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.     

CCR5-△32突变基因地域和人群分布的研究进展

艾滋病即获得性免疫缺陷综合症(AIDS)对人类健康造成极大威胁。引起该病的病原体是人类免疫缺陷病毒1型(HIV-1)。HIV-1通过与CD4~+受体以及CC趋化因子受体5(CCR5)或CXC趋化因子受体4(CXCR4)辅受体结合而感染细胞,当CCR5发生32个碱基缺失突变时,其在细胞膜的表达量减少,导致HIV-1无法有效地入侵细胞。我们把这种突变的CCR5称为第一外显子缺失32个碱基的CC趋化因子受体5(CCR5-△32)。近年来,通过对CCR5-△32的深入研究, AIDS的治疗获得很大进展。我们主要总结了该基因的结构功能并且详细统计了不同地区不同人群该基因的分布情况,以期对AIDS的治疗提供帮助。     

趋化因子RANTES和SDF-1细胞内共表达抑制HIV-1感染的研究

目的　观察HIV 1辅受体CCR5和CXCR4的配体在细胞内共表达抑制HIV 1感染的作用。方法　应用磷酸钙沉淀法共转染HIV 1辅受体及其配体的质粒 ,制成辅受体表型剔除的靶细胞 ,与转染HIV 1膜蛋白质粒的细胞混合 ,观察合胞体形成并记数 ;脂质体介导法将含有报告基因CAT而缺失HIV包膜蛋白的质粒与HIV包膜蛋白质粒共转染 2 93细胞 ,包装成具有一次感染活性的假病毒 ,感染转化pCMV R K S K、pCMV R K、pCMV S K或pCMV的PM 1细胞 ,采用同位素薄层层析分析法检测CAT活性。结果　pCMV R K S K转染可以显著抑制M及T嗜性HIV膜蛋白诱导的合胞体形成 ;CAT检测发现与pCMV转染组相比 ,当两种嗜性重组病毒感染pCMV R K S K转染组PM 1细胞时 ,仅检测到背景水平的CAT活性。结论　HIV 1辅受体CCR5 CXCR4表型剔除可以明显抑制M和T嗜性HIV 1病毒进入靶细胞     

HIV-1辅助蛋白负性调节因子下调细胞膜表面分子的研究进展

人类免疫缺陷病毒1(HIV-1)感染机体之后,其辅助蛋白负性调节因子(Nef)可以通过其功能不同的结构域,以不同的机制,对靶细胞表面的多种细胞膜分子进行调节,同时增强病毒的感染力和抑制抗体类别转换。这些机制使得HIV-1侵染的靶细胞避免超感染,保证HIV-1在宿主细胞合适而稳定的环境中进行增殖、完成生命周期,从而实现HIV-1在人体内的长期潜伏和免疫逃逸。本文综述了Nef的结构域以及其下调多种靶细胞膜表面分子CD4、MHC-Ⅰ、CC趋化因子受体5(CCR5)、CXC趋化因子受体4(CXCR4)等的机制,以期加深对Nef蛋白功能的理解,为HIV-1的防治提供新的理论线索。     

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。     

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.     

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。     

淋巴细胞HIV-1辅受体表型剔除阻断病毒感染的研究

目的　观察HIV 1辅受体CCR5和CXCR4表型剔除对HIV 1DP1株感染的阻断作用。方法　用含有pLNCX R K S K的重组逆转录病毒液感染原代人PBLs(外周血淋巴细胞 ) ,抗体 免疫磁珠法分离筛选转化成功PBLs,流式细胞仪检测筛选效率 ;HIV 1DP1株攻击转化PBLs ,进行合胞体形成和p2 4抗原分泌检测。结果　抗 NGFR 免疫磁珠法获得了转化成功的PBLs ,流式细胞仪检测发现pLNCX R K S K转染组 77.4%的PBLsNGFR(神经生长因子受体 )标记物为阳性 ;HIV 1DP1株攻击后 ,未转染组和pLNCX转染组可以见到明显的合胞体形成 ,而在pLNCX R K S K转化PBLs没有见到合胞体形成 ;pLNCX R K S K转染组在感染后第 4、7和 10天皆可发现显著的p2 4抗原分泌抑制 ,抑制率分别为 15%、43 %、19%。结论　细胞内趋化因子通过与CCR5和CXCR4细胞内结合 ,使HIV 1两类主要辅受体难以在PBLs表面表达 ,从而可以达到阻断HIV 1病毒感染的目的     

针对HIV-1 进入细胞过程的抑制剂研究进展

HIV-1进入宿主细胞的过程可简单归纳为:HIV-1首先通过其囊膜糖蛋白复合物gp120-gp41中的gp120与靶细胞上的受体CD4结合,使得gp120的构象发生改变,并继而与靶细胞上的辅受体CXCR4或CCR5结合,结果导致gp41的构型改变,暴露出其融合肽并插入到宿主细胞膜,从而启动病毒膜与细胞膜的融合,完成病毒进入宿主细胞的感染过程.1针对HIV-1 gp120与CD4结合反应的抑 制剂 1.1 可溶性CD4片段及其衍生物早期研究曾证明重组表达的可溶性CD4片段对体外培养的HIV-1具有明显的抑制活性,在此基础上研制的重组融合蛋白-CD4-IgG2则进一步延长了其在体内的半衰期;该制剂的I/II期临床试验结果表明,一次性静脉给予0.2～10mg/kg剂量时,受试者均能很好耐受,未发现其有免疫原性及其他副作用.     

趋化因子受体CCR5反义RNA在真核细胞中的表达

目的 构建趋化因子受体CCR5反义RNA真核表达载体并获取重组假病毒颗粒以用于抗HIV-1研究，方法 用RT-PCR法从健康人外周血单个核细胞（PBMCs)中获得趋化因子受体CCR5翻译起始区的基因片段，并以正、反两个方面定向插入到真核表达载体pLXSN上，重组载体用脂质体转染剂（lipofectAMINE)转染PA317包装细胞，抗-G418克隆的细胞上清经逆转录后用荧光定量PCR（FQ-PCR）测定假病毒滴度，进一步感染NIH/3T3细胞。结果 CCR5正、反义RNA的真核表达载体。经PA317细胞包装形成的假病毒颗粒已成功地感染NIH/3T3细胞，目的基因在该细胞中得到整合与表达。结论 从PBMCs中获得的趋化因子受体CCR5基因片段通过逆转录病毒载体可转移至真核细胞中并得到表达，为进一步研究CCR5反义RNA的抗HIV-1作用奠定了基础。     

The frequency of CCR5Delta32 and CCR2-64I in southern Iranian normal population

Host genetic control of HIV infection involves certain polymorphisms of some chemokine receptor genes that are associated with susceptibility and progression of HIV-1 infection. Recent data suggest that two important polymorphisms in CCR2 and CCR5 chemokine receptors, CCR5Delta32 and CCR2-64I, prevent HIV transmission and delay disease progression. In this study allele and haplotype frequencies of the CCR5Delta32 and CCR2-64I mutations were determined in southern Iranian normal population using PCR and PCR restriction fragment length polymorphism (PCR-RFLP) assays. Allele frequencies and the fit to the Hardy-Weinberg equilibrium (HWE) were evaluated by Arlequin population genetic software. Frequencies of CCR5Delta32 and CCR2-64I alleles were 0.0146 and 0.1221, respectively. Moreover, higher and lower haplotype frequencies in 341 normal individuals were CCR2/CCR5 (0.8636) and CCR5/CCR2-64I (0.1217), respectively. Only one case with CCR5Delta32/CCR2-64I haplotype was found among the studied normal population. This data is the first finding on the frequencies of CCR5Delta32 and CCR2-64I alleles in Iranian population. Results of the present study suggest that low frequency of CCR5Delta32 allele may be related to higher genetic susceptibility to the HIV-1 infection in Iranians. Results also suggest that the CCR2-64I mutation is sufficiently common in Iranians and may be associated with slower HIV infection progression in Iran.     

Polymorphism of CC chemokine receptors CCR2 and CCR5 in Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disease of the intestine that is characterized by mononuclear cell infiltration and a predominant Th1 lymphocyte response. We tested the hypothesis that CC chemokine receptors CCR2 and CCR5 might be important in the regulation of the intestinal immune response in this disease, and we speculated that carriers of a defective 32 base pair deletion mutant of CCR5, CCR5Delta32, which results in a non-functional receptor, might be protected from CD. Using polymerase chain reaction (PCR) and PCR restriction fragment length polymorphism (PCR-RFLP) gene frequencies of CCR5Delta32 and of CCR2-641 (replacement of valine-64 by isoleucine in the CCR2 gene) in healthy controls (n=346) and in CD patients (n=235) were determined. In CD patients, subgroup phenotypic analyses were performed according to the Vienna classification. The overall gene frequency of CCR5Delta32 (9.8%) and CCR2-641 (7.6%) in CD patients did not deviate significantly from healthy controls (9.2 and 8.2%, respectively), nor did we observe a significant deviation from the predicted Hardy-Weinberg distribution. No significant differences in the CD phenotype classification for the different CCR5 and CCR2 alleles were observed, except for a trend to disease sparing of the upper gastrointestinal tract (carrier frequency 0 versus 19.6%, Delta=1 9.6%, P=0.079) as well as a more stricturing disease behaviour (23.5 versus 16.2%, Delta=7.3%, P=0.136) in carriers of the mutant CCR5Delta32 allele. These results indicate that the different CCR5 but not CCR2 alleles may influence disease behaviour and thereby contribute to the observed heterogeneity of CD. However, the associations observed are limited and await replication in other datasets. CCR2 and CCR5 polymorphisms are unlikely to be important determinants of overall disease susceptibility.     

Homozygous and heterozygous CCR5-Delta32 genotypes are associated with resistance to HIV infection

OBJECTIVE: To investigate evidence for resistance to HIV-1 infection associated with the heterozygous genotype CCR5-+/Delta32 and with the homozygous genotype CCR5-Delta32/Delta32, which results in a nonfunctional CCR5 receptor. DESIGN: Cohort study of initially HIV-seronegative high-risk individuals from eight different cities. Enrollment data were analyzed to investigate the association of demographic factors and risk behaviors with CCR5 genotypes on the assumption that increased genotype prevalence among persons with histories of longer or more intensive exposure to HIV would indicate HIV resistance associated with that genotype. Longitudinal data were analyzed to investigate the association of HIV seroincidence with CCR5 genotypes. The cohort of 2996 individuals included 1892 men who have sex with men (MSM), 474 male injection drug users (IDUs), 347 women at heterosexual risk, and 283 female IDUs. MEASUREMENTS: CCR5 genotype, HIV serostatus, demographic factors, and risk behaviors during the 6 months before enrollment, followed by measurement of HIV seroincidence during the subsequent 18 months (for men) and 24 months (for women). RESULTS: Forty (1.3%) subjects were homozygous CCR5-Delta32/Delta32 and 387 (12.9%) were heterozygous CCR5-+/Delta32. All but 1 CCR5-Delta32/Delta32 individuals and 51 CCR5-+/Delta32 individuals were Caucasian. Among 1531 Caucasian MSM, CCR5-+/Delta32 individuals were present more frequently (22.3%) among those reporting unprotected receptive anal intercourse than among those not reporting this risk (15.9%) (p =.002), suggesting a selective advantage of the heterozygous genotype. CCR5-+/Delta32 individuals also had a significantly reduced relative risk of HIV seroconversion adjusted for unprotected receptive anal intercourse compared with CCR5-/+ individuals (relative risk = 0.30, 95% confidence interval [CI]: 0.08-0.97). CCR5-Delta32/Delta32 prevalence among Caucasian MSM was significantly associated with age among subjects recruited from high HIV seroprevalence cities (New York City and San Francisco) (odds ratio [OR] for each decade increase in age = 2.57, CI: 1.56-4.21) but not among those recruited from lower HIV prevalence sites (Boston, Chicago, Philadelphia, Seattle, and Providence/Pawtucket, Rhode Island) (OR = 1.20, CI: 0.75-1.89). CONCLUSIONS: Cross-sectional and longitudinal analyses indicated that among high-risk HIV seronegative MSM, CCR5-+/Delta32 and CCR5-Delta32/Delta32 are associated with protection against HIV infection. These findings imply that strategies aimed at reducing susceptibility to HIV infection by blocking CCR5 receptor sites need not seek blockage of all receptor sites to achieve an imperfect but substantial degree of protection.     

银屑病患者外周血单个核细胞CCR5的表达及其意义

目的研究银屑病患者外周血单个核细胞趋化因子受体5（CCR5）的表达及其与银屑病皮损面积和严重程度指数（PASI）的关系。方法分离35例中重度寻常型银屑病患者及30例健康对照者外周血单个核细胞（PBMCs）,用RT-PCR法测定PBMCs培养前后CCR5 mRNA的表达水平,免疫荧光标记-流式细胞仪检测CCR5阳性细胞比率。结果治疗前银屑病患者外周血单个核细胞中CCR5 mRNA表达水平明显高于治疗后及健康对照组,并与PASI呈正相关（r=0.516,P〈0.05）。结论 CCR5可能通过活化与趋化单个核细胞到银屑病皮损而参与了银屑病的发病。     

Role of the CCR5 delta 32 allele in resistance to HIV-1 infection in west Africa

OBJECTIVE: To determine the frequency of the mutant CCR5 delta 32 allele in high-risk HIV-seronegative Africans as compared with the general African population, and to assess its in vitro protective efficacy against HIV-1 infection. STUDY DESIGN: In the homozygous form, the CCR5 delta 32 allele confers resistance to macrophage-tropic (M-tropic) strains of HIV-1. Assuming that genetic characteristics favoring HIV resistance would prevail in a high-risk HIV-seronegative population, we examined the CCR5 genotypes of female commercial sex workers (CSWs) from Dakar, Senegal, who have remained uninfected for an elongated period. METHODS: The CCR5 genetic profile of study participants was determined by polymerase chain reaction (PCR) amplification of genomic DNA followed by sequencing. Peripheral blood mononuclear cells (PBMCs) were infected with different strains of HIV-1 and monitored by p24 enzyme-linked immunosorbent assay (ELISA). RESULTS: We confirmed the presence of two CCR5wt/delta 32 genotypes among 139 individuals (1.44%). PBMCs from these 2 heterozygous individuals were also found to be less susceptible to in vitro infection by an M-tropic HIV-1 primary isolate. CONCLUSIONS: Evidence was found of an increased prevalence of the CCR5wt/delta 32 genotype in a high-risk HIV-seronegative cohort in West Africa. Furthermore, reduced susceptibility to HIV-1 infection among heterozygous individuals supports a role for 32-bp CCR5 deletion in HIV-1 resistance.     

Evolution of the CCR5 Delta32 mutation based on haplotype variation in Jewish and Northern European population samples

The chemokine receptor 5 (CCR5) serves as a fusion cofactor for macrophage-tropic strains of HIV-1. In addition, CCR5 has been shown to mediate the entry of poxviruses into target cells. Individuals homozygous for the Delta32 deletion-mutation have no surface expression of CCR5 and are highly protected against HIV-1 infection. To gain insights into the evolution of the mutation in modern populations, the relatively high frequency of the Delta32-ccr5 allele in some European and Jewish populations is explored here by examining haplotypes of 3p21.3 constructed of five polymorphic marker loci surrounding CCR5. By sampling Ashkenazi, non-Ashkenazi and non-Jewish populations, we utilize the natural experiment that occurred as a consequence of the Jewish Diaspora, and demonstrate that a single mutation was responsible for all copies of Delta32. This mutation must have moved from Northern European populations to the Ashkenazi Jews where evidence suggests that Delta32 carriers of both groups were favored by repeated occurrence of epidemic small pox beginning in the 8th century AD.     

Genetic variation at the chemokine receptors CCR5/CCR2 in myocardial infarction

Our objective was to examine the association between myocardial infarction (MI) and two DNA-polymorphisms at the proinflammatory chemokine receptors CCR2 (I64V) and CCR5 (32 bp deletion, (Delta)ccr5), defining if these polymorphisms influence the age for the onset of MI. A total of 214 patients with an age at the first MI episode <55 years, 96 patients that suffered the first MI episode when older than 60 years, and 360 population controls were polymerase chain reaction genotyped for the CCR2-V64I and CCR5-Delta32/wt polymorphisms. Patients and controls were male from the same Caucasian population (Asturias, northern Spain). The frequency of the Deltaccr5 allele was significantly higher in controls compared to patients <55 years (P = 0.004), or in patients >60 years compared to patients <55 years (P = 0.002). Taking the patients >60 years as the reference group, non-carriers of the (Delta)ccr5-allele would have a three-fold higher risk of suffering an episode of MI at <55 years of age (OR = 3.06; 95% CI = 1.46-6.42). Gene and genotype frequencies for the CCR2 polymorphism did not differ between patients <55 years and controls or patients >60 years. Our data suggest that the variation at the CCR5 gene could modulate the age at the onset of MI. Patients carrying the (Delta)ccr5-allele would be protected against an early episode of MI. CCR5 and the CCR5-ligands are expressed by cells in the arteriosclerotic plaque. Thus, the protective role of (Delta)ccr5 could be a consequence of an attenuated inflammatory response, that would determine a slower progression of the arteriosclerotic lesion among (Delta)ccr5-carriers. Our work suggests that the pharmacological blockade of CCR5 could be a valuable therapy in the treatment of MI.     

中国HIV-1感染疾病长期不进展者CCR2-64I、SDF1-3’A和CCR5Δ32的基因变异研究

目的 探讨CCR2-641、SDF1-3’A、CCR5Δ32基因变异对中国HIV—1感染疾病长期不进展者（long-term nonprogressors，LTNPs）疾病进程的影响。方法 收集17例中国HIV-1感染LTNPs和39例中国HIV-1感染疾病典型进展者（typical progressors，TPs）的抗凝全血标本，用全自动核酸提取仪提取基因组DNA，采用PCR／RFLP技术对CCR2、SDF1、CCR5基因进行检测分析。结果 LTNP组的CCR2-64I、SDF1-3’A基因突变率分别为50％和62．5％，TP组的CCR2-64I和SDF1-3’A基因突变率分别为23．08％、33．33％，LTNP组CCR2—64I、SDF1-3’A基因突变率明显高于TP组（P〈0．05）；LTNP组有1例CCR5Δ32杂合突变，未发现纯合变异，而TP组未发现CCR5Δ32突变。结论 CCR2-64I、SDF1-3’A和CCR5Δ32基因突变可能是中国HIV-1感染者疾病长期不进展的保护性因素之一。     

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.