Current status of the immunomodulation and immunomediated therapeutic strategies for multiple sclerosis

Relationship between Hypoxic and Immune Pathways Activation in the Progression of Neuroinflammation: Role of HIF-1α and Th17 Cells

Neuroinflammation is a common event in degenerative diseases of the central and peripheral nervous system, triggered by alterations in the immune system or inflammatory cascade. The pathophysiology of these disorders is multifactorial, whereby the therapy available has low clinical efficacy. This review propounds the relationship between the deregulation of T helper cells and hypoxia, mainly Th17 and HIF-1α molecular pathways, events that are involved in the occurrence of the neuroinflammation. The clinical expression of neuroinflammation is included in prevalent pathologies such as multiple sclerosis, Guillain-Barré syndrome, and Alzheimer's disease, among others. In addition, therapeutic targets are analyzed in relation to the pathways that induced neuroinflammation.

The Impact of Hypoxia in Early Pregnancy on Placental Cells

Oxygen levels in the placental microenvironment throughout gestation are not constant, with severe hypoxic conditions present during the first trimester. This hypoxic phase overlaps with the most critical stages of placental development, i.e., blastocyst implantation, cytotrophoblast invasion, and spiral artery remodeling initiation. Dysregulation of any of these steps in early gestation can result in pregnancy loss and/or adverse pregnancy outcomes. Hypoxia has been shown to regulate not only the self-renewal, proliferation, and differentiation of trophoblast stem cells and progenitor cells, but also the recruitment, phenotype, and function of maternal immune cells. In this review, we will summarize how oxygen levels in early placental development determine the survival, fate, and function of several important cell types, e.g., trophoblast stem cells, extravillous trophoblasts, syncytiotrophoblasts, uterine natural killer cells, Hofbauer cells, and decidual macrophages. We will also discuss the cellular mechanisms used to cope with low oxygen tensions, such as the induction of hypoxia-inducible factor (HIF) or mammalian target of rapamycin (mTOR) signals, regulation of the metabolic pathway, and adaptation to autophagy. Understanding the beneficial roles of hypoxia in early placental development will provide insights into the root cause(s) of some pregnancy disorders, such as spontaneous abortion, preeclampsia, and intrauterine growth restriction.

Clinical Importance of a Cytokine Network in Major Burns

Major burns elicit an acute inflammatory response including various inflammatory cytokines. Cytokines play mutual interacting roles in inflammatory diseases. There is little evidence of the clinical significance of the cytokine network in patients with major burns. This study aimed to investigate the clinical significance of the cytokine network in patients with major burn. This prospective observational study comprising 38 patients with major burns (total body surface area (%TBSA) ≥ 20%) and 12 healthy controls was conducted from April 2014 to December 2016. Blood samples were collected from patients at six points: day 1, day 2, days 3-5, 1 week, 2 weeks, and 1 month after the burn injury. Inflammatory cytokines (interferon [IFN]-α, IFN-γ, interleukin [IL]-1β, IL-6, IL-8, IL-12/IL-23p40, IL-17A, monocyte chemotactic protein-1 [MCP-1], TNF-α), and anti-inflammatory cytokines (IL-4, IL-10) were measured. Twenty-eight-day mortality, %TBSA, prognostic burn index (PBI) and Sequential Organ Failure Assessment (SOFA), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were evaluated. Hierarchical clustering analysis and network visualization showed one cluster and network, respectively. Both were formed by four cytokines including IL-6, IL-8, IL-10, and MCP-1 on days 1 and 2, suggesting the presence of a cytokine network in the early hospital phase. Each cytokine showed significant associations with the SOFA score within 5 days and 1 month after burn injury. Cox regression analysis highlighting days 1 and 2 showed significant correlation of IL-6, IL-8, and IL-10 with 28-day mortality. We showed a cytokine network and its relation with prognosis and injury severity on days 1 and 2 and suggest that this cytokine network may play a role in major burns.

Amlexanox attenuates experimental autoimmune encephalomyelitis by inhibiting dendritic cell maturation and reprogramming effector and regulatory T cell responses

Background

Amlexanox (ALX), a TBK1 inhibitor, can modulate immune responses and has anti-inflammatory properties. To investigate its role in regulating the progression of experimental autoimmune encephalomyelitis (EAE), we studied the effect of ALX on the maturation of dendritic cells (DCs) and the responses of effector and regulatory T cells (Tregs).

Methods

In vitro, bone marrow-derived DCs (BMDCs) were cultured and treated with ALX. Their proliferation, maturation, and their stimulatory function to induce T cells responses were detected. In vivo, the development of EAE from different groups was recorded. At the peak stage of disease, HE, LFB, and electronic microscope (EM) were used to evaluate inflammation and demyelination. Maturation of splenic DC and Th1/Th17/Treg response in the CNS and peripheral were also detected. To further explore the mechanism underlying the action of ALX in DC maturation, the activation of TBK1, IRF3, and AKT was analyzed.

Results

Our data indicated that ALX significantly inhibited the proliferation and maturation of BMDCs, characterized by the reduced MHCII, a co-stimulatory molecule, IL12, and IL-23 expression, along with morphological alterations. Co-culture of ALX-treated BMDCs inhibited allogeneic T cell proliferation and MOG-specific T cell response. In EAE mice, ALX significantly attenuated the EAE development by decreasing inflammatory infiltration and demyelination in the spinal cords, accompanied by reduced frequency of splenic pathogenic Th1 and Th17 cells and increased Tregs. Moreover, ALX treatment decreased Th1 and Th17 cytokines, but increased Treg cytokines in the CNS and spleen. Notably, ALX treatment reduced the frequency and expression of CD80 and CD86 on splenic DCs and lowered IL-12 and IL-23 secretion, further supporting an impaired maturation of splenic DCs. In addition, ALX potently reduced the phosphorylation of IRF3 and AKT in BMDC and splenic DCs, both of which are substrates of TBK1 and associated with DC maturation.

Conclusions

ALX, a TBK1 inhibitor, mitigated EAE development by inhibiting DC maturation and subsequent pathogenic Th1 and Th17 responses while increasing Treg responses through attenuating the TBK1/AKT and TBK1/IRF3 signaling.

The clinical importance of a cytokine network in the acute phase of sepsis

Sepsis remains a major cause of death. Cytokines interact closely with each other and play a crucial role in the progression of sepsis. We focussed on the associations of a cytokine network with prognosis and disease severities in sepsis. This retrospective study included 31 patients with sepsis and 13 healthy controls. Blood samples were collected from patients on days 1, 2, 4, 6, 8, 11 and 15 and from healthy controls. Levels of PAI-1, IFN-α, IFN-γ, IL-1β, IL-6, IL-8, IL-12/IL-23p40, IL-17A, TNF-α, MCP-1, IL-4 and IL-10 were measured. SOFA, JAAM DIC and ISTH DIC scores were evaluated at the same times blood samples were taken. Network analysis revealed a network formed by PAI-1, IL-6, IL-8, MCP-1 and IL-10 on days 1, 2 and 4 throughout the acute phase of sepsis. There were positive correlations of each cytokine and the combined score (IL-6 + IL-8 + IL-10 + MCP-1) with the SOFA, JAAM DIC and ISTH DIC scores throughout the acute phase. A Cox proportional hazards model focussed on the acute phase showed that the above combined score was significantly related with patient prognosis, suggesting that the cytokine network of IL-6, IL-8, MCP-1 and IL-10 could play a pivotal role in the acute phase of sepsis.

Oriental Medicine Samhwangsasim-tang Alleviates Experimental Autoimmune Encephalomyelitis by Suppressing Th1 Cell Responses and Upregulating Treg Cell Responses

Oriental medicine Samhwangsasim-tang (SHSST) has traditionally been used in East Asia to treat hypertension and its complications. However, little is known about its potential value regarding the treatment of chronic inflammatory diseases such as multiple sclerosis (MS). In this study, we investigated whether SHSST has a beneficial effect in treating myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE). Onset-treatment with SHSST was found to alleviate neurological symptoms as well as demyelination and glial activation in the spinal cords from the EAE mice. The SHSST also attenuated the mRNA or protein expression of pro-inflammatory cytokines (interleukin-1beta and tumor necrotic factor-alpha); chemokines (RANTES, monocyte chemotactic protein-1, and macrophage inflammatory protein-1alpha); inducible nitric oxide synthase; and cyclooxygenase-2 in correspondence with the down-regulation of the nuclear factor-kappa B and mitogen-activated protein kinases signal pathways in the spinal cords from EAE mice. Interestingly, the protective effect of the SHSST was related to a decreased number of Th1 cells and an increased number of Treg cells in spinal cords from EAE mice. Taken together, our finding firstly suggested that SHSST could delay or mitigate EAE with a wide therapeutic time-window by suppressing Th1 cell responses and upregulating Treg cell responses. Also, our findings are strong enough to warrant further investigation of SHSST as a treatment for chronic autoimmune diseases including MS.

3H-1,2-dithiole-3-thione as a novel therapeutic agent for the treatment of experimental autoimmune encephalomyelitis

3H-1,2-dithiole-3-thione (D3T), the simplest member of the sulfur-containing dithiolethiones, is found in cruciferous vegetables, and has been previously reported to be a potent inducer of antioxidant genes and glutathione biosynthesis by activation of the transcription factor Nrf2. D3T is a cancer chemopreventive agent and possesses anti-inflammatory properties. Although D3T has been shown to protect against neoplasia, the effect of D3T in the autoimmune inflammatory disease multiple sclerosis/experimental autoimmune encephalomyelitis (EAE) is unknown. The present study is the first report of the therapeutic effect of D3T in EAE. Our results show D3T, administered post immunization, not only delays disease onset but also dramatically reduces disease severity in EAE. Strikingly, D3T, administered post disease onset of EAE, effectively prevents disease progression and exacerbation. Mechanistic studies revealed that D3T suppresses dendritic cell activation and cytokine production, inhibits pathogenic Th1 and Th17 differentiation, represses microglia activation and inflammatory cytokine expression, and promotes microglia phase II enzyme induction. In summary, these results indicate that D3T affects both innate and adaptive immune cells, and the protective effect of D3T in EAE might be attributed to its effects on modulating dendritic cell and microglia activation and pathogenic Th1/Th17 cell differentiation.

IKKβ-mediated inflammatory myeloid cell activation exacerbates experimental autoimmune encephalomyelitis by potentiating Th1/Th17 cell activation and compromising blood brain barrier

Background

The inflammatory myeloid cell activation is one of the hallmarks of experimental autoimmune encephalomyelitis (EAE), yet the in vivo role of the inflammatory myeloid cell activation in EAE has not been clearly resolved. It is well-known that IKK/NF-κB is a key signaling pathway that regulates inflammatory myeloid activation.

Methods

We investigated the in vivo role of inflammatory myeloid cell activation in myelin oligodendrocyte glycoprotein (MOG) peptides-induced EAE using myeloid cell type-specific ikkβ gene conditional knockout-mice (LysM-Cre/Ikkβ^F/F).

Results

In our study, LysM-Cre/Ikkβ^F/F mice had alleviated clinical signs of EAE corresponding to the decreased spinal demyelination, microglial activation, and immune cell infiltration in the spinal cord, compared to the wild-type mice (WT, Ikkβ^F/F). Myeloid ikkβ gene deletion significantly reduced the percentage of CD4⁺/IFN-γ⁺ (Th1) and CD4⁺/IL-17⁺ (Th17) cells but increased the percentages of CD4⁺/CD25⁺/Foxp3⁺ (Treg) cells in the spinal cord and lymph nodes, corresponding to the altered mRNA expression of IFN-γ, IL-17, IL-23, and Foxp3 in the spinal cords of LysM-Cre/Ikkβ^F/F EAE mice. Also, the beneficial effect of myeloid IKKβ deletion in EAE corresponded to the decreased permeability of the blood brain barrier (BBB).

Conclusions

Our findings strongly suggest that IKK/NF-kB-induced myeloid cell activation exacerbates EAE by activating Th1 and Th17 responses and compromising the BBB. The development of NF-κB inhibitory agents with high efficacy through specific targeting of IKKβ in myeloid cells might be of therapeutic potential in MS and other autoimmune disorders.

Electronic supplementary material

The online version of this article (doi:10.1186/s13024-016-0116-1) contains supplementary material, which is available to authorized users.

Restrained Th17 response and myeloid cell infiltration into the central nervous system by human decidua-derived mesenchymal stem cells during experimental autoimmune encephalomyelitis

BACKGROUND

Multiple sclerosis is a widespread inflammatory demyelinating disease. Several immunomodulatory therapies are available, including interferon-β, glatiramer acetate, natalizumab, fingolimod, and mitoxantrone. Although useful to delay disease progression, they do not provide a definitive cure and are associated with some undesirable side-effects. Accordingly, the search for new therapeutic methods constitutes an active investigation field. The use of mesenchymal stem cells (MSCs) to modify the disease course is currently the subject of intense interest. Decidua-derived MSCs (DMSCs) are a cell population obtained from human placental extraembryonic membranes able to differentiate into the three germ layers. This study explores the therapeutic potential of DMSCs.

METHODS

We used the experimental autoimmune encephalomyelitis (EAE) animal model to evaluate the effect of DMSCs on clinical signs of the disease and on the presence of inflammatory infiltrates in the central nervous system. We also compared the inflammatory profile of spleen T cells from DMSC-treated mice with that of EAE control animals, and the influence of DMSCs on the in vitro definition of the Th17 phenotype. Furthermore, we analyzed the effects on the presence of some critical cell types in central nervous system infiltrates.

RESULTS

Preventive intraperitoneal injection of DMSCs resulted in a significant delay of external signs of EAE. In addition, treatment of animals already presenting with moderate symptoms resulted in mild EAE with reduced disease scores. Besides decreased inflammatory infiltration, diminished percentages of CD4(+)IL17(+), CD11b(+)Ly6G(+) and CD11b(+)Ly6C(+) cells were found in infiltrates of treated animals. Early immune response was mitigated, with spleen cells of DMSC-treated mice displaying low proliferative response to antigen, decreased production of interleukin (IL)-17, and increased production of the anti-inflammatory cytokines IL-4 and IL-10. Moreover, lower RORγT and higher GATA-3 expression levels were detected in DMSC-treated mice. DMSCs also showed a detrimental influence on the in vitro definition of the Th17 phenotype.

CONCLUSIONS

DMSCs modulated the clinical course of EAE, modified the frequency and cell composition of the central nervous system infiltrates during the disease, and mediated an impairment of Th17 phenotype establishment in favor of the Th2 subtype. These results suggest that DMSCs might provide a new cell-based therapy for the control of multiple sclerosis.

Melatonin enhances interleukin-10 expression and suppresses chemotaxis to inhibit inflammation in situ and reduce the severity of experimental autoimmune encephalomyelitis

Melatonin is the major product secreted by the pineal gland at night and displays multifunctional properties, including immunomodulatory functions. In this study, we investigated the therapeutic effect of melatonin in experimental autoimmune encephalomyelitis (EAE). We demonstrated that melatonin exhibits a therapeutic role by ameliorating the clinical severity and restricting the infiltration of inflammatory Th17 cells into the CNS of mice with myelin oligodendrocyte glycoprotein (MOG)-induced EAE. Furthermore, melatonin enhances splenic interleukin (IL)-10 expression in regulatory T cells by inducing IL-27 expression in the splenic DC; it also suppresses the expression of IFN-γ, IL-17, IL-6, and CCL20 in the CNS and inhibits antigen-specific T cell proliferation. However, there were no significant differences in the percentage of splenic regulatory T cells. These data provide the first evidence that the therapeutic administration of melatonin is effective in mice with EAE and modulates adaptive immunity centrally and peripherally. Thus, we suggest that melatonin could play an adjunct therapeutic role in treating human CNS autoimmune diseases such as multiple sclerosis. Melatonin merits further studies in animals and humans.

(E)-1,3-diphenyl-1H-pyrazole derivatives containing O-benzyl oxime moiety as potential immunosuppressive agents: Design, synthesis, molecular docking and biological evaluation

A series of novel (E)-1,3-diphenyl-1H-pyrazole derivatives containing O-benzyl oxime moiety were firstly synthesized and their immunosuppressive activities were evaluated. Among all the compounds, 4n exhibited the most potent inhibitory activity (IC50 = 1.18 μM for lymph node cells and IC50 = 0.28 μM for PI3Kγ), which was comparable to that of positive control. Moreover, selected compounds were tested for their inhibitory activities against IL-6 released in ConA-simulated mouse lymph node cells, 4n exhibited the most potent inhibitory ability. Furthermore, in order to study the preliminary mechanism of the compounds with potent inhibitory activity, the RT-PCR experiment was performed to assay the effect of selected compounds on mRNA expression of IL-6. Among them, compound 4n strongly inhibited the expression of IL-6 mRNA.

An Oriental Medicine, Hyungbangpaedok-San Attenuates Motor Paralysis in an Experimental Model of Multiple Sclerosis by Regulating the T Cell Response

The preventive and therapeutic mechanisms in multiple sclerosis are not clearly understood. We investigated whether Hyungbangpaedok-san (HBPDS), a traditional herbal medicine, has a beneficial effect in experimental autoimmune encephalomyelitis (EAE) mice immunized with myelin oligodendrocyte glycoprotein peptide (MOG_35-55). Onset-treatment with 4 types of HBPDS (extracted using distilled water and 30%/70%/100% ethanol as the solvent) alleviated neurological signs, and HBPDS extracted within 30% ethanol (henceforth called HBPDS) was more effective. Onset-treatment with HBPDS reduced demyelination and the recruitment/infiltration and activation of microglia/macrophages in the spinal cord of EAE mice, which corresponded to the reduced mRNA expression of pro-inflammatory cytokines (TNF-α, IL–6, and IL–1β), iNOS, and chemokines (MCP–1, MIP–1α, and RANTES) in the spinal cord. Onset-treatment with HBPDS inhibited changes in the components of the blood-brain barrier such as astrocytes, adhesion molecules (ICAM–1 and VCAM–1), and junctional molecules (claudin–3, claudin–5, and zona occludens–1) in the spinal cord of EAE mice. Onset-treatment with HBPDS reduced the elevated population of CD4⁺, CD4⁺/IFN-γ⁺, and CD4⁺/IL–17⁺ T cells in the spinal cord of EAE mice but it further increased the elevated population of CD4⁺/CD25⁺/Foxp3⁺ and CD4⁺/Foxp3⁺/Helios⁺ T cells. Pre-, onset-, post-, but not peak-treatment, with HBPDS had a beneficial effect on behavioral impairment in EAE mice. Taken together, HBPDS could alleviate the development/progression of EAE by regulating the recruitment/infiltration and activation of microglia and peripheral immune cells (macrophages, Th1, Th17, and Treg cells) in the spinal cord. These findings could help to develop protective strategies using HBPDS in the treatment of autoimmune disorders including multiple sclerosis.

Pathologic and Protective Roles for Microglial Subsets and Bone Marrow- and Blood-Derived Myeloid Cells in Central Nervous System Inflammation

Inflammation is a series of processes designed for eventual clearance of pathogens and repair of damaged tissue. In the context of autoimmune recognition, inflammatory processes are usually considered to be pathological. This is also true for inflammatory responses in the central nervous system (CNS). However, as in other tissues, neuroinflammation can have beneficial as well as pathological outcomes. The complex role of encephalitogenic T cells in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE) may derive from heterogeneity of the myeloid cells with which these T cells interact within the CNS. Myeloid cells, including resident microglia and infiltrating bone marrow-derived cells, such as dendritic cells (DC) and monocytes/macrophages [bone marrow-derived macrophages (BMDM)], are highly heterogeneous populations that may be involved in neurotoxicity and also immunoregulation and regenerative processes. Better understanding and characterization of myeloid cell heterogeneity is essential for future development of treatments controlling inflammation and inducing neuroprotection and neuroregeneration in diseased CNS. Here, we describe and compare three populations of myeloid cells: CD11c⁺ microglia, CD11c⁻ microglia, and CD11c⁺ blood-derived cells in terms of their pathological versus protective functions in the CNS of mice with EAE. Our data show that CNS-resident microglia include functionally distinct subsets that can be distinguished by their expression of CD11c. These subsets differ in their expression of Arg-1, YM1, iNOS, IL-10, and IGF-1. Moreover, in contrast to BMDM/DC, both subsets of microglia express protective interferon-beta (IFNβ), high levels of colony-stimulating factor-1 receptor, and do not express the Th1-associated transcription factor T-bet. Taken together, our data suggest that CD11c⁺ microglia, CD11c⁻ microglia, and infiltrating BMDM/DC represent separate and distinct populations and illustrate the heterogeneity of the CNS inflammatory environment.

Molecular biomarkers in cerebrospinal fluid of multiple sclerosis patients

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system, usually occurring in young adults and leading to disability. Despite the progress in technology and intensive research work of the last years, diagnosing MS can still be challenging. A heterogenic and complex pathophysiology with various types of disease courses makes MS unique for each patient. There is an urgent need to identify markers facilitating rapid and accurate diagnosis and prognostic assessments with regard to optimal therapy for each MS patient. Cerebrospinal fluid (CSF) is an outstanding source of specific markers related to MS pathology. Molecules reflecting specific pathological processes, such as inflammation, cellular damage, and loss of blood-brain-barrier integrity, are detectable in CSF. Clinically used biomarkers of CSF are oligoclonal bands, IgG-index, measles-rubella-zoster-reaction, anti-aquaporin 4 antibodies, and antibodies against John Cunningham virus. Many other potential biomarkers have been proposed in recent years. In this review we examine the current scientific knowledge on CSF molecular markers that could guide diagnosis and discrimination of different MS forms, support treatment decisions, or be helpful in monitoring and predicting disease progression, therapy response, and complications such as opportunistic infections.

Treatment with Vitamin D/MOG Association Suppresses Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is an animal model to study multiple sclerosis (MS). Considering the tolerogenic effects of active vitamin D, we evaluated the therapeutic effect of myelin oligodendrocyte glycoprotein (MOG) associated with active vitamin D in EAE development. EAE was induced in female C57BL/6 mice by immunization with MOG emulsified with Complete Freund's Adjuvant plus Mycobacterium tuberculosis. Animals also received two intraperitoneal doses of Bordetella pertussis toxin. One day after immunization, mice were treated with 0,1 μg of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) every other day during 15 days (on days 1, 3, 5, 7, 9, 11, 13 and 15). MOG (150 μg) was co-administered on days 3 and 11. The administration of 1,25(OH)2D3 or MOG determined significant reduction in EAE incidence and in clinical scores. When MOG was associated with 1,25(OH)2D3 the animals did not develop EAE. Spleen and central nervous system (CNS) cell cultures from this group produced less IL-6 and IL-17 upon stimulation with MOG in comparison to the EAE control group. In addition, this treatment inhibited dendritic cells maturation in the spleen and reduced inflammatory infiltration in the CNS. The association of MOG with 1,25(OH)2D3 was able to control EAE development.

Korean Red Ginseng and Ginsenoside-Rb1/-Rg1 Alleviate Experimental Autoimmune Encephalomyelitis by Suppressing Th1 and Th17 Cells and Upregulating Regulatory T Cells

The effects of Korean red ginseng extract (KRGE) on autoimmune disorders of the nervous system are not clear. We investigated whether KRGE has a beneficial effect on acute and chronic experimental autoimmune encephalomyelitis (EAE). Pretreatment (daily from 10 days before immunization with myelin basic protein peptide) with KRGE significantly attenuated clinical signs and loss of body weight and was associated with the suppression of spinal demyelination and glial activation in acute EAE rats, while onset treatment (daily after the appearance of clinical symptoms) did not. The suppressive effect of KRGE corresponded to the messenger RNA (mRNA) expression of proinflammatory cytokines (tumor necrosis factor-α [TNF-α] and interleukin [IL]-1β), chemokines (RANTES, monocyte chemotactic protein-1 [MCP-1], and macrophage inflammatory protein-1α [MIP-1α]), adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], and platelet endothelial cell adhesion molecule [PECAM-1]), and inducible nitric oxide synthase in the spinal cord after immunization. Interestingly, in acute EAE rats, pretreatment with KRGE significantly reduced the population of CD4(+), CD4(+)/IFN-γ(+), and CD4(+)/IL-17(+) T cells in the spinal cord and lymph nodes, corresponding to the downregulation of mRNA expression of IFN-γ, IL-17, and IL-23 in the spinal cord. On the other hand, KRGE pretreatment increased the population of CD4(+)/Foxp3(+) T cells in the spinal cord and lymph nodes of these rats, corresponding to the upregulation of mRNA expression of Foxp3 in the spinal cord. Interestingly, intrathecal pretreatment of rats with ginsenosides (Rg1 and Rb1) significantly decreased behavioral impairment. These results strongly indicate that KRGE has a beneficial effect on the development and progression of EAE by suppressing T helper 1 (Th1) and Th17 T cells and upregulating regulatory T cells. Additionally, pre- and onset treatment with KRGE alleviated neurological impairment of myelin oligodendrocyte glycoprotein(35-55)-induced mouse model of chronic EAE. These results warrant further investigation of KRGE as preventive or therapeutic strategies for autoimmune disorders, such as multiple sclerosis.

Deletion of IL-4Rα in the BALB/c mouse is associated with altered lesion topography and susceptibility to experimental autoimmune encephalomyelitis

The regulation of cytokine expression by immune deviation from a pro-inflammatory to anti-inflammatory or "regulatory" milieu is crucial to the prevention of permanent central nervous system (CNS) damage in neuroinflammation. Earlier studies in the murine experimental autoimmune encephalomyelitis (EAE) model pointed to an anti-inflammatory role for the Th2 cytokine, IL-4, which was not confirmed in IL-4Rα-deficient mice (IL-4Rα(-/-)). To examine the pathological consequences of loss of responsiveness to Th2 cytokines, we compared lesion evolution in IL-4Rα(-/-) and wild type (WT) BALB/c mice immunized with PLP180-199 and investigated how altering the magnitude of the antigen-specific autoimmune response in this model affected the pathology. We found that while changing the magnitude of the peripheral antigen-specific response differentially affected the incidence of clinical disease in WT BALB/c relative to IL-4Rα(-/-) mice, the differences in incidence did not correlate to differences in pro-inflammatory cytokine production. Additionally, although only approximately 75% of WT mice developed clinical disease, lesions were observed in 100% of the mice, principally in the cerebellum, mid-brain and cerebral hemispheres, and lesion load increased with increasing pro-inflammatory cytokine production. Despite being resistant to disease induction with increasing pro-inflammatory cytokine production, lesion incidence in IL-4Rα-deficient animals was equal to their WT counterparts. However, lesion severity in IL-4Rα-deficient animals was preferentially reduced in the mid-brain and cerebral hemispheres. From these studies, we conclude that signaling through IL-4Rα has little effect on regulating the peripheral pro-inflammatory cytokine profile in this EAE variant but has distinct effects on the determination of lesion topography.

Blocking initial infiltration of pioneer CD8(+) T-cells into the CNS via inhibition of SHP-2 ameliorates experimental autoimmune encephalomyelitis in mice

BACKGROUND AND PURPOSE

In contrast to T-cell priming in the periphery, therapeutic strategies targeting the initiation step of T-cell trafficking into the CNS have not been extensively investigated. In this study, we examined the effect of NSC-87877, a potent Src homology 2-containing protein tyrosine phosphatase 2 (SHP-2) inhibitor, on experimental autoimmune encephalomyelitis (EAE) and elucidated its unique mechanism of action.

EXPERIMENTAL APPROACH

C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein35-55 and monitored for clinical severity of disease and histopathological features in the CNS. Levels of cytokines in serum were measured by elisa. Effects of NSC-87877 on expressions of chemokines and cytokines in the CNS were determined by quantitative PCR.

KEY RESULTS

NSC-87877-treated mice developed conventional TH 1 and TH 17 responses, but were highly resistant to the induction of EAE. NSC-87877 decreased the accumulation of lymphocytes in the CNS and increased the functional expression of chemokine receptor CXCR7 on CD8(+) T-cells. Adoptive transfer of T-cells from 2D2-transgenic mice restored EAE susceptibility in NSC-87877-treated mice, indicating that NSC-87877 only targets the initial migration of pioneer T-cells. Furthermore, T-cell-conditioned SHP-2-deficient mice treated with NSC-87877 were no longer resistant to EAE, suggesting that inhibition of SHP-2 contributes to the amelioration of EAE by NSC-87877.

CONCLUSIONS AND IMPLICATIONS

NSC-87877 almost completely abolished the development of EAE by blocking the initial infiltration of pioneer CD8(+) T-cells into the uninflamed CNS. These results reveal a critical role for SHP-2 in regulating EAE pathogenesis and indicate that NSC-87877 is a potential candidate for the treatment of relapsing-remitting multiple sclerosis.

Comparative assessment of PDE 4 and 7 inhibitors as therapeutic agents in experimental autoimmune encephalomyelitis

BACKGROUND AND PURPOSE

PDE4 inhibition suppresses experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). However, side effects hinder PDE4 inhibitors clinical use. PDE7 inhibition might constitute an alternative therapeutic strategy, but few data about the anti-inflammatory potential of PDE7 inhibitors are currently available. We have used the EAE model to perform a comparative evaluation of PDE4 and PDE7 inhibition as strategies for MS treatment.

EXPERIMENTAL APPROACH

Two PDE7 inhibitors, the sulfonamide derivative BRL50481 and the recently described quinazoline compound TC3.6, were assayed to modulate EAE in SJL mice, in comparison with the well-known PDE4 inhibitor Rolipram. We evaluated clinical signs, presence of inflammatory infiltrates in CNS and anti-inflammatory markers. We also analysed the effect of these inhibitors on the inflammatory profile of spleen cells in vitro.

KEY RESULTS

TC3.6 prevented EAE with efficacy similar to Rolipram, while BRL50481 had no effect on the disease. Differences between both PDE7 inhibitors are discussed. Data from Rolipram and TC3.6 showed that PDE4 and PDE7 inhibition work through both common and distinct pathways. Rolipram administration caused an increase in IL-10 and IL-27 expression which was not found after TC3.6 treatment. On the other hand, both inhibitors reduced IL-17 levels, prevented infiltration in CNS and increased the expression of the T regulator cell marker Foxp3.

CONCLUSIONS AND IMPLICATIONS

These results provide new information about the effects of Rolipram on EAE, underline PDE7 inhibition as a new therapeutic target for inflammatory diseases and show the value of TC3.6 to prevent EAE, with possible consequences for new therapeutic tools in MS.

Cannabis use by individuals with multiple sclerosis: effects on specific immune parameters

Cannabinoids affect immune responses in ways that may be beneficial for autoimmune diseases. We sought to determine whether chronic Cannabis use differentially modulates a select number of immune parameters in healthy controls and individuals with multiple sclerosis (MS cases). Subjects were enrolled and consented to a single blood draw, matched for age and BMI. We measured monocyte migration isolated from each subject, as well as plasma levels of endocannabinoids and cytokines. Cases met definition of MS by international diagnostic criteria. Monocyte cell migration measured in control subjects and individuals with MS was similarly inhibited by a set ratio of phytocannabinoids. The plasma levels of CCL2 and IL17 were reduced in non-naïve cannabis users irrespective of the cohorts. We detected a significant increase in the endocannabinoid arachidonoylethanolamine (AEA) in serum from individuals with MS compared to control subjects, and no significant difference in levels of other endocannabinoids and signaling lipids irrespective of Cannabis use. Chronic Cannabis use may affect the immune response to similar extent in individuals with MS and control subjects through the ability of phytocannabinoids to reduce both monocyte migration and cytokine levels in serum. From a panel of signaling lipids, only the levels of AEA are increased in individuals with MS, irrespective of Cannabis use or not. Our results suggest that both MS cases and controls respond similarly to chronic Cannabis use with respect to the immune parameters measured in this study.

Bone marrow-derived mesenchymal stem cells affect immunologic profiling of interleukin-17-secreting cells in a chemical burn mouse model

PURPOSE

This study investigated interleukin (IL)-17-secreting cell involvement in sterile inflammation, and evaluated the effect of mesenchymal stem cells (MSCs) on IL-17-secreting cell immunologic profiling.

METHODS

Twenty mice were sacrificed at time points of 6 hours, 1 day, 1 week, and 3 weeks (each group, n = 5) after the cornea was chemically injured with 0.5N NaOH; IL-17 changes in the cornea were evaluated using enzyme-linked immunosorbent assay. Further, IL-17 secreting cells were assessed in the cervical lymph nodes by a flow cytometer. Rat MSCs were applied intraperitoneally in a burn model (n = 10), IL-17-secreting T helper 17 (Th17) cell and non-Th17 cell changes were checked using a flow cytometer in both cornea and cervical lymph nodes at 1 week, and compared with those in the positive control (n = 10).

RESULTS

IL-17 was highest in the cornea at 1 week, while, in the cervical lymph nodes, IL-17-secreting cells showed early increase at 6 hours, and maintained the increase through 1 day to 1 week, and levels returned to the basal level at 3 weeks. Specifically, the non-Th17 cells secreted IL-17 earlier than the Th17 cells. When the MSCs were applied, IL-17 secretion was reduced in CD3(+)CD4(-)CD8(-), CD3(+)CD4(+)CD8(-), and CD3(+) CD4(-)CD8(+) cells of the cervical lymph nodes by 53.7%, 43.8%, and 50.8%, respectively. However, in the cornea, IL-17 secretion of CD3(+)CD4(-)CD8(-) cells was completely blocked.

CONCLUSIONS

The results indicated that both IL-17-secreting non-Th17 and Th17 cells were involved in the chemical burn model, and MSCs appeared to mainly modulate non-Th17 cells and also partially suppress the Th17 cells.

PET imaging in multiple sclerosis

Positron emission tomography (PET) is a non-invasive technique for quantitative imaging of biochemical and physiological processes in animals and humans. PET uses probes labeled with a radioactive isotope, called PET tracers, which can bind to or be converted by a specific biological target and thus can be applied to detect and monitor different aspects of diseases. The number of applications of PET imaging in multiple sclerosis is still limited. Clinical studies using PET are basically focused on monitoring changes in glucose metabolism and the presence of activated microglia/macrophages in sclerotic lesions. In preclinical studies, PET imaging of targets for other processes, like demyelination and remyelination, has been investigated and may soon be translated to clinical applications. Moreover, more PET tracers that could be relevant for MS are available now, but have not been studied in this context yet. In this review, we summarize the PET imaging studies performed in multiple sclerosis up to now. In addition, we will identify potential applications of PET imaging of processes or targets that are of interest to MS research, but have yet remained largely unexplored.

Formula-feeding is associated with shift towards Th1 cytokines

PURPOSE

Breast-feeding (BF) versus formula-feeding (FF) may be a factor for the development and differentiation of T-cell subsets and cytokine production in infancy and childhood. We therefore investigated T-cell subpopulations and their cytokine production by flow cytometry as well as cytokine levels in serum samples in breast-fed versus formula-fed infants and children.

METHODS

Heparinised blood was taken from 191 healthy infants and children. Peripheral blood mononuclear cells were stimulated with phorbol-mystriate-acetate and ionomycin in the presence of brefeldin. T-cell subsets and cytokines were determined by flow cytometry. Furthermore, serum concentrations of IFNγ and IL4 were measured using ELISA. An IFNγ/IL4 ratio was calculated to estimate the Th1/Th2 balance.

RESULTS

Children who were formula-fed show higher numbers of memory T and T helper cells. After stimulation, the number of IFNγ-positive memory T-cells was increased up to the age of 6 years. Breast-fed infants show higher percentages of IL4-positive T helper cells. At ELISA determination, formula-fed children showed higher IFNγ levels than breast-fed children, while IL4 levels did not differ. The IFNγ/IL4 ratio (FACS and ELISA) was elevated in formula-fed infants and children.

CONCLUSION

This systematic analysis of cytokine profiles during childhood in dependency of BF allows a better understanding of immune maturation and demonstrates the influence of early feeding on immune function throughout childhood, even after cessation of BF. FF induces a shift towards Th1 cytokines in children. This may have an influence on the development of autoimmune disease in later life.

Comparison of human adult stem cells from adipose tissue and bone marrow in the treatment of experimental autoimmune encephalomyelitis

INTRODUCTION

While administration of ex vivo culture-expanded stem cells has been used to study immunosuppressive mechanisms in multiple models of autoimmune diseases, less is known about the uncultured, nonexpanded stromal vascular fraction (SVF)-based therapy. The SVF is composed of a heterogeneous population of cells and has been used clinically to treat acute and chronic diseases, alleviating symptoms in a range of tissues and organs.

METHODS

In this study, the ability of human SVF cells was compared with culture-expanded adipose stem cells (ASCs) and bone-derived marrow stromal cells (BMSCs) as a treatment of myelin oligodendrocyte glycoprotein (35-55)-induced experimental autoimmune encephalitis in C57Bl/6J mice, a well-studied multiple sclerosis model (MS). A total of 1×10⁶ BMSCs, ASCs, or SVF cells were administered intraperitoneally concomitantly with the induction of disease. Mice were monitored daily for clinical signs of disease by three independent, blinded investigators and rated on a scale of 0 to 5. Spinal cords were obtained after euthanasia at day 30 and processed for histological staining using luxol fast blue, toluidine blue, and hematoxylin and eosin to measure myelin and infiltrating immune cells. Blood was collected from mice at day 30 and analyzed by enzyme-linked immunosorbent assay to measure serum levels of inflammatory cytokines.

RESULTS

The data indicate that intraperitoneal administration of all cell types significantly ameliorates the severity of disease. Furthermore, the data also demonstrate, for the first time, that the SVF was as effective as the more commonly cultured BMSCs and ASCs in an MS model. All cell therapies also demonstrated a similar reduction in tissue damage, inflammatory infiltrates, and sera levels of IFNγ and IL-12. While IFNγ levels were reduced to comparable levels between treatment groups, levels of IL-12 were significantly lower in SVF-treated than BMSC-treated or ASC-treated mice.

CONCLUSIONS

Based on these data, it is evident that SVF cells have relevant therapeutic potential in an animal model of chronic MS and might represent a valuable tool for stem cell-based therapy in chronic inflammatory disease of the central nervous system. SVF offers advantages of direct and rapid isolation procedure in a xenobiotic-free environment.

Administration of murine stromal vascular fraction ameliorates chronic experimental autoimmune encephalomyelitis

Administration of adipose-derived stromal/stem cells (ASCs) represents a promising therapeutic approach for autoimmune diseases since they have been shown to have immunomodulatory properties. The uncultured, nonexpanded counterpart of ASCs, the stromal vascular fraction (SVF), is composed of a heterogeneous mixture of cells. Although administration of ex vivo culture-expanded ASCs has been used to study immunomodulatory mechanisms in multiple models of autoimmune diseases, less is known about SVF-based therapy. The ability of murine SVF cells to treat myelin oligodendrocyte glycoprotein35-55-induced experimental autoimmune encephalitis (EAE) was compared with that of culture-expanded ASCs in C57Bl/6J mice. A total of 1 × 10(6) SVF cells or ASCs were administered intraperitoneally concomitantly with the induction of disease. The data indicate that intraperitoneal administration of ASCs significantly ameliorated the severity of disease course. They also demonstrate, for the first time, that the SVF effectively inhibited disease severity and was statistically more effective than ASCs. Both cell therapies also demonstrated a reduction in tissue damage, a decrease in inflammatory infiltrates, and a reduction in sera levels of interferon-γ and interleukin-12. Based on these data, SVF cells effectively inhibited EAE disease progression more than culture-expanded ASCs.

HLA class I & II alleles in multiple sclerosis patients from Puerto Rico

Multiple Sclerosis (MS) is a complex disease where genetic and environmental factors have been implicated. The onset of symptoms occurs in individuals from twenty to fifty years of age, producing a progressive impairment of motor, sensory and cognitive functions. MS is more frequent in females than in males with a ratio of 4:1. The prevalence of the MS varies among ethnics groups such as Europeans, Africans and Caucasians. The estimated prevalence of MS in Puerto Rico is 42 for each 100,000 habitants, which is more than the prevalence reported for Central America and the Caribbean. In spite of this prevalence, the genetic component of MS has not been explored in order to know the alleles' expression of Puerto Rican MS patients and compare it with the allele expression in other ethnic groups. Thirty-five patients and 31 control subjects were genotyped. The allele frequencies expressed in this sample were similar to those expressed for Puerto Ricans in the National Marrow Donor Program Registry (n = 3,149). The most prevalent alleles for MS patients were HLA-DRB1*01 and *03. HLA-DQB1*04 was the most frequent in the control group and HLA-A*30, in MS patients. These findings are in agreement with published data. HLA-DQB1*04 was a marginal protector in this sample and this role has not been described before. The accuracy of the results is limited due to the sample size. After performing a statistical power analysis it showed that by increasing the sample the values would be significant.

Possible role of interleukin-17 in a prime/challenge model of multiple sclerosis

No one single pathogen has been identified as the causative agent of multiple sclerosis (MS). Alternately, the likelihood of an autoimmune event may be nonspecifically enhanced by different infectious agents. In a novel animal model of MS, SJL/J mice primed through infection with a recombinant vaccinia virus (VV) encoding myelin proteolipid protein (PLP) (VV(PLP)) were susceptible to a central nervous system (CNS) inflammatory disease following administration of a nonspecific immunostimulant [complete Freund's adjuvant (CFA) plus Bordetella pertussis (BP)]. Mononuclear cells isolated from the brains, but not the spleens, of VV(PLP)-primed CFA/BP challenged mice produced interleukin (IL)-17 and interferon-γ and transferred a CNS inflammatory disease to naïve SJL/J mice. Administration of curdlan, a T helper 17 cell inducer, unexpectedly resulted in less severe clinical and histological signs of disease, compared to CFA/BP challenged mice, despite the induction of IL-17 in the periphery. Further examination of the VV(PLP)-prime CFA/BP challenge model may suggest new mechanisms for how different pathogens associated with MS can protect or enhance disease.

Evaluation of Th17-related cytokines and receptors in multiple sclerosis patients under interferon β-1 therapy

Th17-related cytokines (IL-17, IL-23, and IL-26) and receptors (IL-17R and IL-23R) were evaluated in MS patients under immunomodulatory IFN-β1 therapy during a 2year follow-up. Before the initiation of treatment, no significant difference was found in cytokine or receptor expression between controls and MS patients. Of the three cytokines evaluated, IL-26 was the highest in the patients' sera. The amount of IL-17 and CD13(+)IL-17R(+) cells was steadily decreased whereas IL-23 and IL-26 levels were gradually increased with IFN-β1 therapy. The patients in progressive phase had very high levels of IL-17. Th17-associated parameters should be considered in the immunomodulatory IFN-β1 therapy of MS.