神经肽Y对多发性硬化动物模型血清Th1细胞因子的影响

目的 探讨神经肽Y(NPY)对实验性自身免疫性脑脊髓炎(EAE)豚鼠发病及血清Th1细胞因子TNF-α、IFN-γ水平的影响,研究NPY对EAE发病的作用及其可能的免疫机制.方法 30只豚鼠随机分为健康对照组、EAE对照组、NPY干预组3组,向健康对照组和EAE对照组侧脑室注射生理盐水、向NPY干预组侧脑室注射等量NPY各1次,1周后造模,观察EAE对照组、NPY干预组的发病潜伏期、神经功能障碍评分情况及3组豚鼠血清TNF-α、IFN-γ水平.结果 与EAE对照组相比较,NPY干预组发病潜伏期明显延长(P<0.001),高峰期神经功能障碍评分明显降低(P<0.001),血清TNF-α、IFN-γ水平均降低(P<0.05).结论 向侧脑室注射NPY对EAE豚鼠的发病确具有抑制作用,而且其保护机制可能是通过降低TNF-α、IFN-γ水平而实现.     

阿托伐他汀对实验性自身免疫性脑脊髓炎脑组织IL-1β、IL-6影响的研究

目的探讨实验性自身免疫性脑脊髓炎（EAE）豚鼠脑组织细胞因子的变化,探讨阿托伐他汀对EAE发病保护作用的免疫调节机制。方法粗制碱性髓鞘蛋白抗原（Wistar大鼠全脊髓匀浆）＋完全福氏完全佐剂（CFA）免疫豚鼠建立EAE模型。40只豚鼠分成正常对照组、EAE对照组、EAE低剂量组和EAE高剂量组,每组10只,雌雄各半;放射免疫法测定正常对照组、EAE各组高峰期脑组织IL-1β、IL-6含量。结果EAE对照组、EAE低剂量组和EAE高剂量组脑组织IL-1β、IL-6水平显著高于正常对照组,EAE高、低剂量组脑组织IL-1β、IL-6水平比EAE对照组低,EAE高剂量组脑组织IL-1β、IL-6水平比EAE低剂量组低（P〈0.05）。结论EAE豚鼠存在明显免疫功能紊乱,阿托伐他汀有降低EAE模型脑组织IL-1β、IL-6水平作用,其对EAE发病的免疫保护机制可能是通过抑制IL-1β、IL-6产生而发挥。     

粪菌移植对实验性自身免疫性脑脊髓炎小鼠肠道功能及细胞因子的影响

目的探讨粪菌移植(fecal microbiota transplantation,FMT)对实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)小鼠发病、肠道功能和细胞因子白细胞介素-1β(IL-1β)、IL-6、肿瘤坏死因子-α(TNF-α)的影响。方法选择30只清洁级SPF级雌性C57BL/6小鼠,随机分为正常对照组、EAE模型组、FMT干预组,每组10只。采用髓鞘少突胶质细胞糖蛋白肽35-55(MOG35-55)抗原免疫法制备EAE模型。FMT干预组于造模第2天给予粪便滤液0.4 mL灌胃,1次/d,共14 d;正常对照组、EAE模型组以相同方式给予等量生理盐水灌胃。观察各组小鼠发病情况;于EAE模型组和FMT干预组发病高峰时、正常对照组28 d时取小鼠粪便定量检测肠道菌群数量,计算双歧杆菌与肠杆菌的比值(Bifidobacterium/Enterobacter value,B/E值);ELISA法检测各组小鼠血清、脑组织IL-1β、IL-6、TNF-α的表达。结果与EAE模型组比较,FMT干预组小鼠发病潜伏期、达高峰期时间延迟,神经功能评分减低(均P0.05)。EAE模型组B/E值小于1,FMT干预组B/E值大于1,且FMT干预组B/E值较EAE模型组高(P0.05)。与正常对照组比较,EAE模型组血清和脑组织IL-1β、IL-6、TNF-α表达水平均增加(均P0.05),而FMT干预组IL-1β、IL-6、TNF-α表达水平较EAE模型组减低(均P0.05)。结论 EAE小鼠存在肠道菌群紊乱,定植抗力差,细胞因子表达升高;FMT能改善EAE小鼠肠道菌群紊乱,提高肠道定植抗力,减轻炎症反应和神经功能障碍。     

阿托伐他汀对实验性变态反应性脑脊髓炎T辅助细胞功能的影响

目的探讨阿托伐他汀对实验性变态反应性脑脊髓炎(EAE)豚鼠T辅助细胞功能的影响,探讨阿托伐他汀对EAE发病保护作用的免疫调节机制。方法皮下注射粗制碱性髓鞘蛋白(MBP)建立EAE模型。40只豚鼠分成4组:正常对照组、EAE对照组、EAE低剂量组和EAE高剂量组,每组10只,雌雄各半。ELISA法测定EAE发病高峰期外周血单个核细胞培养上清液的细胞因子INF-γ、IL-4水平。结果EAE对照组IL-4浓度低于正常对照组(P<0.01),EAE高、低剂量组IL-4浓度高于EAE对照组(P<0.01),EAE高剂量组IL-4浓度比EAE低剂量组高(P<0.01)。EAE对照组IFN-γ浓度高于正常对照组(P<0.01),EAE高、低剂量组IFN-γ浓度低于EAE对照组(P<0.01),EAE高剂量IFN-γ浓度比EAE低剂量组低(P<0.01)。结论EAE豚鼠存在Th1细胞的过度活化、Th2细胞分泌活性降低;阿托伐他汀能具有抑制Th1细胞活性、提高Th2细胞分泌能力,具有调节Th1/Th2失衡作用。     

神经肽Y对小神经胶质细胞活化状态和生成IL-1β的影响

目的探讨神经肽Y(NPY)对原代小神经胶质细胞生物活性及生成IL-1β的影响。方法培养的原代大鼠皮层小胶质细胞,将细胞分为Control组、LPS组、NPY+LPS组、NPY组和BIBP3226+NPY+LPS组,每组3个样本,培养各组细胞6h。经免疫细胞化学荧光染色后,显微镜下观察小胶质细胞的形态学变化。Elisa方法检测培养液中IL-1β蛋白含量,RT-PCR方法检测小胶质细胞中IL-1βm RNA表达水平。结果孵育各组小胶质细胞6h后,LPS组培养液中IL-1β蛋白的含量及细胞中IL-1βm RNA表达水平分别为(961.00±83.50)pg/m L和5.59±0.87,显著高于Control组的96.33±24.58 pg/m L和1.05±0.12(P0.05),小胶质细胞处于活化状态;LPS+NPY组IL-1β蛋白含量和m RNA表达水平分别为(411.33±55.00)pg/m L和1.93±0.45,与LPS组相比显著降低(P0.05),小胶质细胞活化水平降低;IBP3226+NPY+LPS组IL-1β蛋白含量和m RNA表达水平分别为(886.00±97.53)pg/m L和4.51±0.71,与LPS+NPY组相比显著增高(P0.05);LPS组和IBP3226+NPY+LPS组之间无统计学意义。NPY组与对照组无统计学意义。结论 NPY通过作用于NPY Y1受体降低小神经胶质细胞的生物活性,抑制其生成IL-1β。     

雷公藤多甙对EAE大鼠脊髓β-APP和IL-17表达的影响

目的观察雷公藤多甙对实验性自身免疫性脑脊髓炎(EAE)大鼠脊髓中β-APP和IL-17表达的影响。方法将30只大鼠随机分为空白对照组(CON组)、模型组(EAE组)、治疗组(TWP组),建模后分别行神经功能评分,大鼠脊髓组织行HE染色,免疫组化检测脊髓中β-APP和IL-17表达水平。结果与EAE组比较,TWP组大鼠发病率下降,平均神经功能评分降低,炎性细胞浸润减少,在神经功能评分和病理学改变方面差异明显(P<0.05);免疫组化示TWP组较EAE组β-APP和IL-17表达水平降低(P<0.05)。结论雷公藤多甙对EAE大鼠有一定保护作用,可能与抑制β-APP、IL-17表达有关。     

奥曲肽对EAE豚鼠外周血单个核细胞分泌IFN-γ、IL-4水平的影响

目的通过研究奥曲肽对急性实验性自身免疫性脑脊髓炎(EAE)豚鼠外周血单个核细胞(PBMC)分泌γ干扰素(IFN-γ)、白细胞介素-4(IL-4)水平的影响,探讨奥曲肽对EAE发病保护作用的免疫学机制。方法将40只雌性豚鼠随机分为健康对照组、EAE对照组和EAE高、低剂量治疗组,每组各10只。EAE对照组及EAE高、低剂量治疗组采用粗制髓鞘碱性蛋白(cMBP)诱发急性EAE,EAE低、高剂量治疗组自造模前7 d始分别按体质量3、12 μg/(kg·d)予皮下注射奥曲肽直至试验结束。观察4组豚鼠神经功能障碍评分变化,并用ELISA法测定PBMC培养上清液中IFN-γ和IL-4水平变化。结果 EAE高、低剂量治疗组神经功能障碍评分较EAE对照组显著降低(P0.01,P0.05),且EAE高剂量治疗组降低更明显(P0.05)。PBMC分泌IFN-γ水平EAE低、高剂量治疗组、EAE对照组较健康对照组显著升高(P0.01),EAE高、低剂量治疗组较EAE对照组显著降低(均P0.01),且EAE高剂量治疗组降低更明显(P0.05)。PBMC分泌IL-4水平EAE对照组较健康对照组明显降低(P0.01),EAE高、低剂量较EAE对照组均明显增高(均P0.01),且EAE高剂量治疗组增高更明显(P0.05)。EAE对照组及EAE高、低剂量治疗组发病高峰期外周血IFN-γ/IL-4比值与神经功能障碍评分均呈正相关(r=0.753、P0.05,r=0.835、P0.01,r=0.779、P0.01)。结论奥曲肽对EAE豚鼠发病具有保护作用,其作用机制可能是通过抑制IFN-γ生成、促进IL-4生成而发挥对Th1/Th2失衡的调节作用。     

黄芩苷对实验性自身免疫性脑脊髓炎大鼠髓鞘的保护作用

目的观察黄芩苷(BAC)对实验性自身免疫性脑脊髓炎(EAE)大鼠髓鞘的保护作用。方法将大鼠随机分为正常对照(NC)组、EAE组、地塞米松(DXM)组和BAC组。抗原免疫1周后分别予以DXM组和BAC组大鼠DXM和BAC治疗7d;观察免疫后14d各组动物发病情况、脊髓病理变化及髓鞘碱性蛋白(MBP)的表达。结果(1)EAE组、DXM组和BAC组大鼠于抗原免疫后8～10d发病,发病潜伏期分别为9.62d、11.0d、9.85d,DXM组较EAE组潜伏期显著延长(P<0.05),BAC组与EAE组间差异无统计学意义;各组发病率分别为75.0%、66.7%、80%,各组间差异无统计学意义。(2)病程中EAE组和DXM组质量较BAC组明显下降(均P<0.05);DXM组和BAC组神经功能评分明显优于EAE组(均P<0.05)。(3)与EAE组比较,DXM组脊髓病灶数明显减少(P<0.05),BAC组病灶数有所减少,但差异无统计学意义。(4)与EAE组比较,DXM组和BAC组脊髓MBP阳性数显著增多(均P<0.05)。结论BAC对缓解EAE大鼠的临床症状、减轻髓鞘脱失的作用与DXM相似,而没有质量降低的不良反应。     

托法替尼对实验性自身免疫性脑脊髓炎大鼠滤泡调节性T细胞/滤泡辅助性T细胞平衡及CXCL13、转化生长因子-β1表达的影响

目的探讨托法替尼对实验性自身免疫性脑脊髓炎(EAE)大鼠滤泡调节性T细胞(Tfr)/滤泡辅助性T细胞(Tfh)平衡及CXCL13、转化生长因子-β1(TGF-β1)表达的影响。方法选择50只Wistar雌性大鼠,随机分为正常对照组、EAE对照组、托法替尼小、中、大剂量防治组,每组10只。采用髓鞘碱性蛋白及完全弗氏佐剂制造EAE模型。从造模前3 d开始EAE对照组及小、中、大剂量托法替尼防治组分别予以生理盐水和托法替尼1、2、4 mg/kg/d灌胃,连续10 d。观测大鼠发病情况、脾组织中Tfh和Tfr比例、Tfr/Tfh比值变化、脑组织匀浆中CXCL13、TGF-β1含量变化。结果EAE对照组大鼠发病潜伏期(10.20±1.99)d,托法替尼小、中、大剂量防治组发病潜伏期分别为(16.70±1.50)d、(20.20±2.44)d和(22.90±1.79)d,托法替尼各防治组发病潜伏期均较EAE对照组延长(P0.01)。EAE对照组大鼠进展期(10.50±1.84)d,托法替尼小、中、大剂量防治组发病进展期分别为(8.00±2.00)d、(5.60±1.51)d和(3.00±1.16)d,托法替尼各防治组发病进展期均较EAE对照组缩短(P0.01)。EAE对照组大鼠发病高峰期神经功能障碍评分(3.80±1.03)分,托法替尼小、中、大剂量防治组发病高峰期神经功能障碍评分分别为(2.30±1.34)分、(1.20±1.40)分和(0.60±0.84)分,托法替尼各防治组发病高峰期神经功能障碍评分均较EAE对照组降低(P0.01)。托法替尼各防治组与EAE对照组比较,Tfh细胞比例显著降低,Tfr细胞比例及Tfr/Tfh比值显著升高,CXCL13含量明显减少、TGF-β1含量明显增加,且呈剂量依赖关系,剂量越大作用越明显(P0.01;P0.05)。结论托法替尼对EAE大鼠发病具有防治作用,且呈剂量依赖关系。其防治作用机制可能与下调EAE大鼠Tfh比例及CXCL-13的表达,上调Tfr比例及TGF-1的表达,维持Tfr/Tfh平衡,并促使平衡向Tfr偏移有关。     

咪唑克生对实验性自身免疫性脑脊髓炎大鼠小胶质细胞激活和白介素17、肿瘤坏死因子α表达的影响

目的观察咪唑克生对实验性自身免疫性脑脊髓炎(EAE)大鼠脑组织中小胶质细胞、白介素17(IL-17)、肿瘤坏死因子α(TNF-α)表达的影响。方法 SD大鼠30只随机分成3组:EAE-咪唑克生组(免疫当日开始给予咪唑克生2 mg·kg~(-1),腹腔注射,连续14 d)、EAE-生理盐水组(给予相同剂量生理盐水)和空白对照组。用豚鼠全脊髓匀浆免疫诱导制作EAE大鼠模型。每天观察评估各组大鼠神经功能变化;苏木精-伊红染色观察病理学改变;免疫组化法检测小胶质细胞(Iba1阳性)的激活与表达水平;酶联免疫吸附试验(ELISA)法检测发病高峰期(免疫后15 d)脑组织中IL-17,TNF-α表达水平。结果与EAE-生理盐水组比较,EAE-咪唑克生组(1)日均神经功能评分降低(P0.05),最大临床症状评分显著降低(P0.01);(2)苏木精-伊红染色:中枢炎症细胞浸润减少(P0.05);(3)免疫组化:Iba1阳性细胞表达减少(P0.05);而EAE-生理盐水组大鼠腰髓内Iba1阳性细胞表达较空白对照组明显升高(P0.01);(4)ELISA:炎性细胞因子IL-17和TNF-α表达明显降低(P0.01)。结论咪唑克生能够减缓大鼠EAE病情,其机制可能与抑制中枢神经系统小胶质细胞激活,下调中枢神经系统炎症因子IL-17和TNF-α的表达,扰乱中枢神经系统内炎症因子的平衡有关。     

钙激活中性蛋白酶抑制剂对实验性自身免疫性脑脊髓炎的保护作用

目的　建立豚鼠实验性自身免疫性脑脊髓炎 ( EAE)病理模型 ,研究钙激活中性蛋白酶 ( calpain)对 EAE的作用。方法　将牛脊髓匀浆与等量完全福 (氏 )佐剂充分混合 ,注射于豚鼠后肢足底诱发 EAE。发病豚鼠分别注射 calpain抑制剂与地塞米松 ,观察其对 EAE临床症状及病理变化的影响。结果　模型组豚鼠免疫致敏后相继出现明显的 EAE症状 ,表现为行动困难 ,摄食减少 ,体重进行性下降 ,肢体瘫痪 ,发病率为 87.5 % ( 2 8/3 2 )。豚鼠注射 calpain抑制剂后可观察到脱髓鞘病变明显减轻 ,神经元丢失减少 ,但炎性细胞浸润仍然存在。结论　calpain参与了 EAE的神经病理损伤过程 ,calpain抑制剂对 EAE有一定保护作用     

Induction of experimental autoimmune encephalomyelitis in guinea pigs using myelin basic protein and myelin glycolipids

Strain 13 guinea pigs were immunized with galactocerebroside, asialo-GM1 (GA1) or GM4 ganglioside in association with myelin basic protein (MBP) in complete Freund's adjuvant (CFA) to produce experimental autoimmune encephalomyelitis (EAE). The clinical and pathological features, serum antibodies, and lipid compositions of affected brains and spinal cords were compared with those of guinea pigs immunized with MBP, in CFA, alone. Perivascular demyelination was seen in brains from all guinea pigs immunized with GA1/MBP. The incidence and degree of demyelination in this group were significantly higher than in the group immunized with only MBP. The onset of EAE was slightly, but significantly, retarded in groups of animals immunized with GM4/MBP and there was no detectable demyelination. Otherwise, no significant differences were detected between groups. Augmentation of EAE by myelin glycolipids may provide some important clues in understanding the mechanism of demyelinating diseases.     

Sites at which neuropeptide Y modulates parasympathetic control of heart rate in guinea pigs and rats.

Immunohistological evidence indicates that neuropeptide Y (NPY) is present in the cardiac innervation of numerous species. The present experiments determined if NPY influences in vivo parasympathetic control of heart rate in guinea pigs and rats by either pre- or postganglionic mechanisms or by an interaction at muscarinic receptors at the sino-atrial node. Urethane-anesthetized animals were prepared with arterial and venous catheters, and ECG leads. The cervical vagi were sectioned and propranolol was administered to minimize reflex changes in heart rate. Methacholine injection, carbachol injection, or electrical stimulation of the peripheral end of the vagus nerve was performed to activate the neuroeffector site, intracardiac ganglion cells, or preganglionic neurons, respectively. All three trials were performed before, during, and after NPY infusion. No differences in methacholine- or carbachol-induced bradycardia were observed between control and NPY groups in either species. NPY infusion inhibited vagal-mediated bradycardia in guinea pigs and in rats. However, NPY inhibited vagal-mediated bradycardia at a lower dose in guinea pigs (1 microgram/kg/min) than in rats (4 micrograms/kg/min). These data indicate that NPY modulates cardiac vagal preganglionic, but not postganglionic nerve function or neuroeffector sites at the sino-atrial node, in guinea pigs and rats. Furthermore, due to the different effective dosages, NPY may play a greater modulatory role in guinea pigs than in rats.     

Experimental allergic encephalomyelitis in cobra venom factor-treated and C4-deficient guinea pigs.

Experimental allergic encephalomyelitis (EAE) was studied in guinea pigs with an inherited deficiency of the fourth component of complement (C4) and in guinea pigs injected with cobra venom factor to deplete the third component and late-acting components of complement. EAE was elicited by immunization with homologous spinal cord or purified basic protein. Administration of cobra factor after the injection of encephalitogenic emulsion delayed the onset and reduced the intensity of the clinical manifestations of EAE. In addition, cobra factor markedly reduced mortality during the sixty days of observation. However, pathological changes of perivascular infiltration and demyelination were similar in cobra factor-treated and untreated animals. Clinical signs of EAE an mortality in C4-deficient guinea pigs were no different from those in normocomplementemic controls. Thus, although activation of the classic complement pathway does not appear to be involved in the production of EAE in guinea pigs, our results suggest a possible role of the alternative complement pathway in the pathogenesis of EAE.     

The role of myelin lipids in experimental allergic encephalomyelitis: Part 2. Influence on disease production by encephalitogenic doses of myelin basic protein

Hartley guinea pig CNS myelin lipids (TL) were combined with an encephalitogenic dose (50 micrograms) of myelin basic protein (MBP) and injected together with complete Freund's adjuvant (CFA) into juvenile strain 13 guinea pigs. All the animals developed acute EAE and recovered, but only 50% had a single mild relapse during an observation period of 12 months. To determine the effect of individual myelin lipids on EAE, purified fractions comprising the galactocerebrosides (GC) or gangliosides (GANG) were combined with 50 micrograms MBP together with phosphatidyl choline (PC) and cholesterol (CHOL) and injected with CFA into juvenile Hartley guinea pigs. Control animals received MBP mixed with PC and CHOL or MBP alone, in CFA. The incidence of acute EAE was similar in all groups, but the highest percent recovery (69%) was seen in animals immunized with the MBP-GC combination. All animals that developed acute EAE in the control groups died. Histologically, CNS myelin breakdown was present during the acute attack except in the MBP control group. Parameters of cell-mediated immunity (CMI) showed good correlation with the clinicopathological findings in animals that received MBP-GC or MBP alone. In most animals, serum anti-MBP antibodies were detected as early as 10 days post-immunization (p.i.) whereas anti-lipid antibodies were found at 90 days p.i. Animals that received MBP-PC did not show any positive CMI or serum antibodies although they developed severe disease. The results indicate that myelin lipids, especially the galactocerebrosides, contribute to the development of chronic EAE; however, the mechanism by which this occurs is still obscure.     

Ameliorating effects of hyperbaric oxygenation on experimental allergic encephalomyelitis

The effect of hyperbaric oxygenation (OHP) on survival and quality of survival of guinea pigs afflicted with experimental allergic encephalomyelitis (EAE) was investigated. EAE was induced in Hartley and Strain 13 animals by intradermal injections of whole guinea pig spinal cord in complete Freund's adjuvant. The inoculated animals were divided into control and treatment groups; the treated animals received OHP in a variety of treatment schedules. Clinical signs of EAE were quantitated and mean survival times were measured. When Hartley animals were exposed to 100% O₂ at 2.5 atmospheres absolute (ATA) for 2 hr/day from 5–19 days postinoculation, the mean survival time (± SE) was 19.1 ± 1.6 days relative to 15.7 ± 0.7 days in the control (p<0.050). When Strain 13 guinea pigs were treated with 100% O₂ at 2 ATA for 4 hr/day on 5–16 days, the mean survival time was 21.6 ± 0.6 days compared to 16.0 ± 0.4 days for the control (p<0.001). Clinical sign measurements demonstrated that the onset of EAE in the treated animals of both strains occurred between 4–6 days after these signs became detectable in control animals. These results suggest that OHP therapy can ameliorate EAE in afflicted guinea pigs.     

In vivo demyelinating activity of sera from animals with chronic experimental allergic encephalomyelitis. Antibody nature of the demyelinating factor and the role of complement

Sera from guinea pigs and rats with chronic experimental allergic encephalomyelitis were injected into the cerebrospinal fluid (CSF) of normal recipient rats. Guinea pig sera induced demyelination in the central and (or) peripheral nervous system, whereas injection of rat sera resulted in demyelination in the peripheral nervous system only. Control sera did not induce demyelination. Demyelinating activity in guinea pig sera was confined to the IgG-fraction; in rat sera the IgG- as well as the IgM-fraction were able to induce demyelination. The demyelinating activity was abolished when the sera were absorbed with with sensitising antigen (guinea pig spinal cord tissue) or when immunoglobulins were removed from the sera. When chronic EAE sera from rats were injected into the CSF of rats, complement was not required for the induction of demyeLination. The presence of complement, however, augmented the demyelinating activity. Decomplemented chronic EAE sera from guinea pigs failed to induce demyelination after injection into the CSF of rats. Injection of control and non-demyelinating or demyelinating EAE sera into the subarachnoid space of normal recipient rats induced a weak inflammatory response with increased numbers of large mononuclear cells in the meninges. It is discussed that in vivo a complex interaction of antibodies, complement and effector cells is responsible for induction of demyelination.     

Experimental allergic encephalomyelitis

Summary Previous studies have shown that Strain 13 guinea pigs sensitised for experimental allergic encephalomyelitis (EAE) as adults usually develop an acute, fatal form of disease while animals inoculated as juveniles usually display a chronic relapsing form. The present study reports that following repeated short-interval blood sampling by cardiac puncture for the estimation of lymphocyte populations, some adult Strain 13 guinea pigs sensitised for acute EAE unexpectedly survived and developed chronic EAE, while a group of juveniles sensitised for chronic EAE and bled under the same conditions, developed a more severe, acute form of EAE. It is suggested that this reversal of disease course was related to the depletion of circulating factors.     

Suppression of acute and chronic experimental allergic encephalomyelitis in strain 13 guinea pigs: A clinical and pathological study

Adult inbred Strain 13 guinea pigs develop an acute, fatal form of experimental allergic encephalomyelitis (EAE) about 2 weeks after a single injection of isologous spinal cord in complete Freund's adjuvant (CFA), but similarly injected juveniles develop a delayed, rarely fatal chronic form. Thirty-seven sensitised adult Strain 13 animals were separated into 2 groups. One group was permitted to develop acute EAE. The other group was injected intramuscularly with 1 mg of guinea pig or bovine myelin basic protein (MBP) in incomplete Freund's adjuvant (IFA) on day 2, 7 or 10 post-inoculation (PI) followed by 0.2 mg in IFA every third day for a total of 10 doses. Animals in the unsuppressed group succumbed to acute EAE 13–16 days post-sensitisation. No animal in the suppressed group died during this period. Animals treated with MBP beginning 2 days PI showed no clinical signs, but mild clinical manifestations occurred in animals suppressed from days 7 and 10 PI. These signs remitted by 21 days post-sensitisation. One suppressed animal (out of 21) died during the fourth week postsensitisation. The other 20 suppressed animals appeared clinically normal towards the end of the course of MBP injections and remained so for the 6 months of study. Morphological examination revealed that CNS lesions occurred in all animals. In animals suppressed with MBP beginning on day 2 PI, lesions consisted only of a few meningeal inflammatory cells. Animals given MBP beginning on day 7 or 10 PI and sampled 1–2 weeks later, had lesions which could not be distinguished from those occurring in the non-suppressed acute EAE group. In time, the suppressed animals developed lesions which were typical of chronic EAE with remyelination as a predominant feature. Preliminary experiments on the suppression of chronic EAE in 5 juvenile Strain 13 guinea pigs have revealed that 3 MBP-injected animals failed to develop clinical disease over a 28-week period of study although lesions typical of chronic EAE were present. Simultaneously, 2 non-suppressed juvenile animals developed clinical signs by 12 weeks. These were associated with both acute inflammation and demyelination superimposed upon regions of chronic demyelinative activity.     

辣椒素加重EAE的发病及其作用机制的探讨

为探讨脊髓P物质(SP)在自身免疫性疾病发病中的作用，本实验以豚鼠(GP)奎脊髓匀浆(spinal Cord homogenate，SCH)为抗原建立了实验性变态反应性脑脊髓炎(experimental allergic encephalomyelitis，EAE)模型。从皮下注射辣椒素(capsaicin，Cap)以耗竭脊髓SP，观察其对EAE发病及免疫功能的影响。结果表明：单纯注射辣椒素组豚鼠不发生EAE，但皮下注射辣椒素14d后，再以SCH免疫动物则发病率增高，病情加重，潜伏期缩短，并伴有细胞及体液免疫功能亢进，表现在淋巴细胞转化水平及血清抗SCH抗体滴度增高；在EAE发病高峰期脊髓后角及后根神经节SP含量明显增高，提示脊髓后角及初级感觉神经元中SP参与EAE发病过程。这部分SP具有抑制免疫的功能，在EAE发病高峰期脊髓后角及后根神经节SP含量增高可反馈性地抑制免疫反应使之不致过强，故具有保护性意义。