ConA刺激对CD4+CD25+调节性T细胞趋化特性及其表面趋化因子受体CCR4/CCR6表达的影响

目的：体外动态观察ConA激活的调节性T细胞表面趋化因子受体的表达变化及其趋化特性，为利用调节性T细胞诱导免疫耐受提供线索。方法：①流式细胞仪分选出CD4hiCD12710CD25 hiint细胞。②纯化的调节性T细胞与CD4^＋CD25一T细胞分别用ConA（10Fg／m1）刺激0、24和48小时后，用趋化因子CCL1、CCI5、CCL20、CCI_22做趋化实验，观察各趋化因子作用下调节性T细胞与CD4^＋CD25-T细胞的趋化特性。同时，流式细胞仪检测CCR4与CCR6的表达。结果：①分离得到的调节性T细胞纯度为97．4％，活细胞率为95％，得率：4．1％。②CCL1、CCL20、CCL22均可趋化调节性T细胞，且在ConA激活后趋化效率随时间而改变。CCL1与CCL22对调节性T细胞的趋化指数显著高于CD4^＋CD25^-T细胞；CCL20对调节性T细胞和CD4^＋CD25-T细胞趋化指数都很高；CCL5对调节性T细胞趋化性则显著弱于CD4^＋CD25^-T细胞。③ConA刺激后，调节性T细胞趋化因子受体CCR4、CCR6的表达均明显高于对照组细胞（CD4^＋CD25^-细胞）。随着ConA刺激时间延长，两组细胞CCR4的表达均持续增强；两组细胞CCR6的表达均在刺激24小时后表达明显增强，48小时后CCR6的表达略有减弱，呈下降趋势。结论：①磁珠阴性分选结合流式细胞仪技术可分选出较高纯度及活率的调节性T细胞。②调节性T细胞与CD4^＋CD25^-T细胞相比，二者具有不同的趋化特性。CCL1对调节性T细胞的趋化作用较特异，CCL-22趋化作用较强，CCL5趋化作用较弱。而CCL20对CD4^＋CD25-T细胞和调节性T细胞趋化作用都强。③ConA刺激后48小时内趋化因子CCLl、CCL20、CCL-22对调节性T细胞的趋化作用随刺激时间而增强。④ConA刺激可以增强受体CCR4、CCR6表达。⑤提示趋化因子受体的表达与细胞活化状态有关，且不同受体表达变化趋势不同。     

ConA刺激对CD4~+CD25~+调节性T细胞趋化特性及其表面趋化因子受体CCR4/CCR6表达的影响

目的体外动态观察ConA激活的调节性T细胞表面趋化因子受体的表达变化及其趋化特性,为利用调节性T细胞诱导免疫耐受提供线索。方法常规分离正常健康人外周血单个核细胞,免疫磁珠阴性分选CD4+T细胞;加FITC-An-tiCD4抗体,APC-AntiCD25抗体,PE-AntiCD127抗体上流式细胞仪分选出CD4hiCD127loCD25hi-int细胞。纯化的调节性T细胞与CD4+CD25-T分别用ConA(10μg/mL)刺激0、24、48h后,用趋化因子CCL1、CCL5、CCL20、CCL22做趋化实验,观察各趋化因子作用下调节性T细胞与CD4+CD25-T细胞的趋化特性。同时,流式细胞仪检测CCR4与CCR6的表达。结果分离得到的调节性T细胞纯度为97.4%,活细胞率为95%,得率:4.1%。CCL1、CCL20、CCL22均可趋化调节性T细胞,且在ConA激活后趋化效率随时间而改变。CCL1与CCL22对调节性T细胞的趋化指数显著高于CD4+CD25-T细胞;CCL20对调节性T细胞和CD4+CD25-T细胞趋化指数都很高;CCL5对调节性T细胞趋化性则显著弱于CD4+CD25-T细胞。ConA刺激后...     

趋化因子受体CCR5在病毒性肝炎患者PBMC中的表达

Ｌｏｃａｔｉ等[1] 报道外周血单个核细胞中的细胞因子趋化因子受体 5 (ＣＣＲ5 )的表达与ＨＩＶ的感染有一定的关系 ,且与激活的Ｔｈ1和Ｔｃ1细胞密切相关。本文用流式细胞仪对病毒性肝炎患者外周血单个核细胞 (ＰＢＭＣ )ＣＣＲ5的表达水平进行了检测 ,部分作了细胞培养前后的检测。籍以了解病毒性肝炎患者体内的ＣＣＲ5的表达状况 ,同时探讨ＣＣＲ5在病毒性肝炎发病机制中的作用。1　材料与方法1 1　研究对象　依据 1995北京传染病学与寄生虫学会制定的诊断标准确诊的乙型肝炎 (ＨＢ )患者 2 0例 ,另选健康者 2 0例以资对照 (ＮＣ )。1 2…     

趋化因子受体CCR5及CXCR4在HIV-1感染中的作用

趋化因子(chemokines)是一类具有趋化作用的小分子肤,其受体CCR5和CXCR4在HIV-1病毒进人免疫细胞过程中起重要作用.趋化因子结合到含有7个疏水跨膜螺旋的G蛋白偶联的受体超家族,通过一定的信号传导途径引起生理效应,包括趋化作用、免疫调节、抗病毒免疫、调节造血与血管生成以及参与细胞生长和代谢.     

HIV-1协同受体CXCR4、CCR5及相关趋化因子SDF-1在胎盘的表达

目的：研究HIV-1协同受体CXCR4、CCR5及CXCR4的特异性配体SDF-1在人胎盘组织的表达，探索HIV-1子宫内垂直传播的分子机制。方法：半定量RT-PCR检测早、中、晚孕期胎盘及早孕滋养细胞CXCR4、CCR5 mRNA水平；免疫组化和免疫细胞化学检测早孕胎盘及原代培养滋养细胞CXCR4、CCR5蛋白表达；原位杂交及免疫组化分析SDF-1在早孕胎盘的表达；ELISA测定滋养细胞SDF-1的动态分泌水平。结果：各孕期胎盘表达CXCR4及CCR5 mRNA；CXCR4蛋白定位于滋养细胞，而CCR5蛋白定位于绒毛基质中。滋养细胞可转录并翻译SDF-1，且能分泌可溶性SDF-1。结论：滋养细胞同时表达CXCR4及SDF-1，SDF-1可能通过降调CXCR4而拮抗X4-HIV-1感染胎儿细胞；R5-HIV-1或许能通过滋养层裂隙感染CCR5^#基质细胞和/或Hotbauer细胞，从而发生子宫内垂直传播。     

趋化因子受体CXCR4在人肺癌高转移细胞株的表达和意义

目的：以人肺癌高、低转移细胞株95D、95C为研究对象，研究趋化因子受体CXCR4的表达及其在肿瘤细胞体外转移潜能中的作用和意义。方法：采用RT-PCR检测95D、95C细胞CXCR4 mRNA的表达情况；以PMA活化肿瘤细胞，研究CXCR4 mRNA表达水平与细胞活性状态的关系；应用钙离子内流实验验证其表达是否具有功能；通过趋化实验观察CXCR4特异性配件SDF-α和裸鼠组织匀浆液对95D细胞的趋化迁移作用；通过MTT法测定95D细胞对SDF-1α作用的增殖反应。结果：95D细胞功能性地高表达趋化因子受体CXCR4，且其表达水平与细胞活性状态有关；CXCR4特异性配件SDF-1α和裸鼠肺、淋巴结组织匀浆均可在体外趋化95D细胞的迁移，SDF-1α还可促进95D细胞的增殖。结论：95D细胞功能性高表达趋化因子受体CXCR4可能与人肺癌细胞株95D的体外高转移潜能有关。     

人趋化因子受体CCR6在HEK293细胞内的稳定表达及其功能分析

目的:构建稳定表达人趋化因子受体6(CCR6)的HEK293细胞株。方法:将CCR6基因和Gα16质粒共转到HEK293细胞中,并挑取稳定表达CCR6基因的HEK293细胞克隆。采用体外趋化实验、钙流实验、RT-PCR、Western blot及免疫荧光染色法,检测CCR6在HEK293细胞表面的表达。结果:经上述实验证实,CCR6基因和Gα16质粒共转染的HEK293细胞上,可稳定表达CCR6,且具有生物学活性。结论:成功地在HEK293细胞表面稳定表达具有生物学活性的CCR6,为研究CCR6的生物学功能及筛选CCR6的拮抗剂奠定了基础。     

CD4~+CD25~+调节性T细胞活化对CCR4/CCR5膜表达及功能的影响

目的探讨CD3/CD28抗体包被磁珠刺激活化的小鼠CD4+CD25+调节T细胞(Treg)表面趋化因子受体CCR4/CCR5表达及免疫抑制功能变化。方法采用磁性激活细胞分离器(MACS)纯化C57BL/6小鼠脾细胞中的CD4+CD25+T细胞,采用CD3/CD28抗体包被磁珠与鼠重组白细胞介素2刺激0、2、4 d后,流式细胞仪检测CCR4与CCR5的表达,3H-TdR掺入法检测细胞增殖活性。结果活化的CD4+CD25+T细胞CCR4的表达率明显高于CD4+CD25-T细胞对照组,CCR5的表达率明显低于对照组细胞。CD4+CD25+调节T细胞CCR4、CCR5的表达随活化时间延长持续增强,CD4+CD25-T细胞CCR5表达则逐渐减弱、CCR4表达无显著变化。活化的CD4+CD25+T细胞可明显抑制CD4+CD25-T细胞增殖,当比值为1∶1时抑制率达88.4%。结论 CD3/CD28抗体包被磁珠刺激可以增强CD4+CD25+T细胞膜表面CCR4、CCR5表达;活化CD4+CD25+T细胞免疫抑制功能强于新鲜分离的CD4+CD25+T细胞。     

糖皮质激素治疗对ITP患者外周血趋化因子受体CCR3、CCR5、CXCR3表达的影响

原发免疫性血小板减少症(primary immune thrombocytopenia,ITP)是临床最常见的自身免疫性出血性疾病[1-2].研究证明,慢性ITP是一种以Th1细胞异常聚集为特征的Th1优势性自身免疫性疾病[3-4].Th1和Th2细胞分别表达不同的趋化因子受体,并与不同的趋化因子结合,其中Th1细胞优...     

Differential roles for CXCR3 in CD4+ and CD8+ T cell trafficking following viral infection of the CNS

Lymphocyte infiltration into the central nervous system (CNS) following viral infection represents an important component of host defense and is required for control of viral replication. However, the mechanisms governing inflammation in response to viral infection of the CNS are not well understood. Following intracranial (i.c.) infection of susceptible mice with mouse hepatitis virus (MHV), mice develop an acute encephalomyelitis followed by a chronic demyelinating disease. The CXC chemokine ligand 10 (CXCL10) is expressed following MHV infection and signals T cells to migrate into the CNS. The functional contribution of the CXCL10 receptor CXCR3 in host defense and disease in response to MHV infection was evaluated. The majority of CD4+ and CD8+ T cells infiltrating the CNS following MHV infection express CXCR3. Administration of anti-CXCR3 antibody reduced CD4+ T cell infiltration (p相似文献   

Expression of chemokine receptors CXCR4, CXCR5 and CCR7 on B and T lymphocytes from patients with primary antibody deficiency

The interaction of chemokines and their receptors directs lymphocyte migration, and is involved in the distribution and organization of lymphocytes within lymphoid tissues. We reasoned that abnormal chemokine receptor expression might give rise to defects of lymphocyte migration into and within lymphoid tissues, and consequently be associated with defective antibody production in primary antibody deficiencies. In this study, we have investigated the expression of chemokine receptors CXCR4, CXCR5 and CCR7 on lymphocyte subpopulations (naive and memory B cells; CD4⁺ and CD8⁺ T cells) in a cohort of patients with primary antibody deficiency (n = 23), and compared these with a group of healthy controls (n = 19). We show that there were significant differences in both the proportions of lymphocytes expressing, and the levels of expression of, specific chemokine receptors on individual lymphocyte subpopulations between patients and controls. Furthermore, these changes appeared more pronounced in patients with more severe antibody deficiency. These data support the hypothesis that abnormal lymphocyte trafficking may be involved in the pathogenesis of primary antibody deficiencies.     

Expression of the chemokine receptors CCR4, CCR5, and CXCR3 by human tissue-infiltrating lymphocytes.

Differential expression of adhesion molecules and chemokine receptors has been useful for identification of peripheral blood memory lymphocyte subsets with distinct tissue and microenvironmental tropisms. Expression of CCR4 by circulating memory CD4(+) lymphocytes is associated with cutaneous and other systemic populations while expression of CCR9 is associated with a small intestine-homing subset. CCR5 and CXCR3 are also expressed by discrete memory CD4(+) populations in blood, as well as by tissue-infiltrating lymphocytes from a number of sites. To characterize the similarities and differences among tissue-infiltrating lymphocytes, and to shed light on the specialization of lymphocyte subsets that mediate inflammation and immune surveillance in particular tissues, we have examined the expression of CCR4, CXCR3, and CCR5 on CD4(+) lymphocytes directly isolated from a wide variety of normal and inflamed tissues. Extra-lymphoid tissues contained only memory lymphocytes, many of which were activated (CD69(+)). As predicted by classical studies, skin lymphocytes were enriched in CLA expression whereas intestinal lymphocytes were enriched in alpha(4)beta(7) expression. CCR4 was expressed at high levels by skin-infiltrating lymphocytes, at lower levels by lung and synovial fluid lymphocytes, but never by intestinal lymphocytes. Only the high CCR4 levels characteristic of skin lymphocytes were associated with robust chemotactic and adhesive responses to TARC, consistent with a selective role for CCR4 in skin lymphocyte homing. In contrast, CXCR3 and CCR5 were present on the majority of lymphocytes from each non-lymphoid tissue examined, suggesting that these receptors are unlikely to determine tissue specificity, but rather, may play a wider role in tissue inflammation.     

Functional analysis of the CC chemokine receptor 5 (CCR5) on virus-specific CD8+ T cells following coronavirus infection of the central nervous system

Intracranial infection of C57BL/6 mice with mouse hepatitis virus (MHV) results in an acute encephalomyelitis followed by a demyelinating disease similar in pathology to the human disease multiple sclerosis (MS). T cells participate in both defense and disease progression following MHV infection. Expression of chemokine receptors on activated T cells is important in allowing these cells to traffic into and accumulate within the central nervous system (CNS) of MHV-infected mice. The present study evaluated the contributions of CCR5 to the activation and trafficking of virus-specific CD8(+) T cells into the MHV-infected CNS mice. Comparable numbers of virus-specific CD8(+) T cells derived from immunized CCR5(+/+) or CCR5(-/-) mice were present within the CNS of MHV-infected RAG1(-/-) mice following adoptive transfer, indicating that CCR5 is not required for trafficking of these cells into the CNS. RAG1(-/-) recipients of CCR5(-/-)-derived CD8(+) T cells exhibited a modest, yet significant (P 相似文献   

Human adult CD34- progenitor cells functionally express the chemokine receptors CCR1, CCR4, CCR7, CXCR5, and CCR10 but not CXCR4

The homing and tissue-specific recruitment of bone marrow-derived progenitor cells is a major issue in stem cell research and therapy. Chemokine biology plays a central role in the homing and trafficking of leukocytes. Here we show functional expression of the chemokine receptors CCR1, CCR4, CCR7, CCR10, and CXCR5 on primary isolates of CD34- mesenchymal progenitor cells as well as immortalized mesenchymal stem cell (MSC) lines. Although mRNA expression of CXCR4 was detected in both primary cells and immortalized clones, the receptor was not expressed on the cell surface. On the basis of this expression profile, the MSC could potentially home to secondary lymphatic organs (CCR7, CXCR5), skin (CCR4, CCR10), small intestine (CCR10), and salivary glands (CCR10). To study tissue-specific homing, murine CD34- MSC lines showing concordant chemokine receptor expression were either transiently labeled with CMFDA, or were stably transfected with green fluorescent protein (GFP) expression plasmids. The MSC were then injected into syngeneic healthy mice, and the distribution of the cells determined. The injected cells efficiently homed to spleen, thymus, and lymph nodes. In addition, cells were found in the mucosa of the small intestine, skin, and salivary gland. No significant recruitment to bone marrow, liver, or kidney was seen. Chemokine biology may play an important role in the homeostasis and potentially tissue recruitment of early adult progenitor cells.     

CCR4 and CXCR3 play different roles in the migration of T cells to inflammation in skin,arthritic joints,and lymph nodes

CCR4 and CXCR3 are expressed on several T‐cell subsets in inflamed tissues, yet their role in tissue‐specific recruitment is unclear. We examined the contributions of CCR4 and CXCR3 to T‐cell recruitment into inflamed joints in collagen‐induced arthritis, antigen‐draining lymph nodes (LNs) and dermal inflammatory sites (poly I:C, LPS, concanavalin A, and delayed type hypersensitivity), using labeled activated T cells from CXCR3^?/?, CCR4^?/?, and WT mice. Both CXCR3 and CCR4 deficiency reduced the development of arthritis, but did not affect Th1‐cell recruitment to the inflamed joints. Accumulation in inflamed LNs was highly CXCR3 dependent. In contrast, CCR4‐deficient Th1 cells had an increased accumulation in these LNs. Migration to all four dermal inflammatory sites by activated Th1 and T cytotoxic cells and memory CD4⁺ T cells was partially CXCR3‐dependent, but Treg‐cell migration was independent of CXCR3. The subset of cells expressing CCR4 has skin‐migrating properties, but CCR4 itself is not required for the migration. Thus, migration into these inflamed tissues is CCR4‐independent, and partially dependent on CXCR3, except for Treg cells, which require neither receptor. CCR4 may therefore affect retention of T cells in different tissues rather than trafficking out of the blood.     

Kinetics and expression patterns of chemokine receptors in human CD4+ T lymphocytes primed by myeloid or plasmacytoid dendritic cells

We investigated the kinetics of expression of 12 chemoattractant receptors as a function of cell division following priming of human naive CD4+ T cells by different populations of dendritic cells (DC) and under conditions favoring Th1 or Th2 differentiation. Two chemokine receptors, CXCR3 and CXCR5, were rapidly up-regulated following T cell activation by either monocyte-derived DC, myeloid DC (mDC) or plasmacytoid DC (pDC). While CXCR5 expression was transient, expression of CXCR3 at advanced cell divisions was dependent on differentiation, being expressed at high levels on Th1 cells. Several other receptors (CCR2, CCR3, CCR4, CCR5, CXCR6 and CRTh2) were acquired progressively as a function of cell division and in a fashion that was influenced by polarizing cytokines. The Th2-associated chemoattractant receptors CRTh2 and CCR3 were up-regulated with slower kinetics compared to the Th1-associated receptors CXCR3 and CXCR6, consistent with a different kinetics and efficiency of polarization. Moreover, CCR4 and CXCR6 were preferentially induced in T cells activated by mDC and pDC, respectively. Finally, CXCR5 and CCR7 were also rapidly and transiently up-regulated in memory T cells following TCR stimulation. These results indicate a complex chemokine receptor regulation dependent on both T cell activation and differentiation state. In addition, they reveal the existence of DC-specific cues for the regulation of T cell migratory capacity.     

The chemokine receptor CXCR3 mediates rapid and shear-resistant adhesion-induction of effector T lymphocytes by the chemokines IP10 and Mig

Integrin-mediated adhesion to the vascular endothelium is an essential step in leukocyte diapedesis. We show that the chemokines 10-kDa inflammatory protein (IP10) and monokine induced by IFN (Mig) induce rapid and transient adhesion of human IL-2-stimulated T lymphocytes (IL-2 T cells) to immobilized integrin ligands through their receptor CXCR3, which is selectively expressed on activated T cells. Induction of adhesion by IP10 and Mig was already observed at subnanomolar concentrations and was maximal at 5 – 10 nM, resulting in three- to sixfold increase in adhesion of IL-2 T cells over background. No effect was seen with resting naive/memory T cells which lack CXCR3 and migration responses to IP10 and Mig. Both chemokines are produced in human umbilical vein endothelial cells (HUVEC) upon stimulation with IFN-γ and TNF-α. These chemokines induce IL-2 T cell adhesion also when captured on the surface of endothelial cells. Under conditions of flow, IL-2 T cells roll and rapidly adhere to IP10/Mig-expressing HUVEC, and anti-CXCR3 mAb treatment reduces arrest and firm adhesion. This is the first study that shows chemokine-induced adhesion in activated memory/effector T cells which represent the fraction of T cells that are selectively mobilized in inflammation. The critical role of IFN-γ as inducer of IP10/Mig production in HUVEC indicates that these chemokines are essential mediators of effector T cell recruitment to IFN-γ-dependent pathologies.     

Hormonal and embryonic regulation of chemokine receptors CXCR1, CXCR4, CCR5 and CCR2B in the human endometrium and the human blastocyst

Chemokines are implicated in the implantation process. The aim of this study was to investigate mRNA expression and protein levels of chemokine receptors CXCR1, CXCR4, CCR5 and CCR2B in human endometrium throughout the menstrual cycle, during HRT and in the human blastocyst. The regulation of chemokine receptors in the endometrial epithelium was also studied using an in-vitro model for the apposition phase of human implantation. We found up-regulation of endometrial CXCR1 mRNA (419-fold increase), CCR5 mRNA (612-fold increase) and CCR2B mRNA (657 fold-increase) during the luteal phase peaking in the pre-menstrual endometrium. CXCR4 mRNA levels presented a specific although modest (18-fold increase) up-regulation during the implantation window. These findings were corroborated at the protein level in natural and HRT cycles. Immunoreactive CCR5 and CCR2B receptors were detected in human blastocysts whereas CXCR4 and CXCR1 were not present. Chemokine receptors in cultured endometrial epithelial cells showed an up-regulation and polarization of CXCR1, CXCR4 and CCR5 receptors when a human blastocyst was present. The specific distribution and regulation of chemokine receptors in the endometrial epithelium and the human blastocyst suggest a possible implication of these receptors in the apposition and adhesion phases of human implantation.