurring in this organ throughout the different phases of the disease. We induced experimental autoimmune encephalomyelitis (EAE) in C57BL/6 females and sacrifice them at the onset (day 16) and chronic phases of disease (day 23), along with non-induced controls. We observed thymic atrophy in EAE mice at the onset that remained until the chronic phase of disease. This atrophy was associated with a preferential loss of the CD4⁺CD8⁺ double positive thymocytes, an intermediate population between the more immature CD4⁻CD8⁻ double negative and the most mature single positive thymocytes. This was accompanied by an increase in the thymic medullary/cortical ratio and by an altered expression levels of genes important for T cell survival. During the chronic phase, the thymi remained atrophic, but reacquired the normal proportion of the main four thymocyte populations and the normal medullary/cortical ratio. Importantly, at the onset phase, and accompanying these thymic alterations, EAE animals presented an increased percentage of demyelinating lesion area in the cerebellum, and an increased expression of interferon gamma (Ifng), interleukin (Il) 12a, and Il17a. This study suggests dynamic thymic alterations occurring in response to EAE, from the induction to the chronic phase, that might help to elucidate the MS pathophysiology.

Stem Cells as Potential Targets of Polyphenols in Multiple Sclerosis and Alzheimer's Disease

Alzheimer's disease (AD) and multiple sclerosis are major neurodegenerative diseases, which are characterized by the accumulation of abnormal pathogenic proteins due to oxidative stress, mitochondrial dysfunction, impaired autophagy, and pathogens, leading to neurodegeneration and behavioral deficits. Herein, we reviewed the utility of plant polyphenols in regulating proliferation and differentiation of stem cells for inducing brain self-repair in AD and multiple sclerosis. Firstly, we discussed the genetic, physiological, and environmental factors involved in the pathophysiology of both the disorders. Next, we reviewed various stem cell therapies available and how they have proved useful in animal models of AD and multiple sclerosis. Lastly, we discussed how polyphenols utilize the potential of stem cells, either complementing their therapeutic effects or stimulating endogenous and exogenous neurogenesis, against these diseases. We suggest that polyphenols could be a potential candidate for stem cell therapy against neurodegenerative disorders.

ESC-derived thymic epithelial cells expressing MOG prevents EAE by central and peripheral tolerance mechanisms

Experimental autoimmune encephalomyelitis (EAE) is an animal model for multiple sclerosis (MS), and is induced by immunization with disease-causative self-antigens such as myelin oligodendrocyte glycoprotein (MOG). We have previously reported that transplantation of MOG expressing thymic epithelial progenitors (TEPs) derived from 129S6SvEv Tac mouse embryonic stem cells (mESCs) prevented the development of EAE. In this study, we expand our previous studies to show that transplantation of MOG expressing mESC-TEPs derived from C57BL/6 mice also prevents EAE development. Furthermore, by using a MOG-specific T cell receptor (TCR) transgenic mouse model, we demonstrate that both central and peripheral tolerances are involved in the prevention of EAE induced by MOG expressing mESC-TEPs. Our results suggest that transplantation of human ESC-TEPs expressing MOG may provide an effective approach for the induction of MOG-specific immune tolerance, thereby the prevention and treatment of MS.

Therapeutic efficacy of multipotent adult progenitor cells versus mesenchymal stem cells in experimental autoimmune encephalomyelitis

AIM

In this study, we have evaluated the therapeutic efficacy of mouse multipotent adult progenitor cells (mMAPCs) in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, and compared it with mouse mesenchymal stem cells (mMSCs).

MATERIALS & METHODS

We administered PKH26-labeled mMAPC and mMSC into EAE mice and evaluated their therapeutic efficacy.

RESULTS

The mMAPC-treated mice in comparison with the mMSC group exhibited a higher suppression of EAE (p < 0.05), and a higher fold expression of neuronal genes GAP43, NG2, PDGFR, Nestin, SMI 32, BDNF and NT 3 in spinal cord (p < 0.05), suggesting a better neuroprotective and regenerative potential of mMAPC than mMSC.

CONCLUSION

MAPC may be a potential cell type, which is superior to mesenchymal stem cell for the treatment of EAE/multiple sclerosis.

Transplantation of Donor-Origin Mouse Embryonic Stem Cell-Derived Thymic Epithelial Progenitors Prevents the Development of Chronic Graft-versus-Host Disease in Mice

Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for many malignant and nonmalignant diseases. However, chronic graft-versus-host disease (cGVHD) remains a significant cause of late morbidity and mortality after allogeneic HSCT. cGVHD often manifests as autoimmune syndrome. Thymic epithelial cells (TECs) play a critical role in supporting negative selection and regulatory T-cell (Treg) generation. Studies have shown that damage in TECs is sufficient to induce cGVHD. We have previously reported that mouse embryonic stem cells (mESCs) can be selectively induced to generate thymic epithelial progenitors (TEPs) in vitro. When transplanted in vivo, mESC-TEPs further develop into TECs that support T-cell development. We show here that transplantation of donor-origin mESC-TEPs into cGVHD recipients induces immune tolerance to both donor and host antigens and prevents the development of cGVHD. This is associated with more TECs and Tregs. Our results suggest that embryonic stem cell-derived TEPs may offer a new tool to control cGVHD. Stem Cells Translational Medicine 2017;6:121-130.

Lymphocyte-activation gene 3(+) (LAG3(+)) forkhead box protein 3(-) (FOXP3(-)) regulatory T cells induced by B cells alleviates joint inflammation in collagen-induced arthritis

Rheumatoid arthritis (RA) is an autoimmune disease in which dysregulated immune cells primarily target synovial joints. Despite recent advances in the treatment of RA, including the introduction of biologic therapies and employment of combination disease-modifying antirheumatic drug strategies, remission rates remain suboptimal. Previous studies have demonstrated that the adoptive transfer of induced regulatory T cells (iTregs) was effective in treating a murine model of collagen-induced arthritis (CIA). The objective of this study was to develop optimal potential iTreg-based therapy for CIA by adoptively transferring LAG3(+) Treg-of-B cells. B-cell-induced Treg-of-B cells expressed LAG3 but not Foxp3 (designated LAG3(+) Treg-of-B), and secreted IL-4, IL-10, and TGF-β. Furthermore, LAG3(+) Treg-of-B cells suppressed the proliferation of CD4(+)CD25(-) responder T cells through both LAG3 and IL-10 production. In the murine CIA model, adoptive transfer of LAG3(+) Treg-of-B cells alleviated the joint severity as well as local and systemic inflammation. Treatment with LAG3(+) Treg-of-B cells also promoted IL-10 production in lymphocytes isolated from the spleen and draining lymph nodes. Moreover, mice receiving LAG3(+) Treg-of-B cell treatment showed significantly less pronounced osteolysis in the hind footpads, which correlated with the downregulation of tartrate-resistant acid phosphatase expression. In conclusion, we identified a novel subset of Tregs for CIA treatment. This insight may facilitate exploring novel regulatory T-cell-based therapies for human autoimmune diseases.