Phenotypic analysis of the medullary-type CD4−CD8+ thymocytes in mice

Phenotypic analysis of the medullary-type CD4 CD8⁺ (CD8SP) thymocytes has revealed phenotypic heterogeneity within this cell population. The phenotype of mature peripheral CDS⁺T cells is TCRαβ⁺CD3⁺Qa-2⁺HSA 3G11⁻6C10, whereas in the medullary-type CD8SP thymocytes, 20% are Qa-2⁺; 33%, HAS; 30%, 3G11; and 70% are 6C10. The disparate expression patterns of these four cell surface markers suggest that medullary-type CD8SP thymocytes may undergo phenotypic maturation process. According to the distribution of these four cell surface markers, six subgroups of CD8SP thymocytes have been identified. The precursor-progeny relationship along with developmental pathway is postulated as follows: 6C10⁺HSA⁺3G11 Qa-2→ 6C10⁺HSA⁺ 3G11⁺Qa-2 → 6C10 HSA⁺3G11⁺Qa-2 → 6C10⁻HSA⁻3G11⁺Qa-2 → 6C10⁻HSA⁻3G11 Qa-2 → 6C10⁻HA S 3G11 Qa-2⁺, the cells in the last subgroup exit the thymus and home into periphery.     

正常来源CD4+CD25+细胞在小鼠肺癌模型中的抗肿瘤作用

CD4+CD25+细胞是一群具有免疫抑制活性的T细胞,又称为调节性T细胞(regulatory T cells,Tregs).肿瘤发生中Tregs会抑制T细胞的活化,促进肿瘤的发生、发展,而正常生理来源的Tregs回输后产生的免疫调节作用是未知的.为探讨正常生理状态下Tregs的免疫调节作用,利用小鼠肺癌模型和细胞移植...     

CD4+CD25+Foxp3+调节性T细胞在口腔鳞状细胞癌中的表达及意义

目的探讨CD4~+CD25~+Foxp3~+调节性T细胞在口腔鳞状细胞癌中的表达情况.方法应用免疫组化SP法检测42例原发口腔鳞状细胞癌患者的癌组织和20例口腔良性肿瘤患者正常黏膜上皮组织中Foxp3的表达,采用χ2检验进行统计学分析.结果 Foxp3阳性的CD4~+CD25~+调节性T细胞在口腔鳞状细胞癌中的表达显著高于正常口腔黏膜组织,差异具有显著统计学意义(P0.01).Foxp3蛋白表达与肿瘤分化程度相关,在高、中分化组为63.64%,低分化组为100%,差异具有统计学意义(P0.05).且其阳性率与肿瘤TNM分期相关,Foxp3蛋白表达在Ⅲ~+Ⅳ期阳性率为88.24%,在Ⅰ~+Ⅱ期表达的阳性率为60%(P0.05).Foxp3蛋白表达与患者年龄、性别、淋巴结转移未见明显相关性(P0.05).结论 CD4~+CD25~+Foxp3~+Treg细胞在口腔鳞状细胞癌中的大量浸润与肿瘤的发生、发展、浸润、转移密切相关,可能是导致口腔鳞状细胞癌患者不能进行有效抗肿瘤免疫的重要原因之一.     

CpG ODN对初生仔猪外周血CD4+和CD8+T淋巴细胞的影响

以猪伪狂犬病毒为模式病毒，研究了CpG ODN对仔猪外周血中CD4^＋，CD8^＋T淋巴细胞的影响．实验结果表明：疫苗组初生仔猪血液中CD4^＋／CD8^＋T淋巴细胞比例随年龄的增加逐渐降低，而CpG ODN能有效抑制其降低（P〈0．05）；CpG ODN的使用也可以阻止伪狂犬病毒导致的血液中CD4^＋T淋巴细胞比例的降低；联合免疫CpG ODN和猪伪狂犬病毒活疫苗，可以诱导初生仔猪血清中猪伪狂犬病毒特异性抗体迅速产生并达到较高的水平（P〈0．05）；这表明CpG ODN能显著增强动物的免疫应答能力．     

原发性肝癌患者射频消融后外周血CD4+CD25+Foxp3+Treg细胞对预后的影响

目的研究射频消融术治疗原发性肝癌患者外周血CD4+CD25+Foxp3+调节性T细水平与预后的关系.方法回顾性分析102例原发性肝癌患者经射频消融治疗后外周血CD4+CD25+Foxp3+/CD4+比值与生存时间的关联.结果原发性肝癌患者射频术后CD4+CD25+Foxp3+细胞占CD4+T的比例显著降低,与临床分期、肿瘤大小、AFP水平相关.CD4+CD25+Foxp3+调节性T细胞数目与生存率相关.结论原发性肝癌患者射频消融治疗后外周血Treg水平是判断预后的独立预测指标.     

Tunable and enhanced luminescence of Ba2−xCaxSiO4−yN2/3y:Eu2+ phosphors for white light-emitting diodes

Color tuning and luminescence enhancement are predominant challenges for improving the performance of white light emitting diodes(LEDs) toward commercial application. In this paper, a novel promising Ba_(2-x)Ca_xSiO_(4-y)N_(2/3y):Eu~(2+) tphosphors with tunable and enhanced luminescence for phosphors converted LEDs(pc-LEDs) have been successfully synthesized by a direct gas-reduction nitridation method. The effects of Ca and N doping on the phase purity, morphology and optical properties of Ba_(2-x)Ca_xSiO_(4-y)N_(2/3y):Eu~(2+) tphosphors were also systematically investigated. The optical results show that Ba_(2-x)Ca_xSiO_(4-y)N_(2/3y):Eu~(2+) tphosphors can be actively excited over a broad range from 250 to430 nm. With the adding of different concentrations of Ca~(2+) tions in phosphors, the emission color wavelength can be tailored from 501 to 441 nm by a 375 nm NUV LED excitation source. Furthermore, it has been found that the emission and absorption of Ba_(2-x)Ca_xSiO_(4-y)N_(2/3y) tphosphor can be significantly improved when N~(3-) ions were introduced into the host lattices. The intensity of Ba_(1.5)Ca_(0.5)SiO_(4-y)N_(2/3y):Eu~(2+) tphosphor was 3.4 times higher than the phosphor without N doping. The fabrication and characterization of pc-LEDs using Ba_(2-x)Ca_xSiO_(4-y)N_(2/3y):Eu~(2+) tphosphors-silica gel as the coating layer onto 375 nm-emitting In Ga N LED caps demonstrated the superior optical and current tolerant properties,making it a promising and competitive candidate for commercial utilization in white LED applications.     

Generalized Lévy walks and the role of chemokines in migration of effector CD8+ T cells

Chemokines have a central role in regulating processes essential to the immune function of T cells, such as their migration within lymphoid tissues and targeting of pathogens in sites of inflammation. Here we track T cells using multi-photon microscopy to demonstrate that the chemokine CXCL10 enhances the ability of CD8+ T cells to control the pathogen Toxoplasma gondii in the brains of chronically infected mice. This chemokine boosts T-cell function in two different ways: it maintains the effector T-cell population in the brain and speeds up the average migration speed without changing the nature of the walk statistics. Notably, these statistics are not Brownian; rather, CD8+ T-cell motility in the brain is well described by a generalized Lévy walk. According to our model, this unexpected feature enables T cells to find rare targets with more than an order of magnitude more efficiency than Brownian random walkers. Thus, CD8+ T-cell behaviour is similar to Lévy strategies reported in organisms ranging from mussels to marine predators and monkeys, and CXCL10 aids T cells in shortening the average time taken to find rare targets.     

肿瘤患者外周血CD4+和CD8+T淋巴细胞TCR Vβ基因克隆化分析

目的探讨肿瘤患者T细胞抗原受体(TCR)Vβ基因克隆化改变特征.方法应用多引物巢式PCR技术检测肿瘤患者外周血CD4+T细胞和CD8+T细胞TCR Vβ基因22个亚家族的克隆化改变,与正常对照组比较,分析肿瘤患者TCR单克隆改变的特点.结果 CD8+T细胞TCRVβ基因亚家族单克隆改变的数量多于CD4+T细胞;肿瘤患者的CD4+T细胞中,只有Vβ2,Vβ7和Vβ8三个亚家族单克隆改变高于正常对照组(P0.01或P0.05),其他Vβ亚家族单克隆改变与正常对照组无明显差异.肿瘤患者的CD8+T细胞中,有14个Vβ亚家族单克隆改变均高于正常对照组(P0.01或P0.05);4组肿瘤患者中,CD4+T细胞和CD8+T细胞的TCR Vβ7亚家族的单克隆改变均明显高于正常对照组(P0.01或P0.05).结论通过检测TCR Vβ基因克隆化改变,可以初步了解T细胞对肿瘤的免疫应答状况.     

半刚性振转靶模型在H+CD4→HD+CD3反应散射中的应用

应用半刚性振转靶 (SVRT)模型和含时波包法对H CD4 →HD CD3反应体系进行了量子计算 ,给出了该体系基态的反应几率 ,散射截面和热速率常数等量子结果 ,并比较了H同位素D在该体系中的替代效应     

Characteristics of TCRαβ+CD4-CD8- thymocytes in fetal thymic organ culture

TCRαβ+CD4-CD8- (TCR+ DN) thymocytes at different developmental periods, i.e. after either 9 or 18 days of culture in the fetal thymic organ culture (FTOC) system, were characterized in the properties of phenotype, proliferation, differentiation and apoptosis. The results showed that anti-CD3 mAb significantly promoted proliferation of TCRαβ+ DN cells generated after 18 days of culture in FTOC, whereas the cells generated after 9 days of culture responded to anti-CD3 mAb by proliferation weakly. IL-7 efficiently induced TCRαβ+ DN cells at day 9 of FTOC to differentiate into TCRαβ+CD4+/CD8+ SP cells without detectable transitional stage of TCRαβ+CD4+CD8+ (DP) cells. In contrast, fewer TCRαβ+ DN cells generated after 18 days of FTOC were induced to differentiate into SP cells. The thymic stromal cell line MTEC5 cells synergized with IL-7 to promote the differentiation of TCRαβ+ DN cells. In addition, TCRαβ+ DN cells were shown to be less susceptible to apoptosis compared with the other major thymocyte subsets. Taken together, these data have provided insight into the characteristics of TCRαβ+ DN thymocytes.     

The Distribution of a CP-asymmetric quantity in the decay channelJ/Ψ→π + π − π 0

The distribution of a CP-asymmetric quantityA in the decay channelJ/ψ→π ⁺ π ^? π ⁰ is investigated. This dimensionless quantityA is constructed from the momenta of the π-meson final states, namely A=P _x ^{π +} P _y ^{π ?} -P _x ^{π ?} P _y ^{π ?}, whereP _h,P _x ^h andP _y ^h are the module of the momentum of a hadron h, the x- and y-components of that momentum respectively, theJ/ψ particle is produced by e⁺ e^? collision, and the direction of the momentum of e⁺ is taken to be the positive direction ofz axis. There would exists the violation under the combined transformation of charge conjugation and space reflection (CP violation) when the average ofA among a lot of events, 〈A〉, be examined to be nonzero clearly from data. In this way, 748 events are selected from the BES experimental data, and analyzed. The corresponding averageA-value is measured to be 〈A〉 = 0.010 39 ± 0.014 61 ± 0.015 2. Further, some discussion of our result, the size of the data sample being need for further attempt and a possible perspective are given.     

Effect of MTECl on the functional expression of TCRαβ~ + 3G11~- 6C10~-CD4~+CD8~- thymocyte subset

A murine CD4+ thymocyte subset with phenotype of TCRαβ + 3G11- 6C10- CD4 + CD8- CD69 +/- HSAmed/locontains the cells in relatively functional matured status. The functional property of the cells in this subset is characterized by the unique pattern of cytokine production at transitional stage from Th0 to Th2 type with the latter being the dominant type. After being co-cultured with murine thymic medullary epithelial cell line (MTEC1) cells, a murine thymic medullary type epithelial cell line, the TCRαβ(T 3G11 6C10-CD4 + CD8- CD69+/- HSAmed/l? thy-mocytes, has exhibited significantly higher levels of proliferation capability and IL-6 production, whereas the production of IL-4 and IL-10 is suppressed after co-culturing with MTECl. By contrast, MTECl could not induce thymocytes to secrete Th1 type of cytokines. The results suggest that MTECl can regulate functional status of this thymocyte subset and induce them to develop into a specialized Th2 subset.     

Synthesis and luminescence properties of Mn4+-dopant Ca14Zn6Ga10−xAlxO35 solid solution

Mn~(4+)-activated oxide phosphors,owing to their desirable spectral features,eco-friendly and low cost,are emerging as a new class of non-rare-earth red phosphors for warm white LEDs.However,these phosphors possess low photoluminescence quantum efficiency excited by blue chip currently.Herein we report an isostructural solid solution of Ca_(14)Zn_6Ga_(10-x)Al_xO_(35):0.15Mn~(4+)(0≤x≤10)synthesized by a traditional solidstate reaction route.The microstructure and luminescent performance of this red-emitting phosphor are investigated in detail with the aids of X-ray diffraction,diffuse reflection spectra,photoluminescence spectra/decay/QE,and temperature-dependent PL/QE measurements.Blue shift of energy peaks of~4A_2→~4T_1and~4A_2→~4T_2transition is illustrated by the Tanabe–Sugano diagram and the configurational coordinate diagram.The crystal field strength(Dq)and the Racah parameters(B and C)are carefully calculated to estimate the nephelauxetic effectβrespectively.Particularly we achieve external and internal quantum efficiencies as high as26.1%and 40.3%for Ca_(14)Zn_6Ga_6Al_4O_(35):0.15Mn~(4+)excited by 466 nm,the highest one ever reported in Mn~(4+)activated oxide phosphors under the similar condition.     

Hydrogen absorption properties of amorphous (Ni0.6Nb0.4−yTay)100−xZrx membranes

Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work the melt spun(Ni_(0.6)Nb_(0.4-y)Ta_y)_(100-x)Zr_x with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T 400 °C, even in a hydrogen atmosphere(1-10 bar), the amorphous structure was retained. The crystallization process was characterized by differential thermal analysis and the activation energy of such process was obtained. The hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method,and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear change of the hydrogen solubility was observed with the variation of the Zr content. The values of the hydrogenation enthalpy changed from ~37 k J/mol for x=30 to ~9 k J/mol for x=20. The analysis of the volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum of energy levels.     

Oxidation and adsorption of Co at Pt−Au-SPE electrodes

Pt−Au-SPE electrodes made by the successive chemical deposition of Au and Pt on Nafion membranes were tested and compared with the single metal-SPE electrodes for surface oxidation, CO adsorption and oxidation. Part of the surface of the binary metal electrodes behaves differently from either Au or Pt single metal-SPE electrode for CO_ads oxidation, revealing surface modulation effects in the binary metal electrode. However, these mudulated surfaces have no appreciable contribution to the electrode activity for CO oxidation. The electrode activity for CO oxidation is mainly governed by the total Pt surface area of the binary electrodes. The predeposited Au was found to be favorable for higher dispersion of the successively deposited Pt. Foundation item: Supported by the National Natural Science Foundation of China Biography: YANG Jing (1972-), female, Lecturer, Wuhan University of Technology.     

抗原对CD8+T细胞记忆的贡献

基于T细胞的逆线性分化假说建立了非线性理论模型,利用此模型,得出记忆T细胞逆线性分化模型确有记忆机制,并发现记忆强度与抗原量有直接的关系。     

a+N1+of+N2结构的语用功能

英语中表述份量的结构有数词+可数名词的单复数;数词/a+名词1+of+名词2。本文主要讨论的是a+名词1+of+名词2这一结构的三大语用功能:纯粹表量功能,表量修辞兼具以及纯粹比喻功能。     

孕鼠免疫激活对其子鼠调节性CD4~+CD25~+T细胞分化及功能影响的初步研究

CD4~+CD25~+T细胞是一种重要的调节性T细胞,在机体免疫反应中发挥着重要作用,探明孕鼠感染细菌对其子鼠调节性T细胞分化和功能的影响具有一定的生物学意义。用LPS介导的孕鼠免疫激活模型来模拟孕妇细菌感染.发现50μg/kg LPS诱导妊娠12.5 d的C57BL/6孕鼠产生大量的炎症细胞因子IL-6和TNF-α.孕鼠免疫激活导致成年LPS子鼠脾脏CD4~+CD25~+调节性T细胞增多。在实验性自身免疫性脑脊髓炎动物模型中成年LPS子鼠出现免疫耐受.免疫组LPS子鼠的外周淋巴结中CD4~+CD25~+调节性T细胞增多。该工作为后继深入探讨孕鼠免疫激活是如何调控成年LPS子鼠CD4~+CD25~+调节性T细胞的表达和功能奠定了一定的基础.     

体外激活CD8~+T细胞表达CD69及γ-干扰素的研究

目的 :研究正常人外周血CD8+T细胞体外活化表达早期活化标志CD69分子及γ -干扰素 (IFN -γ)的规律 方法 :以佛波醇酯 (PDB) +离子霉素 (Ion)或植物血凝素 (PHA)体外活化人外周血单个核细胞 (PBMC) ,利用流式细胞术分析CD8+T细胞表达CD69及IFN -γ的情况 结果 :PDB +Ion和PHA活化CD8+T细胞CD69的表达率 ( % )分别为 78.4± 5.3和 2 7.4± 4 .4 ( x±s) ,明显高于对照组 ( 1.5± 0 .6) (P <0 .0 5) 当monensin存在时以PDB +Ion及PHA刺激 4h后IFN -γ阳性CD8+T细胞的百分比分别为 2 9.7± 6.5及 5.9± 1.8,均明显高于对照组 ( 0 .7± 0 .2 ) (P <0 .0 5) ,其中前者表达率高于后者 (P <0 .0 5) 结论 :PDB +Ion和PHA均可刺激CD8+T细胞表达CD69以及IFN -γ ,前者的刺激作用明显强于后者