Regulation of experimental autoimmune encephalomyelitis: Inhibition of adoptive experimental autoimmune encephalomyelitis by ‘recovery-associated suppressor cells’

We have previously shown the presence of suppressor cells in Lewis rats at the time of spontaneous recovery from experimental autoimmune encephalomyelitis (EAE). These cells, called ‘recovery-associated suppressor cells’ (RASC), are capable of preventing active EAE and inhibiting in vitro the specific proliferative response of encephalitogenic anti-MBP T cell line cells. The present investigations were undertaken in order to lend support to the hypothesis that RASC play an active role in the recovery. We found that RASC can prevent adoptive EAE when admixed with already activated, but not resting, anti-MBP T cells or when injected into the recipients separately from the encephalitogenic cells. They can also arrest the course of an ongoing disease when injected after the beginning of the clinical signs. This study provides the first direct demonstration of the downregulation of an ongoing EAE by suppressor cells.     

阿伐他汀对实验性自身免疫性脑脊髓炎免疫功能的影响

目的观察阿伐他汀（Atorvastatin）对EAE的治疗作用并初探其治疗机制。方法以豚鼠脑、脊髓为原料提取髓鞘碱性蛋白MBP,免疫Lewis大鼠建立EAE模型。建模后每日对大鼠神经症状进行评分,采用ELISA法检测大鼠脾细胞培养上清液中IFN-γ、IL-12和IL-4水平。结果与EAE组相比,Atorvastatin组大鼠发病时间有所延迟,症状有不同程度减轻。与正常组相比,EAE组大鼠17d、21d时,IL-4水平明显升高（P〈0．01）,13,17,21d时IFN-γ、IL-12水平均明显升高（P〈0．01）;IFN-γ、IL-12浓度与神经症状评分有较强的正相关关系（RIFN-γ=0．904,P〈0．01;RIL-12=0．885,P〈0．01）。与EAE组相比,Atorvastatin组13d、17d时IL-4水平明显升高（P〈0．01）。IFN-γ、IL-12水平在13,17,21d时均显著低于EAE组（P〈0．05）。结论Alorvastalin能改善EAE大鼠的症状,其机制可能与纠正Th1／Th2失衡有关。     

辛伐他汀抑制大鼠实验性自身免疫性脑脊髓炎的实验研究

目的 探讨辛伐他汀(STATINS)对实验性自身免疫性脑脊髓炎IEAE)的作用及机理.方法 Wistar大鼠55只采用随机数字表法分为EAE组(15只)、STATINS组(15只)、雷公藤(TP)组(15只)、正常对照组(10只).使用STATINS干预EAE大鼠,以TP为阳性对照,观察大鼠P53蛋白、IL-6、TNF-α、TGF-β的表达变化.结果 与EAE组相比,STATINS组发病率降低、临床症状减轻、体质量下降减少、病灶数减少、潜伏期延长,而TP组临床症状减轻、病灶数减少,差异均有统计学意义(P＜0.05),TP组体质量变化、潜伏期、发病率无显变化,差异无统计学意义(P＞0.05);STATINS组IL-6和TNF-α的表达降低,P53蛋白和TGF-β的表达增高;TP组仅TNF-α的表达降低,差异均有统计学意义(P＜0.05).与TP组相比较,STATINS组P53蛋白与TGF-β的表达增加,差异有统计学意义(P＜0.05),而TNF-α及Ⅱ-6的表达差异无统计学意义(P＞0.05).结论 STATINS可以有效抑制EAE.其可能的机制是抑制IL-6和TNF-α等促炎症因子的表达,促进P53蛋白与TGF-β的表达,效果可能优于TP.     

A combination of adoptive transfer and antigenic challenge induces consistent murine experimental autoimmune encephalomyelitis in C57BL/6 mice and other reputed resistant strains

Adoptive EAE was induced in SJL mice by the transfer of MBP-primed and in vitro-stimulated donor lymph node cells into naive syngeneic recipients. Priming donor mice with OVA instead of restimulating MBP-primed donor cell with OVA resulted in no transfer of EAE. This apparent lack of disease, however, could be overcome if the recipients were subsequently challenged with MBP. When this transfer-challenge technique was applied to BALB/c and C57BL/6 mice, these reputed (MBP)EAE-resistant strains developed consistent and severe disease similar to that seen in susceptible strains. In fact, a survey of eleven (MBP)EAE-resistant strains, defined on the basis of their inability to mount an encephalitogenic response in recipient mice following the transfer of MBP-primed and in vitro activated lymph node cells, revealed that EAE could be induced in all these strains. Since the surveyed strains represented a wide spectrum of genetic backgrounds as well as the common MHC congenic haplotypes (H-2b,d,k,m,r,s,v), it is concluded that the machinery for recognition of MBP, i.e. MHC genes and the appropriate T cell receptors, is functionally intact in these resistant mice. While MHC and T cell receptor genes are required for T cell responses, they are not the limiting factors that confer resistance in murine EAE.     

Variation in experimental autoimmune encephalomyelitis scores in a mouse model of multiple sclerosis

Multiple sclerosis (MS) is a common demyelinating central nervous system disease associated with progressive physical impairment. To study the mechanism underlying disease pathogenesis and develop potential treatments, experimental autoimmune encephalomyelitis (EAE) is often used as an animal model. EAE can be induced in various species by introducing specific antigens, which ultimately result in motor dysfunction. Although the severity of the paralysis is indicated using the EAE score, there is no standard scoring system for EAE signs, and there is variability between research groups with regard to the exact EAE scoring system utilized. Here, we describe the criteria used for EAE scoring systems in various laboratories and suggest combining EAE score with another quantitative index to evaluate paralysis, such as the traveled distance, with the goal of facilitating the study of the mechanisms and treatment of MS.     

雌激素在实验性自身免疫性脑脊髓炎中的保护作用

多发性硬化(multiple sclerosis,MS)与其他多种自身免疫性疾病一样存在着性别差异,表现为:与男性相比,女性发病率较高,且初发时间也较早。女性患者在妊娠期伴随着体内雌激素水平的波动,MS患者复发次数和严重程度也出现明显变化[1]。在MS动物模型即实验性自身免疫性脑脊髓炎(exp     

雌激素对实验性自身免疫性脑脊髓炎小鼠的抗炎机制

目的 探讨雌激素减轻实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)炎症反应的可能机制.方法 用MOG35-55多肽诱发60只EAE小鼠模型,做去卵巢术.分为治疗组(n=30)和对照组(n=30),治疗组予雌激素治疗.比较两组EAE小鼠的临床症状评分.取脑和脊髓,行H-E染色观察病理学改变,实时荧光定量PCR及ELISA检测EAE小鼠CNS中白细胞介素(interleukin,IL)-17、IL-23、肿瘤坏死因子α(tumor necrosis factor α,TNF-α)、干扰素γ(interferon γ,IFN-γ)、IL-4水平.结果 治疗组EAE小鼠与对照组相比临床症状减轻(P＜0.05);H-E染色显示治疗组炎细胞浸润减少(P＜0.05),实时荧光定量PCR及ELISA结果示治疗组CNS中IL-17、IL-23、TNF-α、IFN-γ表达降低而IL-4增加(P＜0.05).结论 雌激素可能通过降低IL-17、IL-23、TNF-α、IFN-γ,增加IL-4,从而减轻EAE小鼠炎症反应.     

Suppression of experimental autoimmune encephalomyelitis by oral administration of myelin basic protein VI. Suppression of adoptively transferred disease and differential effects of oral vs. intravenous tolerization

Antigen-driven tolerance is an effective method of suppressing cell-mediated immune response. We have previously shown that oral administration of myelin basic protein (MBP) suppresses experimental autoimmune encephalomyelitis (EAE) when it is actively induced by MBP emulsified in complete Freund's adjuvant. In order to further study antigen-driven tolerance is this model, we investigated the effect of oral tolerization on adoptively transferred EAE and compared oral tolerance to intravenously (i.v.) administered MBP in both actively induced EAE and adoptively transferred EAE. Although orally tolerized animals were not protected from adoptively transferred EAE, spleen cells from orally tolerized animals suppressed adoptively transferred EAE when co-transferred with encephalitogenic cells or when injected into recipient animals at a different site at the time encephalitogenic cells were transferred. This suppression was mediated by CD8⁺ T cells, correlated with suppression of DTH responses to MBP, and was associated with decreased inflammation in the spinal cord. Unlike oral tolerization, spleen cells from i.v. tolerized animals did not suppress adoptively transferred EAE when co-transfered with encephalotogenic cells although i.v. tolerized animals were protected from adoptively transferred EAE. MBP peptides were then utilized to further characterize differences between i.v. and oral tolerization in the actively induced disease model. Both orally and intravenously administered MBP suppressed actively induced EAE. However, EAE was only suppressed by prior i.v. tolerization with the encephalitogenic MBP peptide 71–90, but not with the non-encephalitogenic peptide 21–40, whereas prior tolerization with 21–40 did suppress actively induced EAE when administered orally. These results suggest a different mechanism of tolerance is initiated by oral vs. intravenous administered antigen. Specifically, oral tolerization suppresses primarily by the generation of active suppression whereas the dominant mechanism of suppression associated with i.v. tolerization appears most consistent with the elicitation of clonal anergy.     

实验性自身免疫性脑脊髓炎小鼠的磁共振研究

目的研究动物模型实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小 鼠中枢神经系统的MR表现。方法使用PLP139-151免疫接种雌性SJL／J小鼠诱导EAE。分别取复发期和缓解期 的EAE小鼠行脑和脊髓常规MR及Gd—DTPA增强MR扫描,并做组织病理学检查。结果PLP139-151能较好的诱 导出慢性复发-缓解型EAE模型,Gd-DTPA增强MR检查能充分显示血脑屏障的破坏,反映脑和脊髓的病灶,而且 显示的病灶相对信号强度复发期明显高于缓解期,在病灶处均可见炎症细胞浸润,髓鞘脱失,病灶周围或远离病灶 处炎症反应轻微。结论Gd—DTPA增强MR检查能准确反映血脑屏障的破坏,病变累及部位及病变程度,为今后使 用药物干预EAE判断疗效、指导进行较准确的病变部位取材时提供了一种更为客观的手段。     

The selective M-CSF receptor tyrosine kinase inhibitor Ki20227 suppresses experimental autoimmune encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), can be induced by the immunization of mice with myelin antigens in the form of myelin oligodendrocyte glycoprotein (MOG). Macrophage colony-stimulating factor (M-CSF) is required for the development of individual mononuclear phagocyte populations and is involved in the immune response. We previously reported that Ki20227 (N-{4-[(6,7-dimethoxy-4-quinolyl)oxy]-2-methoxyphenyl}-N'-[1-(1,3-thiazole-2-yl)ethyl]urea) is a highly selective M-CSF receptor (c-fms) tyrosine kinase inhibitor. In our current study, we investigated whether Ki20227 has suppressive effects upon EAE and indeed found that this drug significantly reduced the severity of this disease both preventively and therapeutically. Notably also, Ki20227 treatments inhibited the turn-over/expansion of myeloid cells provoked by the immunization and subsequent MOG-specific T cell responses in our EAE animal model. These findings suggest that M-CSF plays a pivotal role in the development of EAE and that Ki20227 and its derivatives may be candidate drugs for the treatment of human MS.     

Antigen-specific inhibition of the adoptive transfer of experimental autoimmune enceophalomyelitis in Lewis rats

The efficacy of antigen-specific immunoregulation as a treatment for the efferent limb of an autoimmune disease was tested in a rat model of adoptive experimental autoimmune encephalomyelitis (EAE). Lewis rats receiving 4–5 × 10⁷ guinea pig (GP) myelin basic protein (MBP)-activated lymph node T cell blasts from GPMBP/CFA sensitized donors routinely show clinical signs of disease 5–6 days post transfer. Intravenous injection of GPMBP coupled to syngeneic splenocytes using the chemical cross-linker carbodiimide was effective in completely abrogating the experssion of clinical EAA in rats that received MBP-specific T cells 2 days previously. Partial inhibition was also observed in rats injected as early as day 0 (the same day as MBP-specific T cell transfer) and as late as 1 day prior to the onset of clinicla signs (days 4–5 post trasfer). Unresponsiveness was shwon to be dose-dependent, dependent on the route of injection of the neuroantigen-coupled splenocytes, and was antigen-specific. Splenocytes coupled with GP or rat MBP (which are identical within the major encephalitogenic GP68–86 Lewis rat determinant with the exception of the residue at position 80) were equally efficient at eliminating disease expression in recipients of GPMBP-specific T cells. In contrast, splenocytes coupled with bovine or rabbit MBP (which differ significantly from GPMBP within the 68–86 region) had no inhibitory effects. The antigen specificity of the tolerance induction was also illustrated by the fact that splenocytes coupled with GP68–86, but not those coupled with the truncated GP68–84 peptide, induced profound unresponsiveness. Interestingly, de novo antigen processing by the antigen-coupled cells did not appear to be necessary as the inclusion of antigen processing inhibitors had no effect on inhibition of disease. However, the use of the carbodiimide couplign reagent was critical for the induction of unrespnosiveness as essentially equivalent amounts of ¹²⁵I-labelled MBP were bound in its presence or absence, but only splenocytes incubated in the presence of both MBP and carbodiimide inhibited clinical expression of disease. Antigen-specific tolerance is thus an effective means of inhibiting expression of clinical disease in teh rat EAE model, and a powerful tool for determining the fine epitope specificity of encephalitogenic T cells.     

Activation of mitogen-activated protein kinases in experimental autoimmune encephalomyelitis

The expression of mitogen-activated protein (MAP) kinases, including extracellular signal-regulated kinase (ERK), c-Jun NH(2)-terminal protein kinase (JNK), and p38, was analyzed in experimental autoimmune encephalomyelitis (EAE) in rats.

Western blot analysis showed that the three MAP kinases (phosphorylated ERK (p-ERK), p-JNK, and p-p38) were increased significantly in the spinal cords of rats with EAE at the peak stage as compared with the levels in controls (p<0.05), and both p-ERK and p-JNK declined slightly in the recovery stage of EAE. Immunohistochemistry showed that p-ERK was constitutively expressed in brain cells, including astroglial cells, and showed enhanced immunoreactivity in those cells in EAE, while some T cells and macrophages were weakly immunopositive for p-ERK in EAE lesions. Both p-JNK and p-p38 were intensely immunostained in T cells in EAE lesions, while a few glial cells and astrocytes were weakly positive for both.

Taking all these facts into consideration, we postulate that increased expression of the phosphorylated form of each MAP kinase plays an important role in the initiation of acute monophasic EAE. Differential expression of three MAP kinases was discerned in an animal model of human autoimmune central nervous system diseases, including multiple sclerosis.     

实验性自身免疫性脑脊髓炎大鼠模型脑组织硫化氢的变化

目的 观察实验性自身免疫性脑脊髓炎(EAE)模型大鼠脑组织中硫化氢(H2S)动态变化,探讨H2S与多发性硬化(MS)的关系. 方法 按随机区组设计方法将SD大鼠分成对照组及模型组,每组78只.模型组制备EAE模型,对照组用生理盐水代替诱导乳剂,余措施相同.采用HE染色、尼氏染色观察2组大鼠脑组织病理变化;比较不同时间点(建模后5、10、15、20、25、30、35、40、45、50、55、60 d和65 d)2组大鼠平均临床评分;采用比色法检测各时间点H2S和丙二醛(MDA)水平. 结果 (1)HE和尼氏染色显示模型组中可见明显的炎性细胞浸润现象及血管袖套形成,对照组未发现明显改变.(2)模型组于建模后第20天及第50天出现2次发病高峰,临床评分分别为(4.0±0.55)分和(3.5±0.25)分;对照组的评分为0分.(3)模型组大鼠各时间点脑组织中H2S表达量随着发病呈逐渐下降趋势,从第10天开始低于对照组,差异有统计学意义(P＜0.05).相反,模型组大鼠各时间点脑组织中MDA呈逐渐增加趋势,从第10天开始高于对照组,差异有统计学意义(P＜0.05).对照组大鼠H2S和MDA水平无明显变化.(4)模型组大鼠脑组织中H2S水平的变化与临床评分、MDA水平呈负相关(r=0.960,P=0.000;r=-0.920,P=0.000);临床症状评分和MDA水平呈正相关(r=0.910,P=0.000). 结论 H2S在EAE模型中表达明显降低,在MS中的作用机制有待进一步研究.     

Adoptive transfer of experimental allergic encephalomyelitis: Recipient response to myelin basic protein-reactive lymphocytes

We have used adoptive transfer of myelin basic protein (MBP)-reactive lymphocytes in the Lewis rat model of experimental allergic encephalomyelitis (EAE) to identify stages of effector cell development and to investigate the nature of the subsequent recipient response to the transferred cells. Depending on the timing of cell collection, lymph node cells (LNC) obtained from MBP-CFA (MBP emulsified in complete Freund's adjuvant)-immunized donors may directly transfer clinical disease; however, independent of disease development, recipients of LNC develop early onset of clinical disease following immunization of the recipients with MBP-CFA, consistent with the presence of MBP-memory cells in the LNC transfer inoculum. Similarly obtained spleen cells do not directly transfer disease and do not contain MBP-memory cells (as defined by the early onset of clinical disease following MBP-CFA challenge). Spleen cells adoptively transfer clinical disease only following in vitro culture stimulation with antigen or selected mitogens. Recipients of the primary culture-derived encephalitogenic spleen cells also develop an accelerated onset of clinical disease following MBP-CFA challenge, indicative of the presence of MBP-memory cells, and are not vaccinated. Encephalitogenic T cell lines adoptively transfer clinical disease, and in most cases recipients are vaccinated to MBP-CFA-induced active disease, but remain susceptible to adoptively transferred disease. Co-transfer of encephalitogenic T cell line cells with MBP-reactive lymph node or encephalitogenic spleen cells does not alter the vaccination response. We have found that during the process of T cell line development, the vaccinating phenotype is acquired following the second antigen stimulation cycle. These studies also demonstrate that regulation induced by T cell vaccination blocks the development of effector cells from precursor cells and that such regulation is also equally effective in blocking disease development in recipients which have increased numbers of memory cells. Thus, the response to T cell vaccination, once established, is fully capable of inhibiting the development of effector cells from increased numbers of precursor/memory cells, a response that would be needed in the clinical application of vaccination-induced resistance.     

Th17细胞与多发性硬化/实验性自身免疫性脑脊髓炎

多发性硬化(multiple sclerosis,MS)及其理想动物模型实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)是主要累及中枢神经系统的自身免疫性疾病.     

Enhancing effects of irrelevant lymphocytes on adoptive transferred experimental allergic encephalomyelitis

To help understand effector mechanisms in experimental allergic encephalomyelitis (EAE) we examined the effects of adding ‘irrelevant’ lymphocytes from non-EAE donors to major basic protein (MBP)-reactive lymphocytes in the adoptive transfer of EAE (Tr-EAE). The intravenous injection of tentanus toxoid-reactive lymphocytes (TT-cells) and phytohemagglutinin-stimulated lymphocytes on the same day or 2 days after intra-arterial injection of MBP-reactive lymphocytes enhanced the clinical and pathological expression of Tr-EAE. In lymphocyte trafficking studies there was significant accumulation of these injected TT-cells in the central nervous system during enhanced transfer of EAE. W3/25-positive cells were much more predominant in lesion of central nervous system when reinjected with TT cells along with MBP cells compared with lesions of rats injected with MBP cells alone. These findings suggest possible participation of lymphocytes other than MBP-reactive cells in the expression of EAE and provide a useful model to further explore effector mechanism in the future.     

Phagocytosis of apoptotic lymphocytes by oligodendrocytes in experimental autoimmune encephalomyelitis

The alterations in oligodendrocytes in myelin basic protein-induced acute experimental autoimmune encephalomyelitis (EAE) in the Lewis rat were studied using the technique of pre-embedding immunolabelling with the Rip monoclonal antibody, which specifically labels the cytoplasm of the cell bodies and processes of oligodendrocytes. In spinal cord sections of untreated and dexamethasone-treated rats with EAE, we found that apoptotic lymphocytes were phagocytosed by Rip-positive oligodendrocytes as well as by CD11b/c-positive macrophages/ microglia and by astrocytes expressing glial fibrillary acidic protein. Morphologically normal lymphocytes were also internalised by these cell types, a phenomenon known as emperipolesis. We suggest that this phenomenon represents the phagocytosis of lymphocytes that have undergone the plasma membrane alterations of apoptosis without yet manifesting the nuclear condensation of apoptosis. We also found an increase in the number of clusters of two to four oligodendrocytes, mainly in the grey matter, suggesting proliferation of cells of the oligodendrocyte lineage. Received: 14 March 1997 / Revised: 4 August 1997 / Accepted: 8 August 1997     

Autonomic regulation of experimental autoimmune encephalomyelitis in IL-4 knockout mice

The effect of chemical sympathectomy induced with 6-hydroxydopamine (OHDA) on experimental autoimmune encephalomyelitis (EAE) was studied in wild type and IL-4^−/− C57BL/6 (B6) mice. When actively sensitized with myelin oligodendrocyte glycoprotein (MOG)_35–55 peptide, control B6 mice developed a mild form of EAE with full recovery. The sympathectomized mice developed paralysis with higher maximum disease score and did not recover completely, indicating that the sympathetic nervous system (SNS) down-modulates the process of EAE. Unexpectedly, however, sympathectomy resulted in suppression of EAE in IL-4^−/− mice, implying that control of actively induced EAE by the SNS depends on the genetic background of mice. We also induced EAE by passive transfer of MOG_35–55-reactive lymph node cells, and this disease was augmented by sympathectomy in both wild type and knockout animals. Further experiments showed that changes in T cell populations and the activity of antigen presenting cells might be responsible for the altered immune response and clinical course after sympathetic ablation. Our studies indicate that the absence of a single cytokine can severely alter nervous–immune system interactions.     

Differential recognition of sequences within the encephalitogenic region of myelin basic protein capable of eliciting cell-mediated immune responses in experimental autoimmune encephalomyelitis

The fine specificity of myelin basic protein (MBP) epitopes capable of eliciting in vivo delayed-type hypersensitivity responses in Lewis rats with experimental autoimmune encephalomyelitis (EAE) was compared to those eliciting in vitro antigen-specific T cell proliferation and augmentation of disease transfer. Utilizing a panel of synthetic peptides with sequences representing the 68–86 region of guinea pig (GP-) or bovine myelin basic protein (B-MBP), animals were primed with one species of peptide and subsequently challenged with either the same peptide or peptides with truncations or substitutions representative of the other species of MBP. In regard to minimal length sequences capable of eliciting delayed-type hypersensitivity (DTH), rats primed with GP-MBP and complete Freund's adjuvant (CFA) exhibited a hierarchical pattern of responsiveness to challenge with a series of truncated peptides, ranking as follows: GP-68–86 > GP-72–86 > GP-68–84 > > GP-75–86 = no activity. This response pattern corresponds to that previously reported for T cell proliferation and activation for disease transfer. Furthermore, a comparison of these T cell-mediated immune parameters, as elicited by the substituted peptides, revealed the response patterns of DTH reactivity to be similar to that previously described for in vitro T cell proliferation with significant DTH responses generated only by the peptide species for which the animal was primed. In contrast, a cross-reactive pattern of recognition was observed in cells mediating disease transfer, with all four 68–86 sequences capable of augmenting activation for adoptive transfer of disease, regardless of the peptide species for which the animal was primed. The differential antigen recognition patterns observed for these EAE-associated immune responses supports the hypothesis that multiple T_H cell subsets are involved in disease pathogenesis.