Targeting innate receptors with MIS416 reshapes Th responses and suppresses CNS disease in a mouse model of multiple sclerosis

Neutrophils as regulators of macrophage-induced inflammation in a setting of allogeneic bone marrow transplantation

Clinical data reveal that patients with allogeneic hematopoietic stem cell transplantation (HSCT) are vulnerable to infection and prone to developing severe sepsis, which greatly compromises the success of transplantation, indicating a dysregulation of inflammatory immune response in this clinical setting. Here, by using a mouse model of haploidentical bone marrow transplantation (haplo-BMT), we found that uncontrolled macrophage inflammation underlies the pathogenesis of both LPS- and E.coli-induced sepsis in recipient animals with graft-versus-host disease (GVHD). Deficient neutrophil maturation in GVHD mice post-haplo-BMT diminished modulation of macrophage-induced inflammation, which was mechanistically dependent on MMP9-mediated activation of TGF-β1. Accordingly, adoptive transfer of mature neutrophils purified from wild-type donor mice inhibited both sterile and infectious sepsis in GVHD mice post-haplo-BMT. Together, our findings identify a novel mature neutrophil-dependent regulation of macrophage inflammatory response in a haplo-BMT setting and provide useful clues for developing clinical strategies for patients suffering from post-HSCT sepsis.

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Macrophage inflammation leads to the development of post-haplo-BMT sepsis

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Impaired neutrophil maturation diminishes regulation of macrophage inflammation

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Extramedullary granulopoiesis fails to support neutrophil maturation after haplo-BMT

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Neutrophils regulate macrophage inflammation via MMP9-mediated TGF-β1 activation

PD-1/PD-L Axis in Neuroinflammation: New Insights

The approval of immune checkpoint inhibitors (ICIs) by the Food and Drug Administration (FDA) led to an improvement in the treatment of several types of cancer. The main targets of these drugs are cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death protein-1/programmed death-ligand 1 pathway (PD-1/PD-L1), which are important inhibitory molecules for the immune system. Besides being generally safer than common chemotherapy, the use of ICIs has been associated with several immune-related adverse effects (irAEs). Although rare, neurological adverse effects are reported within the irAEs in clinical trials, particularly in patients treated with anti-PD-1 antibodies or a combination of both anti-CTLA-4 and PD-1 drugs. The observations obtained from clinical trials suggest that the PD-1 axis may play a remarkable role in the regulation of neuroinflammation. Moreover, numerous studies in preclinical models have demonstrated the involvement of PD-1 in several neurological disorders. However, a comprehensive understanding of these cellular mechanisms remains elusive. Our review aims to summarize the most recent evidence concerning the regulation of neuroinflammation through PD-1/PD-L signaling, focusing on cell populations that are involved in this pathway.

Targeted Delivery Platforms for the Treatment of Multiple Sclerosis

Multiple sclerosis (MS) is a neurodegenerative condition of the central nervous system (CNS) that presents with varying levels of disability in patients, displaying the significance of timely and effective management of this complication. Though several treatments have been developed to protect nerves, comprehensive improvement of MS is still considered an essential bottleneck. Therefore, the development of innovative treatment methods for MS is one of the core research areas. In this regard, nanoscale platforms can offer practical and ideal approaches to the diagnosis and treatment of various diseases, especially immunological disorders such as MS, to improve the effectiveness of conventional therapies. It should be noted that there is significant progress in the development of neuroprotective strategies through the implementation of various nanoparticles, monoclonal antibodies, peptides, and aptamers. In this study, we summarize different particle systems as well as targeted therapies, such as antibodies, peptides, nucleic acids, and engineered cells for the treatment of MS, and discuss their potential in the treatment of MS in the preclinical and clinical stages. Future advances in targeted delivery of medical supplies may offer new strategies for complete recovery as well as practical treatment of progressive forms of MS.

NOD-like receptors in autoimmune diseases

Autoimmune diseases are chronic immune diseases characterized by dysregulation of immune system, which ultimately results in a disruption in self-antigen tolerance. Cumulative data show that nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) play essential roles in various autoimmune diseases, such as inflammatory bowel disease (IBD), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis, multiple sclerosis (MS), etc. NLR proteins, consisting of a C-terminal leucine-rich repeat (LRR), a central nucleotide-binding domain, and an N-terminal effector domain, form a group of pattern recognition receptors (PRRs) that mediate the immune response by specifically recognizing cellular pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs) and triggering numerous signaling pathways, including RIP2 kinase, caspase-1, nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK) and so on. Based on their N-terminal domain, NLRs are divided into five subfamilies: NLRA, NLRB, NLRC, NLRP, and NLRX1. In this review, we briefly describe the structures and signaling pathways of NLRs, summarize the recent progress on NLR signaling in the occurrence and development of autoimmune diseases, as well as highlight numerous natural products and synthetic compounds targeting NLRs for the treatment of autoimmune diseases.

Failed, Interrupted, or Inconclusive Trials on Immunomodulatory Treatment Strategies in Multiple Sclerosis: Update 2015-2020

In the past decades, multiple sclerosis (MS) treatment has experienced vast changes resulting from major advances in disease-modifying therapies (DMT). Looking at the overall number of studies, investigations with therapeutic advantages and encouraging results are exceeded by studies of promising compounds that failed due to either negative or inconclusive results or have been interrupted for other reasons. Importantly, these failed clinical trials are informative experiments that can help us to understand the pathophysiological mechanisms underlying MS. In several trials, concepts taken from experimental models were not translatable to humans, although they did not lack a well-considered pathophysiological rationale. The lessons learned from these discrepancies may benefit future studies and reduce the risks for patients. This review summarizes trials on MS since 2015 that have either failed or have been interrupted for various reasons. We identify potential causes of failure or inconclusiveness, looking at the path from basic animal experiments to clinical trials, and discuss the implications for our current view on MS pathogenesis, clinical practice, and future study designs. We focus on anti-inflammatory treatment strategies, without including studies on already approved and effective DMT. Clinical trials addressing neuroprotective and alternative treatment strategies are presented in a separate article.

The Helminth Parasite Heligmosomoides polygyrus Attenuates EAE in an IL-4Rα-Dependent Manner

Helminth parasites are effective in biasing Th2 immunity and inducing regulatory pathways that minimize excessive inflammation within their hosts, thus allowing chronic infection to occur whilst also suppressing bystander atopic or autoimmune diseases. Multiple sclerosis (MS) is a severe autoimmune disease characterized by inflammatory lesions within the central nervous system; there are very limited therapeutic options for the progressive forms of the disease and none are curative. Here, we used the experimental autoimmune encephalomyelitis (EAE) model to examine if the intestinal helminth Heligmosomoides polygyrus and its excretory/secretory products (HES) are able to suppress inflammatory disease. Mice infected with H. polygyrus at the time of immunization with the peptide used to induce EAE (myelin-oligodendrocyte glycoprotein, pMOG), showed a delay in the onset and peak severity of EAE disease, however, treatment with HES only showed a marginal delay in disease onset. Mice that received H. polygyrus 4 weeks prior to EAE induction were also not significantly protected. H. polygyrus secretes a known TGF-β mimic (Hp-TGM) and simultaneous H. polygyrus infection with pMOG immunization led to a significant expansion of Tregs; however, administering the recombinant Hp-TGM to EAE mice failed to replicate the EAE protection seen during infection, indicating that this may not be central to the disease protecting mechanism. Mice infected with H. polygyrus also showed a systemic Th2 biasing, and restimulating splenocytes with pMOG showed release of pMOG-specific IL-4 as well as suppression of inflammatory IL-17A. Notably, a Th2-skewed response was found only in mice infected with H. polygyrus at the time of EAE induction and not those with a chronic infection. Furthermore, H. polygyrus failed to protect against disease in IL-4Rα^−/− mice. Together these results indicate that the EAE disease protective mechanism of H. polygyrus is likely to be predominantly Th2 deviation, and further highlights Th2-biasing as a future therapeutic strategy for MS.

First-in-human phase I clinical trial of the NY-ESO-1 protein cancer vaccine with NOD2 and TLR9 stimulants in patients with NY-ESO-1-expressing refractory solid tumors

Cholesteryl pullulan (CHP) is a novel antigen delivery system. CHP and New York esophageal squamous cell carcinoma 1 (NY-ESO-1) antigen complexes (CHP-NY-ESO-1) present multiple epitope peptides to the MHC class I and II pathways. Adjuvants are essential for cancer vaccines. MIS416 is a non-toxic microparticle that activates immunity via the nucleotide-binding oligomerization domain 2 (NOD2) and TLR9 pathways. However, no reports have explored MIS416 as a cancer vaccine adjuvant. We conducted a first-in-human clinical trial of CHP-NY-ESO-1 with MIS416 in patients with NY-ESO-1-expressing refractory solid tumors. CHP-NY-ESO-1/MIS416 (μg/μg) was administered at 100/200, 200/200, 200/400 or 200/600 (cohorts 1, 2, 3 and 4, respectively) every 2 weeks for a total of 6 doses (treatment phase) followed by one vaccination every 4 weeks until disease progression or unacceptable toxicity (maintenance phase). The primary endpoints were safety and tolerability, and the secondary endpoint was the immune response. In total, 26 patients were enrolled. Seven patients (38%) continued vaccination in the maintenance phase. Grade 3 drug-related adverse events (AEs) were observed in six patients (23%): anorexia and hypertension were observed in one and five patients, respectively. No grade 4–5 drug-related AEs were observed. Eight patients (31%) had stable disease (SD). Neither augmentation of the NY-ESO-1-specific IFN-γ-secreting CD8⁺ T cell response nor an increase in the level of anti-NY-ESO-1 IgG1 was observed as the dose of MIS416 was increased. In a preclinical study, adding anti-PD-1 monoclonal antibody to CHP-NY-ESO-1 and MIS416 induced significant tumor suppression. This combination therapy is a promising next step.

Inflammatory Role of TLR-MyD88 Signaling in Multiple Sclerosis

Multiple sclerosis (MS) is a neuro-autoimmune and neurodegenerative disorder leading to chronic inflammation, demyelination, axonal, and neuronal loss in the central nervous system (CNS). Despite intense research efforts, the pathogenesis of MS still remains unclear. Toll-like receptors (TLRs) are a family of type I transmembrane receptors that play a crucial role in the innate immune response. Myeloid differentiation factor 88 (MyD88) is the adaptor of major TLRs. It has been widely considered that the TLR-MyD88 signaling pathway plays an important role in the occurrence and development of autoimmune disease. Data have revealed that the TLR-MyD88 signaling may be involved in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), an animal model for MS, by regulating the antigen presentation of dendritic cells, the integrity of blood-brain barrier (BBB), and the activation of T cells and B cells. Here, we summarize the role of TLRs and MyD88 in MS and discuss the possible therapies that are based on these molecules.

Innate signaling within the central nervous system recruits protective neutrophils

There is great interest in understanding how the central nervous system (CNS) communicates with the immune system for recruitment of protective responses. Infiltrating phagocytic monocytes and granulocytes are implicated in neuroinflammation in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE). To investigate how CNS endogenous signals can be harnessed to promote anti-inflammatory programs, we have used a particulate Toll-like receptor 9 and nucleotide-oligomerization domain 2 bispecific innate ligand (MIS416), to address whether its phagocytosis within the CNS recruits protective myeloid cells. We find that MIS416 injected intrathecally into the cerebrospinal fluid via the cisterna magna induced a local chemokine response that recruited blood-derived monocytes and neutrophils to the CNS. These cells phagocytosed MIS416. The increase in EAE severity normally seen from time of onset did not occur in mice receiving MIS416. This suppression of disease symptoms was dependent on expression of the type I interferon receptor (IFNAR). Transfer of intrathecal MIS416-induced neutrophils suppressed EAE in recipient mice, while monocytes did not transfer protection. MIS416-induced neutrophils showed increased IL-10 expression that was IFNAR1-driven. In contrast to intrathecal administration, intravenous administration of MIS416 led to monocyte but not neutrophil infiltration to the CNS. We thus identify a CNS-intrinsic and -specific phagocytosis-induced recruitment of anti-inflammatory neutrophils that contribute to CNS homeostasis and may have therapeutic potential.

Progressive multiple sclerosis: from pathophysiology to therapeutic strategies

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that involves demyelination and axonal degeneration. Although substantial progress has been made in drug development for relapsing-remitting MS, treatment of the progressive forms of the disease, which are characterized clinically by the accumulation of disability in the absence of relapses, remains unsatisfactory. This unmet clinical need is related to the complexity of the pathophysiological mechanisms involved in MS progression. Chronic inflammation, which occurs behind a closed blood-brain barrier with activation of microglia and continued involvement of T cells and B cells, is a hallmark pathophysiological feature. Inflammation can enhance mitochondrial damage in neurons, which, consequently, develop an energy deficit, further reducing axonal health. The growth-inhibitory and inflammatory environment of lesions also impairs remyelination, a repair process that might protect axons from degeneration. Moreover, neurodegeneration is accelerated by the altered expression of ion channels on denuded axons. In this Review, we discuss the current understanding of these disease mechanisms and highlight emerging therapeutic strategies based on these insights, including those targeting the neuroinflammatory and degenerative aspects as well as remyelination-promoting approaches.

Pharmacotherapy in Secondary Progressive Multiple Sclerosis: An Overview

Multiple sclerosis is an immune-mediated inflammatory disease of the central nervous system characterised by demyelination, neuroaxonal loss and a heterogeneous clinical course. Multiple sclerosis presents with different phenotypes, most commonly a relapsing-remitting course and, less frequently, a progressive accumulation of disability from disease onset (primary progressive multiple sclerosis). The majority of people with relapsing-remitting multiple sclerosis, after a variable time, switch to a stage characterised by gradual neurological worsening known as secondary progressive multiple sclerosis. We have a limited understanding of the mechanisms underlying multiple sclerosis, and it is believed that multiple genetic, environmental and endogenous factors are elements driving inflammation and ultimately neurodegeneration. Axonal loss and grey matter damage have been regarded as amongst the leading causes of irreversible neurological disability in the progressive stages. There are over a dozen disease-modifying therapies currently licenced for relapsing-remitting multiple sclerosis, but none of these has provided evidence of effectiveness in secondary progressive multiple sclerosis. Recently, there has been some early modest success with siponimod in secondary progressive multiple sclerosis and ocrelizumab in primary progressive multiple sclerosis. Finding treatments to delay or prevent the courses of secondary progressive multiple sclerosis is an unmet and essential goal of the research in multiple sclerosis. In this review, we discuss new findings regarding drugs with immunomodulatory, neuroprotective or regenerative properties and possible treatment strategies for secondary progressive multiple sclerosis. We examine the field broadly to include trials where participants have progressive or relapsing phenotypes. We summarise the most relevant results from newer investigations from phase II and III randomised controlled trials over the past decade, with particular attention to the last 5 years.

MIS416 Enhances Therapeutic Functions of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Against Experimental Colitis by Modulating Systemic Immune Milieu

Human adult stem cells, including umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs), have recently been considered a promising alternative treatment for inflammatory bowel disease (IBD) due to their unique immunomodulatory properties and ability to promote tissue regeneration. However, despite many years of research and pre-clinical studies, results from clinical trials using these cells have been diverse and conflicting. This discrepancy is caused by several factors, such as poor engraftment, low survival rate, and donor-dependent variation of the cells. Enhancement of consistency and efficacy of MSCs remains a challenge for the feasibility of cell-based therapy. In this study, we investigated whether administration of MIS416, a novel microparticle that activates NOD2 and TLR9 signaling, could enhance the therapeutic efficacy of hUCB-MSCs against Crohn’s disease, using dextran sulfate sodium (DSS)-induced colitis model. Colitis was experimentally induced in mice by using 3% DSS, and mice were administered a retro-orbital injection of MIS416 and subsequent intraperitoneal injection of hUCB-MSCs. Mice were examined grossly, and blood, spleen, and colon tissues were subsequently collected for further ex vivo analyses. To explore the effects of MIS416 on the therapeutic process, hUCB-MSCs and primary isolated immune cells were cultured with MIS416, and in vitro assays were performed. Compared to the single administration of hUCB-MSCs, co-administration with MIS416 improved the therapeutic efficiency of the stem cells by significantly alleviating the symptoms of IBD. Interestingly, MIS416 did not exert any direct effect on the immunomodulatory capacity of hUCB-MSCs. Instead, systemically injected MIS416 altered the immune milieu in the colon which caused hUCB-MSCs to be more readily recruited toward the lesion site and to suppress inflammation more efficiently. In addition, considerable numbers of regulatory immune cells were stimulated as a result of the cooperation of MIS416 and hUCB-MSCs. These findings indicate that co-administration with MIS416 enhances the therapeutic potential of hUCB-MSCs by systemically regulating the immune response, which might be an effective strategy for overcoming the current obstacles to stem cell therapy in clinical practice.

Role of Inflammasomes in Neuroimmune and Neurodegenerative Diseases: A Systematic Review

Inflammasomes are multiprotein complexes that can sense pathogen-associated molecular patterns and damage-associated molecular signals. They are involved in the initiation and development of inflammation via activation of IL-1β and IL-18. Many recent studies suggest a strong correlation between inflammasomes and neurological diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD), and Parkinson's disease (PD). Several components of inflammasomes, such as nucleotide-binding oligomerization domain- (NOD-) like receptor, absent in melanoma 2- (AIM2-) like receptors (ALRs), apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and caspase-1, as well as the upstream factors and downstream effectors, are associated with the initiation and development of MS and its animal model, experimental autoimmune encephalomyelitis. Additionally, inflammasomes affect the efficacy of interferon-β therapy in patients with MS. Finally, the strong association of inflammasomes with AD and PD needs to be further studied. In this review of latest literatures, we comprehensively tease out diverse roles of different kinds of inflammasomes in neuroimmune and neurodegenerative diseases, especially in the perspective of double roles involved in pathogenesis, and identify future research priorities.

Innate IFN-γ ameliorates experimental autoimmune encephalomyelitis and promotes myeloid expansion and PDL-1 expression

The innate immune system plays a central role in the immune-mediated pathology of multiple sclerosis, and is a therapeutic target for progressive disease. Recently, it has been demonstrated that MIS416, a novel immunomodulatory microparticle that activates NOD-2 and TLR-9-signaling, has disease-modifying activity in multiple sclerosis models. This activity is dependent on innate IFN-γ; however, the precise immune regulatory mechanisms amplified by MIS416 have not previously been determined. Using the experimental autoimmune encephalomyelitis model, MIS416 treatment was associated with IFN-γ–dependant expansion of Treg number and increased suppressive function; however, these cells did not account for disease reduction. Additionally, MIS416 treatment stimulated increased nitric oxide production that was IFN-γ–dependant but dispensable for protection. Finally, MIS416-mediated protection was shown to correlate with IFN-γ–dependant expansion of PDL-1-expressing peripheral myeloid cells, a subset of which was found to be selectively recruited to the brain. This central nervous system trafficking was independent of neuro-inflammatory signals as it occurred in MIS416-treated healthy mice. Together, these findings provide insight into regulatory myeloid cell activities amplified by MIS416-mediated NOD-2 and TLR-9 signalling and highlight the potential importance of these cells in accessing the brain where they may act locally and contribute to the control of neuroinflammation.

Evaluation of neurological changes in secondary progressive multiple sclerosis patients treated with immune modulator MIS416: results from a feasibility study

BACKGROUND

While disease progression can be readily monitored in early stage relapsing multiple sclerosis (MS), it is more challenging for secondary progressive multiple sclerosis (SPMS). This advanced stage of disease has distinct pathophysiology due to compartmentalization of neuroinflammatory activity within the central nervous system, resulting in increased incidence and severity of cognitive dysfunction. The shift in the dominant disease pathways is underscored by the failure of relapsing therapies to benefit SPMS patients, highlighting the need for novel treatment strategies and clinical trial endpoints that are well-aligned with potential benefits. The Expanded Disability Status Scale (EDSS) is widely used but is weighted towards ambulatory ability, lacking sensitivity to other aspects of neurological impairment experienced in more severely disabled SPMS patients, so may not effectively capture their clinical status.To investigate the feasibility of an alternative clinical trial endpoint model for a phase 2B trial of an immune modulator for SPMS, the potential for treatment efficacy-based patient-centered outcomes was assessed within the context of a before and after, 12-week clinical trial of safety and tolerability.

METHODS

Patients treated with MIS416 for 12 weeks were evaluated for clinical status at baseline and end of dosing, using the established Multiple Sclerosis Functional Composite, Short Form Health Survey, and Expanded Disability Status Scale. Responder status was determined for eight outcome measures based on minimally important change, defined using published studies. To evaluate the patients' immune response to MIS416, blood plasma samples collected at baseline and pre- and 24-h post doses 1-4 were analyzed using multiplex cytokine quantification assays.

RESULTS

Using a combination of patient-centered outcomes, MIS416 treatment was associated with improved clinical status for 10/11 patients: eight patients showed improvement on two to five outcome measures, five of which also showed improvement by EDSS. Multi-dimensional scaling analysis of MIS416-induced factors quantified in individual patients, revealed immune response patterns which had a strong concordance with the extent of the patients' clinical response.

CONCLUSIONS

The data support the feasibility of using patient-centered outcomes as additional clinical trial endpoints, for determining the efficacy of disease-modifying therapies, in secondary progressive multiple sclerosis patients.

TRIAL REGISTRATION

ClinicalTrial.gov, NCT01191996.

Reprogramming the Local Lymph Node Microenvironment Promotes Tolerance that Is Systemic and Antigen Specific

Many experimental therapies for autoimmune diseases, such as multiple sclerosis (MS), aim to bias T cells toward tolerogenic phenotypes without broad suppression. However, the link between local signal integration in lymph nodes (LNs) and the specificity of systemic tolerance is not well understood. We used intra-LN injection of polymer particles to study tolerance as a function of signals in the LN microenvironment. In a mouse MS model, intra-LN introduction of encapsulated myelin self-antigen and a regulatory signal (rapamycin) permanently reversed paralysis after one treatment during peak disease. Therapeutic effects were myelin specific, required antigen encapsulation, and were less potent without rapamycin. This efficacy was accompanied by local LN reorganization, reduced inflammation, systemic expansion of regulatory T cells, and reduced T cell infiltration to the CNS. Our findings suggest that local control over signaling in distinct LNs can promote cell types and functions that drive tolerance that is systemic but antigen specific.

Innate immunity in Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune disease of exocrine tissue that primarily affects women. Although patients typically experience xerostomia and xerophthalmia, numerous systemic disease manifestations are seen. Innate immune hyperactivity is integral to many autoimmune diseases, including SS. Results from SS mouse models suggest that innate immune dysregulation drives disease and this is a seminal event in SS pathogenesis. Findings in SS patients corroborate those in mouse models, as innate immune cells and pathways are dysregulated both in exocrine tissue and in peripheral blood. We will review the role of the innate immune system in SS pathogenesis. We will discuss the etiology of SS with an emphasis on innate immune dysfunction. Moreover, we will review the innate cells that mediate inflammation in SS, the pathways implicated in disease, and the potential mechanisms governing their dysregulation. Finally, we will discuss emerging therapeutic approaches to target dysregulated innate immune signaling in SS.

The function of NOD-like receptors in central nervous system diseases

NOD-like receptors (NLRs) are critical cytoplasmic pattern-recognition receptors (PRRs) that play an important role in the host innate immune response and immunity homeostasis. There is a growing body of evidence that NLRs are involved in a wide range of inflammatory diseases, including cancer, metabolic diseases, and autoimmune disorders. Recent studies have indicated that the proteins of the NLR family are linked with the pathophysiology of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), and psychological diseases. In this review, we mainly focus on the role of NLRs and the underlying signaling pathways in central nervous system (CNS) diseases. © 2016 Wiley Periodicals, Inc.

Multiple sclerosis: Therapeutic applications of advancing drug delivery systems

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, which is accompanying with demyelination, neurodegeneration and sensibility to oxidative stress. In MS, auto-reactive lymphocytes cross the blood-brain barrier (BBB) and reside in the perivenous demyelinating lesions which create various distinct inflammatory demyelinated plaques situated predominantly in the white matter. The current MS-related therapeutic approaches can be classified into disease-modifying therapies (DMTs) and symptomatic therapy. DMTs suppress circulating immune cells, inhibit passing the BBB and decrease the inflammatory responses. Recent advances have remarkably delayed disease development and improved the quality of life for numerous patients. In spite of major improvements in therapeutic options, there are some limitations regarding the routes of administration and the necessity for repeated and long-term dosing in which cause to systemic disadvantageous consequences and patient non-compliance. Nanotechnology presents promising approaches to improve autoimmune disease treatment with the capability to overcome many of the limitations common to the current immunosuppressive and biological therapies. Here we emphasis on nanomedicine-based drug delivery approaches of biological immunomodulatory mediators for the treatment of multiple sclerosis. This comprehensive review details the most successful drugs in MS therapy and also focuses on conceptions and clinical potential of novel nanomedicine attitudes for inducing immunosuppression and immunological tolerance in MS to modulate abnormal and pathologic immune responses.

A Personalized Approach in Progressive Multiple Sclerosis: The Current Status of Disease Modifying Therapies (DMTs) and Future Perspectives

Using the term of progressive multiple sclerosis (PMS), we considered a combined population of persons with secondary progressive MS (SPMS) and primary progressive MS (PPMS). These forms of MS cannot be challenged with efficacy by the licensed therapy. In the last years, several measures of risk estimation were developed for predicting clinical course in MS, but none is specific for the PMS forms. Personalized medicine is a therapeutic approach, based on identifying what might be the best therapy for an individual patient, taking into account the risk profile. We need to achieve more accurate estimates of useful predictors in PMS, including unconventional and qualitative markers which are not yet currently available or practicable routine diagnostics. The evaluation of an individual patient is based on the profile of disease activity.Within the neurology field, PMS is one of the fastest-moving going into the future.

Advancing drug delivery systems for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system. It is characterized by demyelination of neurons and loss of neuronal axons and oligodendrocytes. In MS, auto-reactive T cells and B cells cross the blood-brain barrier (BBB), causing perivenous demyelinating lesions that form multiple discrete inflammatory demyelinated plaques located primarily in the white matter. In chronic MS, cortical demyelination and progressive axonal transections develop. Treatment for MS can be stratified into disease-modifying therapies (DMTs) and symptomatic therapy. DMTs aim to decrease circulating immune cells or to prevent these cells from crossing the BBB and reduce the inflammatory response. There are currently 10 DMTs approved for the relapsing forms of MS; these vary with regard to their efficacy, route and frequency of administration, adverse effects, and toxicity profile. Better drug delivery systems are being developed in order to decrease adverse effects, increase drug efficacy, and increase patient compliance through the direct targeting of pathologic cells. Here, we address the uses and benefits of advanced drug delivery systems, including nanoparticles, microparticles, fusion antibodies, and liposomal formulations. By altering the properties of therapeutic particles and enhancing targeting, breakthrough drug delivery technologies potentially applicable to multiple disease treatments may rapidly emerge.

Targeting myeloid cells in the tumor microenvironment enhances vaccine efficacy in murine epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is typically diagnosed at advanced stages, and is associated with a high relapse rate. Patients in remission are ideal candidates for immunotherapy aimed at cure or prolonging disease-free periods. However, immunosuppressive pathways in the tumor microenvironment are obstacles to durable anti-tumor immunity. In a metastatic syngeneic mouse model of EOC, immunosuppressive macrophages and myeloid-derived suppressor cells (MDSCs) accumulate in the local tumor environment. In addition, resident peritoneal macrophages from non-tumor-bearing mice were highly immunosuppressive, abrogating stimulated T cell proliferation in a cell contact-dependent manner. Immunization with microparticles containing TLR9 and NOD-2 ligands (MIS416) significantly prolonged survival in tumor-bearing mice. The strategy of MIS416 immunization followed by anti-CD11b administration further delayed tumor progression, thereby establishing the proof of principle that myeloid depletion can enhance vaccine efficacy. In patients with advanced EOC, ascites analysis showed substantial heterogeneity in the relative proportions of myeloid subsets and their immunosuppressive properties. Together, these findings point to immunosuppressive myeloid cells in the EOC microenvironment as targets to enhance vaccination. Further studies of myeloid cell accumulation and functional phenotypes in the EOC microenvironment may identify patients who are likely to benefit from vaccination combined with approaches that deplete tumor-associated myeloid cells.

Therapeutic Advances and Future Prospects in Progressive Forms of Multiple Sclerosis

Identifying effective therapies for the treatment of progressive forms of multiple sclerosis (MS) is a highly relevant priority and one of the greatest challenges for the global MS community. Better understanding of the mechanisms involved in progression of the disease, novel trial designs, drug repurposing strategies, and new models of collaboration may assist in identifying effective therapies. In this review, we discuss various therapies under study in phase II or III trials, including antioxidants (idebenone); tyrosine kinase inhibitors (masitinib); sphingosine receptor modulators (siponimod); monoclonal antibodies (anti-leucine-rich repeat and immunoglobulin-like domain containing neurite outgrowth inhibitor receptor-interacting protein-1, natalizumab, ocrelizumab, intrathecal rituximab); hematopoetic stem cell therapy; statins and other possible neuroprotective agents (amiloride, riluzole, fluoxetine, oxcarbazepine); lithium; phosphodiesterase inhibitors (ibudilast); hormone-based therapies (adrenocorticotrophic hormone and erythropoietin); T-cell receptor peptide vaccine (NeuroVax); autologous T-cell immunotherapy (Tcelna); MIS416 (a microparticulate immune response modifier); dopamine antagonists (domperidone); and nutritional supplements, including lipoic acid, biotin, and sunphenon epigallocatechin-3-gallate (green tea extract). Given ongoing and planned clinical trial initiatives, and the largest ever focus of the global research community on progressive MS, future prospects for developing targeted therapeutics aimed at reducing disability in progressive forms of MS appear promising.

Expression of the Kynurenine Pathway in Human Peripheral Blood Mononuclear Cells: Implications for Inflammatory and Neurodegenerative Disease

The kynurenine pathway is a fundamental mechanism of immunosuppression and peripheral tolerance. It is increasingly recognized as playing a major role in the pathogenesis of a wide variety of inflammatory, neurodegenerative and malignant disorders. However, the temporal dynamics of kynurenine pathway activation and metabolite production in human immune cells is currently unknown. Here we report the novel use of flow cytometry, combined with ultra high-performance liquid chromatography and gas chromatography-mass spectrometry, to sensitively quantify the intracellular expression of three key kynurenine pathway enzymes and the main kynurenine pathway metabolites in a time-course study. This is the first study to show that up-regulation of indoleamine 2,3-dioxygenase (IDO-1), kynurenine 3-monoxygenase (KMO) and quinolinate phosphoribosyltransferase (QPRT) is lacking in lymphocytes treated with interferon gamma. In contrast, peripheral monocytes showed a significant elevation of kynurenine pathway enzymes and metabolites when treated with interferon gamma. Expression of IDO-1, KMO and QPRT correlated significantly with activation of the kynurenine pathway (kynurenine:tryptophan ratio), quinolinic acid concentration and production of the monocyte derived, pro-inflammatory immune response marker: neopterin. Our results also describe an original and sensitive methodological approach to quantify kynurenine pathway enzyme expression in cells. This has revealed further insights into the potential role of these enzymes in disease processes.

Safety, tolerability and pharmacodynamics of a novel immunomodulator, MIS416, in patients with chronic progressive multiple sclerosis

Background

Preclinical studies have demonstrated that MIS416, a bacterially derived immune modulator, targets myeloid cells following systemic delivery. MIS416 stimulated myeloid cells have the capacity to regulate innate inflammation, a potential therapeutic target for progressive multiple sclerosis.

Objectives

To determine the safety, tolerability, pharmacodynamics and maximum tolerated dose and/or recommended Phase 2 dose of MIS416.

Methods

An open-label, non-randomized, phase II, dose-escalation study, in patients with progressive multiple sclerosis: dose-escalation phase, with MIS416 administered once weekly for four weeks to determine maximum tolerated dose; and dose-confirmation phase, administered once weekly for up to 12 weeks.

Results

The safety profile indicates the majority of adverse events were mild or moderate, tolerable, self-limiting and consistent with the known bioactivity of MIS416 (acute flu-like symptoms). Maximum tolerated dose was not reached. A dose of 500 µg/week was recommended for the Phase 2 dose.

Conclusion

MIS416 is well tolerated at a dose of 500 µg/week. The adverse event profile is consistent with the mechanism of action of MIS416, indicating bioactivity within the signal transduction pathways and supported by induction of a known MIS416 pharmacodynamic marker. It is recommended that safety and efficacy of MIS416 is investigated further in a larger randomized controlled trial.

http://clinicaltrials.gov reference NCT01191996