Differential expression of metallothioneins in the CNS of mice with experimental autoimmune encephalomyelitis

Multiple sclerosis is an inflammatory, demyelinating disease of the CNS. Metallothioneins-I+II are antioxidant proteins induced in the CNS by immobilisation stress, trauma or degenerative diseases which have been postulated to play a neuroprotective role, while the CNS isoform metallothionein-III has been related to Alzheimer's disease. We have analysed metallothioneins-I-III expression in the CNS of mice with experimental autoimmune encephalomyelitis. Moreover, we have examined the putative role of interferon-gamma, a pro-inflammatory cytokine, in the control of metallothioneins expression during experimental autoimmune encephalomyelitis in interferon-gamma receptor knockout mice with two different genetic backgrounds: 129/Sv and C57BL/6x129/Sv.Mice with experimental autoimmune encephalomyelitis showed a significant induction of metallothioneins-I+II in the spinal cord white matter, and to a lower extent in the brain. Interferon-gamma receptor knockout mice suffered from a more severe experimental autoimmune encephalomyelitis, and interestingly showed a higher metallothioneins-I+II induction in both white and grey matter of the spinal cord and in the brain. In contrast to the metallothioneins-I+II isoforms, metallothionein-III expression remained essentially unaltered during experimental autoimmune encephalomyelitis; interferon-gamma receptor knockout mice showed an altered metallothionein-III expression (a slight increase in the spinal cord white matter) only in the C57BL/6x129/Sv background. Metallothioneins-I+II proteins were prominent in areas of induced cellular infiltrates. Reactive astrocytes and activated monocytes/macrophages were the sources of metallothioneins-I+II proteins.From these results we suggest that metallothioneins-I+II but not metallothionein-III may play an important role during experimental autoimmune encephalomyelitis, and indicate that the pro-inflammatory cytokine interferon-gamma is unlikely an important factor in this response.     

Costimulatory molecule expression on leukocytes from mice with experimental autoimmune encephalomyelitis treated with IFN-beta.

Interferon-beta (IFN-beta) is of benefit in the treatment of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), but the mechanisms by which it exerts this beneficial effect remain uncertain. The present data demonstrate that IFN-beta therapy impairs the proliferative response to concanavalin A (ConA) and myelin basic protein (MBP), decreases expression of the CD80 molecule on leukocytes of treated mice, and may thereby impede the Th1 cell activation-promoting anergy in EAE. Moreover, IFN-beta therapy increases expression of the CTLA4 molecule, which induces a counterregulatory Th2 response. The reduction of CD80 expression with concomitant increase of CTLA4 expression alters the course of EAE and may be useful as a monitor in therapy with IFN-beta.     

乳腺癌患者原发磷酸化信号转导与转录激活因子3活性和白细胞介素-17表达的临床意义

目的 探讨炎性信号通路磷酸化信号转导和转录激活因子3（p-STAT）的原发活化状态及下游细胞因子白细胞介素（IL）-17表达在乳腺癌发生和发展中的作用及其对预后的影响。 方法 运用免疫组织化学Envision两步法检测了379例乳腺癌患者以及匹配癌旁245例乳腺腺病中IL-17表达和原发性p-STAT3的活化状态,分析了它们与乳腺癌组织学分型、TNM分期、临床分期及预后的相关性。统计学分析：计量数据使用t检验法,计数数据使用χ2 检验法。结果 1. IL-17在乳腺癌中的阳性表达率为95.8%,显著高于乳腺腺病中的阳性表达率85.3%（χ2=21.363,P<0.001）;具有活性的p-STAT3在乳腺癌中的阳性率为93.6%,也显著高于乳腺腺病中的阳性率62.0%（χ2=97.702,P<0.001）。2. IL-17和p-STAT3在乳腺癌 (包括乳腺浸润性导管癌、乳腺浸润性小叶癌和腺导管原位癌分型) 中的阳性率与乳腺癌组织学分型无相关性（χ2=1.245, P=0.535＞0.05）。3. IL-17和p-STAT3在乳腺癌中的强阳性率分别与淋巴结的转移成正相关（IL-17: χ2=7.806, P<0.01; p-STAT3: χ2=4.053, P<0.05）。4. 在乳腺癌组织中,IL-17表达与p-STAT3活性呈正相关（rs=0.136, P<0.01）。 结论 原发增高的p-STAT3活性及高表达的炎性细胞因子IL-17可能协同作用,产生炎性微环境,从而参与乳腺癌的发生和发展。     

Genetic control of interleukin-4-induced activation of the human signal transducer and activator of transcription 6 signaling pathway

The interleukin (IL)-4-induced Stat6 signaling pathway is active in a variety of cell types, including immune cells and cancer cells, and plays an important role in the regulation of gene expression, such as CD23 and major histocompatibility complex class II. Using a semiquantitative gel shift assay in which nuclear Stat6 activities were scored, three Stat6 activation phenotypes were defined as Stat6(high) (intense banding), Stat6(low) (medium intensity banding), and Stat6(null) (very low to no discernible banding). These Stat6 phenotypes correlated well with levels of CD23 expression, but not with those of human leukocyte antigen-DR cell-surface display. Pedigree analyses revealed a Mendelian inheritance pattern that can be explained by two STAT6 Pathway (STAT6P) activation genotypes, which we term A and a, where STAT6P*A determines an active Stat6 signaling and STAT6P*a determines an inactive Stat6 signaling, with incomplete dominance. Total Stat6 protein levels failed to correlate with the above Stat6 phenotypes allowing us to propose that IL-4-induced Stat6 signaling is a polygenic quantitative trait regulated by a collection of several contributing genetic loci that functionally interact. The Stat6(null) phenotype may result from a defect in Stat6 signaling, which has important implications with respect to the pathogenesis of cancer and Th1/Th2 cytokine imbalance in autoimmune diseases in general.     

磷脂酰肌醇-3激酶/蛋白激酶B/FoxO1信号通路和白细胞介素17在小鼠实验性自身免疫性脑脊髓炎中的表达变化

目的 探讨磷脂酰肌醇-3激酶(PI3K)/蛋白激酶B(Akt)/FoxO1和白细胞介素17(IL-17)与自身免疫性脑脊髓炎(EAE)发病的相关机制.方法 将C57BL/6小鼠60只随机分为对照组和模型组(EAE),每组30只.采用髓鞘少突胶质细胞糖蛋白(MOG35～55)联合完全弗氏佐剂诱导建立EAE模型.观察各组小...     

T cell necessity in the pathogenesis of experimental autoimmune encephalomyelitis in mice.

Cellular transfer of experimental autoimmune encephalomyelitis (EAE) was effected in mice with lymph node and spleen cells from appropriately immunized donors. In contrast to lymphoid cells, immune serum did not transfer this autoimmune disease nor did serum have any facilitating or inhibitory effect on the capacity of lymphoid cells to transfer EAE. Transfer of EAE was effected in normal mice, lightly irradiated (350 rad) and lethally irradiated (850 rad) and bone marrow-protected mice, but not in mice which had been given 850 rad total-body irradiation. There was a striking augmentation of severity of transferred EAE in the lightly irradiated recipients, possibly attributable to selective radiosensitivity of suppressor T cells. Cell-mediated immunity but not circulating antibody to basic protein of myelin was demonstrated in recipients with transferred EAE. The immune lymphoid cells responsible for transfer of EAE were T lymphocytes. Thus transfer was successful after passage of sensitized cells through anti-immunoglobulin columns and was abrogated following treatment with anti-Thy-1 serum and complement. Neonatally thymectomized mice failed to develop either EAE, cell mediated immunity or humoral antibody against myelin basic protein (BPM). Inhibition of EAE and immune responsiveness was solely due to the removal of the source of thymus lymphocytes, because reconstitution of neonatally thymectomized mice with T lymphocytes completely restored these functions. It is concluded that T lymphocytes are required for the production and adoptive transfer of EAE, for the development of cell-mediated immunity to BPM and for the production of antibody to BPM.     

Co-infection with Trypanosoma brucei brucei prevents experimental autoimmune encephalomyelitis in DBA/1 mice through induction of suppressor APCs

The immune system has co-evolved with the infectious agents that challenge it, and in response pathogens have developed different mechanisms to subvert host immunity. A wealth of evidence suggests that infections are important components in the development of a functional immune system, and understanding the modulation of the host immune system by pathogens may offer new therapeutic strategies in a non-infectious setting. We investigated how infection with the protozoan parasite Trypanosoma brucei brucei (Tbb) modulates the autoimmune response to recombinant myelin oligodendrocyte glycoprotein (rMOG) in DBA/1 mice. Mice harbouring a Tbb infection did not develop experimental autoimmune encephalomyelitis (EAE) induced by immunization with rMOG in CFA, an animal model for the human autoimmune disease multiple sclerosis. Additionally, mice infected with the parasite at the time of immunization or 1 week later developed less severe EAE than uninfected controls. Protected mice displayed a markedly diminished rMOG-specific proliferation and IFNgamma production in lymph node cells and had correspondingly low titres of serum anti-rMOG IgG. Antigen-presenting cells (APCs) from spleens of Tbb-infected mice presented rMOG less efficiently to rMOG-specific T cells in vitro than did splenic APCs from uninfected mice and could also inhibit antigen-specific proliferation in control in vitro cultures. This suppressive effect is at least in part due to increased release of IL-10. Transfer of splenic APCs from Tbb-infected mice into mice immunized with rMOG-CFA 7 days previously abrogated disease significantly. These findings indicate that infections can prevent autoimmunity and that APCs might be used as immunomodulants.     

哮喘大鼠模型信号转导子和转录激活子6在气道上皮细胞表达增强

目的探讨哮喘大鼠肺组织中信号转导子和转录激活子6(STAT6)的活化规律及其意义。方法将SD大鼠随机分为对照组和哮喘组,后者根据末次激发后处死时相不同分成0、3、8、24、72、120和144 h组。采用透射电镜、细胞计数、免疫组化和图像分析等,分别观察肺组织超微结构、支气管肺泡灌洗液(BALF)中嗜酸性粒细胞(EOS)数量及STAT6蛋白表达。结果①哮喘组肺组织EOS炎性浸润较对照组明显增加;②哮喘组STAT6蛋白主要在气道上皮细胞表达;③3 h时STAT6即开始明显升高,24 h达到峰值,其后有所下降;④STAT6蛋白表达的变化与BALF中EOS绝对值及EOS%的动态变化均显著正相关(P<0.01)。结论哮喘大鼠气道上皮细胞存在STAT6的持续活化及过度表达,并与EOS的生成密切相关,提示STAT6的活化在哮喘气道炎症调控中起重要作用。