巨噬细胞炎症因子1α对人脑微血管内皮细胞通透性的影响

目的研究巨噬细胞炎症因子1α(MIP-1α)是否具有开通血脑屏障的作用。方法以重组人MIP-1α直接作用于人脑微血管内皮细胞(HBMEC),免疫荧光方法检测紧密连接蛋白ZO-1的分布变化、跨内皮细胞电阻、HRP穿过HBMEC单层的改变、HBMEC细胞CC趋化因子受体5(CCR5)的表达,以及MIP-1α中和抗体和分泌MIP-1α的模式细胞(6T-CEM)与HBMEC单层共同温育时ZO-1的分布变化。结果MIP-1α作用下,HBMEC单层紧密连接结构被破坏,通透性增加,引起HBMEC细胞CCR5受体的表达,MIP-1α中和抗体阻断6T-CEM细胞对HBMEC单层ZO-1分布的改变。结论MIP-1α可能通过CCR5改变HBMEC单层通透性促进T淋巴细胞穿过血脑屏障。     

神经肽P物质对小鼠脾NK细胞迁移及趋化因子受体表达的影响

探讨神经肽P物质(substance P,SP)对小鼠NK细胞迁移能力和趋化因子受体表达的影响,揭示SP对NK细胞迁移功能的调节作用。采用Transwell法检测SP对C57BL/6小鼠脾NK细胞迁移活性的影响;实时荧光定量PCR检测趋化因子受体(CCR5、CXCR4)的mRNA表达水平;流式细胞术检测趋化因子受体(CCR5、CXCR4)的膜表达水平。结果显示,选用10~(-14)～10~(-6)mol/L SP处理小鼠脾NK细胞,在较低浓度范围内,NK细胞迁移作用随着SP浓度的升高而增强;在较高浓度范围内,NK细胞迁移作用随着SP浓度的升高而回落至基础水平。在所选浓度范围内,SP均可增加CCR5 mRNA和CXCR4 mRNA表达;受较低浓度SP刺激后,CCR5和CXCR4表达阳性细胞数随SP浓度升高而逐渐增加,而受较高浓度SP刺激后,CCR5和CXCR4表达阳性细胞数随SP浓度升高而逐渐回降,该趋势与SP促进NK细胞趋化活性的作用趋势基本一致。这些结果提示SP对NK细胞具有直接趋化作用,且SP对某些趋化因子受体的表达有一定的调节作用,这些趋化因子受体的表达可能参与了SP对NK细胞迁移活动的调控。     

受激活调节正常T细胞表达和分泌因子及其受体CCR1、CCR5在大鼠附睾的表达与定位

目的:观察受激活调节正常T细胞表达和分泌因子(RANTES)与其受体CCR1、CCR5在大鼠附睾中的表达和定位.方法:采用免疫组织化学法检测成年大鼠附睾上皮RANTES及其受体的细胞定位,免疫荧光双标染色分别显示RANTES与CCR1、CCR5的细胞共定位情况.RT-PCR检测RANTES及其受体mRNA表达水平,免疫印迹检测RANTES及其受体的蛋白量.结果:RANTES与其受体CCR1、CCR5在大鼠附睾各段呈特异性表达.免疫印迹在大鼠附睾各段检测到RANTES及其受体CCR1、CCR5特异性蛋白条带.RANTES与其受体CCR1、CCR5在大鼠附睾上皮主要表达于基细胞.双重免疫荧光显示RANTES与CCR1、CCR5在附睾管基细胞共存.结论:RANTES可能通过自分泌或(和)旁分泌方式在大鼠附睾基细胞功能活动方面起重要作用.     

趋化因子受体在人卵巢黄素化颗粒细胞中的表达

为探讨人卵巢黄素化颗粒细胞中趋化因子受体的表达,收集生殖中心接受卵母细胞胞浆单精子注射(intracellularsperm injection ICSI)治疗的妇女卵巢黄素化颗粒细胞,于体外分离培养。免疫细胞化学检测细胞纯度,RT-PCR检测颗粒细胞中趋化因子受体的转录水平,流式细胞术检测蛋白表达水平。结果显示,经过免疫细胞化学鉴定,原代培养的颗粒细胞纯度达95%以上;趋化因子受体以CXCR4转录水平最高,另外,CXCR6、CCR2、CCR6、CCR7转录水平也较高;流式细胞术检测CXCR4及CXCR6蛋白水平高表达,CCR3表达相对较低。人卵巢黄素化颗粒细胞中表达多种趋化因子受体,它们可能在卵泡液局部免疫调节、卵泡发育和卵母细胞成熟中发挥了重要的作用。     

CCR6与免疫细胞关联性研究进展

趋化因子受体6(chemokine receptor 6,CCR6)是趋化因子受体CCR亚家族成员之一,可表达在单核细胞、树突状细胞、T细胞、B细胞等多种免疫细胞上。新近研究显示,CCR6在免疫细胞介导的炎症反应、移植排斥反应以及肿瘤免疫逃逸等中发挥了重要作用。本文就其相关研究进展做一综述。     

CCR5与 HIV-1感染的分子机制研究进展

趋化因子受体5(CCR5)作为一个辅助受体在HIV-1进入巨噬细胞的过程中发挥重要作用.在不同人种中,CCR5存在天然的突变基因型,其中包括纯合子和杂合子基因型,它们对HIV-1的易感性也各不相同.实验室中膜外袢的点突变、缺失突变、插入及膜内基元的信号转导研究从分子水平揭示了一些氨基酸和空间结构对辅助受体的功能起关键性的作用,这对深入了解HIV-1与受体作用的分子机制,为寻找有效的阻断途径无疑是必需的和重要的.     

miRNA-467b在EAE中对炎性T细胞浸润的影响

为探讨miRNA-467b在实验性自身免疫性脑脊髓膜炎(experimental autoimmune encephalomyelitis,EAE)中对炎性T细胞浸润的影响,我们首先采用real-time PCR及FACS方法检测EAE小鼠脾脏单个核细胞中CXCR3、CCR5、CCR2、CCR6的mRNA和蛋白表达水平,并在MOG反应性T细胞中过表达miRNA-467b,FACS方法检测趋化因子受体CXCR3、CCR6的表达变化,并进一步通过Boyden小室(transwell实验)的方法,体外观察miRNA-467b对细胞迁移的影响。结果发现,EAE小鼠脾脏中CCR5、CCR2、CCR6的转录及蛋白表达水平显著上升,在MOG特异性的T细胞中过表达miRNA-467b后,可降低Th1表面趋化因子受体的表达,减少Th1向transwell板下室中的迁移,提示miRNA-467b可以通过影响细胞的迁移进而调节EAE的疾病进程。     

新型干扰素——IFN-λ抗HIV-1感染

目的 研究干扰素λ(IFN-λ)是否对HIV-1感染人臣噬细胞有抑制作用,并对可能介导IFN-λ抗HIV-1作用的受体和辅助受体表达水平进行研究,初步探讨其抗HIV-1感染的机制.方法 HIV-1毒株感染人巨噬细胞前用IFN-λ处理细胞24 h,感染后第4天、第8天以及第12天分别检测感染细胞上清中HIV-1逆转录酶(RT)活性和p24蛋白水平,并用实时定量PCR检测细胞上IFN-λ受体、CD4、CCR5、CXCR4的表达.结果 IFN-λ对HIV-1感染人巨噬细胞具有明显抑制作用,且此作用与其剂量及作用时间呈正相关.但IFN-λ对CD4、CCR5、CXCR4的表达影响无统计学意义.结论 IFN-λ能有效抑制HIV-1感染人口噬细胞,并证实这一作用是通过其受体发挥功能的.但IFN-λ介导的抗HIV-1作用不是通过CIM、CCR5、CXCR4起作用而是存在有其他的抗病毒机制.     

HIV/AIDS患者NK细胞趋化因子受体表达研究

目的:探讨中国HIV/AIDS患者NK细胞表面趋化因子受体CXCR4、CCR5表达情况。方法:采用流式细胞仪分析HIV/AIDS患者外周血NK细胞表面趋化因子受体CCR5和CXCR4的表达。结果:未治疗典型HIV/AIDS患者NK细胞表面趋化因子受体CXCR4和CCR5与正常对照无显著差异(P >0 0 5 ) ,HIV长期不进展者NK细胞CCR5受体低于未治疗的典型HIV/AIDS患者(P <0 0 5 ) ,与正常对照相比无显著差异(P =0 0 5 ) ;HAART治疗组NK细胞趋化因子受体CCR5表达显著低于未治疗典型HIV/AIDS患者(P <0 0 1)。结论:趋化因子受体CCR5在NK细胞上表达的变化与疾病的不同阶段密切相连,对NK趋化因子受体的检测有助于艾滋病疾病进程的研究     

CCR5在慢性乙型肝炎中的研究进展

<正>趋化因子受体5(CCR5)是一类趋化因子受体,它之所以现在受到世界医学界的日益关注,主要由于十几年前它作为HIV的辅助受体之一[1],CCR5基因编码区32 bp片段的缺失(即CCR5Δ32)导致其不表达在T细胞表面,从而能够阻止HIV感染[2]。研究发现CCR5作为一个免疫反应的调节因子受体主要通过调节炎症[3],调整免疫细胞的运动及其功能而发挥重要作用[4-8]。CCR5及其配体能够吸引效应T细胞进入肝脏并且调节炎性细胞分泌的炎性细胞因子如IFN-γ和细胞表面分子Fas L     

Peripheral T cells overexpress MIP-1alpha to enhance its transendothelial migration in Alzheimer's disease

It is unclear how circulating T cells cross the blood-brain barrier (BBB) and participate in the inflammation process in Alzheimer's disease (AD). Here we showed significantly higher macrophage inflammatory protein-1alpha (MIP-1alpha) expression in peripheral T lymphocytes of AD patients than age-matched controls. T cells crossing of the human brain microvascular endothelial cells (HBMECs) which constitute the BBB, were almost completely abrogated by anti-MIP-1alpha antibody. MIP-1alpha induced the expression of CCR5, a potential MIP-1alpha receptor, on HBMECs. HBMECs tranfected with CCR5 resulted in increased T cells transendothelial migration. CCR5 antagonist (2D7 mAb) blocked the T cells transmigration. The MIP-1alpha-CCR5 interaction promoted T cells transendothelial migration via ROCK (Rho kinase). Furthermore, Abeta injection into rats' hippocampus induced MIP-1alpha overexpression accompanied with increased T lymphocytes occurrence in the brain cortex and this enhanced T cells entry was effectively blocked by anti-MIP-1alpha antibody. These data are the first to suggest that the interaction between MIP-1alpha overexpressed by T cells and CCR5 on HBMECs is involved in AD patients' T cells migrating from blood to brain.     

Peripheral T cells derived from Alzheimer's disease patients overexpress CXCR2 contributing to its transendothelial migration, which is microglial TNF-alpha-dependent

The mechanism of circulating T cells entry into the brain in Alzheimer's diseases (AD) remains unclear. Here, we showed that peripheral T cells derived from AD patients overexpress CXCR2 to enhance its transendothelial migration. T cells migration through in vitro blood-brain barrier model was effectively blocked by anti-CXCR2 antibody or IL-8 (a CXCR2 ligand) RNAi in human brain microvascular endothelial cells (HBMECs). Amyloid beta (Abeta) injection in rat hippocampus upregulated CXCR2 expression accompanied with increased T cells occurrence in the brain, and this enhanced T cells entry was effectively blocked by CXCR2 antagonist. Furthermore, anti-TNF-alpha antibody blocked IL-8 production in HBMECs and T cells transendothelial migration caused by the culture supernatant of microglia treated with Abeta. Blockage of intracerebral TNF-alpha abolished the upregulation of CXCR2 in peripheral T cells and the increased T cells occurrence in the brain induced by Abeta injection in rat hippocampus. These data suggest that CXCR2 overexpression in peripheral T cells is intracerebral microglial TNF-alpha-dependent and TNF-alpha primes T cells transendothelial migration in Alzheimer's diseases.     

Chemokines stimulate bidirectional migration of human mesenchymal stem cells across bone marrow endothelial cells

Mesenchymal stem cells (MSCs) can be mobilized from the bone marrow and enter the circulation. Conversely, MSCs can be recruited from the circulation and into the bone marrow. For these migratory pathways, MSCs have to traverse the bone marrow endothelium, in a basal-to-apical and apical-to-basal direction, respectively. Here we describe the migratory cues that drive MSC transendothelial migration in both directions with focus on chemokines. Live cell imaging and electron microscopy were used to examine the interaction of human MSCs with human bone marrow endothelial cells (HBMECs), and MSC transmigration analyzed. Chemokines CXCL12, CXCL13, CXCL16, CCL11, and CCL22 significantly enhanced transendothelial migration in an apical-to-basal and basal-to-apical direction, showing preferences in terms of their capacity to stimulate the direction of migration. For apical-to-basal migration CXCL16 was the most effective (6-fold stimulation), with the rank order being CXCL16>CCL11>CXCL13>CCL22>CXCL12. In the basal-to-apical direction CCL22 was the most effective (5-fold enhancement), with the remaining chemokines being roughly equal. When MSCs interacted with HBMECs they flattened, extended long microvilli (filopodia) and podosome-like protrusions that inserted into the endothelial cells. In conclusion, chemokines enhance the migration of MSCs bidirectionally across HBMECs, with directional preferences shown for different chemokines.     

Expression and modulation of IFN-gamma-inducible chemokines (IP-10, Mig, and I-TAC) in human brain endothelium and astrocytes: possible relevance for the immune invasion of the central nervous system and the pathogenesis of multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) mediated by blood-derived immune cells invading the CNS. This invasion could be determined by chemokines, and their role within the MS-affected brain is still poorly defined. We investigated the expression by RT-PCR and protein release by ELISA of the interferon-gamma (IFN-gamma)-inducible chemokines in human brain microvascular endothelial cells (HBMECs) and astrocytes. The monokine induced by IFN-gamma (Mig) behaves as a homing chemokine constitutively expressed in HBMECs and astrocytes, whereas the IFN-gamma-inducible 10-kDa protein (IP-10) and IFN-inducible T cell alpha-chemoattractant (I-TAC) are induced only after inflammatory stimuli. The biologic activity of IFN-gamma-inducible chemokines from an endothelial source was analyzed, and the transendothelial migration of activated lymphocytes was partly antagonized by specific antibodies, especially anti-Mig antibody. Our data highlight the capability of cells of the CNS to activate the chemoattractant machinery in a proinflammatory environment and in MS.     

趋化因子受体CCR5、CCR7、CXCR3和CXCR6在丙肝患者肝内及外周血CD4+ T淋巴细胞上的表达及其意义

目的比较趋化因子受体CCR5、CCR7、CXCR3和CXCR6在丙肝患者肝内和外周血CD4^＋T淋巴细胞表面表达水平及其意义,同时进一步了解其与肝脏组织学炎症反应的关系.方法采用荧光标记抗趋化因子受体的单克隆抗体对肝内及外周血中CD4^＋T淋巴细胞表面的趋化因子受体进行染色后,采用9色11参数流式细胞仪LSRⅡ进行检测分析.结果（1）肝内CCR5^＋、CXCR3^＋或/和CXCR6^＋的CD4^＋T淋巴细胞频数高于外周血（P＜0.001）,而CCR7^＋CD4^＋T淋巴细胞频数低于外周血（P＜0.001）;（2）肝内CCR5^＋或CXCR6^＋的活性（CD38^＋）CD4^＋T淋巴细胞频数高于外周血（P＜0.05）;（3）肝内表达2种或2种以上趋化因子受体CCR5、CXCR3和CXCR6的CD4^＋T淋巴细胞频数明显高于外周血（P＜0.001）,而不表达或仅表达一种上述趋化因子受体CD4^＋T淋巴细胞频数明显低于外周血（P＜0.001）;（3）CCR5和CXCR6在肝内CD4^＋T淋巴细胞表面的表达有中等度相关;（4）肝内组织学炎症明显组表达趋化因子受体CCR5、CXCR3或CXCR6的CD4^＋T淋巴细胞频数高于炎症轻微组.结论趋化因子受体CCR5、CXCR3和CXCR6可能介导CD4^＋T淋巴细胞向肝内迁徙定植,并参与肝脏炎症的病理免疫学反应过程.     

T cell interaction with ICAM-1-deficient endothelium in vitro: transendothelial migration of different T cell populations is mediated by endothelial ICAM-1 and ICAM-2.

The trafficking of T lymphocytes is carefully regulated by adhesive interactions with the vascular endothelium. Depending on their maturation and activation stage, T lymphocytes exhibit distinctive patterns of homing and recirculation, which is at least partly due to the selective expression of cell adhesion molecules (CAM) on the T cell surface. In order to define whether the differential usage of CAM during the steps of transendothelial migration is involved in organ-specific recirculation of different T cell subsets we compared the interaction of three different T cell populations with mouse endothelioma cell lines in vitro. Using a novel approach, where we directly compared T cell interaction with ICAM-1-deficient endothelium to wild-type endothelium, we recently demonstrated that endothelial ICAM-1 and ICAM-2 play a key role in mediating the transendothelial migration of CD4(+) memory T cells. Here we show that endothelial ICAM-1 and ICAM-2 are equally required for the transendothelial migration of other T cell populations such as thymocytes and T lymphoma cells, which differ from CD4(+) memory T cells in their maturation and activation stage, as well as in their surface expression of adhesion molecules. Our data therefore demonstrate that transendothelial migration of different T cell populations is mediated by the same endothelial CAM, i.e. ICAM-1 and ICAM-2, and thus subset-specific interaction of T cells with endothelial cells must be regulated prior to transendothelial migration.     

Activation of pertussis toxin-sensitive CXCL12 (SDF-1) receptors mediates transendothelial migration of T lymphocytes across lymph node high endothelial cells

In this study we examined the role of chemokines in regulating T lymphocyte transmigration across the lining high endothelial cells (HEC) of high endothelial venules (HEV). The roles played by CCL21 (SLC), CCL19 (MIP-3 beta, ELC) and CXCL12 (SDF-1) were assessed using an in vitro transendothelial migration culture system, which constitutively supports high levels of lymphocyte transmigration. We determined that transmigration of T lymphocytes across HEC is inhibitable by treatment of the T lymphocytes with pertussis toxin (PTX) (80% inhibition). This was attributed to blockade of Gi-protein coupled receptors of T lymphocytes, since a non-ADP-ribosylating form of PTX had no significant effect on transendothelial migration. Inhibition of Gi-protein-coupled receptors on the endothelium had no effect on T cell transmigration. Treatment of T lymphocytes with a desensitizing concentration of CXCL12 caused a 60% reduction in T lymphocyte migration across HEC, and the CXCR4 antagonist SDF-1P2G reduced transmigration by 40%. Desensitizing concentrations of CCL21 and CCL19 had no significant effects on T lymphocyte transendothelial migration. Homologous desensitization of T lymphocytes to each chemokine was confirmed in a transwell migration assay. An approximately 3-kb mRNA corresponding to rat SDF-1 beta was constitutively expressed in HEC and cell surface CXCL12 was detectable by enzyme-linked immunosorbent assay. Together, these findings support a pivotal role for HEC-expressed CXCL12 and its receptor on T cells in the regulation of T lymphocyte homing to lymph nodes.     

HIV/AIDS患者CCR5、CXCR4的表达与疾病进展的关系

目的　了解HIV AIDS患者淋巴细胞表面第二受体CCR5、CXCR4的表达 ,分析其与疾病进展的关系 ,探讨HIV感染的免疫基础。方法　收集 33例HIV AIDS患者及 13例健康对照的抗凝全血 ,用流式细胞仪检测第二受体CCR5、CXCR4的表达 ,并分析第二受体表达与病毒载量、CD4 + T淋巴细胞绝对值及T淋巴细胞活化 (HLA DR+ CD38+ )的相关性。结果　艾滋病组CD4 + 、CD8+ T淋巴细胞表面CCR5表达高于无症状HIV 1感染组及健康对照 (P <0 .0 0 1) ;艾滋病组CD8+ T淋巴细胞表面CXCR4表达低于健康对照 (P <0 .0 1)。HIV AIDS患者CD4 + 、CD8+ T淋巴细胞表面CCR5的表达与病毒载量明显正相关 (P <0 .0 1) ;与CD4 + T淋巴细胞绝对值明显负相关 (P <0 .0 1) ,与T淋巴细胞活化(HLA DR+ CD38+ )水平明显正相关 (P <0 .0 0 1)。结论　HIV 1感染者第二受体CCR5的表达与机体对HIV的免疫反应及疾病进展密切相关。     

Involvement of CCR5 in the passage of Th1-type cells across the blood-retina barrier in experimental autoimmune uveitis

Although the recruitment of T helper cell type 1 (Th1)/Th2 cells into peripheral tissues is essential for inflammation and the host response to infection, the traffic signals that enable the distinct positioning of Th1/Th2 cells are unclear. We have determined the role of CC chemokine receptor 5 (CCR5) in this using experimental autoimmune uveitis (EAU) as a model system. In EAU, Th1-like cells are preferentially recruited into the retina across the blood-retina barrier, partly as a result of expression of the adhesion molecules P-selectin glycoprotein ligand 1 and lymphocyte function-associated antigen-1 on these cells. CD3+ T cells, infiltrating the retina, also expressed the chemokine receptor CCR5, and CCR5 ligands, macrophage-inflammatory protein-1alpha (MIP-1alpha), MIP-1beta, and regulated on activation, normal T expressed and secreted (RANTES), were strongly expressed in the retina at peak EAU. Th1-like cells, polarized in vitro, expressed high levels of CCR5. The trafficking of these CCR5+ cells was examined by tracking them after adoptive transfer in real time in vivo at an early disease stage using scanning laser ophthalmoscopy. Treatment of the cells with antibody against CCR5 prior to transfer resulted in a reduction in their infiltration into the retina. However, rolling velocity, rolling efficiency, and adherence of the cells to retinal endothelium were not reduced. CCR5 is clearly important for Th1 cell recruitment, and this study demonstrates for the first time in vivo that CCR5 may act at the level of transendothelial migration rather than at the earlier stage of rolling on the endothelium.