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     

早、中、晚孕期胎盘因子对人外周血淋巴细胞CD4、CCR5和CXCR4表达的影响

目的 通过研究早、中、晚孕期胎盘因子(PF)对人外周血淋巴细胞(PBLs)中CD4、CCR5和CXCR4表达的作用,探讨PF在人免疫缺陷病毒-1(HIV-1)垂直传播中的作用及其机理.方法 制备早、中、晚孕期PF.分离人外周血单个核细胞,并分别与相对浓度为25%的早、中、晚孕期PF作用,培养24 h后收集细胞,荧光抗体标记,流式细胞术检测外周血淋巴细胞(PBLs)中CD4、CCR5和CXCR4表达,以及CD4 T细胞中CCR5 细胞、CXCR4 细胞、CCR5 CXCR4 细胞所占的百分率.结果 各孕期PF均可显著降低PBLs中CCR5的表达,其中早孕期PF的作用明显强于中、晚孕期PF的作用;各孕期PF组CD4 T细胞中CCR5 细胞的百分率均显著低于对照组,早孕期PF组CD4 T细胞中CCR5 细胞的百分率明显低于中、晚孕期PF组;各孕期PF组CD4 T细胞中CCR5 CXCR4 细胞的百分率均显著低于对照组,早孕期PF组CD4 T细胞中CCR5 CXCR4 细胞的百分率显著低于晚孕期PF组.结论 各孕期PF均可显著降低PBLs中CCR5的表达,以及CD4 T细胞中CCR5 细胞和CCR5 CXCR4 细胞的百分率,早孕期PF作用最强,中、晚孕期PF效应相当,PF可能通过抑制R5病毒的人胞而具有抗R5病毒的作用,并可能在阻断HIV-1宫内感染中具有重要作用.     

Phenotypic Knockout of HIV-1 Chemokine Coreceptor CXCR4 and CCR5 by Intrakines for Blocking HIV-1 Infection

To investigate the phenotypic knockout of HIV-1 chemokine coreceptor CXCR4 and CCR5 by intrakines and its inhibitory effect on HIV-1 infection. Primary human PBLs were transduced with the recombinant vector pLNCX-R-K-S-K(△NGFR), followed by anti-NGFR/anti-IgG-magnetic bead method selection and FCM detection. The transduced PBLs were infected with DP1 HIV-1 virus thereafter envelope-mediated syncytium formation and p24 detection were carried out to study the blockage of HIV-1 infection by co-inactivation of CCR5 and CXCR4. pLNCX-R-K-S-K (△NGFR)-transduced PBILs were isolated with an anti-NGFR/anti-IgG-magnetic bead method. After isolation, about 70% of the PBLs were positive for the NGFR marker. When the transduced PBLs were infected with DP1 HIV-1 virus, envelop-mediated syncytium formation was almost completely inhibited by pLNCX-R-K-S-K(△NGFR) transfection. Also, p24 antigen was very low in the cultures of pLNCX-R-K-S-K (△NGFR) transduced PBLs. pLNCX-R-K-S-K(△NGFR) transduction inhibited the production of DP1 p24 antigen by 15%, 43% and 19% on days 4, 7 and 10 respectively. The lymphocytes with the phenotypic knockout of CCR5 and CXCR4 could protect primary human PBLs from DP1 HIV-1 virus infection.     

人PBMCs内表达CCR5Delta32蛋白对HIV-1辅受体抑制作用的研究

目的:在人PBMCs内表达CCR5Delta32蛋白,研究其对细胞表面HIV-1辅受体CCR5和CXCR4的抑制作用。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PBMCs,Western blot检测目的蛋白的表达。继续培养靶细胞,FACS分析细胞表面CCR5和CXCR4分子的变化。结果:成功构建了pLenti-CCR5Delta32慢病毒载体,包装后产生重组慢病毒。将其转染PBMCs,Western blot检测到目的蛋白的表达。FACS分析表明,靶细胞内目的蛋白的表达对靶细胞表面辅受体CCR5和CXCR4的产生起抑制作用,抑制率在转染后第6天达到高峰(CCR5的抑制率为51.69%,CXCR4的抑制率为61.05%)。结论:靶细胞内目的蛋白的成功表达及其对靶细胞表面HIV-1辅受体CCR5和CXCR4产生的抑制作用,为后续的AIDS基因治疗研究奠定了基础。     

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。     

趋化因子及受体与中国HCV/HIV合并感染相关性的研究

目的：探讨趋化因子自细胞介素8（IL-8）、干扰素诱导蛋白10（IFN-inducible 10-kdaprotein，IP-10）及趋化因子受体CCR5、CXCR3，在丙肝病毒（HCV）单纯感染，艾滋病病毒（HIV）单纯感染和HCV／HIV合并感染过程中的表达及意义。方法：采用流式细胞术，检测HCV感染组（n=21）、HIV感染组（n=14）、HCV／HIV感染组（n=28）及正常对照组（n=30）人外周血CD4^＋T淋巴细胞和CD8^＋T淋巴细胞表面CCR5、CXCR3的表达。ELISA方法检测血清趋化因子IL-8、IP-10含量。结果：HCV感染组、HIV感染组和HCV／HIV合并感染组，血清IP-10水平都明显升高，而在合并感染组水平最高；血清IL-8水平在3组亦明显升高。HIV感染组及HCV／HIV合并感染组CD4^＋T细胞表面CXCR3表达显著降低（P〈0．001），CD8^＋T细胞表面CXCR3表达显著升高（P〈0．001）；HCV感染组CD4^＋及CD8^＋T细胞表面CXCR3表达轻度升高，但差异不显著。HCV感染组及HCV／HIV合并感染组CD4^＋及CD8^＋T细胞表面CCR5表达显著降低（P〈0.001）；HIV感染组CD4^＋及CD8^＋T细胞表面CCR5表达显著升高（P〈0.001）。结论：中国HCV／HIV合并感染患者中，血清IL-8和IP-10水平都明显升高；受体CXCR3在CD4^＋T细胞表面表达降低，而在CD8^＋T细胞表面表达升高；受体CCR5在CD4^＋及CD8^＋T细胞表面表达降低，提示趋化因子及受体与HCV／HIV合并感染密切相关。     

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     

HIV-1感染者淋巴细胞活化与第二受体表达的研究

目的：了解HIV－1感染者体内淋巴细胞的活化情况及表达第二受体CCR5、CXCR4的淋巴细胞活化状态，分析这些指标与疾病严重程度的关系，探讨HIV感染的免疫基础。方法：用三色标记法流式细胞术检测24例HIV－1感染者及13例健康对照的抗凝血标本，分析活化标志物HLA－DR及第二受体CCR5、CXCR4的表达等指标。结果：HIV－1感染者CD8^ T淋巴细胞的HLA－DR表达高于健康对照（P＜0．001）；HIV－1感染者表达CCR5、CXCR4的CD8^ T淋巴细胞活化明显高于健康对照（P＜0．001）；表达CCR5CD4^ 、CD8^ T淋巴细胞与表达CXCR4相比HL－DR表达均明显增高（P＜0．001）；CD4^ 、CD8^ T淋巴细胞的活化状态与CD4百分率的变化明显关系。结论：HIV－1感染者CD8^ T淋巴细胞及表达不同第二受体的CD8^ T淋巴细胞活化程度明显增高，活化程度与疾病进程相关。     

T-20抗HIV病毒临床治疗进展

自1996年发现趋化因子受体是HIV-1的辅助受体以来,人们就希望以辅助受体为抗HIV-1病毒治疗的靶标,通过阻断或限制CCR5和CXCR4的功能阻止HIV-1进入宿主细胞。通过辅助受体的抑制剂来阻断HIV-1的感染可以大大降低病毒复制和进入细胞的机会,尤其值得重视的是抗HIV的小分子化学药物没有免疫原性,通过改进化学结构和给药途径,可以提高药物的生物利用度,降低其毒性,有望成为新一代的抗HIV和艾滋病药物。     

中国经采供血HIV感染长期不进展者CD4~+T淋巴细胞趋化因子受体表达研究

目的:了解中国经采供血HIV感染长期不进展者CD4+T淋巴细胞趋化因子受体表达,分析其与疾病不进展的关系。方法:收集43例经采供血HIV感染长期不进展者、82例无症状HIV感染者、35例AIDS病人及40例健康对照的抗凝全血,用流式细胞仪检测趋化因子受体CCR5、CXCR4的表达,并分析其与病毒载量、CD4+T淋巴细胞绝对值及T淋巴细胞活化的相关性。结果:长期不进展组CD4+T细胞表面CCR5的表达明显低于无症状HIV感染组及AIDS组(P0.01),与健康对照无显著差异;CD4+T细胞表面CXCR4的表达各组无显著差异。CD4+T细胞表面CCR5的表达与CD4+T细胞数量显著负相关(r=-0.498,P0.05),与病毒载量无显著相关性。CD4+T细胞表面CCR5的表达与HLA、CD38在CD4+、CD8+T细胞的表达水平显著正相关(P0.001,CD38在CD4+T细胞的表达除外),CD4+T细胞表面CXCR4的表达与HLA在CD4、CD8+T细胞的表达水平显著负相关(P0.01)。结论:HIV感染长期不进展者CD4+T细胞趋化因子受体CCR5表达维持较低水平,与疾病不进展相关。     

Phenotytic Knockout of HIV-1 Chemokine Coreceptor CXCR4 and CCR5 by Intrakines for Blocking HIV-1 Infection

Acquired immunodeficiency syndrome (AIDS) and humanimmunodeficiency virus (HIV) infection continues to bemajor global health concerns. Although highly active an-tiretroviral therapy (HAART) has led to profound and pro-longed reductions in circulating viru…     

Localization of HIV-1 co-receptors CCR5 and CXCR4 in the brain of children with AIDS.

The chemokine receptors CCR5 and CXCR4 are co-receptors together with CD4 for human immunodeficiency virus (HIV)-1 entry into target cells. Macrophage-tropic HIV-1 viruses use CCR5 as a co-receptor, whereas T-cell-line tropic viruses use CXCR4. HIV-1 infects the brain and causes a progressive encephalopathy in 20 to 30% of infected children and adults. Most of the HIV-1-infected cells in the brain are macrophages and microglia. We examined expression of CCR5 and CXCR4 in brain tissue from 20 pediatric acquired immune deficiency syndrome (AIDS) patients in relation to neuropathological consequences of HIV-1 infection. The overall frequency of CCR5-positive perivascular mononuclear cells and macrophages was increased in the brains of children with severe HIV-1 encephalitis (HIVE) compared with children with mild HIVE or non-AIDS controls, whereas the frequency of CXCR4-positive perivascular cells did not correlate with disease severity. CCR5- and CXCR4-positive macrophages and microglia were detected in inflammatory lesions in the brain of children with severe HIVE. In addition, CXCR4 was detected in a subpopulation of neurons in autopsy brain tissue and primary human brain cultures. Similar findings were demonstrated in the brain of adult AIDS patients and controls. These findings suggest that CCR5-positive mononuclear cells, macrophages, and microglia contribute to disease progression in the central nervous system of children and adults with AIDS by serving as targets for virus replication.     

Coreceptor usage by HIV-1 and HIV-2 primary isolates: the relevance of CCR8 chemokine receptor as an alternative coreceptor

The human immunodeficiency virus replication cycle begins by sequential interactions between viral envelope glycoproteins with CD4 molecule and a member of the seven-transmembrane, G-protein-coupled, receptors' family (coreceptor).In this report we focused on the contribution of CCR8 as alternative coreceptor for HIV-1 and HIV-2 isolates. We found that this coreceptor was efficiently used not only by HIV-2 but particularly by HIV-1 isolates. We demonstrate that CXCR4 usage, either alone or together with CCR5 and/or CCR8, was more frequently observed in HIV-1 than in HIV-2 isolates. Directly related to this is the finding that the non-usage of CXCR4 is significantly more common in HIV-2 isolates; both features could be associated with the slower disease progression generally observed in HIV-2 infected patients.The ability of some viral isolates to use alternative coreceptors besides CCR5 and CXCR4 could further impact on the efficacy of entry inhibitor therapy and possibly also in HIV pathogenesis.     

The Rhesus Macaque CCR3 Chemokine Receptor Is a Cell Entry Cofactor for HIV-2, but Not for HIV-1

The eotaxin receptor (CCR3) is a CD4-associated coreceptor for human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2). By comparison with other chemokine receptors, such as CCR5 and CXCR4, the primary sequences of human CCR3 and its rhesus macaque homolog were markedly different in their extracellular domains. Human CD4⁺cells expressing CCR3 from either human or macaque origin could be infected by HIV-2, with apparently similar efficiency, but only cells expressing human CCR3 could be infected by HIV-1. It suggests that HIV-1 and HIV-2 envelope proteins interact differently with the CCR3 coreceptor. HIV-1 could infect cells expressing chimeric human/macaque CCR3 bearing either the first and second, or the third and fourth extracellular domains of human CCR3. As previously observed for CCR5, there seems to be a certain functional redundancy between domains supporting the coreceptor activity of CCR3. In spite of their close genetic relationship to HIV-2, two macaque simian immunodeficiency virus strains were apparently unable to use the CCR3 coreceptor from either human or simian origin.     

Selective infection of CD4 effector memory T lymphocytes leads to preferential depletion of memory T lymphocytes in R5 HIV-1-infected humanized NOD/SCID/IL-2Rγ mice

To investigate the events leading to the depletion of CD4⁺ T lymphocytes during long-term infection of human immunodeficiency virus type 1 (HIV-1), we infected human CD34⁺ cells-transplanted NOD/SCID/IL-2Rγ^null mice with CXCR4-tropic and CCR5-tropic HIV-1. CXCR4-tropic HIV-1-infected mice were quickly depleted of CD4⁺ thymocytes and both CD45RA⁺ naïve and CD45RA⁻ memory CD4⁺ T lymphocytes, while CCR5-tropic HIV-1-infected mice were preferentially depleted of CD45RA⁻ memory CD4⁺ T lymphocytes. Staining of HIV-1 p24 antigen revealed that CCR5-tropic HIV-1 preferentially infected effector memory T lymphocytes (T_EM) rather than central memory T lymphocytes. In addition, the majority of p24⁺ cells in CCR5-tropic HIV-1-infected mice were activated and in cycling phase. Taken together, our findings indicate that productive infection mainly takes place in the activated T_EM in cycling phase and further suggest that the predominant infection in T_EM would lead to the depletion of memory CD4⁺ T lymphocytes in CCR5-tropic HIV-1-infected mice.     

Chemokine signaling and HIV-1 fusion mediated by macrophage CXCR4: implications for target cell tropism

To better understand CXCR4 function on macrophages and the relationship between coreceptor use and macrophage tropism among diverse HIV-1 isolates, we analyzed macrophage pathways involved in Env-mediated fusion, productive HIV-1 infection, and chemokine-elicited signaling. We found that both CXCR4 and CCR5 transduced intracellular signals in monocyte-derived macrophages, activating K+ and Cl- ion channels and elevating intracellular calcium in response to their chemokine ligands stromal cell-derived factor-1alpha and macrophage inflammatory protein-1beta, respectively. The prototype T-tropic X4 strain IIIB infected macrophages poorly, and this was associated with failure of the IIIB Env to fuse efficiently with target macrophages despite functional CXCR4. In contrast, several primary X4 isolates mediated efficient CXCR4-dependent fusion and productive macrophage infection. Several R5X4 strains could fuse with and infect macrophages through both CCR5 and CXCR4. Thus, macrophages express functional CXCR4 and CCR5 but primary and prototype X4 isolates differ in their ability to utilize macrophage CXCR4. Isolates classified as X4 based on coreceptor use may be phenotypically either T-tropic or dual-tropic and, conversely, phenotypically dual-tropic isolates may be either R5X4 or X4 based on coreceptor use.     

人类免疫缺陷病毒-1包膜糖蛋白进化对抗原表位及病毒亲嗜性的影响

目的调查同一供体来源的人类免疫缺陷病毒（HIV）-1感染不同个体后病毒包膜糖蛋白的变异、病毒侵入靶细胞能力以及包膜抗原主要中和表位的变化,为了解病毒感染规律及机体抗病毒免疫奠定基础。方法对病毒包膜糖蛋白基因序列进行基因离散分析;用包膜蛋白表达质粒与HIV-1骨架质粒共转染293T细胞构建包膜包膜假病毒,用假病毒感染HIV-1靶细胞U87．CD4．CCR5或U87．CD4．CXCR4细胞检测假病毒侵入靶细胞的能力及病毒亲嗜性;对包膜糖蛋白中已知的广谱中和抗体识别表位进行分析。结果24个有完整开放读码框的env基因克隆与河南省HIV-1毒株CNHN24的基因离散率为（7．91±0．78）％,与云南省分离毒株RIA2的基因离散率为（6．904-0．79）％。各可变区基因离散率呈现严重不均衡性,其中,VI／V2区的离散率最高,V4区的离散率次之,V3区离散率最小。包膜假病毒中既有CCR5亲嗜性和CXCR4亲嗜性的,也有双亲嗜性的包膜。而且上述包膜中主要中和表位IgGlbl2、2F5和4E10抗体识别表位保守,但447—52D抗体识别表位变异较大。结论同一来源的HIV包膜糖蛋自在4～7年间的不同受者体内发生了较大变异并影响了病毒侵入靶细胞的能力;主要广谱中和抗体的识别表位部分保守。     

Down-regulation of CXCR4 expression by SDF-KDEL in CD34 hematopoietic stem cells: An anti-human immunodeficiency virus strategy

CXCR4 plays an essential role as the first discovered coreceptor for the entry of T cell tropic isolates of HIV-1. Blocking the surface expression of this receptor may be a potential strategy to prevent HIV-1 infection. A lentiviral vector, pLenti6/V5-S-K, expressing a SDF-KDEL fusion protein was constructed and a replication-incompetent lentiviral stock was produced. The lentiviral stock was transduced into CD34⁺ hHSC and the transient expression of the recombinant protein, SDF-1, was assayed using indirect immunofluorescence. The surface expression of CXCR4 in CD34⁺ hHSC pretreated with different amounts of recombinant lentiviral vectors was detected by flow cytometric analysis. A marked down-regulation of CXCR4 expression in the cells transduced with recombinant lentiviral vectors pLenti6/V5-S-K was observed by flow cytometry with PE-conjugated anti-human CXCR4 monoclonal antibodies which showed the percentages of the inhibition effects of CXCR4-SDF-1 mediated syncytium formation are presented by concentration. P24 antigen levels of cell culture supernatants were detected on the 4th, 7th, and 10th day, with 10³ TCID50 HIV-1 infected CD34⁺ hHSC to evaluate the inhibitory effect of pLenti6/V5-S-K transduction on HIV-1 infection. The cells transfected with pLenti6/V5-S-K had a significant reduction of HIV-1 DP27 infection compared to controls (P < 0.05).     

Therapeutic effect of RANTES-KDEL on inhibition of HIV-1 in CD34(+) human hematopoietic stem cells (hHSC)

Cell surface receptors, such as the CCR5 chemokine receptors, represent key determinants of the human immunodeficiency virus type 1 (HIV-1) entry into target cells. The CC-chemokine, RANTES (regulated upon activation, normal T-cell expressed and secreted), a ligand for CCR5, have been targeted to the lumen of endocytoplasmic reticulum (ER) using a KDEL (ER-retention signal) fusion termed RANTES-KDEL and this construct was found to prevent effectively transport of newly synthesized CCR5 to the cell surface. Lentiviral vectors have emerged as potent and versatile tools of gene transfer for basic and applied research are able to transduce nondividing cells and maintain sustained long-term expression of transgenes. For this reason, an HIV-based lentiviral vector expressing RANTES-KDEL, pLenti6/V5-R-K, was constructed and then cotransfected with the ViraPower Packaging Mix (pLP1, pLP2, and pLP/VSVG) into 293FT cells to produce a replication-incompetent lentivirus stock. The lentiviral stock was titrated using HeLa cells, and the expression of the gene of interest, RANTES, was detected by indirect immunofluorescence. Based on the above results, the lentiviral stock was transduced into CD34(+) human hematopoietic stem cells (hHSC) separated magnetically from the cord blood (the purity was 96.8% evaluated by flow cytometry). Finally, the levels of p24 in the cultures of pLenti6/V5-R-K-transduced CD34(+) hHSC were detected after infection by HIV-1 DP1 (a R5-tropic HIV-1 strain, which was isolated by the Centers for Disease Control and Prevention of China in Henan province in 2000 from a Chinese man who had asymptomatic HIV-1 infection with a history of blood transfusions). It was shown that pLenti6/V5-R-K transduction inhibited expression of the DP1 p24 antigen by 51%, 58% and 60% on the 4th, 7th and 10th day respectively (P<0.05).