Suppression of experimental allergic encephalomyelitis in the Lewis rat by the matrix metalloproteinase inhibitor Ro31-9790

Matrix metalloproteinases (MMPs) are implicated in the tissue destruction associated with inflammatory demyelinating diseases such as multiple sclerosis. The effect of a hydroxamate inhibitor of MMPs, Ro31-9790, on inflammatory demyelination was assessed in two acute models of experimental allergic encephalomyelitis (EAE). Daily intraperitoneal injections of Ro31-9790 (50mgkg^–1), beginning either at the time of disease induction or from day 3 post induction, significantly reduced the clinical severity of adoptively transferred EAE. Administration of the inhibitor from the day of induction of active EAE prevented disease onset in 9/10 animals. However, in a repeat study, in which clinical disease was much more severe in the vehicle treated animals, the inhibitor was less effective. Clinical signs and CNS histopathology correlated well, with greater numbers of inflammatory lesions associated with increased disease severity. The present study confirms a role for the MMP cascade in inflammation in EAE.     

实验性变态反应性脑脊髓炎模型研究进展

实验性变态反应性脑脊髓炎（EAE）动物模型是研究人类多发性硬化（MS）的理想动物模型,在神经免疫性疾病研究中具有重要意义。了解EAE模型（被动免疫模型和主动免疫模型）制备的有关问题,包括实验动物的品系、性别、年龄的选择,抗原的选择,佐剂的选择,免疫方法的选择,模型的制作,动物临床发病过程,病情评分等及其在研究多发性硬化的发病机制、炎症反应和临床前药物试验等研究中的应用,以及存在的局限性具有重要意义。     

Th1细胞和Th17细胞在多发性硬化和实验性变态反应性脑脊髓炎发生中的作用

多发性硬化(MS)是一种由效应性T细胞介导的中枢神经系统自身免疫性脱髓鞘疾病,其病因和发病机制迄今不明.实验性变态反应性脑脊髓膜炎(EAE)为MS的动物模型.传统观念认为Th1细胞是MS自身免疫反应中主要的效应性T细胞.然而,Th17细胞的发现使Th1细胞的核心作用受到挑战.     

尿酸与多发性硬化关系的研究进展

多发性硬化(MS)是一种T细胞介导的自身免疫性疾病,其确切病因及发病机制尚不清楚,免疫学因素在发病中起着关键作用,其中在免疫细胞的效应阶段过氧化亚硝酸盐(ONOO)起重要作用.尿酸是嘌呤核苷酸代谢的终产物,是内源性的抗氧化剂和过氧化亚硝酸盐的天然清除剂,在MS病人的病理损害过程中具有保护作用.MS病人的血清尿酸水平显著...     

Monoclonal antibody therapy in experimental allergic encephalomyelitis and multiple sclerosis

Experimental autoimmune encephalomyelitis (EAE) is a T-cell-mediated demyelinating disease of the central nervous system that has been used as an animal model for multiple sclerosis (MS). Based on the exciting results in EAE, a number of novel immunotherapies employing biotechnological products, rather than conventional immunosuppressants, are being developed for the treatment of MS. In this review, we delineate the rationale for monoclonal antibody (MAb) therapy in EAE and MS and summarize the various levels at which immune intervention was performed. For each approach, we discuss the role of MAbs at the level of lymphocyte and cytokine networks, chemokines, and adhesion molecules or their receptors.     

Wistar大鼠多病程实验性变态反应性脑脊髓炎的模型建立

目的：建立Wistar大鼠多病程实验性变态反应性脑脊髓炎（EAE）的动物模型，并进行病理学研究，为多发性硬化（MS）的研究提供实验依据。方法：以豚鼠全脊髓匀浆（GPSCH）为抗原免疫Wistar大鼠建立EAE的动物模型，并在光镜下观察不同发病类型EAE的病理改变。结果：根据病理和临床表现可将Wistar大鼠EAE模型分为5种发病形式：急性型、缓解一复发型、持续进展型、良性型和隐匿型。光镜下可见不同发病时期的EAE的病理改变有所不同，但都以血管“袖套”状改变、脑室周围及白质有脱髓鞘改变为主，伴有神经元肿胀变性。结论：首次建立了大鼠多病程的EAE，是研究多发性硬化的理想动物模型。     

基质金属蛋白酶在实验性变态反应性脑脊髓炎病理改变中的作用及意义

目的：研究实验性变态反应性脑脊髓炎（EAE）的病理变化及基质金属蛋白酶（MMPs）的表达，探讨MMPs在EAE病理改变中的作用及意义。方法：应用光镜、电镜观察EAE大鼠模型组织学改变，利用免疫组化方法研究MMP-2、-9的表达。结果：光镜下可见小血管周围炎细胞浸润，呈袖套状改变，血管周围明显脱髓鞘，电镜下可见髓鞘松散、断裂，轴索细胞器消失，神经元内质网扩张脱颗粒。免疫组化染色MMP-2、-9在脊膜细胞、炎细胞和内皮细胞内均呈阳性表达。结论：MMPs参与EAE发病的各个环节，具有破坏血脑屏障、降解髓鞘、损伤轴索和产生免疫原的作用。     

实验性变应性脑脊髓炎髓鞘脱失机制的研究

目的：探讨自身免疫性脱髓鞘疾病的中枢神经系统(CNS)髓鞘脱失发生机制。方法：采用同源脑白质匀浆建立猴实验性变应性脑髓炎(EAE)模型，并用流式细胞仪检测血和脑脊液淋巴细胞亚群的变化，用免疫组化技术和电镜观察脑组织病理变化。结果：急性EAE猴脑脊液CD4^ T淋巴细胞明显升高，CD8^ T淋巴细胞和B淋巴细胞轻度升高；颞叶深部白质有大量CD4^ T淋巴细胞和少量CD8^ T淋巴细胞浸润，而对照组均未见变化；髓鞘内板层松解和轴突髓鞘分离，而髓鞘外板层正常，轴突也保存完好，少突胶质细胞(ODC)的部分胞浆明显水肿，线粒体肿胀，嵴模糊或断裂，核部分溶解。结论：提示EAE脱髓鞘免疫因子最早攻击的靶是少突胶质细胞，而不是髓鞘本身。     

The relevance of animal models in multiple sclerosis research

Multiple Sclerosis (MS) is a complex disease with an unknown etiology and no effective cure, despite decades of extensive research that led to the development of several partially effective treatments. Researchers have only limited access to early and immunologically active MS tissue samples, and the modification of experimental circumstances is much more restricted in human studies compared to studies in animal models. For these reasons, animal models are needed to clarify the underlying immune-pathological mechanisms and test novel therapeutic and reparative approaches. It is not possible for a single mouse model to capture and adequately incorporate all clinical, radiological, pathological and genetic features of MS. The three most commonly studied major categories of animal models of MS include: (1) the purely autoimmune experimental autoimmune/allergic encephalomyelitis (EAE); (2) the virally induced chronic demyelinating disease models, with the main model of Theiler's Murine Encephalomyelitis Virus (TMEV) infection and (3) toxin-induced models of demyelination, including the cuprizone model and focal demyelination induced by lyso-phosphatidyl choline (lyso-lecithine). EAE has been enormously helpful over the past several decades in our overall understanding of CNS inflammation, immune surveillance and immune-mediated tissue injury. Furthermore, EAE has directly led to the development of three approved medications for treatment in multiple sclerosis, glatiramer acetate, mitoxantrone and natalizumab. On the other hand, numerous therapeutical approaches that showed promising results in EAE turned out to be either ineffective or in some cases harmful in MS. The TMEV model features a chronic-progressive disease course that lasts for the entire lifespan in susceptible mice. Several features of MS, including the role and significance of axonal injury and repair, the partial independence of disability from demyelination, epitope spread from viral to myelin epitopes, the significance of remyelination has all been demonstrated in this model. TMEV based MS models also feature several MRI findings of the human disease. Toxin-induced demyelination models has been mainly used to study focal demyelination and remyelination. None of the three main animal models described in this review can be considered superior; rather, they are best viewed as complementary to one another. Despite their limitations, the rational utilization and application of these models to address specific research questions will remain one of the most useful tools in studies of human demyelinating diseases.     

The influence and impact of ageing and immunosenescence (ISC) on adaptive immunity during multiple sclerosis (MS) and the animal counterpart experimental autoimmune encephalomyelitis (EAE)

The human ageing process encompasses mechanisms that effect a decline in homeostasis with increased susceptibility to disease and the development of chronic life-threatening illness. Increasing age affects the immune system which undergoes a progressive loss of efficiency, termed immunosenescence (ISC), to impact on quantitative and functional aspects of innate and adaptive immunity. The human demyelinating disease multiple sclerosis (MS) and the corresponding animal model experimental autoimmune encephalomyelitis (EAE) are strongly governed by immunological events that primarily involve the adaptive arm of the immune response. MS and EAE are frequently characterised by a chronic pathology and a protracted disease course which thereby creates the potential for exposure to the inherent, on-going effects and consequences of ISC. Collective evidence is presented to confirm the occurrence of established and unendorsed biological markers of ISC during the development of both diseases. Moreover, results are discussed from studies during the course of MS and EAE that reveal a premature upregulation of ISC-related biomarkers which indicates untimely alterations to the adaptive immune system. The effects of ISC and a prematurely aged immune system on autoimmune-associated neurodegenerative conditions such as MS and EAE are largely unknown but current evaluation of data justifies and encourages further investigation.     

Effect of geranylgeranylacetone on optic neuritis in experimental autoimmune encephalomyelitis

Optic neuritis is an acute inflammatory demyelinating syndrome of the central nervous system (CNS) that often occurs in multiple sclerosis (MS). Since it can cause irreversible visual loss, especially in the optic-spinal form of MS or neuromyelitis optica (NMO), the present study was conducted to assess the effects of geranylgeranylacetone (GGA) on optic neuritis in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Myelin oligodendrocyte glycoprotein-induced EAE mice received oral administration of GGA at 500 mg/kg or vehicle once daily for 22 days. The effects of GGA on the severity of optic neuritis were examined by morphological analysis on day 22. Visual functions were measured by the multifocal electroretinograms (mfERG). In addition, the effects of GGA on severity of myelitis were monitored both on clinical signs and morphological aspects. The visual function, as assessed by the second-kernel of mfERG, was significantly improved in GGA-treated mice compared with vehicle-treated mice. GGA treatment decreased the number of degenerating axons in the optic nerve and prevented cell loss in the retinal ganglion cell layer. However, the severity of demyelination in the spinal cord remained unaffected with the treatment of GGA. These results suggest that oral GGA administration has beneficial effect on the treatment for optic neuritis in the EAE mouse model of MS.     

Pathogenic mechanisms and experimental models of multiple sclerosis

Multiple sclerosis (MS) is a devastating autoimmune disease that affects more than 1 million people worldwide and severely compromises motor and sensory function through demyelination and axonal loss. This review covers current therapies, lessons learned from failed clinical trials, genetic susceptibility, key cell types involved, animal models, gene expression, and biomarker information. The current first-line therapies for MS include the type I interferons (IFN-I) and glatiramer acetate (GA) but because of their limited effectiveness new therapeutic modalities are required. Tysabri is an anti very late antigen-4 antibody that antagonizes the migration of multiple cell types and appears more efficacious as compared to the IFNs or GA. Tysabri blocks the transmigration of T cells and monocytes, which indicates that blocking multiple cell types may increase the effectiveness of the therapy. However, this therapy may increase the risk of progressive multifocal leukoencephalopathy. The major cell types hypothesized to be pathogenic include T cells and antigen-presenting cells, including B cells. The correlation of the animal model experimental autoimmune encephalomyelitis (EAE) of MS and its predictive value to determine efficacy in the clinic appears limited. However, all current therapies do demonstrate efficacy in EAE models. There are also examples of mechanisms that have worked in EAE but have failed in the clinic, such as the TNFα antagonists and anti-p40 (a subunit of IL-12 and IL-23). The MS field would benefit if clinical biomarkers were available to monitor clinical efficacy. The etiology of MS remains elusive but additional understanding of mechanisms involved in the pathogenesis of MS may guide us to more effective treatment and management of this autoimmune disease.     

Absence of Notch1 in murine myeloid cells attenuates the development of experimental autoimmune encephalomyelitis by affecting Th1 and Th17 priming

Inhibition of Notch signalling in T cells attenuates the development of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Growing evidence indicates that myeloid cells are also key players in autoimmune processes. Thus, the present study evaluates the role of the Notch1 receptor in myeloid cells on the progression of myelin oligodendrocyte glycoprotein (MOG)_35‐55‐induced EAE, using mice with a myeloid‐specific deletion of the Notch1 gene (MyeNotch1KO). We found that EAE progression was less severe in the absence of Notch1 in myeloid cells. Thus, histopathological analysis revealed reduced pathology in the spinal cord of MyeNotch1KO mice, with decreased microglia/astrocyte activation, demyelination and infiltration of CD4⁺ T cells. Moreover, these mice showed lower Th1 and Th17 cell infiltration and expression of IFN‐γ and IL‐17 mRNA in the spinal cord. Accordingly, splenocytes from MyeNotch1KO mice reactivated in vitro presented reduced Th1 and Th17 activation, and lower expression of IL‐12, IL‐23, TNF‐α, IL‐6, and CD86. Moreover, reactivated wild‐type splenocytes showed increased Notch1 expression, arguing for a specific involvement of this receptor in autoimmune T cell activation in secondary lymphoid tissues. In summary, our results reveal a key role of the Notch1 receptor in myeloid cells for the initiation and progression of EAE.     

Age-related changes in multiple sclerosis and experimental autoimmune encephalomyelitis

A better understanding of the pathological mechanisms that drive neurodegeneration in people living with multiple sclerosis (MS) is needed to design effective therapies to treat and/or prevent disease progression. We propose that CNS-intrinsic inflammation and re-modelling of the sub-arachnoid space of the leptomeninges sets the stage for neurodegeneration from the earliest stages of MS. While neurodegenerative processes are clinically silent early in disease, ageing results in neurodegenerative changes that become clinically manifest as progressive disability. Here we review pathological correlates of MS disease progression, highlight emerging mouse models that mimic key progressive changes in MS, and provide new perspectives on therapeutic approaches to protect against MS-associated neurodegeneration.     

Suppression of experimental autoimmune encephalomyelitis in Lewis rats by antibodies against CD2

The immunotherapeutic potential of three anti-rat CD2 monoclonal antibodies (mAb) (OX34, OX54, OX55) and the combination of OX54 with OX55 was tested in Lewis rat experimental autoimmune encephalomyelitis (EAE). In actively induced EAE, a single injection of OX34 2 days before immunization with myelin basic protein (MBP) in complete Freund's adjuvant (CFA) completely prevented or greatly attenuated EAE in all animals. Injection of OX54 acted moderately suppressive while OX55 or OX54/55 did not affect disease severity. Abrogation of EAE by OX34 was not restricted to its application before immunization. Therapeutic administration of all three mAb and the Ab combination from onset of first clinical signs efficiently blocked progression of disease and prevented all animals from developing hind limb paresis. In adoptive transfer EAE induced with in vitro activated cells of an encephalitogenic T helper line, clinical and histological signs were completely prevented by injection of OX34 on the day of cell transfer and 4 days later, underlining the strong impact of anti-CD2 mAb on the effector phase of disease. Immunocytofluorometric analysis of peripheral blood lymphocytes after a single Ab injection demonstrated that all mAb induced a variable degree of transient reduction in T cell numbers and modulation of CD2 antigens. In contrast to the other mAb, OX34 persisted on lymphocytes for at least 11 days, which may explain its unique suppressive effect on EAE after a single injection before immunization. The assumption that prophylactic administration of OX34 also inhibits MBP-induced EAE, due to persistence into the effector phase, was substantiated by the finding that none of the mAb prevented generation of an antigen-specific cellular response in MBP/CFA-immunized animals. Since none of the Ab induced T cell unresponsiveness or inhibited T cell activation by antigen- or Ab-mediated stimulation of the T cell receptor, we suggest that their marked action on the effector phase of EAE may rely on inhibition of T cell infiltration into the central nervous system. The demonstrated efficacy of these anti-CD2 mAb in EAE suggests a potential therapeutic role that may be equal to that of anti-CD4 or anti-T cell receptor Ab.     

The action of TH17 cells on blood brain barrier in multiple sclerosis and experimental autoimmune encephalomyelitis

Th17 cells, known as a highly pro-inflammatory subtype of Th cells, are involved very early in numerous aspects of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) neuropathology. A crucial event for the formation and accumulation of MS lesions is represented by the disruption of the blood brain barrier (BBB) in relapsing-remitting MS. Th17 cells also contribute to the progression of MS/EAE. These events will allow for the passage of inflammatory cells into the brain. Secondary to this, increased recruitment of neutrophils occurs, followed by increased protease activity that will continue to attract macrophages and monocytes, leading to brain inflammation with sustained myelin and axon damage.This review focuses mainly on the role of Th17 cells in penetrating the BBB and on their important effects on BBB disruption via their main secretion products, IL-17 and IL-22. We present the morphological aspects of Th17 cells that allow for intercellular contacts with BBB endothelial cells and the functional/secretory particularities of Th17 cells that allow for intercellular communications that enhance Th17 entry into the CNS. The cytokines and chemokines involved in these processes are described. In conclusion, Th17 cells can efficiently cross the BBB using pathways distinct from those used by Th1 cells, leading to BBB disruption, the activation of other inflammatory cells and neurodegeneration in MS patients.     

Human mesenchymal stem cells abrogate experimental allergic encephalomyelitis after intraperitoneal injection, and with sparse CNS infiltration

Multiple sclerosis is a currently incurable inflammatory demyelinating syndrome. Recent reports suggest that bone marrow derived mesenchymal stem cells may have therapeutic potential in experimental models of demyelinating disease, but various alternative mechanisms, ranging from systemic immune effects to local cell replacement, have been proposed. Here we used intraperitoneal delivery of human mesenchymal stem cells to help test (a) whether human cells can indeed suppress disease, and (b) whether CNS infiltration is required for any beneficial effect. We found pronounced amelioration of clinical disease but profoundly little CNS infiltration. Our findings therefore help confirm the therapeutic potential of mesenchymal stem cells, show that this does indeed extend to human cells, and are consistent with a peripheral or systemic immune effect of human MSCs in this model.     

重组腺病毒转导的MSC导向的CNTF基因靶向性治疗MS对髓鞘和轴突的保护作用

目的:探讨重组腺病毒转导的骨髓间充质细胞导向(MSC)的睫状神经营养因子(CNTF)基因靶向性治疗多发性硬化对髓鞘和轴突的保护机制.方法:先构建、扩增、纯化Ad-CNTF-IBES-GFP,在体外培养MSC细胞.将1×108Ad-CNTF-IRES-GFP转染MSCS1×106,测定上清液中CNTF的浓度.再用MOG 35-55建立C57BL/6小鼠EAE模型,将Ad-CNTF-IRES-GFP转染的MSC移植治疗EAE小鼠,观察其病情评分;免疫荧光观察其病变部位的外源性MSO数量;免疫组化观察少突胶质细胞前体细胞(OPC)-NG2( )细胞在病变部位的数量,Western blot和免疫组化法观察神经生长因子CNTF表达,免疫组化观察促凋亡蛋白Caspase-3表达;病理观察髓鞘、轴突损伤情况;电镜观察髓鞘和轴突以及ODC损伤情况;所有的数据用(x)±s表示.采用SPSS 13.0进行统计分析.结果用多因素方差分析,P＜0.05差异有显著性.结果:MSC-Ad-CNTF-IRES-GFP治疗的EAE小鼠病情显著减轻.不仅平均发病时间缩短,发病率下降,病情减轻,而且病情严重程度也明显减轻.外源性MSC出现在EAE的脊髓病变部位.治疗后的EAE小鼠脊髓病变部位的NG2( )表达明显增加,促凋亡蛋白Caspaae-3的表达明显降低.治疗后的EAE小鼠病变部位的髓鞘和轴突变性明显减轻.结论:MSC-AD-CNTF-GFP可有效治疗EAE动物.其机制可能是:Ad-CNTF-IRES-GFP转染的MsC细胞定向去病变部位,升高其部位CNTF水平和NG2( )细胞数量,减轻其部位髓鞘、轴突及ODC损伤,减少促凋亡蛋白Caspase-3表达.     

T cells in multiple sclerosis and experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS), which involves autoimmune responses to myelin antigens. Studies in experimental autoimmune encephalomyelitis (EAE), an animal model for MS, have provided convincing evidence that T cells specific for self‐antigens mediate pathology in these diseases. Until recently, T helper type 1 (Th1) cells were thought to be the main effector T cells responsible for the autoimmune inflammation. However more recent studies have highlighted an important pathogenic role for CD4⁺ T cells that secrete interleukin (IL)‐17, termed Th17, but also IL‐17‐secreting γδ T cells in EAE as well as other autoimmune and chronic inflammatory conditions. This has prompted intensive study of the induction, function and regulation of IL‐17‐producing T cells in MS and EAE. In this paper, we review the contribution of Th1, Th17, γδ, CD8⁺ and regulatory T cells as well as the possible development of new therapeutic approaches for MS based on manipulating these T cell subtypes.     

Immunological mechanisms in multiple sclerosis

Multiple sclerosis (MS) remains a leading cause of neurologic disability among young adults. Clinical manifestations of the disease result from immune-mediated demyelination of the central nervous system. Most patients experience new symptoms in a relapsing-remitting pattern, although the course is highly variable from person to person and even in the same individual over time.Recent neuropathological studies reveal that in addition to the surrounding myelin sheath, nerve axons themselves are targets of injury in MS lesions. Characterization of the inflammatory infiltrates present in MS brain and spinal cord tissue shows that active lesions can be segregated into 1 of 4 subtypes, with each individual having only a single pattern of involvement. Studies in animal models demonstrate that a number of myelin proteins can become immune system targets resulting in demyelination, and these models have also served to define multiple immunological mechanisms of disease. Translational studies using peripheral blood samples have characterized differences in the various myelin protein-reactive immune responses of MS patients and controls, and these investigations have validated some, but not all, of the disease mechanisms uncovered in animals. Adaptive and innate immunity both appear to contribute to disease pathogenesis within the target tissue of the central nervous system.Immunomodulatory therapies have been developed that partially arrest disease relapses and progression. Studies to dissect how these agents work have shed light on underlying disease mechanisms in MS. More effective interventions in the future will need to target multiple points in disease pathways.