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。     

早、中、晚孕期胎盘因子体外抗HIV-1的研究

目的 探讨早、中、晚孕期胎盘因子(PF)体外抗人免疫缺陷病毒-1(HIV-1)及在HIV-1垂直传播中的作用.方法 荧光染料Calcien-AM标记的H9/HIV-1ⅢB分别与早、中、晚孕期不同稀释浓度的PF作用后,与MT2细胞培养,荧光显微镜下观察合胞休的形成;用HIV-1ⅢB感染MT2细胞,并分别与早、中、晚孕期不同稀释浓度的PF作用后,用MTT法检测HIV-1感染细胞的存活率,用ELISA方法检测细胞培养上清中p24抗原水平.结果 各孕期PF并不能抑制MT2和H9/HIV-1ⅢB细胞的融合,但可以增加HIV-1感染细胞的存活率及减少HIV-1 p24抗原的表达,且效应以早孕期PF最大,中孕期PF其次晚孕期PF最小,并与剂量呈正相关.结论 PF在体外具有抗HIV-I的作用,并呈现孕期和剂量相关性,可能在阻断HIV-1垂直传播中具有一定作用.     

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。     

趋化因子受体CXCR4及CCR5真核表达载体的构建及其在卵巢癌细胞中的表达

目的:构建人CXCR4及CCR5真核表达重组质粒,转染人卵巢癌细胞SKOV3,建立稳定转染细胞系并观察其表达效果。方法:从人外周血单个核细胞中提取RNA,采用反转录PCR技术扩增CXCR4及CCR5的基因编码序列,将序列克隆至真核表达载体pEGFP,经酶切和测序鉴定后,应用脂质体转染技术将质粒cancer.pEGFP-CXCR4和pEGFP-CCR5分别导入不表达CXCR4及CCR5蛋白的SKOV3细胞,经G418抗性筛选得到阳性细胞克隆并扩大培养成系。分别采用免疫荧光染色和流式细胞术方法(FCM)检测稳定转染细胞株CXCR4和CCR5的表达。结果:构建了真核表达载体pEG-FP-CXCR4和pEGFP-CCR5;得到了抗G418阳性细胞克隆;免疫荧光染色和FCM检测结果显示,转染质粒的SKOV3细胞表达CXCR4和CCR5。结论:成功建立稳定表达趋化因子受体CXCR4和CCR5的卵巢癌细胞株,为CXCR4和CCR5在卵巢癌中的研究工作提供依据及平台。     

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.     

传染性单核细胞增多症外周血白细胞CCR5和CD30的表达

传染性单核细胞增多症 (IM )患者感染EB病毒后的免疫病理改变与Th1/Th2免疫应答的失衡有着密切的关系。但由于缺乏特异性高且操作简便的Th1、Th2细胞标志物 ,长期以来 ,这方面的研究仅基于测定其所代表的细胞因子含量上。由于细胞因子是以网络形式存在 ,影响其分泌的因素诸多 ,仅从Th分泌的细胞因子分析Th1/Th2功能有一定的局限性。近发现 ,CCR5、CD30分别为Th1、Th2细胞特异表达 ,且与激活Th1、Th2密切相关 ,因此可作为其相应的表面标记物[1,2 ] 。为了阐明Th1、Th2细胞在IM早期的作用 ,我们采用流式细胞检测仪检测患者PBMC中C…     

风湿性关节炎患者T细胞表达CCR5和CXCR3的三色流式细胞分析

目的 在单细胞水平上，研究类风湿性关节炎（RA）患者滑液及外周血中T淋巴细胞上CCR5及CXCR3的表达，并结合临床资料分析其在RA发病中的可能作用机制及临床应用。方法 分离15例RA患者的滑液单个核细胞（SFMC）、外周血单个核细胞（PBMC），及15正常人PBMC（对照），以三色荧光素标记物进行流式细胞术分析T细胞上CCR5及CXCR3的表达。结果 与PBMC相比较，RA患者SFMC中T细胞上CCR5及CXCR3的表达显著增高（特别是CCR5）；而CXCR3的表达个体差异较大；与正常人相比较，RA患者初发或活动期未治时，PBMC中CCR5及CXCR3的表达明显增多。CCR5及CXCR3的表达率与患者的ESR及CRP相关。结论 CCR5^ T细胞积聚在RA患者的病变关节内，且与RA的病情密切相关。     

CCR5△32、CCR5m303、CCR2-64I、SDF1-3''A基因多态性对中国HIV-1感染者预后的影响

目的研究CCR5A32、CCR5m303、CCR2-64I、SDF1—3’A基因多态性对中国HIV-1感染者预后的影响。方法对在深圳地区发现的HIV-1感染者进行流行病学调查，应用PCR／RFLP技术分析感染者CCR5G32、CCR5m303、CCR2-64I、SDF1-3’A4种基因的多态性，对部分人群进行HIV-1血浆病毒载量和CD4^＋细胞计数的检测，判断感染者的潜伏期，使用SPSS11．0统计软件分析基因多态性对感染者病毒载量和潜伏期的影响。结果在189例HIV-1感染者中没有发现CCR5A32和CCR5-m303突变基因型，SDF1—3’A的等位基因频率为26．14％，CCR2—64I的等位基因频率为19．82％。方差分析发现，CCR2-64I基因野生型与杂合型的两组HIV-1感染者人群病毒载量对数的大小差异无统计学意义（P=0．272），两组人群潜伏期的长短差异无统计学意义（P=0．662）。SDF1基因野牛型、杂合型和纯合型的3组HIV-1感染者人群病毒载量对数的大小差异有统计学意义（P=0．001），但3组人群潜伏期的长短差异无统计学意义（P=0．228）。结论CCR2-64I基因突变对中国汉族HIV-1感染者病毒载量没有明显影响，因而也不影响感染者的潜伏期。SDF1-3’A基因突变对于病毒载量有降低作用，但对延长感染者潜伏期可能没有作用。     

SLE患者外周血中CD4~+CXCR5~+T细胞表达ICOS和PD1的相关性研究

本研究检测ICOS、PD-1在SLE患者外周血CD4+CXCR5+T细胞上的表达水平并分析其与SLE临床特征的相关性。采用流式细胞仪检测60例SLE患者及40例健康对照组外周血中CD4+CXCR5+T细胞占CD4+T细胞的比例,同时检测CD4+CXCR5+T细胞上ICOS、PD-1的表达水平,并分析其与SLE疾病活动指数(SLEDAI)、SLE肾脏损害及临床指标之间的相关性。结果显示,SLE患者外周血中CD4+ICOShighT细胞、CD4+ICOShighCXCR5+T细胞、CD4+PD1highCXCR5+T细胞比例显著高于健康对照组(P0.05);CD4+ICOShighCXCR5+T细胞比例与SLE患者的抗dsDNA抗体水平呈正相关(P0.05),与SLEDAI评分、免疫球蛋白、C3、C4、ESR、CRP无相关性(P均0.05);SLE患者血清IL-21水平较健康对照组显著升高(P0.05)。提示,循环外周血中生物标志分子高表达的CD4+CXCR5+T细胞异常,可能参与SLE的发病。     

CCR5Delta32基因在人PBMC的表达及其对CCR5/CXCR4分子的影响

目的:在人外周血单个核细胞(PBMC)内表达CCR5Delta32蛋白, 研究该蛋白与CCR5和CXCR4分子间是否存在相互作用.方法:构建pLenti-CCR5Delta32慢病毒载体, 包装后产生重组慢病毒.将其转染PBMC, 荧光显微镜观察转染情况, Western blot鉴定目的蛋白表达, 免疫共沉淀检测目的蛋白与CCR5和CXCR4分子间的相互作用.结果:成功构建了pLenti-CCR5Delta32慢病毒载体, 经包装后产生重组慢病毒, 滴度约为5×108 TU/L.将其转染PBMC, 观察到约半数PBMC胞质内有绿色荧光蛋白表达, 经Western blot鉴定有目的蛋白表达.免疫共沉淀结果显示, CCR5Delta32与CCR5、 CCR5Delta32与CXCR4以异源二聚体形式结合, 之间确实存在着相互作用.结论:成功地构建重组慢病毒载体并将其转染PBMC靶细胞, 观察到目的蛋白与HIV-1两类辅受体(CCR5和CXCR4)间确实存在相互作用.这些工作为后续的AIDS基因治疗研究奠定了基础.     

Constrained use of CCR5 on CD4+ lymphocytes by R5X4 HIV-1: Efficiency of Env-CCR5 interactions and low CCR5 expression determine a range of restricted CCR5-mediated entry

R5X4 HIV-1 has impaired utilization of CCR5 on primary CD4+ lymphocytes but the mechanisms responsible are not well defined. Using a panel of diverse R5X4 Envs we identified a spectrum of CCR5 use on CD4+ lymphocytes. Greater lymphocyte CCR5 use correlated with relative resistance to CCR5 mAbs and small molecule antagonists. Increasing CCR5 expression on lymphocytes increased the proportion of entry mediated by CCR5 for all R5X4 isolates except 89.6. In cell lines with regulated CCR5 expression, strains with greater lymphocyte CCR5 use better exploited limiting levels of CCR5. Introduction of an R306S mutation in the 89.6 V3 domain enhanced its utilization of CCR5 at low levels and switched its preference to CCR5 for lymphocyte entry. Thus, the degree to which R5X4 HIV-1 use primary lymphocyte CCR5 is determined by low CCR5 expression coupled with variations in the efficiency of Env-CCR5 interactions, which is in part governed by V3 sequences.     

Effective activation alleviates the replication block of CCR5-tropic HIV-1 in chimpanzee CD4+ lymphocytes

Human immunodeficiency virus type 1 (HIV-1) originated in chimpanzees; yet, several previous studies have shown that primary HIV-1 isolates replicate poorly in chimpanzee CD4+ T lymphocytes in vitro and in vivo. The reasons for this apparent restriction are not understood. Here, we describe a new activation protocol that led to a reproducible expansion and activation of chimpanzee CD4+ T lymphocytes in vitro. Using this protocol, we uncovered species-specific differences in the activation profiles of human and chimpanzee CD4+ T-cells, including HLA-DR and CD62L. Moreover, we found that improved activation facilitated the replication of both CXCR4 and CCR5-tropic HIV-1 in CD4+ T-cell cultures from over 30 different chimpanzees. Thus, the previously reported “replication block” of CCR5-tropic HIV-1 in chimpanzee lymphocytes appears to be due, at least in large part, to suboptimal T-cell activation.     

Influence of nucleotide polymorphisms in the CCR2 gene and the CCR5 promoter on the expression of cell surface CCR5 and CXCR4

Polymorphisms in the CCR2 gene (CCR2-64I) and the CCR5 promoter (pCCR5-59029G) have been correlated with slower HIV-1 disease progression. How these polymorphisms influence the rate of AIDS progression has remained unclear. We have therefore investigated whether these nucleotide polymorphisms will reduce the expression levels of surface CCR5 and CXCR4, and thus lead to slower AIDS progression. For this, a cohort of Chinese volunteers in Taiwan was subjected to the determination of CCR2 and pCCR5 genotypes followed by analysis of the surface CCR5 and CXCR4 expression on five cell types derived from peripheral blood mononuclear cells by flow cytometry. Several significant associations were detected between genotypes and expression levels of the proteins. The most important finding was that an increased number of CD4(+) cells expressing CCR5 correlated with pCCR5-59029A homozygosity without the interference of both the CCR2-64 and the CCR5 delta 32 (deleted 32 bp) mutations (P: = 0.0453), which is consistent with the previous data on the association of the genotype to AIDS progression. Since different genetic polymorphisms co-exist in human beings, the rate of AIDS progression as well as the risk of rheumatoid arthritis may be governed by the interplay of the array of nucleotide changes and their affected proteins.     

Distribution of the Human Immunodeficiency Virus Coreceptors CXCR4 and CCR5 on Leukocytes of Persons with Human Immunodeficiency Virus Type 1 Infection and Pulmonary Tuberculosis: Implications for Pathogenesis

Expression of CXCR4 was significantly reduced from normal on all cell subsets of persons with pulmonary tuberculosis (TB group), with HIV-1 infection (HIV group), and those with both infections (HIV/TB group), except for on monocytes in the HIV group. The reductions were most notable in the two TB groups. Interestingly, the duration of antituberculosis treatment was significantly negatively correlated with the expression of CXCR4 on CD4⁺ and CD8⁺CD45RO⁺ cells, monocytes and NK cells, viral load, and proportions of CD38-expressing CD8⁺ lymphocytes, in HIV/TB patients. By contrast, CCR5 expression on most cell subsets analyzed was increased in all the disease groups, except for on monocytes in the two TB groups. There was no change in CCR5 expression on CD4⁺ cells when based on the disease groupings. However, higher proportions of CD4⁺CD45RA⁺ and CD8⁺ lymphocytes as well as B cells expressing CCR5 correlated with advancing HIV-1 disease, as did decreased proportions of CXCR4-expressing CD4⁺CD45RA⁺ cells.     

Replicative fitness of CCR5-using and CXCR4-using human immunodeficiency virus type 1 biological clones

CCR5-tropic viruses cause the vast majority of new HIV-1 infections while about half of the individuals infected with HIV-1 manifest a co-receptor switch (CCR5 (R5) to CXCR4 (X4)) prior to accelerated disease progression. The underlying biological mechanisms of X4 outgrowth in AIDS patients are still poorly understood. Although X4 viruses have been associated with increased "virulence" in vivo, in vitro replication and cytopathicity studies of X4 and R5 viruses have led to conflicting conclusions. We studied the replicative fitness of HIV-1 biological clones with different co-receptor tropism, isolated from four AIDS patients. On average, R5 and X4 clones replicated equally well in mitogen-activated T cells. In contrast, X4 variants were transferred more efficiently from dendritic cells to autologous CD4+ T cells. These observations suggest that interaction between X4 viruses, DC and T cells might contribute to the preferential outgrowth of X4 viruses in AIDS patients.     

Graves' disease is associated with an altered CXCR3 and CCR5 expression in thyroid-derived compared to peripheral blood lymphocytes

The mechanisms by which T cells accumulate in the thyroid and support the autoimmune process in patients with Graves' disease (GD) are poorly understood. Chemokines and their receptors may be involved in this process. We have analysed the expression of CXCR3 and CCR5 as Th1-specific chemokine receptors, CCR3 as a marker for Th2 cells, CXCR4 (expressed on unprimed, naive T cells) and CCR2 (known to be involved in autoimmunity) on peripheral blood (PBL) and thyroid-derived lymphocytes (TL) using flow cytometry. Chemokine receptor expression on PBL of GD patients (n = 16) did not differ from that of normal controls (n = 10). In GD, CXCR3+ (67.3 +/- 4.0% versus 45.7 +/- 2.1%) and CCR5+ T cells (42.5 +/- 3.4% versus 18.8 +/- 2.1%) showed a significant enrichment in the TL compared to PBL. The positive cells were contributed mainly by the CD4+CD45R0+ subset. TL are mostly primed CD45R0+ T cells, but surprisingly, they had significantly higher levels of CXCR4+ cells among TL (96.2 +/- 1.0%) compared to PBL (66.8 +/- 4.2%). However, CXCR4 has been induced during in vitro isolation of TL. There was no correlation between chemokine receptors and the level of TSH-receptor and thyroid peroxidase autoantibodies. CCR3+ and CCR2+ cells remained unchanged in TL compared to PBL. We could confirm the results using RT PCR and immunohistology. In summary, TL showed a different chemokine receptor pattern compared to PBL from the same patient. This indicates a role for CXCR3 and CCR5 in the recruitment of T cells to the thyroid in GD.     

Prevalence of CXCR4-tropic viruses in clustered transmission chains at the time of primary HIV-1 infection

During 2003–2010, 555 strains isolated from sexually-infected patients at the time of primary HIV-1 infection (PHI) were characterized. Tree topology revealed that 11.7% of PHIs segregated into transmission clusters. CXCR4-usage was identified in 27 strains (4.9%) and was significantly associated with subtype B (p 0.003) and low CD4 cell count (p 0.01). In clustered and unique PHIs, the prevalence of CXCR4-tropic strains was 1.5% and 5.3%, respectively (p 0.35). Our results are in line with the hypothesis of a mucosal bottleneck contributing to the high prevalence of CCR5 variants during PHI.     

Comparison of in vivo and in vitro evolution of CCR5 to CXCR4 coreceptor use of primary human immunodeficiency virus type 1 variants

During the course of at least 50% of HIV-1 subtype B infections, CCR5-using (R5) viruses evolve towards a CXCR4-using phenotype. To gain insight in the transition from CCR5 to CXCR4 coreceptor use, we investigated whether acquisition of CXCR4 use in vitro of R5 viruses from four patients resembled this process in vivo. R5 variants from only one patient acquired CXCR4 use in vitro. These variants had envelopes with higher V3 charge and higher number of potential N-linked glycosylation sites when compared to R5 variants that failed to gain CXCR4 use in vitro. In this patient, acquisition of CXCR4 use in vitro and in vivo was associated with multiple mutational patterns not necessarily involving the V3 region. However, changes at specific V3 positions were prerequisite for persistence of CXCR4-using variants in vivo, suggesting that positive selection targeting the V3 loop is required for emergence of CXCR4-using variants during natural disease course.     

Increased CCR5 and CXCR4 expression in Ethiopians living in Israel: environmental and constitutive factors.

HIV coreceptors play a major role in determining susceptibility and HIV cell tropism. The present work studied whether the high expression of these coreceptors found on lymphocytes and monocytes of Ethiopian immigrants to Israel (ETH) is the result of environmental and/or constitutive genetic factors. The study of 26 ETH shortly after their arrival to Israel (new ETH), 22 ETH in Israel over 7 years (old ETH), and 20 Caucasian Israelis (non-ETH) enabled us to address this issue. The new ETH had elevated levels of activated HLA-DR+CD4+ and CD38+CD8+ cells in comparison with both old ETH and non-ETH groups (P < 0.01), most probably related to chronic helminthic infections. Surface CCR5 expression, i.e., the percentage of CCR5+ cells and the number of CCR5 molecules/cell, was higher (2- to 3- and 8- to 31-fold, respectively) in activated than in nonactivated CD4+ cells, in all groups. However, CCR5 expression, in both activated and nonactivated CD4+ cells, was higher in both ETH groups than in the non-ETH group. CXCR4 expression was higher in nonactivated CD4+ cells in all groups and was also higher in both ETH groups, in both activated and nonactivated CD4+ cells, than in the non-ETH group. These findings suggest that constitutive factors, in addition to immune activation caused by environmental factors, account for the elevated expression of CCR5 and CXCR4 on CD4+ cells of ETH. This increased HIV coreceptor expression may make ETH more susceptible to HIV infection and may account in part for the rapid spread of AIDS in Ethiopia and the rest of Africa as well.