实验性自身免疫性重症肌无力大鼠T淋巴细胞IFN-γ及其受体表达水平的研究

目的探讨实验性自身免疫性重症肌无力（EAMG）大鼠T淋巴细胞γ-干扰素（IFN-γ）的分泌及其表面IFN-γ受体（IFN-TR）的表达水平。方法健康、雌性Lewis大鼠24只．随机分为正常对照组、完全福（氏）佐剂（CFA）对照组、EAMG组。EAMG组大鼠分别于足垫、腹部及背部皮下多点注射丁（氏）双鳍电鳐的电器官乙酰胆碱受体（AChR）蛋白乳剂1mL，第4周再次注射上述乳剂免疫大鼠。CFA对照组只接受等量的CFA皮下注射。初次免疫后7周．分离各组大鼠脾脏T淋巴细胞并体外培养48h后，应用ELISA和免疫组织化学方法分别检测T淋巴细胞IFN-γ分泌及其表面IFN-γR的表达水平。结果（1）正常大鼠T淋巴细胞体外培养48h后，其上清液中IFN-γ水平很低，而EAMG组大鼠T淋巴细胞培养上清液中IFN-γ水平较CFA对照组与正常组显著增高（P〈0.01）；（2）正常大鼠T淋巴细胞经过体外培养后可见少量IFN-γR阳性细胞．而EAMG组大鼠T淋巴细胞经体外培养后可见较多IFN-γR阳性细胞，其阳性细胞数及其平均吸光度D（λ）值均明显高于CFA对照组与正常组（P〈0.01）。结论EAMG大鼠T淋巴细胞IFN-γ分泌及其表面IFN-γR表达水平明显升高.IFN-γ／IFN-γR的异常表达可能在重症肌无力（MG）的发生过程中发挥重要作用。     

IL-32在神经胶质瘤中的表达及调节机制研究

目的 探讨白细胞介素(IL)-32在神经胶质瘤中的表达及调节机制. 方法 RT-PCR、Western blotting检测体外培养3d的神经胶质瘤细胞株CHG-5、U251 IL-32 mRNA和蛋白的表达;应用10 ng/mL IL-1β、IL-4、IL-6、IL-10、IL-17、肿瘤坏死因子(TNF)-α、TNF-β、干扰素(IFN)-γ作用U251细胞24 h后RT-PCR检测细胞IL-32 mRNA表达的变化;RT-PCR检测不同浓度IL-1β、TNF-α、IFN-γ作用U251细胞不同时间后IL-32 mRNA表达的变化. 结果 U251细胞IL-32 mRNA表达水平高于CHG-5细胞,IL-32蛋白表达水平(0.95±0.42)高于CHG-5细胞(0.28±0.13),差异均有统计学意义(P＜0.05); IL-1β、TNF-α、IFN-γ作用U251细胞24 h后IL-32 mRNA表达量增加,差异有统计学意义(P＜0.05),且IL-32 mRNA的表达量对IL-1β、TNF-α、IFN-γ刺激的浓度和时间有依赖性. 结论 IL-32在神经胶质瘤中高表达,IL-1β、TNF-α、IFN-γ对IL-32 mRNA的表达具有调节作用,且存在时间与剂量依赖性.     

地塞米松对多发性硬化细胞因子的影响

目的:多发性硬化(MS)是一种由Th1细胞介导的自身免疫性疾病,因而减少T细胞产生γ-干扰素(IFN-γ)或增加白细胞介素-10(IL-10)的产生将会达到治疗MS的目的。通过计数分泌细胞因子IFN-γ和IL一10,检测多发性硬化(MS)患者外周血单个核细胞在地塞米松(Dex)影响下的IFN-γ和IL-10的分泌细胞水平。方法:将外周血单个核细胞暴露于中枢神经系统髓鞘索抗原髓鞘碱性蛋白进行体外短时间培养,然后用Dex作对比试验,用酶联免疫斑点试验(ELISPOT)检测IL-10和IFN-γ分泌细胞,同时检测其它神经病组(OND)及健康对照组。结果:显示MS患者IFN-γ分泌细胞水平高于对照组,Dex使MS患者IFN-γ分泌细胞减少,对IL-10分泌细胞无明显影响。结论:MS患者存在Th1/Th2细胞因子的失衡,Dex能抑制MS Th1类细胞因子IFN-γ,恢复其两类细胞因子之间的平衡而对MS患者产生治疗作用。     

大鼠脑出血灶周围区内和血浆中干扰素-γ基因及蛋白的表达

目的观察大鼠脑出血血肿周围组织和血浆中干扰素-γ（IFN-γ）基因及蛋白的变化。方法采用Ⅶ型胶原酶立体定位法制备大鼠尾状核出血动物模型。以逆转录多聚酶链反应（RT—PCR）检测血肿周围组织IFN-γmRNA的表达．采用免疫组化法和酶联免疫吸附法（ELISA）观察脑出血灶周围区和血浆中IFN-γ基因及蛋白在出血后不同时间点的表达。结果脑出血后血肿周围IFN-γ反应阳性细胞和IFN-γ浓度于发病早期（4h）即明显升高．3d达峰值并持续至7d。结论IFN-γ可能参与脑出血后的继发性损伤以及脑出血后迟发性细胞免疫损伤。     

TGF—β1基因修饰的树突状细胞移植对EAMG大鼠T淋巴细胞IFN-γ／IFN-γR表达的影响

目的 探讨TGF-β1基因修饰的树突状细胞(DC)移植对实验性自身免疫性重症肌无力(EAMG)大鼠T淋巴细胞IFN-γ分泌及其表面IFN-γ受体(IFN-γR)表达的影响.方法 近交系、8～10周龄、健康雌性Lewis大鼠25只,随机分为健康对照组、EAMG组、DC对照组、pcDNA3-TGF-β1表达质粒转染的DC(pcDNA3-TGF-β1-DC)组与生理盐水对照组5组.除健康对照组外,各组均采用丁氏双鳍电鳐电器官乙酰胆碱受体(AChR)蛋白二次免疫方法复制EAMG大鼠模型.初次免疫后第5天分别皮下注射2×106 DC、pcDNA3-TGF-β1-DC及等体积生理盐水,健康对照组和EAMG组不接受任何治疗.初次免疫后7周,分离脾脏T淋巴细胞,分别应用酶联免疫吸附试验和免疫组化方法检测T淋巴细胞IFN-γ分泌及其表面IFN-γR表达水平.结果 (1)体外培养48 h后,健康对照大鼠T淋巴细胞上清液中IFN-γ水平很低,而EAMG组大鼠T淋巴细胞上清液中IFN-γ水平显著升高(P<0.001).pcDNA3-TGF-β1-DC治疗组IFN-γ水平与EAMG组差异无统计学意义(P>0.05).(2)健康对照大鼠T淋巴细胞经体外培养后可见少量IFN-γR阳性细胞,而EAMG组大鼠T淋巴细胞经体外培养后可见较多IFN-γR阳性细胞,其阳性细胞数及平均吸光度均明显高于健康对照组(P<0.001);pcDNA3-TGF-β1-DC组IFN-γR阳性细胞数较EAMG组明显增多,其阳性细胞平均吸光度亦明显高于EAMG组(均P<0.01).结论 EAMG组大鼠T淋巴细胞IFN-γ分泌及其表面IFN-γR表达水平明显提高;pcDNA3-TGF-β1-DC治疗可进一步诱导IFN-γR表达,调节T淋巴细胞IFN-γ/IFN-γR表达可能是TGF-β1基因修饰的DC治疗EAMG的机制之一.     

骨髓间充质干细胞对实验性自身免疫性重症肌无力大鼠的治疗作用

目的探讨骨髓间充质干细胞对实验性自身免疫性重症肌无力大鼠模型的治疗作用及其可能机制。方法全骨髓贴壁筛选法分离培养Lewis大鼠骨髓间充质干细胞,流式细胞术检测其表面分子CD34、CD44的表达。经Lewis大鼠尾静脉注射经体外培养至第3代的骨髓间充质干细胞,7d后腹腔注射抗乙酰胆碱受体单克隆抗体(mAb35)建立实验性自身免疫性重症肌无力动物模型,按照Lennon评分标准进行临床症状评分、Western blotting法检测肌肉组织中乙酰胆碱受体蛋白表达、流式细胞术检测外周血CD4+CD25+T细胞比率、酶联免疫吸附试验检测血清转化生长因子-β、干扰素-γ和IL-4表达变化。结果与生理盐水对照组相比,注射骨髓间充质干细胞的实验性自身免疫性重症肌无力大鼠模型临床评分降低(t=8.062,P=0.000),乙酰胆碱受体α蛋白表达水平升高(t=8.092,P=0.000);同时血清转化生长因子-β表达水平升高(t=9.859,P=0.000),干扰素-γ(t=9.040,P=0.000)和IL-4(t=3.320,P=0.004)表达水平降低,两组之间差异均有统计学意义(P<0.05)。结论骨髓间充质干细胞能够显著减轻实验性自身免疫性重症肌无力大鼠模型临床症状,减少乙酰胆碱受体缺失。其作用机制可能与分泌免疫抑制性细胞因子转化生长因子-β上调CD4+CD25+调节性T细胞表达水平,以及抑制炎性促进因子干扰素-γ和IL-4的分泌有关。     

从IFN-γ／IL-33表达变化探讨EAN中的Th1／Th2细胞极化

目的探讨IFN-γ／和IL-33在实验性自身免疫性神经炎（EAN）发病机制中的作用及EAN中的Th1／Th2细胞极化。方法用P253-78肽段免疫Lewis大鼠,建立EAN模型,观察其发病情况和组织病理改变,并检测淋巴细胞增值反应,用RT-PCR技术检测干扰素γ（IFN-γ）和白介素33（IL-33）在大鼠发病高峰期脾脏、淋巴结和坐骨神经中的表达。结果EAN组大鼠临床表现明显,病理检查可见大量炎性细胞浸润;坐骨神经组织、淋巴结,脾脏中IFN-γ mRNA表达显著升高,IL-33mRNA表达明显减少,其引流淋巴结淋巴细胞对P253-78aa的刺激发生强烈的淋巴细胞增殖反应。结论IFN-γ对EAN发病起促进作用,IL-33对EAN大鼠起保护作用;EAN中Th0细胞向Th1的转化明显增强而向Th2细胞的转化则受到抵制。     

髓鞘少突胶质细胞诱导实验性自身免疫性脑脊髓炎小鼠的中枢病理损伤与Th1、Th17细胞分泌炎症细胞因子的变化观察

目的：观察实验性自身免疫性脑脊髓炎（EAE）的中枢神经系统（CNS）病理损伤与Th1、Th17细胞分泌的相关炎症细胞因子的变化,探讨EAE致病的分子免疫学机制。方法：用髓鞘少突胶质细胞（MOG35-55）免疫诱导野生型C57BL／6小鼠制作EAE模型,记录小鼠行为学变化,苏木精-伊红染色观察CNS病理损害,RT-PCR法检测中枢Th1细胞因子γ-干扰素（IFN-γ）、Th17细胞因子IL、17和IL-6的mRNA表达水平。结果：MOG诱导的EAE模型组小鼠出现典型的EAE行为及病理学表现,大脑组织中INF-γ、IL-17和IL-6mRNA表达水平均较CFA对照组有明显升高。结论：在EAE炎症反应的过程中,Th1细胞和Th17细胞激活,各自分泌的炎症细胞因子（INF-γ／IL-6、IL-17）增加,它们可能参与了EAE发病的重要免疫病理机制。EAE的致病并不是单-Th1或者Th17细胞作用的结果,而是两类细胞因子都参与了作用。     

抑郁症患者血清细胞因子水平的研究

目的探讨细胞因子在抑郁症发病中的作用。方法用酶联免疫吸附法检测22例抑郁症患者（抑郁症组）和20名正常人（对照组）的血清白细胞介素（IL）1-β、IL-2、IL-6、肿瘤坏死因子-α（TNF-α）和γ-干扰素（IFN-γ）水平,均以nmol/L计。结果抑郁症组血清IL-2水平为0.46±0.52,明显高于对照组的0.15±0.19（t=2.517,P<0.05）。抑郁症组的IL-1β、IL-6、TNF-α和IFN-γ水平分别为0.32±0.57,0.14±0.37,0.03±0.05和0.05±0.13,与对照组（分别为0.23±0.25,0.08±0.23,0.05±0.09和0.01±0.04）比较,差异无显著性（t分别为0.645,0.589,1.099和1.110,P>0.05）。结论抑郁症患者的血清IL-2水平升高,提示IL-2可能在抑郁症的发病中起一定作用。     

ω-3不饱和脂肪酸DHA改善β淀粉样蛋白沉积致AD的小鼠模型记忆功能的机制研究

目的 探讨ω-3不饱和脂肪酸二十二碳六烯酸(DHA)改善β淀粉样蛋白(Aβ1-42)沉积所致阿尔茨海默病(Alzheimer’s disease,AD)的小鼠模型记忆功能的作用机制。方法 采用Aβ-intrahippocampal injection法向36只小鼠脑内海马部位注射寡聚态Aβ1-42建立AD小鼠模型,随机分为假手术组(羧甲基纤维素钠灌胃)、Aβ模型组(羧甲基纤维素钠灌胃)和Aβ+DHA组(DHA灌胃)。Morris水迷宫检测小鼠的记忆功能;尼氏染色检测海马神经元的变化; ELISA法检测海马组织中肿瘤坏死因子α(TNF-α)和白细胞介素16(IL-16)的含量; Western blot检测海马组织中脑源性神经营养因子(BDNF)、干扰素-γ(IFN-γ)、核转录因子-κB(NF-κB)蛋白表达。结果 与假手术组相比,Aβ模型组和Aβ+DHA组小鼠的潜伏期延长,跨越平台次数和BDNF蛋白相对表达量减少,而TNF-α和IL-16含量、IFN-γ和NF-κB蛋白表达量升高;与Aβ模型组相比,Aβ+DHA组小鼠的潜伏期缩短,跨越平台次数和BDNF蛋白表达量增加,而TNF-α和IL-16含量、IFN-γ和NF-κB蛋白表达量降低,差异均有统计学意义(P 0. 05)。结论 DHA可以改善Aβ1-42致AD小鼠模型记忆功能障碍,其作用机制可能与降低海马组织中TNF-α和IL-16含量,抑制IFN-γ和NF-κB蛋白表达,促进BDNF蛋白表达有关。     

Interleukin 1-β- and tumor necrosis factor-α-mediated regulation of ICAM-1 gene expression in astrocytes requires protein kinase C activity

Several adhesion molecules including intracellular adhesion molecule-1 (ICAM-1) are expressed by astrocytes, the predominant glial cell of the central nervous system (CNS). Such molecules are important in the trafficking of leukocytes to sites of inflammation, and in lymphocyte activation. ICAM-1 is constitutively expressed by neonatal rat astrocytes, and expression is enhanced by the proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), with IL-1β and TNF-α being the strongest inducers. In this study, we have examined the nature of the second messengers involved in ICAM-1 gene expression induced by the cytokines IL-1β and TNF-α. Our results indicate that stimuli related to protein kinase C (PKC) such as the phorbol ester phorbol 12-myristate 13-acetate (PMA) and calcium ionophore A23187 increase ICAM-1 mRNA expression, whereas cyclic nucleotide analogs and PKA agonists have no effect. Pharmacologic inhibitors of PKC such as H7, H8, and calphostin C inhibit ICAM-1 gene expression inducible by IL-1β and TNF-α. Prolonged treatment of astrocytes with PMA results in a time-dependent downregulating of the PKC isoforms α, δ, and ?, and a concomitant diminution of ICAM-1 mRNA expression induced by IL-1β, TNF-α, and PMA itself at specific time points post-PMA treatment. These data, collectively, demonstrate a role for various PKC isoforms in IL-1β and TNF-α enhancement of ICAM-1 gene expression in rat astrocytes. © 1995 Wiley-Liss, Inc.     

Differential regulation by cytokines of human astrocyte nitric oxide production

Reactive nitrogen intermediates, such as nitric oxide (NO), play an important role in host-defense and injury. Human astrocytes released abundant NO upon stimulation with the pro-inflammatory cytokine interleukin (IL)-1β, which was potentiated by interferon (IFN)-γ and tumor necrosis factor (TNF)-α. IL-1 receptor antagonist protein markedly attenuated astrocyte NO production. The anti-inflammatory cytokines IL-4 and IL-10 potently suppressed IL-1β plus IFN-γ-stimulated NO, while transforming growth factor-β preferentially inhibited IL-1β plus TNF-α-stimulated production of NO. These findings suggest that while IL-1 plays a key role in inducing astrocyte NO production, anti-inflammatory cytokines have the capacity to downregulate NO production by IL-1-stimulated astrocytes. © 1995 Wiley-Liss, Inc.     

Interleukin-1 and tumor necrosis factor-mediated regulation of C3 gene expression in human astroglioma cells

In this report, we show that in the human astroglioma cell line D54-MG, both interleukin-1 (IL-1β) and tumor necrosis factor-alpha (TNF-α) enhance C3 gene expression in a time- and dose-dependent manner. Kinetic analysis demonstrates that after 96 h, C3 mRNA levels increase approximately 30-fold and 20-fold in response to IL-1β or TNF-α, respectively. C3 protein production increases proportionally, reaching levels 36-fold and 18-fold higher than untreated controls upon exposure to IL-1β or TNF-α, respectively. D54-MG cells require a minimal 1 h exposure to IL-1β in order to enhance C3 gene expression significantly, while 4 to 8 h are required for TNF-α. Simultaneous treatment of D54-MG cells with IL-1β and interferon-gamma (IFN-γ) resulted in an additive increase in both C3 mRNA and protein expression, a finding not seen with the combination of TNF-α and IFN-γ. Primary rat astrocytes also express increased C3 mRNA levels after 48 h in response to IL-1β (5.3-fold increase) and TNF-α (7-fold increase), while an additive effect was observed upon simultaneous treatment with both IL-1β and IFN-γ. In the central nervous system (CNS), endogenous complement and cytokine production by astrocytes, and enhancement by IFN-γ, a product of activated T cells often seen in the CNS in neural autoimmune disease, may contribute to the pathogenesis of inflammatory demyelinating diseases such as multiple sclerosis.     

IL-27 mediates the response to IFN-β therapy in multiple sclerosis patients by inhibiting Th17 cells

Interferon (IFN)-β is a commonly used therapy for relapsing remitting multiple sclerosis (RRMS). However its protective mechanism is still unclear and the failure of many patients to respond has not been explained. We have found that IFN-β suppressed IL-23 and IL-1β production and increased IL-10 production by human dendritic cells (DC) activated with the TLR2 and dectin-1 agonist zymosan. Furthermore, IFN-β impaired the ability of DC to promote IL-17 production by CD4⁺ T cells, but did not affect IFN-γ production. IFN-β induced IL-27 expression by DC, and neutralisation of IL-27 abrogated the suppressive effects of IFN-β on zymosan-induced IL-1 and IL-23 production and the generation of Th17 cells in vitro. Complementary in vivo studies in a mouse model showed that treatment with IFN-β enhanced expression of IL-27, and reduced IL-17 in the CNS and periphery and attenuated the clinical signs of experimental autoimmune encephalomyelitis (EAE). In addition, the significant suppressive effect of IFN-β on the ability of DC to promote Th17 cells was lost in cells from IL-27 receptor deficient mice. Finally, we showed that PBMC from non-responder RRMS patients produced significantly less IL-27 in response to IFN-β than patients who responded to IFN-β therapy. Our findings suggest that IFN-β mediates its therapeutic effects in MS at least in part via the induction of IL-27, and that IL-27 may represent an alternative therapy for MS patients that do not respond to IFN-β.     

Transforming growth factor-β1 suppresses autoantigen-induced expression of pro-inflammatory cytokines but not of interleukin-10 in multiple sclerosis and myasthenia gravis

Multiple sclerosis (MS) is associated with high levels of circulating T lymphocytes that respond to the myelin antigens myelin basic protein (MBP) and proteolipid protein (PLP) by producing various cytokines including interferon-γ (IFN-γ) that makes MS worse and transforming growth factor-β (TGF-β), an endogenously produced immunosuppressant that might act beneficially. To further define the role of TGF-β in MS, we examined the effects of recombinant TGF-β1 (rTGF-β1) on autoantigen-mediated regulation of cytokines in MS and myasthenia gravis (MG). Blood mononuclear cells (MNC) were cultivated with or without rTGF-β1, and with or without autoantigen or the recall antigen PPD. MNC expressing cytokine mRNA were detected after in situ hybridization with radiolabeled cDNA oligonucleotide probes. Femtogram concentrations of rTGF-β1 suppressed MBP-, PLP- and PPD-induced upregulation of IFN-γ, IL-4, IL-6, tumor necrosis factor-α (TNF-α), TNF-α and perforin in MS, and acetylcholine receptor (AChR)-induced augmentation of these pro-inflammatory cytokines in MG, but had no effects on autoantigen- or PPD-induced expression of IL-10 or TGF-β itself. rTGF-β1 also suppressed numbers of myelin antigen-reactive IFN-γ- and IL-4-secreting cells in MS and AChR-reactive IFN-γ and IL-4 secreting cells in MG. The selective suppressive effects of TGF-β1 on autoantigen-induced upregulation of pro-inflammatory cytokines makes TGF-β1 attractive as a treatment alternative in MS and MG.     

Selenoprotein S expression in reactive astrocytes following brain injury

Selenoprotein S (SelS) is an endoplasmic reticulum (ER)-resident protein involved in the unfolded protein response. Besides reducing ER-stress, SelS attenuates inflammation by decreasing pro-inflammatory cytokines. We have recently shown that SelS is responsive to ischemia in cultured astrocytes. To check the possible association of SelS with astrocyte activation, here we investigate the expression of SelS in two models of brain injury: kainic acid (KA) induced excitotoxicity and cortical mechanical lesion. The regulation of SelS and its functional consequences for neuroinflammation, ER-stress, and cell survival were further analyzed using cultured astrocytes from mouse and human. According to our immunofluorescence analysis, SelS expression is prominent in neurons and hardly detectable in astrocytes from control mice. However, brain injury intensely upregulates SelS, specifically in reactive astrocytes. SelS induction by KA was evident at 12 h and faded out after reaching maximum levels at 3-4 days. Analysis of mRNA and protein expression in cultured astrocytes showed SelS upregulation by inflammatory stimuli as well as ER-stress inducers. In turn, siRNA-mediated SelS silencing combined with adenoviral overexpression assays demonstrated that SelS reduces ER-stress markers CHOP and spliced XBP-1, as well as inflammatory cytokines IL-1β and IL-6 in stimulated astrocytes. SelS overexpression increased astrocyte resistance to ER-stress and inflammatory stimuli. Conversely, SelS suppression compromised astrocyte viability. In summary, our results reveal the upregulation of SelS expression in reactive astrocytes, as well as a new protective role for SelS against inflammation and ER-stress that can be relevant to astrocyte function in the context of inflammatory neuropathologies.     

Demyelination during multiple sclerosis is associated with combined activation of microglia/macrophages by IFN-γ and alpha B-crystallin

Activated microglia and macrophages play a key role in driving demyelination during multiple sclerosis (MS), but the factors responsible for their activation remain poorly understood. Here, we present evidence for a dual-trigger role of IFN-γ and alpha B-crystallin (HSPB5) in this context. In MS-affected brain tissue, accumulation of the molecular chaperone HSPB5 by stressed oligodendrocytes is a frequent event. We have shown before that this triggers a TLR2-mediated protective response in surrounding microglia, the molecular signature of which is widespread in normal-appearing brain tissue during MS. Here, we show that IFN-γ, which can be released by infiltrated T cells, changes the protective response of microglia and macrophages to HSPB5 into a robust pro-inflammatory classical response. Exposure of cultured microglia and macrophages to IFN-γ abrogated subsequent IL-10 induction by HSPB5, and strongly promoted HSPB5-triggered release of TNF-α, IL-6, IL-12, IL-1β and reactive oxygen and nitrogen species. In addition, high levels of CXCL9, CXCL10, CXL11, several guanylate-binding proteins and the ubiquitin-like protein FAT10 were induced by combined activation with IFN-γ and HSPB5. As immunohistochemical markers for microglia and macrophages exposed to both IFN-γ and HSPB5, these latter factors were found to be selectively expressed in inflammatory infiltrates in areas of demyelination during MS. In contrast, they were absent from activated microglia in normal-appearing brain tissue. Together, our data suggest that inflammatory demyelination during MS is selectively associated with IFN-γ-induced re-programming of an otherwise protective response of microglia and macrophages to the endogenous TLR2 agonist HSPB5.