944 resultados para Antigens, CD4


Relevância:

10.00% 10.00%

Publicador:

Resumo:

选取天然产物虎眼万年青作为研究对象,对一其化学成分及药理活性进行了系统的研究。针对不同成分极性的显著差异,分离、纯化出13种化合物,并鉴定了其中的弱极性的小分子物质。采用COZ超临界提取技术,对易挥发的19种成分分别作了鉴定。对其中具有药理活性的多糖、皂营及生物碱等成分,经进一步分离、纯化,并借助现代波谱技术,对其单一成分进行了跟踪、表征。研究了虎眼万年青不同组分的抗肿瘤、抗辐射作用。首次筛选出了有显著药理活性的虎眼万年青中性多糖53,并从非特异性免疫功能、体液免疫功能和细胞免疫功能等角度,即从细胞和分子水平较全面地研究了S3的免疫增强作用。结果表明,53能显著增强小鼠T淋巴细胞的转化、提高NK细胞细胞毒活性,不同程度的使CD3、CD4CD4/CDS升高而使CDS下降,从分子水平证实了S3对辅助性T细胞(Th)的增强作用及对抑制性T细胞(Ts)的降低作用,推测Tl:可能是其主要的原发刺激细胞。此外,S3不仅能促进细胞因子IL-2的产生,还能使IL-1mRNA基因表达量显著增加,从基因水平进一步证实了53有提高小鼠免疫功能的作用。首次利用电喷雾质谱(ESI-MS),在较温和的条件下得到了具有较高稳定性的新型簇合物离子K+K(NO3)n:和NO3-(KNO3)m。并利用现代量子化学程序对低聚合度簇合物离子的可能组态进行了总成键能的计算,给出了相对稳定的组态。计算结果说明,n=2,3,6组态稳定性高的原因是总成键能高,而m≤4阴离子簇合物不能直接形成的原因是由于溶剂化作用。电喷雾质谱的进样过程与晶体的成核过程相类似,通过气相离子簇合物的组态信息和形成机理的研究,可以为晶体成核理论和化学键理论提供某些证据。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the present research, two Chinese rhesus monkeys were inoculated intravenously with 5000 TCID50 of SIVmac239. The changes in the numbers of CD4+ T lymphocyte in peripheral blood, plasma viral loads, proviral DNA and humoral antibodies against virus were periodically monitored during 121 days. At the early stage of infection, proviral DNA had been detected in PBMCs, and infectious SIVmac239 virus had been isolated from PBMCs. At the same period, the numbers of CD4+ T lymphocytes were significantly decreased, and maintained at low level during the 121-day period of infection. Plasma viral loads reached the peak at week 2 post-inoculation and kept at a steady state subsequently. Moreover, antibodies against viral proteins were detected from plasma. All the results showed that the two Chinese rhesus monkeys had been infected with SIVmac239 successfully. This animal model can be applied for further AIDS researches.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

therapeutic drugs, vaccines and mechanisms of human diseases. Little is known about the normal levels of leukocyte subpopulations of Chinese rhesus macaques. To obtain these data, 100 blood samples from Chinese rhesus macaques were collected. The normal range of major leukocyte subpopulations, such as T lymphocytes, B lymphocytes, monocytes, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs), were quantitatively analyzed by flow cytometry through BD trucount tubes. The influence of age and sex on the cell counts of leukocyte subpopulations was analyzed. The counts of CD3+ T cells, CD3+CD4+ T cells, CD3+CD8+ T cells and B cells decreased with age, but those of monocytes, mDCs and pDCs had no significant correlation with age. Significant differences existed in the cell counts of most leukocyte subpopulations between the male and female groups except pDCs. Furthermore the values of the females were higher than those of the males. The study provided basic information about the leukocyte subpopulations of Chinese rhesus macaques, and it may be valuable for immunobiological study of Chinese rhesus macaques. Cellular & Molecular Immunology. 2009;6(6):433-440.

Relevância:

10.00% 10.00%

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:

10.00% 10.00%

Publicador:

Resumo:

本论文主要由3 个相对独立的部分组成:中国恒河猴单核细胞来源的树突 状细胞的表型及功能研究;外周血DC 亚群在SIVmac239 感染的中国恒河猴中 数量及细胞因子的变化以及急性感染期SIVmac239 对中国恒河猴外周血DC 亚 群的凋亡和免疫表型的影响。 非人灵长类动物是人类的近亲,由于在组织结构、免疫、生理和代谢等诸 多方面与人类高度近似,科学界较普遍地利用非人灵长类作为动物模型来进行 艾滋病(AIDS)的发病机制和疫苗研究。中国恒河猴发病缓慢,更适合于HIV 感染的相关研究。在本研究中,我们在体外成功培养了中国恒河猴单核细胞来 源的树突状细胞(monocyte derived dendritic cells,MDDC),并测定其表型和免 疫刺激功能。通过GM-CSF 和IL-4 共同刺激培养单核细胞6 天以后便获得了未 成熟MDDC,随后加入IL-1β、PGE2、LPS 和TNF-α 联合刺激MDDC 成熟。 成熟的MDDC 上调了共刺激分子和CD83 的表达,具有很强的刺激T 淋巴细胞 增殖的能力并分泌大量的IL-12。本研究为后续的DC 疫苗研究奠定了基础。 我们实验室建立了SIVmac239 感染的中国恒河猴动物模型。以该模型为依 托,我们研究了外周血中DC 亚群在急性感染期以及慢性感染期的数量、表型 及功能变化。DC 作为最重要的连接先天免疫与获得性免疫的抗原递呈细胞, 在AIDS 发病进程中扮演着重要的角色。研究发现AIDS 患者血液和淋巴结中 髓样DC(myeloid DC,mDC)和浆细胞样DC(plasmacytoid DC,pDC)会随 着感染的进程而减少,并且伴随着功能损伤。本论文通过研究发现,中国恒河 猴的DC 亚群数量在感染后尽管波动十分剧烈,但并没有显著性地增加或减少, 中文摘要 2 在后期DC 数量能够回升到正常的范围之类,这种回升不同于印度恒河猴,很 可能是中国恒河猴缓慢发病的原因之一。进一步通过研究体外刺激DC 亚群分 泌的细胞因子,我们发现在急性感染期,pDC 分泌的IFN-α 显著提高,并很可 能刺激mDC 成熟并促进了IL-12 的分泌。早期大量细胞因子的分泌有助于控制 病毒复制,但同时也激起了整个免疫系统的活化,促进了疾病进程。而在整个 感染阶段,IFN-α 与CD4+ T 细胞呈正相关,而与病毒载量呈负相关,表明了 IFN-α 对于延缓疾病进程具有重要的意义。 我们测定了急性感染期DC 亚群受病毒影响而发生的表型变化,发现pDC 更容易受到病毒影响而发生凋亡,这可能与pDC 高表达SIV 受体CD4 和CCR5 有关。在感染过程中,尽管mDC 和pDC 都显著地下调了CD4 表达,而上调了 CCR5 的表达,不过仅发现pDC CD4 的表达与病毒载量呈负相关,而CCR5 的 表达与病毒载量呈正相关。在此过程中DC 亚群都会因为病毒的影响而活化, 继而提高CCR7 的表达。同时无论mDC 还是pDC,其表达的CD80 和CD86 都与病毒载量呈正相关。在早期感染中,DC 的活化促使整个免疫系统针对病 毒发挥免疫反应,对于控制疾病发展具有重要意义。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

C-6-carboxylated chitosan obtained by oxidation of chitosan was selectively modified in order to obtain derivatives similar to bacterial antigens. Selective O-acetylation of 6-carboxyl chitosan afforded a modified polysaccharide with the 2-amino group available for further modifications to create carbonyl groups. A deaminative degradation reaction allowed the formation of oligosaccharides with terminal aldehyde groups. Reductive alkylation with lactose introduced lactityl branches which were oxidized with galactose oxidase to give aldehyde groups in its -galactose residues.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

依据虎眼万年青组分中多糖对小鼠巨噬细胞吞噬功能的影响,筛选并优化出60%醇浓度中性多糖活性组分S3,进而研究其对体液免疫、细胞免疫及细胞因子变化的影响,并从细胞和分子水平探讨其作用的机理.方法:采用溶血素测定方法,测定S3对小鼠脾细胞溶血素抗体的诱导作用;采用3H-TdR渗入法,测定S3对ConA诱导小鼠脾淋巴细胞的增殖作用;采用3H-TdR后标记法,测定S3对NK细胞细胞毒活性的影响;以ELISA法测定S3对小鼠脾细胞IL-2产生的影响;利用流式细胞术,检测S3对T淋巴细胞亚群CD3、CD4、CD8、CD4/CD8阳性细胞百分率的影响;采用RT-PCR方法检测IL-2 mBNA的表达水平.结果:S3高、中剂量组能明显增强小鼠脾细胞溶血素抗体的形成(P<0.05);各剂量组均能明显增强ConA诱导的淋巴细胞增殖能力(P<0.001);各剂量组均能增强NK细胞的细胞毒活性并促进IL-2的产生(P<0.001,P<0.01);高、中剂量组CD8阳性细胞百分率明显降低(P<0.001),各剂量组均能显著地提高CD4/CD8阳性细胞百分率(P<0.001);高剂量组可明显促进脾细胞中细胞因子IL-2的mRNA表达,使表达量增加(P<0.05).结论:S3具有较强的增强机体多种免疫功能的作用,可利用开发为一种免疫增强药物.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Edwardsiella tarda is the etiological agent of edwardsiellosis, a systematic disease that affects a wide range of marine and freshwater fish cultured worldwide. In order to identify E. tarda antigens with vaccine potential, we in this study conducted a systematic search for E. tarda proteins with secretion capacity. One of the proteins thus identified was Esa1, which contains 795 amino acid residues and shares extensive overall sequence identities with the D15-like surface antigens of several bacterial species. In silico analyses indicated that Esa1 localizes to outer membrane and possesses domain structures that are conserved among bacterial surface antigens. The vaccine potential of purified recombinant Esa1 was examined in a Japanese flounder (Paralichthys olivaceus) model, which showed that fish vaccinated with Esa1 exhibited a high level of survival and produced specific serum antibodies. Passive immunization of naive fish with antisera raised against Esa1 resulted in significant protection against E. tarda challenge. Taking advantage of the secretion capacity of Esa1 and the natural gut-colonization ability of a fish commensal strain, we constructed an Esa1-expressing recombinant strain, FP3/pJsa1. Western immunoblot and agglutination analyses showed that FP3/pJsa1 produces outer membrane-localized Esa1 and forms aggregates in the presence of anti-Esa1 antibodies. Vaccination analyses showed that FP3/pJsa1 as an intraperitoneal injection vaccine and an oral vaccine embedded in alginate microspheres produced relative percent survival rates of 79% and 52%, respectively, under severe challenging conditions that resulted in 92-96% mortality in control fish. Further analyses showed that following oral vaccination, FP3/pJsa1 was able to colonize in the gut but unable to disseminate into other tissues. Together these results indicate that Esa1 is a protective immunogen and an effective oral vaccine when delivered by FP3/pJsa1 as a surface-anchored antigen. (c) 2010 Elsevier Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

迟缓爱德华氏菌是危害水产养殖业发展的重要病原菌之一,因而其免疫防治研究具有重要意义。论文分析了9种具有保护潜能的迟缓爱德华氏菌蛋白,经过牙鲆免疫保护实验,筛选出EseD和Et18两种有显著性保护效应的抗原。为了提高其保护效应,论文使用基因工程技术将这两种抗原融合到一起,构建重组融合蛋白EEH。结果表明,融合蛋白EEH保护效应较EseD和Et18分别免疫时有所提高。ELISA和Western blotting 结果显示,三种蛋白都能诱导牙鲆产生特异抗体。这些研究为开发迟缓爱德华氏菌疫苗提供了理论基础。 论文克隆分析了迟缓爱德华氏菌AcrAB耐药系统,采用定点突变确定了acrAB、acrR的启动子序列和AcrR在acrAB启动子的结合位点。启动子分析显示,AcrR对acrAB启动子有300倍抑制效应, 对acrR启动子有3倍抑制效应。定点突变显示,K39和R45对AcrR功能具重要性;缺失突变表明,N端205个氨基酸残基是其功能必需。实验筛选出Acriflavine、Ethidium Bromide、Methyl Viologen、Sodium Dodecyl Sulfate等四种AcrR诱导物。分析AcrR过量表达菌株结果显示,其耐药性、生长状况和毒力水平较阴性对照组降低。这些研究加深了我们对迟缓爱德华氏菌耐药机制及其与毒力关系的了解。

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Endothelial cells (EC) shed endothelial microparticles (EMP) in activation and apoptosis. Objectives: We compared the antigenic expression of EMP species released during activation as compared to apoptosis, in three cell lines. Methods: EC from renal and brain microvascular (MiVEC) and coronary macrovascular (MaVEC) origin were incubated with TNF-alpha to induce activation, or deprived of growth factors to induce apoptosis. Antigens expressed on EMP and EC were assayed flow cytometrically and included constitutive markers (CD31, CD51/61, CD105), inducible markers (CD54, CD62E and CD106), and annexin V binding. Results: It was found that in apoptosis, constitutive markers in EMP were markedly increased (CD31>CD105), with a concomitant decrease in expression in EC. Annexin V EC surface binding and annexin V+ EMP were more sharply increased in apoptosis than in activation. In contrast, in activation, inducible markers in EMP were markedly increased in both EMP and EC (CD62E>CD54>CD 106). Coronary MaVEC released significantly less EMP than MiVEC. Conclusion: EC release qualitatively and quantitatively distinct EMP during activation compared to apoptosis. Analysis of EMP phenotypic signatures may provide clinically useful information on the status of the endothelium. (C) 2003 Elsevier Science Ltd. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective:Developing a generalized psychological intervention program, and explore its influence on the emotion, subjective health, and immunity function of the perioperation patients with breast cancer. Method:Sixty patients with breast cancer were randomly divided into intervention and control groups. The clinical psychological intervention was performed on patients in the intervention group for 20 days, in addition to the routine therapy and care. Levels of emotion (SAS & SDS), subjective health (SF-36), and immunity function (t lymphocyte subsets) of the patients were tested. Results: 1.There was no significant difference between the age, income, educational level, and type of prefession of the two groups. There was no significant difference between SAS, SDS, SF-36 and lymphocyte subsets(CD3+, CD4+, CD8+, CD4+/CD8+, NK) of the two groups. 2. Scores of SAS and SDS decreased significantly after intervention in experimental group, while the score of SF-36, the average value of CD4+, CD4+/CD8+, and NK increased significantly. For the control group, the score of depression decreased significantly after intervention, while the score of PF, GH, VT, SF, RE, and MH increased significantly. 3. In comparison of the intervention and control group, the intervention effect of SAS, SDS, SF-36 scores (except SF), CD3+, CD4+, CD4+/CD8+, and NK differed significantly, with the priority of experimental group. 4. SDS, SAS, and CD3+, CD4+, NK correlated in negative respectively, while SDS, SAS, and CD8+ correlated in positive. PF, RP, GH, SF, and MH of subjective health correlated in positive with every index of immunity function in positive, except negative correlation with CD4+/CD8+. BP, RE correlated with CD3+,CD4+,CD8+, and NK in positive. VT correlated in positive with CD3+, CD8+, and NK, in negative with CD4+/CD8+. Conclusions: 1. Anxiety, depression, and subjective health, correlated with immunity function in perioperation patients with breast cancer. 2. Psychological intervention can improve the emotional status, subjective health, and immune function of patients with breast cancer to the optimum in perioperative period.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Neal, M., Meta-stable memory in an artificial immune network, Proceedings of the 2nd International Conference on Artificial Immune Systems {ICARIS}, Springer, 168-180, 2003,LNCS 2787/2003