双类似物鼻黏膜耐受在EAMG发病中的预防作用机制

目的　采用双类似物 (Lys2 62 -Ala2 0 7)对实验性自身免疫性重症肌无力 (EAMG)模型进行鼻黏膜耐受不同时间点预防性给药 ,观察临床及免疫指标变化 ,以探讨其对 EAMG免疫发病中的预防作用机制。方法　应用乙酰胆碱受体 (ACh R)加福 (氏 )佐剂致敏 Lewis大鼠建立 EAMG模型 ,在致敏前 1 0 d(预防耐受 A组 )及致敏当日 (预防耐受 B组 )经鼻腔给药 ,评价给药后 A、B组及对照组大鼠体重、临床症状 ,观察肌电图变化、检测致敏第 42天血清抗 ACh R抗体 Ig G及其亚型含量和第 5 0天处死后淋巴结单个核细胞 (MNC)中 IFN-γ、IL-4及 IL-1 0分泌细胞含量变化。结果　 (1 )急性期和慢性期 A、B组体重增加而临床症状明显轻于对照组 ,慢性期 A组临床症状轻于 B组 ;(2 ) A、B组低频重复电刺激出现明显衰减的阳性率低于对照组 ;(3 )慢性期 A、B组 Ig G含量明显低于对照组 ,且 A组低于 B组 ,各组间抗体亚型 Ig G1含量无明显差异 ,而 A、B组的 Ig G2 a和 Ig G2 b含量明显少于各自对照组 ,B组 Ig G2 b含量高于 A组 ;(4 ) A、B组淋巴结中的 IFN-γ、IL-4及 IL-1 0阳性细胞含量均明显低于各自对照组。结论　Lys2 62 -Ala2 0 7鼻黏膜预防耐受不仅可有效地抑制临床症状 ,并使致病性最强的ACh R特异性 Ig G2抗体分泌量减少 ,Ig G     

设计耐受原并用鼻黏膜耐受治疗EAMG的方法学研究

目的　设计特异性耐受原 ,通过其鼻黏膜耐受治疗对实验性自身免疫性重症肌无力 (EAMG)发病过程的影响 ,以探讨该疗法在模型应用中的可行性。方法　用 Lewis大鼠建立 EAMG模型 ,选取双类似物作为耐受原在致敏同时给予鼻黏膜耐受治疗 ,动态观察大鼠体重及临床评分改变。结果　虽然治疗组大鼠发病率不降低 ,但是在 EAMG急性期和慢性期 ,其临床症状均较对照组减轻 (P <0 .0 5 )。结论　用双类似物鼻黏膜耐受可以达到治疗 EAMG的目的 ,其结果为抗原特异性治疗重症肌无力 (MG)和其他自身免疫性疾病 (AID)提供了依据。     

双类似物鼻粘膜耐受对实验性自身免疫性重症肌无力的影响

目的　在实验性自身免疫性重症肌无力 (EAMG)动物模型采用双类似物进行鼻粘膜免疫耐受 ,观察其临床及免疫功能变化 ,评价疗效并探讨其作用机制。方法　建立Lewis大鼠EAMG动物模型 ,选取经预实验证实有效的最低剂量为治疗量 ,检测致敏同时 (A组 )和缓解期第 1天 (B组 )给予双类似物鼻粘膜免疫耐受治疗后 ,大鼠体重、临床症状、致敏第 35天血清抗AChR抗体IgG含量及其淋巴细胞在不同刺激原作用下的增殖情况。结果　 (1 )治疗后EAMG大鼠体重增加 ,临床症状缓解。 (2 )治疗后血清抗AChR抗体IgG含量 (吸光度 ,A值 ) :A组 (0 98± 0 2 4 )和B组 (0 95± 0 2 6)均少于各自对照组 (分别为 1 1 8± 0 1 0和 1 1 9± 0 1 2 ) ,但A、B组间差异无显著意义。 (3)针对AChR等特异性抗原的淋巴细胞增殖指数 :A组 (1 71± 0 78)和B组 (1 97± 0 56)与对照组 (3 2 4± 1 31和 3 1 9±1 50 )相比均减低 ,增殖反应明显受抑制。结论　双类似物鼻粘膜耐受能明显缓解EAMG的肌无力症状 ,并伴有特异性T、B细胞免疫功能抑制     

双类似物鼻黏膜耐受治疗实验性自身免疫性重症肌无力的免疫机制

目的　用双类似物鼻黏膜耐受治疗实验性自身免疫性重症肌无力 ( EAMG)大鼠 ,探讨其对机体免疫机制的影响。方法　建立 Lewis大鼠的 EAMG模型 ,在致敏同时 ( A组 )及缓解期第 1天 ( B组 )给予双类似物 3 0 0μg/只。动态评估大鼠临床症状 ,检测外周血 ( PB) ACh R-Ab( Ig G)含量 ,检测急、慢性期 PB单个核细胞 ( MNC)及致敏第 5 0天淋巴结、脾 MNC中的 CD4+ CD2 5 + 细胞数改变。结果　治疗组大鼠临床症状减轻 ;治疗组及对照组大鼠 PB中特异性 ACh R-Ab( Ig G)含量随病程延续而增加 ,但在致敏后第 5及第 7周 ,A、B组特异性 Ig G抗体含量比各自对照组显著减低 ( P <0 .0 5 ) ;双类似物鼻黏膜耐受治疗后 ,EAMG大鼠 PB MNC中的 CD4+ 细胞数减少 ( P<0 .0 5 ) ,CD4+ CD2 5 +细胞数相对增加 ( P<0 .0 5 ) ;A、B组淋巴结和脾 MNC中 CD4+细胞数减少( P<0 .0 5 ) ,CD4+ CD2 5 +细胞数只在 B组相对增加 ( P <0 .0 5 )。结论　双类似物鼻黏膜耐受治疗病情进展中的 EAMG有效 ;伴随临床症状缓解 ,治疗组大鼠 ACh R-Ab( Ig G)含量减少且免疫调节性 CD4+ CD2 5 +细胞数相对增多 ;双类似物治疗 EAMG的可行性为抗原特异性治疗重症肌无力 ( MG)和其他自身免疫性疾病 ( AID)提供了依据。     

双类似物鼻黏膜耐受对实验性自身免疫性重症肌无力预防作用机制的研究

目的　观察双类似物 (Lys2 6 2 Ala2 0 7)对实验性自身免疫性重症肌无力 (EAMG)大鼠进行鼻黏膜耐受预防性给药后临床、免疫指标的变化并评价疗效 ,探讨鼻黏膜耐受对EAMG的预防作用机制。方法　建立Lewis大鼠EAMG模型 ,并在致敏前 10d(A组 ,10只 )及致敏当日 (B组 ,10只 )鼻腔给药 ,评价给药后A、B组及相应对照组CA组 (10只 )、CB组 (10只 )大鼠的临床症状并检测肌肉中乙酰胆碱受体 (AChR)含量 ,测定致敏第 4 2天血清抗AChR抗体IgG含量、第 5 0天淋巴结单个核细胞 (MNC)中针对AChR等特异性抗原的淋巴细胞增殖反应和CD4 + 及CD4 + CD2 5 + T细胞。结果　 (1)A、B组急性期和慢性期临床症状明显轻于相应对照组 ,A组慢性期临床症状轻于B组 ;(2 )A、B组慢性期血清抗AChR抗体IgG含量 [分别为 (2 2 0± 3 4 ) μg/ml和 (2 9 4± 4 6 ) μg/ml],明显低于相应对照组 [CA组 (4 2 6± 4 4 ) μg/ml、CB组 (4 3 2± 5 5 ) μg/ml],且A组低于B组 (均P <0 0 1) ;(3)A、B组大鼠肌肉AChR含量丢失明显低于相应对照组 (均P <0 0 1) ,且A组低于B组 (P <0 0 5 ) ;(4 )A、B组较各自对照组针对AChR等特异性抗原的淋巴细胞增殖反应均明显受抑 (均P <0 0 1) ;(5 )A、B组淋巴结中的CD4 + CD2 5 + T细胞含量均明显高于各     

口服耐受及鼻粘膜耐受治疗神经系统自身免疫病

Wells早在1911年发现,豚鼠喂食外源性蛋白数周后可抗御注射该蛋白所引起的严重免疫反应,即所谓免疫耐受（immunologicaltolerance）。但人们注意到获得性免疫耐受可作为许多自身免疫病的治疗途径,并成为临床医学和免疫学研究的热点,则是最近10余年的事情。ID服及具粘膜免疫耐受是治疗自身免疫病的可能出路自身免疫病目前多采用免疫抑制剂治疗,易使患者免疫系统受到普遍性抑制而诱发感染、发生肿瘤或骨髓抑制,也不能有效地防止疾病复发。这促使临床学家和免疫学家致力于寻找更合理的治疗途径,包括应用单克隆抗体或合成多肽等高新技…     

鼻粘膜耐受对实验性重症肌无力大鼠胸腺Fas、BCL-2表达的影响

目的 探讨实验性重症肌无力大鼠经鼻粘膜耐受处理后胸腺淋巴细胞Fas及BCL-2的表达及其免疫耐受的发生机制.方法 将实验大鼠随机分为对照组、EAMG组及耐受组.将EAMG组及耐受组大鼠采用Ra97-116肽段多点皮下注射法制备成EAMG大鼠模型后,再将耐受组大鼠经鼻腔滴注Rα97-116(V108A)行免疫耐受处理,10 d后评估疗效,并采用TUNEL法计数对照组、EAMG组及耐受组大鼠胸腺淋巴细胞阳性凋亡细胞数和免疫组化法检测3组大鼠胸腺淋巴细胞FAS及BCL-2的表达.结果 Rα97-116(V108A)鼻粘膜耐受处理能明显改善EAMG大鼠的肌无力症状,增加其体重及降低AChR抗体滴度.EAMG组大鼠胸腺凋亡细胞效较对照组显著减少,而耐受组大鼠则较EAMG组明显增加,3组间差异具有显著的统计学意义(F=114.15,P<0.01).3组大鼠胸腺细胞FAS的表达也具有统计学差异性(X2=16.48,p<0.05),EAMG组大鼠胸腺细胞FAS表达较对照组显著下调,而耐受组表达增加.EAMG绀胸腺细胞中BCL-2高表达,而耐受组表达量下降,3组之间存在统计学差异(X2=15.82,P<0.05).结论 Rα97-116(V108A)鼻粘膜耐受能明显减轻EAMG大鼠肌无力症状,其自身反应性淋巴细胞的凋亡可能与鼻粘膜耐受的作用机制有关.     

TGF－β高调在鼻腔给予AChR抑制EAMG中起重要作用

用放射标记的ｃＤＮＡ寡核苷酸探针，使用原位杂交技术检测表达γ干扰素（ＩＦＮ－γ）、白细胞介素４（ＩＬ－４）和转移生长因子β（ＴＧＦ－β）ｍＲＮＡ的单个核细胞（ＭＮＣ）。结果表明，实验性自身免疫性重症肌无力（ＥＡＭＧ）对照组大鼠窝和腹股沟淋巴结（ＰＩＬＮ）的ＭＮＣ乙酰胆碱受体（ＡＣｈＲ）诱导的ＩＦＮ－γ、ＩＬ－４ＴＧＦ－βｍＲＮＡ表达细胞数明显增高，与给予ＰＢＳＣＦＡ注射组比较差异显著。鼻腔耐受组与ＥＡＭＧ对照组相比，某些淋巴器官中ＡＣｈＲ诱导的ＩＦＮ－γ、ＩＬ－４数降低，ＡＣｈＲ诱导的ＴＧＦ－β细胞明显上调。提示ＩＦＮ－γ、ＩＬ－４和ＴＧＦ－β与ＥＡＭＧ的发病有关，而ＴＧＦ－β高调在鼻腔ＡＣｈＲ耐受ＥＡＭＧ中起重要作用。     

NKT细胞活化对实验性自身免疫性重症肌无力的影响

目的选取NKT细胞刺激物α-GalCer,经不同时间点腹腔注射小鼠,使其激活NKT细胞,观察对实验性自身免疫性重症肌无力(EAMG)临床表现及其相关免疫指标的影响,从而为治疗EAMG提供新的途径。方法建立C57BL/6小鼠EAMG的动物模型,选取刺激物α-GalCer腹腔注射,通过CD1d递呈引起Vα14+NKT细胞的激活,观察小鼠体重、临床表现及相关免疫指标的变化,探讨不同时间点NKT细胞激活对EAMG产生的效应。结果在C57BL/6小鼠,Vehicle组EAMG的发生率为90%,平均发病天数37±6;α-GalCer预防组疾病的发生率为30%,平均发病天数为51±9。结论a-GalCer提前免疫能激活NKT保护C57BL/6小鼠发生EAMG,该结果为EAMG和其他自身免疫病的防治提供了依据。     

一氧化氮合酶抑制剂对实验性自身免疫性重症肌无力的作用

实验证明，一氧化氮合酶/一氧化氮(NOS／NO)参与了自身免疫反应的多个环节，但关于它们在自身免疫性疾病发病中的作用，目前仍存在争议。Brenner等发现，NOS抑制剂治疗实验性自身免疫性脑脊髓膜炎(EAE)大鼠可以取得肯定的疗效，而Gold等的研究却认为，NOS抑制剂可使主动免疫的EAE大鼠发病明显加重。     

Effects of sex hormones on experimental autoimmune myasthenia gravis.

To examine whether exacerbation of myasthenia gravis (MG) can be induced by changes in sex hormone levels we immunized 20 female Lewis rats with torpedo antigen to induce experimental autoimmune MG (EAMG). Ten of the animals underwent surgical ovariectomy prior to the induction of EAMG and 10 served as controls. Anti-acetylcholine receptor antibody (AChR-ab) titres and the degree of decrement on repetitive stimulation electromyography (REMG) at 3 Hz were obtained at base line and compared between rats with and without ovariectomy and a second control group of naïve rats. Three rats in each group were then injected with excess oestrogen and progesterone for one week, and three of the remaining rats in each group were given sham injections, and the degree of decrement on REMG and AchR-ab titres were re-evaluated. Immune reactivity of peripheral lymphocytes and splenic lymphocytes from all groups and controls was also determined. A comparable number of animals with and without ovariectomy developed clinical and electromyographic EAMG. The extent of decrement on REMG and AChR-ab titres did not change following hormonal replacement. Lymphocyte reactivity was similar for rats with and without ovariectomy. In conclusion, sex hormones do not appear to have an influence on the susceptibility to and the severity of MG.     

Age-related susceptibility to experimental autoimmune myasthenia gravis: Immunological and electrophysiological aspects

Susceptibility to experimental autoimmune myasthenia gravis (EAMG) was found to decrease with aging in both Lewis and Brown Norway (BN) rats. In this study, the difference in susceptibility between young and aged Lewis and BN rats was used to analyze factors determining the clinical severity of EAMG. The incidence and severity of muscular weakness did not correlate with acetylcholine receptor (AChR) loss nor with the ability of antibodies to interfere with AChR function. Aged rats showed significantly lower anti-rat AChR antibody titers than young rats and developed less severe or no clinical signs of disease. In individual young or aged rats, however, no significant correlation was found between the clinical signs of disease and anti-rat AChR titer. Neuromuscular transmission was found to change with aging as measured by single-fiber electromyography (SFEMG). In aged BN rats, increased jitter and blockings were found even before EAMG induction. Despite this disturbed neuromuscular transmission, these aged BN rats were clinically resistant against induction of EAMG. The results of this study indicate that the age-related susceptibility to EAMG is influenced by factors determined by the immune attack as well as mechanisms at the level of the neuromuscular junction. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1091–1101, 1997     

Content and release of acetylcholinesterase in skeletal muscle of rats with experimental autoimmune myasthenia gravis

The effects of experimental autoimmune myasthenia gravis (EAMG) on acetylcholinesterase (AChE) were investigated in diaphragms of adult female Lewis rats. Both total AChE activity per muscle and release of enzyme activity during a 3-h incubation in vitro were measured. Two groups of myasthenic animals were used. Acute EAMG was induced by intravenous injection 48 h earlier with a syngeneic monoclonal autoantibody against the nicotinic acetylcholine receptor (AChR) of rat skeletal muscle; age- and weight-matched controls received a monoclonal anti-AChR antibody nonreactive with mammalian muscle. Chronic EAMG was induced by immunization 4 weeks earlier with AChR purified from Torpedo electroplax; controls received only adjuvants. When preparations from rats with acute or chronic EAMG were compared with the appropriate controls, no statistically significant differences in content or release of AChE activity were detected. Neither was there any change in the relative amounts of the various molecular forms of AChE in samples from animals with chronic EAMG. We conclude that the structural and functional changes arising in EAMG are highly specific for the acetylcholine receptor and associated elements of the neuromuscular junction, but have little impact on the biology of AChE.     

与霍乱毒素B亚单位结合的重组人AChR片断经鼻腔治疗实验性自身免疫性重症肌无力

目的 探讨与霍乱毒素B亚单位结合的重组人AChRα亚单位片断(CTB-Hα1-205)治疗实验性自身免疫性重症肌无力(EAMG)的有效性和基本作用机制.方法 将用AChR诱导的Lewis EAMG鼠随机分为3组:CTB-Hα1-205治疗组、Hα1-205组和CTB-HGG对照组,在诱导EAMG后第14天分别按上述3组从鼻腔滴入CTB-Hα1-205、Hα1-205和CTB-HGG.对各组进行临床分数评估、测定鼠血清中抗AChR特异抗体和淋巴细胞增殖反应.结果 CTB-Hα1-205组和Hα1-205组平均临床分数均较对照组有明显减少,差异有统计学意义(均为P＜0.01),同时CTB-Hα1-205组较Hα1-205组也有明显减少(P＜0.05);与对照组比较,CTB-Hα1-205组和Ha1-205组血清中鼠抗AChR特异抗体IgG、IgG2a、IgG2b和IgG2c的产生均明显被抑制(P＜0.01),CTB-Hα1-205治疗组的IgG、IgG2b和IgG2c较Hα1-205组低,且差异有统计学意义(P＜0.05);另一方面,CTB-Hα1-205组和Hα1-205组的IgG1较对照组却有明显升高(P＜0.05),同时,CTB-Hα1-205组和Hα1-205组对AChR特异性抗原的淋巴细胞增殖反应也被明显抑制(P＜0.05).结论 CTB-Hα1-205比Hα1-205能更加有效治疗EAMG,其作用机制是抑制了自身抗体的产生、IgG亚型的转换和特异的淋巴细胞增殖反应.     

Macrophage apoptosis in muscle tissue in experimental autoimmune myasthenia gravis

Combining in situ tailing and immunocytochemical staining, we demonstrated that the infiltrating macrophages in muscle tissue sections during early phase of experimental autoimmune myasthenia gravis (EAMG) in Lewis rats were eliminated by apoptosis at high frequency. These apoptotic macrophages were colocalized in the end-plate regions. Apopto-sis is a major cause for elimination of infiltrating macrophages during the early phase of EAMG. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:1071–1074, 1998.