银杏提取物对实验性自身免疫性脑脊髓炎小鼠的影响

目的:探讨银杏提取物(GBE)对实验性自身免疫性脑脊髓炎(EAE)小鼠炎症脱髓鞘病变的影响。方法:应用髓鞘少突胶质细胞糖蛋白33-55(MOG33-55)配以完全弗氏佐剂(CFA)免疫小鼠,诱发EAE模型。将小鼠分为CFA对照组、EAE模型组和GBE治疗组(每日腹腔注射GBE70mg/kg)。通过神经功能评分、行为学实验以及免疫荧光染色,观察GBE对EAE小鼠的影响。结果:GBE组小鼠各时间段神经功能评分均低于EAE组(P0.05),行为学检测显示发病高峰期falling latency时间较EAE组延长10s;GBE组较EAE组视神经髓鞘碱性蛋白(MBP)表达水平增高,可见MBP阳性髓鞘结构包绕轴突;海马伞矢状切片免疫荧光染色证实GBE组CD11b阳性小胶质细胞较EAE组明显减少,但是GFAP阳性星形胶质细胞数量与EAE组无明显差别。结论:GBE可能通过抑制小胶质细胞激活从而延缓EAE小鼠脱髓鞘进程,提示GBE对多发性硬化具有一定的治疗作用。     

在实验性自身免疫性脑脊髓炎模型中探讨MS？…

多发性硬化是一种较常见的中枢神经系统脱髓鞘疾病，Ｔ细胞介导免疫在其发病机制中起一定作用。该病的免疫耐受治疗是目前的研究热点之一，本文综述了近几年在其动物模型实验性自身免疫性脑脊髓炎中进行的研究工作的某些方法和进展。     

在实验性自身免疫性脑脊髓炎模型中探讨MS的免疫耐受治疗

多发性硬化是一种较常见的中枢神经系统脱髓鞘疾病 ,T细胞介导免疫在其发病机制中起一定作用。该病的免疫耐受治疗是目前的研究热点之一 ,本文综述了近几年在其动物模型实验性自身免疫性脑脊髓炎中进行的研究工作的某些方法和进展。     

经消化道诱导昆明鼠耐受实验性自身免疫性脑脊髓炎

诱导特异性免疫耐受是多发性硬化治疗学的一个重要研究方向。实验性自身免疫性脑脊髓炎是研究多发性硬化常用的动物模型，在此介绍我们使用同源脊髓匀浆诱导昆明鼠耐受实验性自身免疫性脑脊髓炎的一些实验工作结果及体会。     

胸腺五肽治疗实验性自身免疫性脑脊髓炎的实验研究

目的 应用胸腺五肽(thymopentin,TP-5)干预实验性自身免疫性脑脊髓炎(experiment autoimmue encephalomyelitis,EAE)大鼠,探讨该药物对EAE的治疗作用及其机制.方法 以豚鼠全脊髓匀浆(guinea pig spinal cord homogenate,GPSCH)与完全弗氏佐剂(CFA)为抗原免疫Wistar大鼠建立EAE模型.Wistar大鼠随机分为正常对照组、EAE组、地塞米松(dexamethasone,DXM)组、TP-5小剂量组、TP-5大剂量组.采用双抗体夹心ELISA法检测Wistar大鼠免疫后7、14、21 d不同时间点血清中IL-12、IL-10的含量.结果 与EAE组和TP-5大剂量组比较,TP-5小剂量组和DXM组大鼠的发病率和临床评分显著性降低(P＜0.01);DXM组大鼠的发病率和临床评分低于TP-5小剂量组(P＜0.01).各个时间点EAE组、DXM组、TP-5小剂量组、TP-5大剂量组IL-12含量均较正常对照组明显升高(P＜0.01),免疫后14、21 d DXM组和TP-5小剂量组IL-12水平比EAE组低(P＜0.01);免疫后14、21 dDXM组、TP-5小剂量组IL-10水平与其余3组比较明显升高(P＜0.01).结论 TP-5对EAE有保护作用,其作用机制可能与上调IL-10水平以及下调IL-12水平有关,通过双向调节作用逆转TH1/TH2失衡.     

敲除toll样受体4基因对小鼠实验性自身免疫性脑脊髓炎的影响

目的:研究toll样受体4（TLR4）在小鼠实验性自身免疫性脑脊髓炎（EAE）发病中的作用。方法:C57BL/6野生型（WT）和Tlr4敲除(Tlr4^-/-)小鼠注射髓鞘少突胶质细胞糖蛋白35-55(MOG_35-55)建立EAE模型。定期记录神经功能评分及体重变化;苏木素-伊红（HE）和劳克坚牢蓝（LFB）染色观察脊髓组织内炎症细胞浸润及髓鞘脱失情况;免疫荧光染色检测髓鞘碱性蛋白（MBP）的表达。结果:MOG_35-55免疫后,与WT组相比,Tlr4^-/-小鼠体重下降程度较轻、发病时间延迟、神经功能评分降低、炎性细胞浸润减少、髓鞘脱失减轻、MBP表达增加。结论:敲除Tlr4可减轻EAE小鼠的病理症状。     

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。     

地塞米松对实验性自身免疫性脑脊髓炎小鼠髓鞘保护作用的研究

目的:分析地塞米松对实验性自身免疫性脑脊髓炎(EAE)小鼠炎症反应、髓鞘脱失及髓鞘再生的影响,探讨地塞米松治疗多发性硬化的新作用。方法:应用MOG35-55免疫C57BL/6小鼠建立EAE模型。小鼠随机分为正常对照组、EAE组及地塞米松组,观察各组临床症状;采用HE染色、LFB染色、透射电镜扫描及免疫组化染色方法,检测免疫后第13、20、30 d各组小鼠脊髓组织炎症反应、髓鞘脱失及髓鞘再生情况。结果:地塞米松显著降低EAE小鼠发病率、延缓起病时间、减轻疾病严重程度。各个时间点地塞米松组脊髓组织炎性细胞浸润、髓鞘脱失及轴索变性程度较EAE组明显减轻。免疫后第20、30 d,EAE组Olig2阳性细胞数较正常对照组明显增加;免疫后各时间点,地塞米松组Olig2阳性细胞数较正常对照组均明显增加,第13、20 d较EAE组明显增加。结论:地塞米松可增加脊髓组织Olig2表达、促进髓鞘再生,这可能为地塞米松治疗EAE及多发性硬化的效应途径。     

实验性自身免疫性脑脊髓炎小鼠发病高峰期外周及中枢淋巴细胞亚群的变化

目的:观察髓鞘少突胶质细胞糖蛋白MOG35-55诱导的实验性自身免疫性脑脊髓炎小鼠发病高峰期中枢及外周淋巴细胞亚群的变化,探讨EAE发病高峰期细胞与体液免疫学的变化。方法:用MOG35-55免疫诱导雌性C57BL/6小鼠制作EAE模型,记录小鼠行为学变化,HE染色观察CNS炎症组织病理变化,使用流式细胞仪检测小鼠中枢及外周脾脏淋巴细胞中CD3+CD4+、CD3+CD8+、CD4+CD25+、B220+细胞亚群变化情况。结果:EAE组小鼠中枢神经系统有CD3+CD4+、CD3+CD8+、CD4+CD25+、B220+淋巴细胞的浸润,CFA阴性对照组中枢神经系统未检测到淋巴细胞浸润。EAE组小鼠外周脾细胞中CD3+CD4+、CD3+CD8+细胞较CFA阴性对照组减少(P0.05),B220+细胞较CFA阴性对照组明显升高(P0.01),CD4+CD25+细胞较CFA阴性对照组升高但无统计学差异。结论:小鼠在EAE发病高峰期,外周脾细胞中CD3+CD4+、CD3+CD8+阳性细胞明显减少,B220+明显升高,CD4+CD25+也开始有升高趋势,表明EAE发病高峰期细胞免疫及体液免疫共同调控了EAE的病理过程,T淋巴细胞与B淋巴细胞都起了很重要的主导作用。     

小胶质细胞的活化在实验性自身免疫性脑脊髓炎中的作用

多发性硬化( multiple sclerosis,MS)是一种常见的以中枢神经系统(central nervous system,CNS)炎性脱髓鞘病变为特征的自身免疫性疾病.MS的病因和发病机制非常复杂,由于病理取材的困难性,在体外建立了该病的动物模型-实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE).人MS及其动物模型EAE发病过程中大量炎性细胞入侵CNS并产生多种致炎因子,脑内微环境受到影响.诸多研究表明在EAE或MS发病中静息态小胶质细胞在浸润的T细胞及释放的细胞因子刺激下发生活化,但它们在EAE中的作用目前尚无统一意见.兹将小胶质细胞在EAE中的活化机制及其在炎症/免疫反应中的作用作一综述.     

Blockade of TREM-2 exacerbates experimental autoimmune encephalomyelitis

Triggering receptor expressed on myeloid cells (TREM-2) is a membrane receptor associated with DAP12 that is expressed primarily in myeloid cells, including dendritic cells and microglia, and promotes fusion of osteoclast precursors into multinucleated cells. A rare autosomal recessive condition, Nasu-Hakola disease (NHD) is associated with loss-of-function mutations in DAP12 and TREM-2. The brain pathology observed in NHD patients suggests that disruption of the TREM-2/DAP12 pathway leads to neurodegeneration with demyelination and axonal loss. In this study, we have characterized TREM-2 protein expression on microglia using a newly produced monoclonal antibody directed against the mouse TREM-2 receptor. We report that TREM-2 expression is up-regulated in the spinal cord during both the early inflammatory and chronic phases of myelin oligodendrocyte glycoprotein (MOG)(35-55)peptide-induced experimental autoimmune encaphalomyelitis (EAE). We also demonstrate that TREM-2 is highly expressed on microglial cells in the central nervous system (CNS) during EAE and that blockade of TREM-2 during the effector phase of EAE results in disease exacerbation with more diffuse CNS inflammatory infiltrates and demyelination in the brain parenchyma. These results demonstrate a critical role for TREM-2 during inflammatory responses in the CNS.     

Eotaxin-2 blockade ameliorates experimental autoimmune encephalomyelitis

AIM: To study the effect of blocking the eo-2 pathway on the development and severity of experimental autoimmune encephalomyelitis (EAE). METHODS: We produced mAb directed against eo-2, named D8. MOG35-55 induced-EAE mice were daily intravenously injected with either 25 μg or 100 μg D8, or with vehicle control alone [phosphate-buffered saline (PBS)], starting from day 0 post immunization and were monitored for EAE clinical score (n = 10 in each group). Mice were sacrificed on day 58 and their sera were assessed for the presence of anti-myelin oligodendrocyte glycoprotein (anti-MOG) antibodies autoantibodies, as well as for the profile of pro-inflammatory cytokines and chemokines. Histological analysis of brain sections was performed by hematoxylin and eosin staining. RESULTS: Daily treatment of EAE induced mice with D8 significantly decreased the severity of EAE symptoms. Treatment with both concentrations of D8 ameliorated EAE symptoms compared to PBS treated mice, starting from day 42 post immunization (0.89 ± 0.35 in D8 25 μg and D8 100 μg treated groups vs 2.11 ± 0.38 in the PBS treated group, P = 0.03). A significant improvement in EAE clinical score compared to total IgG treated mice was observed with the higher concentration of D8 (0.81 ± 0.38 in D8 100 μg treated group vs 2.11 ± 0.31 in IgG1 treated group, on day 56 post immunization, P = 0.04). D8 treated mice with EAE did not significantly exhibit lower sera levels of anti-MOG autoantibodies compared to IgG-treated mice. However, they expressed lower sera levels of the pro-inflammatory cytokines: tumor necrosis factor (7.8 ± 0.2 pg/mL in D8 100 μg treated mice vs 19.9 ± 3.4 pg/mL in IgG treated mice, P = 0.005) and interferon-gamma (1.4 ± 0.6 pg/mL in D8 100 μg treated mice vs 3.6 ± 0.4 pg/mL in IgG treated mice, P = 0.02), as well as reduced levels of the chemokine macrophage chemoattractant protein-1 (27.2 ± 3.1 pg/mL in D8 100 μg treated mice vs 63.7 ± 12.3 pg/mL in IgG treated mice, P = 0.03). These findings indicate that blocking the eo-2 pathway in EAE may affect not only eosinophil infiltration into the central nervous system (CNS), but also have an effect on monocytes and T cells, but not humoral, mediated responses. Histological analysis of the brains of D8 treated mice with EAE support that this treatment decreases immune cells infiltrates in the CNS. CONCLUSION: Taken together, these findings suggest a role for eo-2 in EAE pathogenesis and consequentially may support a therapeutic potential of anti-eo-2 neutralizing mAb in multiple sclerosis.     

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.     

Cytokine shifts and tolerance in experimental autoimmune encephalomyelitis

Cytokines play an important role in the pathogenesis of both multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). Effective treatments for both diseases have been shown to alter cytokines in the central nervous system and in activated mononuclear cells. EAE is an animal model that mimics many aspects of multiple sclerosis, and has been widely used to study the mechanisms of disease and therapeutic approaches to multiple sclerosis. Cytokines play an important role in regulation of disease expression in EAE, and in tolerance to disease induction. In this review, we will summarize the current findings on the role of cytokine shifts in the induction of tolerance in EAE. In addition, we will discuss modulation of EAE by altered expression of members of the cytokine-regulated Jak/STAT intracellular signaling pathway.     

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.     

Th1‐mediated experimental autoimmune encephalomyelitis is CXCR3 independent

Drugs that block leukocyte trafficking ameliorate multiple sclerosis (MS). Occurrences of opportunistic infection, however, highlight the need for novel drugs that modulate more restricted subsets of T cells. In this context, chemokines and their receptors are attractive therapeutic targets. CXCR3, a Th1‐associated chemokine receptor, is preferentially expressed on T cells that accumulate in MS lesions and central nervous system (CNS) infiltrates of mice with experimental autoimmune encephalomyelitis (EAE). Surprisingly, mice genetically deficient in either CXCR3 or CXCL10 succumb to EAE following active immunization with myelin antigens. EAE is mediated by a heterogeneous population of T cells in myelin‐immunized mice. Hence, disease might develop in the absence of CXCR3 secondary to the compensatory action of encephalitogenic CCR6⁺ Th17 cells. However, in the current study, we show for the first time that blockade or genetic deficiency of either CXCR3 or of its primary ligand has no impact on clinical EAE induced by the adoptive transfer of highly polarized Th1 effector cells. Our data illustrate the fact that, although highly targeted immunotherapies might have more favorable side effect profiles, they are also more likely to be rendered ineffective by inherent redundancies in chemokine and cytokine networks that arise at sites of neuroinflammation.     

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.     

Edaravone, a free radical scavenger, ameliorates experimental autoimmune encephalomyelitis

Reactive oxygen species (ROS) are implicated in the pathogenesis of multiple sclerosis (MS) and its murine model experimental autoimmune encephalomyelitis (EAE). The effect of edaravone, a free radical scavenger, on EAE was investigated in this study. Treatment with edaravone significantly ameliorated the clinical severity of EAE, and a reduced infiltration of lymphocytes was observed based on a histological analysis. The expression of inducible NO synthase (iNOS) in the spinal cords appeared to be reduced by the treatment with edaravone and this effect was confirmed in vitro. A reduction of both the cellular infiltration and the expression of iNOS may therefore underlie the mechanisms of the beneficial effect of edaravone on EAE.     

Orally administered myelin basic protein in neonates primes for immune responses and enhances experimental autoimmune encephalomyelitis in adult animals

Antigen-driven tolerance is an effective method for suppression of autoimmune diseases. Adult animals can be tolerized against the induction of experimental autoimmune encephalomyelitis (EAE) by both oral and parenteral administration of myelin basic protein (MBP). We have found that in contrast to previous studies of neonatal tolerance in which parenterally administered autoantigens induced tolerance, the oral administration of MBP in neonatal rats did not result in tolerization to MBP, but instead, primed for immunologic responses. Proliferative responses to MBP and its encephalitogenic epitope were present in animals fed with MBP as neonates and co-culture of encephalitogenic T cells with cells from neonatal rats fed with MBP were associated with enhanced MBP responses rather than the suppression observed with cells from adult rats fed with MBP. Furthermore, neonates fed with MBP and immunized 6–8 weeks later with MBP in adjuvant to induce EAE revealed enhancement of disease severity, and were not protected from a second attack upon active reinduction of EAE. Subcutaneous injection of soluble MBP into neonates had no effect on EAE induction as adults, whereas intraperitoneal injection of MBP in neonates was associated with marked suppression of disease in adults. Suppression of EAE began to appear in animals fed with MBP at 4 weeks of age, and was similar to oral tolerance in adult animals when animals were fed at 6 weeks of age. These results suggest that immaturity of the immunoregulatory network associated with oral tolerance and sensitization to autoantigens via the gut in the neonatal period may contribute to the pathogenesis of autoimmune diseases.