日本血吸虫感染小鼠的脾脏CD8+PD-1+T细胞的功能特性

目的研究日本血吸虫感染后小鼠脾脏CD8+PD-1+T细胞含量及功能的变化情况。方法使用日本血吸虫感染5～6周的C57BL/6小鼠,分离脾脏,制备石蜡切片,HE染色,观察组织病变情况;分离淋巴细胞并计数,运用流式细胞术检测CD8+PD-1+T细胞的含量;使用细胞表面染色的方法观察CD8+PD-1+T细胞的CD25、CD69、CXCR5、CD40L的表达变化;经PMA和离子霉素的刺激,使用细胞内细胞因子染色的方法检测IFN-γ、IL-10和IL-12的分泌情况。结果日本血吸虫感染后,小鼠体质量下降(P0.05),而脾脏质量和体积均明显上升(P0.01);脾脏中CD8+PD-1+T细胞的比例和绝对值数目增加(P0.01);感染组CD8+PD-1+T细胞高表达CD69(P0.05),而感染组CD8+PD-1+T细胞CXCR5分子表达显著下降(P0.05);经PMA与离子霉素刺激以后,CD8+PD-1+T细胞IFN-γ分泌增加(P0.05)。结论血吸虫感染5～6周小鼠脾脏中CD8+PD-1+T细胞为一群主要的活化细胞群可大量分泌IFN-γ,在血吸虫感染疾病发挥重要的免疫调节作用。     

卡介苗诱导小鼠脾脏树突状细胞分化作用研究

目的探讨卡介苗(BCG)诱导小鼠脾脏树突状细胞分化作用。方法分别用PBS和BCG免疫小鼠,收集免疫鼠脾单核细胞培养,通过瑞士-姬姆萨染色观察脾单核细胞形态;流式细胞术分析脾巨噬细胞、树突状细胞表型;MTS法检测小鼠脾淋巴细胞增殖;ELISPOT法检测脾淋巴细胞IFN-γ的分泌;ELISA法测定小鼠脾单核细胞分泌IL-2情况。结果与对照组相比,BCG免疫组镜下可见体积大、带毛刺状突起的细胞较多;CD14(P<0.05)、CD40、CD11C、CD86、CD68表达水平增高;小鼠脾淋巴细胞刺激指数增高(P<0.05);分泌IFN-γ的细胞频数增多(P<0.01);脾单核细胞培养上清中IL-2水平明显增高(P<0.01)。结论 BCG可诱导小鼠树突状细胞分化并活化Th1细胞。     

微小RNA-7敲减对小鼠脾脏中T淋巴细胞体外功能的影响

观察微小RNA-7(microRNA-7,miR-7)敲减(Knock down,KD)对小鼠脾脏T淋巴细胞体外功能的影响并探讨其意义。常规分离野生型(wild type,WT)小鼠脾脏T淋巴细胞,经CD3和CD28抗体刺激后,Real-time PCR检测不同时间点(0h;24h;48h)细胞中miR-7的表达变化;进一步用Con A、CD3和CD28抗体刺激miR-7KD小鼠脾脏T淋巴细胞,CCK8检测细胞增殖率;Real-time PCR检测miR-7KD小鼠脾脏T淋巴细胞IL-12、IL-4、IL-6、TNF-α、IFN-γ和IL-10表达的变化;FACS检测CD4+T和CD8+T细胞的数量变化及CD4+T细胞膜分子CD44、CD62L和IL-4、IFN-γ的表达变化。结果显示,WT小鼠脾脏T淋巴细胞活化后,miR-7的表达水平显著上调(P0.05);与WT小鼠相比,在Con A、CD3和CD28抗体作用下miR-7KD小鼠脾脏T淋巴细胞增殖明显增加(P0.05);miR-7KD小鼠脾脏T淋巴细胞IL-12、IL-4、IL-6、TNF-α和IFN-γ水平均明显上调(P0.05),而IL-10表达显著下调(P0.05);FACS检测结果显示CD4+T细胞比例明显上调(P0.05),而CD8+T细胞的比例变化不显著(P0.05);CD4+T细胞膜分子CD62L水平显著下降,CD69及IL-4、IFN-γ的表达水平均显著上调(P0.05)。结果表明,miR-7敲减以后可显著影响小鼠脾脏T淋巴细胞的功能,本实验为后续深入探讨其在T淋巴细胞功能调控中的作用提供实验依据。     

羧胺三唑增强小鼠脾脏淋巴细胞促进结肠癌细胞系MC38和C26凋亡

目的探讨羧胺三唑(CAI)直接或通过小鼠脾脏淋巴细胞间接对小鼠结肠癌细胞系(MC38和C26)存活和凋亡的影响。方法体外培养结肠癌细胞系MC38和C26细胞,分离小鼠脾脏淋巴细胞,MC38和C26细胞分别与小鼠脾脏淋巴细胞共培养,不同浓度CAI处理细胞。CCK-8法检测细胞存活,流式细胞测量术检测细胞凋亡以及小鼠脾脏淋巴细胞中CD4~+CD3~+ T细胞和CD8~+CD3~+ T细胞的比例。结果不同浓度CAI处理MC38和C26细胞后,活细胞数目减少(P0.05、P0.01和P0.001),凋亡率升高(P0.01和P0.001);MC38和C26细胞分别与小鼠脾脏淋巴细胞共培养48 h后,MC38和C26细胞数目减少(P0.001),凋亡率升高(P0.001);不同浓度CAI处理小鼠脾脏淋巴细胞共培养条件下的MC38和C26细胞48 h,与单独小鼠脾脏淋巴细胞处理相比,MC38和C26细胞数目进一步减少(P0.001),凋亡率进一步升高(P0.05和P0.001);不同浓度CAI处理小鼠脾脏淋巴细胞48 h后,小鼠脾脏淋巴细胞中CD4~+CD3~+ T细胞和CD8~+CD3~+ T细胞的比例显著升高(P0.05和P0.01)。结论 CAI抑制MC38和C26细胞存活、促进细胞凋亡,并可能通过升高小鼠脾脏淋巴细胞中CD4~+CD3~+ T细胞和CD8~+CD3~+ T细胞的比例增强小鼠脾脏淋巴细胞抑制MC38和C26细胞存活、促进细胞凋亡。     

GPIF对免疫损伤小鼠T淋巴细胞膜表面共刺激分子表达的影响

目的：分析羊胎盘免疫调节因子(GPIF)对BALB/c小鼠T淋巴细胞共刺激表面抗原分子表达及其细胞因子分泌的影响，探讨羊胎盘免疫调节因子免疫促进作用机理。方法: 60Coγ-ray辐射所致免疫抑制小鼠连续7 d腹腔注射GPIF，流式细胞分析术分析BALB/c小鼠脾细胞表达CD28+、CD152+单阳性细胞百分率，表达CD4+CD28+、CD8+CD28+、CD4+CD152+、CD8+CD152+双阳性细胞百分率；ELISA法检测小鼠血清IL-2、IFN-γ分泌水平。结果: 羊胎盘免疫调节因子显著提高免疫损伤小鼠脾淋巴细胞CD28+、CD4+CD28+、CD8+CD28+阳性细胞百分率(P<0.05，P<0.01)，降低CD152+、CD4+CD152+阳性细胞百分率(P<0.05，P<0.01)，提高小鼠血清IL-2、IFN-γ分泌水平(P<0.01)。结论: 羊胎盘免疫调节因子的免疫促进作用与其调节T淋巴细胞CD28、CD152共刺激分子通路的活化信号传递，降低T淋巴细胞的功能抑制，促进T淋巴细胞的活化有关。活化的T淋巴细胞分泌细胞因子IL-2、IFN-γ，参与细胞因子介导的免疫网络调节。     

芍药苷对牛Ⅱ型胶原诱导的小鼠关节炎模型T细胞作用机制研究

目的:探讨芍药苷(Paeoniflorin)对牛Ⅱ型胶原诱导的小鼠关节炎模型(Collagen-induced arthritis,CIA)T细胞作用机制。方法:采用牛Ⅱ型胶原诱导DBA/1J小鼠建立CIA模型,二次免疫时随机分为两组,一组用芍药苷治疗,另一组用磷酸盐缓冲液治疗作为对照,每天进行临床评分;发病高峰期处死小鼠,HE染色法观察关节病理学变化;3H-甲基胸腺嘧啶(3H-TdR)掺入法检测小鼠脾脏细胞和CD4+T细胞增殖反应;流式细胞技术检测T细胞亚群比例;酶联免疫吸附试验(ELISA)检测小鼠脾脏细胞培养上清中炎性因子分泌情况。结果:芍药苷治疗组小鼠临床评分显著低于对照组(P<0.05);治疗组CD3抗体和CD28抗体刺激的脾脏细胞和CD4+T细胞增殖能力明显减弱(P<0.05),治疗组CII刺激的脾脏细胞和CII特异性CD4+T细胞增殖能力明显减弱(P<0.01);治疗组Th1和Th17细胞亚群比例低于对照组(P<0.01);治疗组脾脏细胞培养上清中IFN-γ和IL-17含量低于对照组(P<0.05)。结论:芍药苷可能通过抑制致病性T细胞增殖,降低Th1和Th17细胞亚群比例,减少炎性细胞因子分泌,从而缓解CIA病情。     

Ag85A DNA疫苗加强免疫显著提高卡介苗初免小鼠的抗结核T细胞免疫应答

目的 构建表达结核分枝杆菌(Mycobacterium tuberculosis,Mtb)免疫优势抗原Ag85A的DNA疫苗,分析其加强免疫后提高卡介苗(BCG)初免小鼠的抗结核T细胞免疫应答.方法 以Mtb毒株H37Rv基因组DNA为模板,PCR扩增Ag85A抗原编码的结构基因并克隆至真核表达载体pVAX1中构建其DNA疫苗;接着,将纯化后的该DNA疫苗加强免疫BCG初免小鼠2针,以BCG和DNA单独免疫小鼠为对照,免疫8周后无菌分离脾淋巴细胞,分别应用IFN-γ ELISPOT和多因子胞内流式细胞术(intracellular staining)分析免疫小鼠的Mtb抗原特异性效应细胞免疫水平与分泌IFN-γ/TNF-α/IL-2的多功能CD4+T细胞频率及其强度以及CD8+T细胞免疫应答.结果 与BCG免疫及DNA单独免疫组相比,Ag85A DNA加强免疫不仅能显著提高小鼠IFN-γ+TNF-α+IL-2+多功能T细胞,IFN-γ+IL-2+、IL-2+TNF-α+双功能T细胞与IL-2+单功能T细胞的频率以及IL-2的分泌能力,还能显著诱导小鼠产生更多分泌IFN-γ和IL-2的CD8+T细胞.结论 本研究成功构建了表达Mtb免疫优势抗原Ag85A的DNA疫苗并分析了其免疫原性,证实了BCG初免-DNA加强的免疫策略可同时显著增强实验小鼠的Mtb抗原特异性CD4+T和CD8+T细胞应答水平,有利于提高BCG的免疫原性,为增强BCG逐渐下降的抗结核保护效果提供新思路.     

羧胺三唑通过抑制NFAT2核转运降低小鼠CD8^+T细胞中程序性死亡受体1的表达

目的研究羧胺三唑(CAI)对CD8+T细胞的作用,并探索其增强活化的T细胞杀伤作用的关键机制。方法用免疫磁珠分选出小鼠CD8+T细胞,分为对照组、CAI组、ZK756326(Ca2+激活剂)组以及CAI+ZK756326组。流式细胞计量术检测细胞内游离钙离子水平;酶联免疫吸附法检测细胞内钙调磷酸酶(CaN)的表达;免疫荧光染色检测细胞活化T细胞核因子2(NFAT2)核转运;染色质免疫共沉淀-qPCR检测细胞中NFAT2调控程序性死亡受体1(PD-1)表达。分离小鼠脾脏细胞毒性T淋巴细胞(CTLs),流式细胞计量术检测其中CD8+T细胞PD-1的表达。结果CAI组显著降低CD8+T细胞内Ca2+浓度(P<0.001),CAI+ZK756326组胞内Ca2+浓度有所升高(P<0.01);CAI显著降低CD8+T细胞中钙调磷酸酶的含量(P<0.001);CAI可显著抑制NFAT2核转运(P<0.001),并使NFAT2依赖的PD-1转录进程显著降低(P<0.001);CAI使小鼠脾脏CTLs细胞中PD-1+CD8+T细胞比例显著减少(P<0.001)。结论CAI通过抑制CD8+T细胞内钙离子水平以及钙调磷酸酶的表达抑制NFAT2核转运,从而降低CD8+T细胞PD-1的表达,进一步产生免疫治疗干预作用。     

HDAC抑制剂丙戊酸对小鼠T淋巴细胞表达细胞因子的影响

目的分析组蛋白去乙酰化酶(HDAC)抑制剂丙戊酸(Valproic acid,VPA)对小鼠T细胞亚群IL-2、IFN-γ和IL-6表达的影响,探讨其抗炎免疫调节作用的机制。方法经VPA处理小鼠淋巴细胞,并在佛波醇酯(PDB)和离子霉素刺激后,以流式细胞术分析CD3+、CD4+和CD8+T细胞表达IL-2、IFN-γ和IL-6的情况。结果淋巴细胞受刺激后,IL-6的表达水平仅稍有提高,而IL-2在CD4+和CD8+T细胞表达率分别为35.49%和5.50%,IFN-γ表达率分别为3.47%和38.60%。经VPA处理后,CD3+T细胞IL-6+、IFN-γ+和IL-6+IFN-γ+的表达均受剂量依赖性抑制(P<0.01)。同样,VPA能够剂量依赖性地降低小鼠CD4+和CD8+T细胞亚群内表达IL-2+、IFN-γ+的细胞比例(P<0.01),对于IL-2+IFN-γ+双阳性细胞的比例也具有明显抑制作用(P<0.01);此外,VPA对CD8+T细胞表达IFN-γ的抑制程度高于CD4+T细胞。结论 HDAC抑制剂VPA通过抑制IL-2和IFN-γ而发挥其抗炎和免疫调节效应。     

STING激动剂联合PD-1抗体通过激活T细胞的抗肿瘤活性抑制肺癌进展的研究北大核心CSCD

目的:探索STING激动剂联合PD-1抗体是否可以有效激活体内的T细胞,发挥抑制肺癌进展的作用。方法:通过CFSE检测T细胞的体外增殖情况;通过ELISA法检测T细胞的细胞因子分泌能力;利用小鼠皮下移植瘤模型验证STING激动剂联合PD-1抗体对肿瘤细胞的体内抑制作用;利用免疫荧光实验检测CD3+T细胞的肿瘤浸润情况;通过流式细胞术检测肿瘤浸润T细胞IFN-γ分泌情况;利用免疫组化法检测肿瘤组织中PD-1的表达水平。结果:STING激动剂可以在体外显著增强T细胞的增殖能力(P<0.0001)以及分泌IL-2(P<0.01)和IFN-γ(P<0.01)的能力;STING激动剂联合PD-1抗体显著抑制路易斯肺癌细胞LLC在小鼠体内的生长(P<0.0001);STING激动剂联合PD-1抗体可以显著增强肿瘤组织中CD3+T细胞的浸润情况(P<0.0001),增加肿瘤组织中IFN-γ阳性的T细胞比例(P<0.0001),同时还可以显著降低肿瘤组织中PD-1的表达水平(P<0.0001)。结论:STING激动剂联合PD-1抗体可以有效激活体内T细胞的抗肿瘤免疫应答,抑制肺癌荷瘤小鼠模型的肿瘤进展,该研究对在肺癌的临床治疗中实践这一联合疗法具有重要意义。     

Haptic selective attention by foot and by hand

Nonvisual perceptions of a wielded object's spatial properties are based on the quantities expressing the object's mass distribution, quantities that are invariant during the wielding. The mechanoreceptors underlying the kind of haptic perception involved in wielding – referred to as effortful, kinesthetic, or dynamic touch – are those embedded in the muscles, tendons, and ligaments. The present experiment's focus was the selectivity of this muscle-based form of haptic perception. For an occluded rod grasped by the hand at some intermediate position along its length, participants can attend to and report selectively the rod's full length, its partial lengths (fore or aft of the hand), and the position of the grip. The present experiment evaluated whether participants could similarly attend selectively when wielding by foot. For a given rod attached to and wielded by foot or attached to (i.e. grasped) and wielded by hand, participants reported (by magnitude production) the rod's whole length or fractional length leftward of the point of attachment. On measures of mean perceived length, accuracy, and reliability, the degree of differentiation of partial from full extent achieved by means of the foot matched that achieved by means of the hand. Despite their neural, anatomical, and experiential differences, the lower and upper limbs seem to abide by the same principles of selective muscle-based perception and seem to express this perceptual function with equal facility.     

Luminol-independent chemiluminescence by phagocytes is markedly enhanced by dexamethasone,not by other glucocorticosteroids

The effect of several glucocorticosteroids on the generation of reactive oxygen species (ROS) was examined. The ROS assessed were O ₂ ^– , H₂O₂, OH·, and chemiluminescence (CL) (determined in the presence or absence of luminol), generated by both opsonized zymosan-stimulated neutrophils or monocytes and by the xanthine-xanthine oxidase system. Except for luminol-independent CL, only high concentrations (10^–4 M) of steroids could decrease each ROS. In contrast, luminol-independent CL generation in the phagocyte system was increased in a dose-dependent manner by the addition of dexamethasone, but not by any other steroid. Further, in lymphocyte cultures stimulated with Con A for four days, luminol-independent CL generation was demonstrated and enhanced by the addition of dexamethasone, although CL generation was not detected in the absence of dexamethasone. These findings provide evidence that CL does not always represent light specific to ROS, and they suggest the possibility that dexamethasone induces emission of light at sites of inflammation.     

Intrastromal invasion by limbal epithelial cells is mediated by epithelial-mesenchymal transition activated by air exposure

Corneal epithelial stem cells are located in the basal layer of the limbus between the cornea and the conjunctiva. Regulation of these limbal epithelial progenitor cells by the stromal niche dictates corneal surface health. To further characterize this process, limbal explants were cultured at the air-fluid interface, termed air-lifting, to stimulate the niche. As compared to submerged cultures, air-lifting significantly promoted epithelial stratification, migration, proliferation, and intrastromal invasion by limbal epithelial cells. Epithelial intrastromal invasion was noted when the limbal, but not corneal, epithelium was recombined with the limbal stroma containing live, but not dead, cells. Invading limbal basal cells displayed up-regulated nuclear expression of p63 and Ki67, down-regulated E-cadherin and cornea-specific keratin 3, and switched expression of beta-catenin from intercellular junctions to the nucleus and cytoplasm, indicating the activation of the Wnt/beta-catenin pathway. Invaded cells isolated by collagenase from the stroma of air-lifted, but not submerged, explants showed vivid clonal growth on 3T3 fibroblast feeder layers and complete epithelial-mesenchymal transition by expressing nuclear p63 and cytoplasmic S100A4. These findings collectively suggest that epithelial-mesenchymal transition via the Wnt/beta-catenin pathway influences the fate of limbal epithelial cells, likely to be progenitor cells, between regeneration and fibrosis when the stromal niche is activated.     

Cohesion by topology: sister chromatids interlocked by DNA

Sister chromatid cohesion is coupled with chromosome replication and influences chromosome segregation and intra-S repair. Specialized proteins, the cohesins, together with other pathways contribute to tether sister chromatids. In this issue of Genes & Development, Wang and colleagues (pp. 2426-2433 demonstrate that TopoIV, a type II DNA topoisomerase, modulates cohesion in Escherichia coli, by removing interlocked DNA junctions between sister chromatids. They propose that DNA precatenanes, arising during replication fork progression, hold sister chromatids together.