5 resultados para TGF-ß, IL-10, Asthma, regulatorische T-Zellen

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

100.00% 100.00%

Publicador:

Resumo:

白细胞介素10(IL-10)是一种作用广泛的抗炎细胞因子,主要功能是限制和最终终止炎症反应.用RACE(rapid amplification of cDNA ends)-PCR方法扩增出鲢白细胞介素10(IL-10)的 cDNA,其全长为1248nt,包含5’非编码区156 nt,3’非编码区552nt,开放阅读框540nt.鲢IL- 10的开放阅读框编码179个氨基酸,其中包含构成两对二硫键的4个保守半胱氨酸.RT-PCR结果显示鲢IL-10 mRNA主要在脾脏、鳃、头肾和肌肉中表达.将鲢IL-10完

Relevância:

100.00% 100.00%

Publicador:

Resumo:

CD4+CD25+调节性T细胞是1995年才发现的一个具有免疫抑制功能的T细胞亚群,主要通过细胞与细胞间直接接触和分泌抑制性细胞因子发挥作用,在维持机体免疫自稳、防止自身免疫以及肿瘤免疫、移植免疫等方面起着重要作用。有关Treg HIV/SIV病毒感染及AIDS的进展关系密切,但却有两种不同的观点。一种认为Treg的数量和功能受到损伤,从而导致宿主免疫系统过度活化。另一种则认为Treg在早期抑制了针对HIV/SIV的特异性的免疫反应,从而导致机体无法清除感染的病毒。本文利用动物模型对CD4+CD25+调节性T细胞在SIV感染后的数量和功能做了动态的检测,并对其中的机制做了初步的探讨。我们首先建立了SIVmac239病毒株对中国起源的恒河猴感染的动物模型,建立了前病毒的检测方法、血浆病毒载量的测定方法、血浆病毒特异性抗体的测定方法,以及病毒的分离方法,并获得了早期感染的相关数据。在研究中我们发现,SIV感染后的1周后即可在恒河猴外周单个核细胞DNA中检测到前病毒。病毒血症也在1周后出现,并很快达到高峰。不同的个体对病毒感染的体液免疫不尽相同,血浆抗体很快出现,但是99003猴抗体下降很快,而99083猴则保持了一定数量的抗体。同时,伴随SIV的感染进程的还有T淋巴细胞的数量变化,CD4+T细胞数量持续下降,而CD8+T细胞数量则在增加,出现CD4/CD8倒置的现象。以上说明恒河猴被SIV所成功感染。在该动物模型的基础上,我们利用体内传代的SIVmac239病毒株,对4只健康恒河猴进行了感染,并对CD4+CD25+调节性T细胞(Treg)亚群在数量上的变化进行了检测,并对其中的机制做了初步探讨。我们在研究中发现,外周血中的Treg在SIV感染后无论是绝对数量还是在占CD4+T细胞中的相对数量均有增加,而且Treg仍然保持了对靶细胞的抑制功能。对腹部淋巴结的分析显示,SIV感染后的一段时期内,该部位FoxP3 mRNA的表达水平也在上升,TGF-β、IL-10的转录也显著增加。前者可以通过抑制树突状细胞间接抑制效应细胞,而后者则是一个抑制性的细胞因子,可以直接作用于靶细胞。因此,我们推测SIV引起免疫系统的过度活化可能不是由于Treg功能的受损,其中的机制需要深入研究。 Treg表达CCR5表面分子(HIV辅助受体之一),同时也有CD4分子的表达,因此推测HIV/SIV可以感染Treg。但是国内外这方面的文献很少。我们对Treg中前病毒的检测发现,SIV可以感染Treg,而且对Treg的感染比例高于CD4+CD25-T细胞。这个结果与Treg绝对数量的上升的结果说明,SIV感染Treg但可能却没有杀伤Treg,因此Treg在数量上有所增加。不过,其中的机制仍有待于进一步的研究。在对SIV引起的体液免疫的研究中还发现,机体针对SIV不同抗原的抗体有不同的模式。部分抗原很快就产生了比较强的反应,但是却不能维持高水平的表达。而针对p27蛋白的抗体产生比较晚,但却长时间维持在比较高的水平。是否这样高水平的抗体有助于控制病毒复制是个值得探讨的问题。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Horseflies are economically important blood-feeding arthropods and also a nuisance for humans, and vectors for filariasis. They rely heavily on the pharmacological propriety of their saliva to get blood meat and suppress immune reactions of hosts. Little information is available on horsefly immune suppressants. By high-performance liquid chromatography (HPLC) purification coupling with pharmacological testing, an immunoregulatory peptide named immunoregulin HA has been identified and characterized from salivary glands of the horsefly of Hybomitra atriperoides (Diptera, Tabanidae). Immunoregulin HA could inhibit the secretion of interferon-gamma (IFN-gamma) and monocyte chemoattractant protein (MCP-1) and increase the secretion of interteukin-10 (IL-10) induced by lipopolysaccharide (LIPS) in rat splenocytes. IL-10 is a suppressor cytokine of T-cell proliferative and cytokine responses. IL-10 can inhibit the elaboration of pro-inflammatory cytokines. Immunoregulin HA possibly unregulated the IL-10 production to inhibit IFN-gamma and MCP-1 secretion in the current experiments. This immunosuppression may facilitate the blood feeding of this horsefly. The current works will facilitate to understand the molecular mechanisms of the ectoparasite-host relationship. 2008 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

树突状细胞(DC)是免疫系统中具有多种免疫功能的关键细胞,但在HIV/AIDS 患者 体内,虽有大量病毒及抗原存在,却不能有效地激发特异性免疫应答。最新的研究显示, HIV/AIDS 血源和性传染的途径虽有不同,但DC 均是早于T 细胞而最先遭受感染的“第一 靶细胞”。已知辅助蛋白(Nef、Rev、Tat、Vif、Vpr 和Vpu)是HIV-1 在宿主细胞内复制 和致病的根本因素。而哪种辅助蛋白、如何影响DC 功能,至今研究结果甚少,结论杂乱 不一。 本论文作为HIV-1 影响DC 功能研究的实验体系部分,旨在为系统比较研究6 个辅助 蛋白对DC 功能的调节和机理奠定基础。采用分子生物学和免疫学技术方法,把辅助蛋白 基因从DNA 和mRNA 水平导入目的细胞DC,在DC 前体及其分化、成熟的各个时相, 连续、动态地分析辅助蛋白对DC 特征性表面标志及免疫相关基因的表达水平、摄取和处 理抗原、激发和调控免疫应答等功能的影响,以期揭示HIV/AIDS 患者DC 功能明显异常 和失调的原因。 首先,分别将6 个辅助蛋白基因克隆到pEGFP-N2 和pCS2+表达载体,得到具有绿色 荧光蛋白融合基因的表达载体,将分别用于DNA 和mRNA 水平转染DC。再以K562 细胞 为模型建立mRNA 转染细胞的基本方法;以人外周血CD14 单核细胞为前体,建立了体外 “2+2”快速诱导DC 的方法。最后,利用Amaxa 转染系统,从DNA 水平研究辅助蛋白对 DC 前体(单核细胞)的功能影响。发现单核细胞转染辅助蛋白与GFP 融合基因5h 后,胞 内蛋白大量表达,且能维持表达48h;其中Nef、Tat、Vpu、Rev、Vif、Vpr 表达效率分别 为35.42%、34.42%、43.42%、 17.07%、13.65%、10.29%;单核细胞转染基因后,表型 CD14、HLA-DR、CD80、CD83、CD86、DC-SIGN 没有明显的表达变化;转染Nef、Vpu、 Rev 辅助蛋白后,单核细胞有10%凋亡;Vpr 能抑制单核细胞IL-10 的分泌,Nef 能促进分 泌IL-6。 总之,通过构建辅助蛋白的表达载体,优化DC 的体外培养过程以及mRNA 转染方法, 并成功将辅助蛋白导入DC 前体,鉴定其表型和功能变化。为研究辅助蛋白影响DC 的功 能和机制建立了稳定而可行的实验系统。

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Depression is one of the most important psychological diseases to threaten human health. “Cytokine theory of depression” suggests that cytokines may play an important role in depression, which provided a new perspective in the study the mechanism and the therapy of depressive symptoms. This view is supported by various findings. Administration of pro-inflammatory cytokine or lipoposaccharide in animal induces depressive-like behavior such as anhedonia and low locomotion, which is very similar to the behavioral symptoms of depression in humans. However, the earlier researches may only pay attention to the short-time behavior effects; the effects of long-time behavior changes have not been clearly reported. In addition, there are few reports about the effects of pro-inflammatory cytokine or anti-inflammatory cytokine on the depressive-like behavior induced by chronic stressors. To further understand the role of cytokines in depression, the purpose of the present study is to investigate the dose and time effects of pro-inflammatory cytokines induced by lipoposaccharide on depressive-like behavior, sensitization effect of pro-inflammatory and blockage effect of anti-inflammatory on depressive-like behavior induced by chronic cold swimming stress. The behavioral observation was carried out using sacharin preference test, open field test and elevated-plus maze. The results indicated that: 1) The activated immunity induced by LPS i.p administration could induce significant depressive-like behavior, but these behaviors had no long-term effect; 2)The depressive-like behaviors induced by stress could be elicited earlier and kept longer by the activated immunity induced by LPS ip ; 4) The chronic activated immunity induced by LPS icv administration could provoke significant depressive-like behavior, and the depressive-like behaviors induced by stress could be enhanced by icv LPS, LPS and stress had certain interact-sensitization effect on depressive-like behavior; 5) Anti-inflammatory cytokines IL-10 icv reversed the depressive-like behaviors induced by the stress. In conclusion, cytokines play an important role in the depressive-like behavior. Both peripheral and central administration of LPS induced a certain depressive-like behavior and enhanced stress-induced depressive behavior. The anti-inflammatory cytokine IL-10 icv could reverse the depressive-like behaviors induced by the stress. Keywords: lipoposaccharide, depressive-like behavior, anhedonia, locomotion, chronic cold swimming stress