Raji细胞免疫酶抑制法检测血清抗HLA—DR抗体

本研究利用Ｒａｊｉ细胞表面具有表达组织相容性抗原ＤＲ（ＨＬＡ－ＤＲ）特点，以及被检血清中抗ＨＬＡ－ＤＲ抗体与抗人ＨＬＡ－ＤＲ单克隆抗体（ＭｃＡｂ）竞争结合Ｒａｊｉ细胞表面ＨＬＡ－ＤＲ抗原的特征，建立检测血清抗ＨＬＡ－ＤＲ抗体的Ｒａｊｉ细胞免疫酶抑制法。对７２例系统性红斑狼疮（ＳＬＥ）患者和１１３例健康者血清检测结果表明：ＳＬＥ患者和健康者血清中抗ＨＬＡ－ＤＲ抗体阳性率分别为３９．０％和１．８％。此     

急性非淋巴细胞白血病与HLA—DR抗原表达关系的研究

应用免疫酶标染色法检测了５７例急性非淋巴细胞白血病患者的ＨＬＡ－ＤＲ和其它细胞免疫类型，其中３８例，表达ＨＬＡ－ＤＲ抗原，表达ＨＬＡ－ＤＲ的的ＡＮＬＬ常伴有ＣＤ７的表达，而较成熟的髓系细胞表面标记ＣＤ１５则不表达，ＨＬＡ－ＤＲ＾＝的ＡＮＬＬ与ＦＡＢ亚型Ｍ１，Ｍ５ａ有密切关系。     

Raji细胞免疫酶抑制法检测血清抗HLA－DR抗体

本研究利用Ｒａｊｉ细胞表面具有表达组织相容性抗原ＤＲ（ＨＬＡ一ＤＲ）特点，以及被检血清中抗ＨＬＡ一ＤＲ抗体与抗人ＨＬＡ一ＤＲ单克隆抗体（ＭｃＡｂ）竞争结合Ｒａｊｉ细胞表面ＨＬＡ一ＤＲ抗原的特征，建立检测血清抗ＨＬＡ一ＤＲ抗体的Ｒａｊｉ细胞免疫酶抑制法。对７２例系统性红斑狼疮（ＳＬＥ）患者和１１３例健康者血清检测结果表明：ＳＬＥ患者和健康各血清中抗ＨＬＡ一ＤＲ抗体阳性率分别为３９．０％和１．８％。此法特异性强、重复性好（阳性血清ＣＶ为４．７％，阴性血清ＣＶ为０％），抗体涌度范围１：５～１：４０。     

抗bcl－2核酶在HL－60细胞中的表达及促进其凋亡的研究

为消除白血病细胞中ｂｃｌ－２基因对细胞凋亡的抑制作用，开辟白血病基因治疗的途径。将合成的针对ｂｃｌ－２ｍＲＮＡ的“锤头型”核酶（Ｒｉｂｏｚｙｍｅ，ＲＺ）基因定向克隆于真核表达载体ｐＤＯＲ－ｎｅｏ，构成ｐＤＯＲ－ＲＺ重组体。通过脂质体Ｌｉｐｏｆｅｃｔｉｎ介导的ＤＮＡ转染法，把ｐＤＯＲ－ＲＺ导入ＨＬ－６０细胞。用Ｓｏｕｔｈ－ｅｒｎ印迹，ＲＮＡ斑点杂交法观察ＲＺ基因在ＨＬ－６０细胞内表达，并通过电镜、流式细胞仪（ＦＣＭ），光镜和ＤＮＡ电泳观察ＲＺ对ＨＬ－６０细胞的影响。结果：①ＲＺ在转染ＨＬ－６０后７２小时得以表达，细胞内ｂｃｌ－２蛋白合成受到抑制。②在ＦＣＭ图谱上可见到明显的凋亡峰，形态观察ＲＺ处理的ＨＬ－６０细胞呈典型的凋亡形态。③足叶乙甙（促凋亡）敏感性试验表明，与未转染的细胞和转染空载体ｐＤＯＲ－ｎｅｏ的细胞相比，转染ｐＤＯＲ－ＲＺ的细胞ＤＮＡ电泳易出现梯状条带。结果说明ＲＺ基因通过逆转录病毒表达载体导入ＨＬ－６０细胞后可成功地表达并抑制ＨＬ－６０细胞ｂｃｌ－２蛋白的合成，并促进ＨＬ－６０细胞凋亡     

溃疡性结肠炎结肠粘膜HLA—DR抗原表达

本文检测了６０例溃疡性结肠炎的３０例正常结肠粘膜上皮细胞ＨＬＡ－ＤＲ抗原表达。结果显示，３０例正常结肠粘膜上皮及腺体不表达ＨＬＡ－ＤＲ抗原，而６０例ＵＣ中有３２例结肠粘膜上皮和腺体不同程度表达该抗原。其中，４２例活动性ＵＣ中２９例表达，１８例非活动ＵＣ仅３例表达，同时发现ＵＣ结肠粘膜上皮表达ＨＬＡ－ＤＲ抗原还与粘膜炎症程度成正比。结果提示，细胞免疫机制在ＵＣ的发病机理中起重要作用。     

抗bcl—2核酶在HL—60细胞中的表达及促进其凋亡的研究

为消除白血病细胞中ｂｃｌ－２基因对细胞凋亡的抑制作用开辟白血病基因治疗的途径。将合成的针对ｂｃｌ－２ｍＲＮＡ的“锤头型”核酶基因定向克隆于真核表达本ＰＤＯＲ－ｎｅｏ，构ｐＤＯＲ－ＲＺ重组体。通过脂质体Ｌｉｐｏｆｅｃｔｉｎ介导的ＤＮＡ转染法，把ｐＤＯＲ－ＲＺ导入ＨＬ－细胞。     

急性非淋巴细胞白血病与HLA-DR抗原表达关系的研究

应用免疫酶标染色法检测了５７例急性非淋巴细胞白血病（ＡＮＬＬ）患者的ＨＬＡ－ＤＲ和其它细胞免疫类型，其中３８例（６６７％）表达ＨＬＡ－ＤＲ抗原，表达ＨＬＡ－ＤＲ抗原的ＡＮＬＬ常伴有ＣＤ７的表达，而较成熟的髓系细胞表面标记ＣＤ１５则不表达，ＨＬＡ－ＤＲ＋的ＡＮＬＬ与ＦＡＢ亚型Ｍ１、Ｍ５ａ有密切关系。ＨＬＡ－ＤＲ－组缓解机会大于ＨＬＡ－ＤＲ＋组（Ｐ＜００５），检测ＨＬＡ－ＤＲ抗原不仅有利于ＡＮＬＬ的诊断而且有助于判断预后。     

特异性反义寡核苷酸抑制白血病细胞株HLA—DPB1基因表达

反义寡核苷酸可以特异性地抑制基因表达，将ＨＬＡ０ＤＰＢ１特异性反义寡核苷酸加入细胞培养基中，对ＨＬ－６０和Ｋ５６２白血病细胞株由γ－干扰素诱导的ＨＬＡ－ＤＰＢ１表达有特异性抑制作用。当反义寡核苷酸浓度在４０μｇ／ｍｌ时，１小时后即出现ＨＬＡ０ＤＰＢ１基因表达抑制现象，持续时间达４８小时，７２小时后表达又逐渐恢复；反义寡核苷酸抑制基因表达有很高的特异性，在ＨＬＡ－ＤＰＢ１表达完全被封闭的情况下，与它     

ICAM—1,HLA—ABC,HLA—DR在乙型肝炎肝细胞表达的意义

为进一步探讨ＨＬＡ－ＡＢＣ,ＨＬＡ－ＤＲ,ＩＣＡＭ－１在乙型肝炎肝细胞损伤中的作用,利用标记的链菌素亲生物蛋白（ＬＳＡＢ）法对９８例乙型肝炎肝穿组织进行ＨＬＡ－ＡＢＣ,ＨＬＡ０－ＤＲ,ＩＣＡＭ－１检测。结果显示ＨＬＡ－ＡＢＣ,ＩＣＡＭ－１在乙型肝炎肝细胞存在广泛表达,且与肝脏病变程度有关,ＨＬＡ－ＤＲ也有一定程度表达,其阳性率分别在８５．７％、８３．７％、２６．５％。阳性表达多位于肝细胞炎性病变或     

溃疡性结肠炎结肠粘膜HLA－DR抗原表达

本文检测了６０例溃疡性结肠炎和３０例正常结肠粘膜上皮细胞ＨＬＡ－ＤＲ抗原表达。结果显示，３０例正常结肠粘膜上皮及腺体不表达ＨＬＡ－ＤＲ抗原；而６０例ＵＣ中有３２例结肠粘膜上皮和腺体不同程度表达该抗原。其中，４２例活动性ＵＣ中２９例表达，１８例非活动性ＵＣ仅３例表达。同时发现ＵＣ结肠粘膜上皮表达ＨＬＡ－ＤＲ抗原还与粘膜炎症程度成正比。结果提示，细胞免疫机制在ＵＣ的发病机理中起重要作用。     

MHC-Ⅱ基因反义RNA导入脐血CD34^＋细胞抑制HLA-DR抗原的表达

将HLA-DRBI基因cDNA片段反向插入逆转录病毒质粒pZIP-neo SV(x)BamHI位点中,构建了HLA-DRB1基因的逆转录病毒反义RNA重组表达载体,用脂质体法导入PA317细胞。用免疫磁珠法分离、富集脐血CD34~ 细胞。将培养的病毒上清感染脐血CD34~ 细胞,筛选获得抗性克隆和进行CFU-GM的培养。用RT-PCR法从经G418选择产生的抗性克隆已证实有反义RNA目的基因的表达。流式细胞仪(FACS)检测转染的脐血细胞中HLA-DR抗原阳性率为28％(对照组为45％),其抑制率为38.2％。结果表明导入脐血细胞的MHC-Ⅱ类基因反义RNA重组体可降低其HLA-DR抗原的表达。本实验结果为用反义核酸技术在临床脐血移植中防止移植物抗宿主反应提供了新方法。     

重组人造血干细胞因子基因在人造血干／祖细胞的转移和表达

目的：拓展造血干细胞因子（ＳＣＦ）的研究和基因治疗途径。方法：利用基因重组技术，构建了编码可溶性人ＳＣＦ基因的逆转录病毒载体ｐＬＸＳＮ－ＳＣＦ，应用脂质体ｌｉｐｏｆｅｃｔｉｎ基因转移法将重组质粒导入Ψ２和ＰＡ３１７病毒包装细胞，经Ｇ４１８选择性培养基筛选，获得产重组病毒的包装细胞ＰＡ３１７／ＳＣＦ，其病毒效价为（２．４～８．５）×１０５ＣＦＵ／ｍｌ，继而感染人造血干／祖细胞。应用多聚酶链反应、ＡＰＡＡＰ免疫组化染色和化学发光－直接酶标法检测人ＳＣＦ基因在细胞中转移和表达。结果：逆转录病毒载体介导的ｒｈＳＣＦ基因在人造血干／祖细胞中获得有效转移和表达。结论：为进一步研究ＳＣＦ的生物学特性及开展干细胞移植等提供了一定的途径。     

Retroviral-mediated transfer of the human glucocerebrosidase gene into cultured Gaucher bone marrow.

Gaucher disease, a lysosomal glycolipid storage disorder, results from the genetic deficiency of an acidic glucosidase, glucocerebrosidase (GC). The beneficial effects of allogeneic bone marrow transplantation (BMT) for Gaucher disease suggest that GC gene transduction and the transplantation of autologous hematopoietic stem cells (gene therapy) may similarly alleviate symptoms. We have constructed a retroviral vector, L-GC, produced by a clone of the amphotropic packaging cell line PA317, which transduces the normal human GC cDNA with high efficiency. Whole-marrow mononuclear cells and CD34-enriched cells from a 4-yr-old female with type 3 Gaucher disease were transduced by the L-GC vector and studied in long-term bone marrow culture (LTBMC). Prestimulation of marrow with IL-3 and IL-6, followed by co-cultivation with vector-producing fibroblasts, produced gene transfer into 40-45% of the hematopoietic progenitor cells. The levels of GC expression in progeny cells (primarily mature myelomonocytic) produced by the LTBMC were quantitatively analyzed by Northern blot, Western blot, and glucocerebrosidase enzyme assay. Normal levels of GC RNA, immunoreactive protein, and enzymatic activity were detected throughout the duration of culture. These studies demonstrate that retroviral vectors can efficiently transfer the GC gene into long-lived hematopoietic progenitor cells from the bone marrow of patients with Gaucher disease and express physiologically relevant levels of GC enzyme activity.     

细胞因子对逆转录病毒载体介导的小鼠骨髓造血干细胞基因转移效率的影响

本实验探讨细胞因子SCF,IL-3和IL-6对基因转移效率的影响,为临床基因治疗提供可靠依据。以小鼠造血干细胞为靶细胞,应用包装细胞株PA317-GCGPXSN制备病毒上清,实施基因转移,采用FACS,GM-CFU,PCR和Southern blot方法测定基因转移效率。实验结果为:SCF,IL-3,IL-6单用或联合应用后,FACS测定的基因转移效率为0.07％-0.20％,GM-CFU测定的结果为20.4％-46.40％,阳性对照组测定的结果则分别为0.06％和10.92％。结论提示SCF/IL-3,SCF/IL-3/IL-6联合应用能显著提高基因转移效率。     

Gene transfer into fetal baboon hematopoietic progenitor cells

We studied hematopoietic progenitors from fetal baboon blood, marrow, and liver at four time points (125, 140, 160, and 175 days) during the third trimester (gestation approximately 180 days) to determine if fetal baboons might be an appropriate model for in utero gene therapy of hematopoietic stem cells (HSCs). Cells were studied for expression of CD34, CD33, CD38, and HLA-DR, for progenitor content in colony-forming cell assays, and for susceptibility of CD34+ progenitors to retrovirus-mediated gene transfer. Throughout the third trimester, the frequency of CD34+ progenitors in blood and marrow appears to remain unchanged at approximately 0.6 and 5.0%, respectively. In liver, progenitors progressively decrease to undetectable levels by day 175. The proportion of fetal baboon bone marrow and liver CD34+ cells expressing CD38 and HLA-DR appears to increase with increasing fetal age, similar to changes reported for human cord blood CD34+ cells. In fetal baboon blood the proportion of CD34+ cells expressing CD33 appears to decrease with increasing gestational age, also similar to changes reported for human cord blood cells. Progenitors from human cord blood and baboon fetal tissues were similarly susceptible to transduction by the gibbon ape leukemia pseudotyped retroviral vector LAPSN(PG13) containing the genes for human placental alkaline phosphatase (AP) and the bacterial neomycin phosphotransferase (neo). Fetal baboon and human hematopoietic progenitor cells undergo similar phenotypic changes during the third trimester of fetal development and are similarly susceptible to retrovirus-mediated gene transfer. The fetal baboon may be a model in which approaches to mobilization and gene transfer into fetal HSCs can be studied.     

Preincubation with endothelial cell monolayers increases gene transfer efficiency into human bone marrow CD34(+)CD38(-) progenitor cells

Retroviral gene transfer studies targeting bone marrow CD34(+)CD38(-) stem cells have been disappointing because of the rarity of these cells, their G(0) cell cycle status, and their low or absent expression of surface retroviral receptors. In this study, we examined whether preincubation of bone marrow CD34(+)CD38(-) stem cells with a hematopoietically supportive porcine microvascular endothelial cell line (PMVECs) could impact the cell cycle status and expression of retroviral receptors in pluripotent CD34+CD38- cells and the efficiency of gene transfer into these primitive target cells. PMVEC coculture supplemented with GM-CSF + IL-3 + IL-6 + SCF + Flt-3 ligand induced >93% of the CD34(+)CD38(-) population to enter the G(1) or G(2)/S/M phase while increasing this population from 1.4% on day 0 to 6.5% of the total population by day 5. Liquid cultures supplemented with the identical cytokines induced 73% of the CD34(+)CD38(-) population into cell cycle but did not maintain cells with the CD34(+)CD38(-) phenotype over time. We found no significant increase in the levels of AmphoR or GaLVR mRNA in PMVEC-expanded CD34(+)CD38(-) cells after coculture. Despite this, the efficiency of gene transfer using either amphotropic vector (PA317) or GaLV vector (PG13) was significantly greater in PMVEC-expanded CD34(+)CD38(-) cells (11.4 +/- 5.6 and 10.9 +/- 5.2%, respectively) than in either steady state bone marrow CD34(+)CD38(-) cells (0.6 +/- 1.7 and 0.2 +/- 0.6%, respectively; p < 0.01 and p < 0.01) or liquid culture-expanded CD34(+)CD38(-) cells (1.4 +/- 3.5 and 0.0%, respectively; p < 0.01 and p < 0.01). Since PMVEC coculture induces a high level of cell cycling in human bone marrow CD34(+)CD38(-) cells and expands hematopoietic cells capable of in vivo repopulation, this system offers potential advantages for application in clinical gene therapy protocols.     

骨髓基质细胞对人造血CD_34~+细胞体外扩增及基因转导的作用

目的：探讨造血基质细胞对人外周血干细胞体外培养扩增及基因转导的促进作用。方法：应用基质细胞支持培养扩增体系进行人造血干细胞体外培养扩增及基因转导。结果：骨髓基质细胞和造血生长因子共同支持组的造血ＣＤ＋３４细胞在体外培养３周后,其造血祖克隆形成能力较单纯造血生长因子支持组高３０．７％（Ｐ＜０．０５）。在有基质细胞支持时,逆转录病毒载体上清转导人造血ＣＤ＋３４细胞后,其造血细胞克隆中Ｎｅｏ基因阳性克隆是无基质支持对照组的２倍。结论：基质细胞的支持有维持造血干细胞原始造血活性及促进基因转导的双重好处。     

Ex vivo culture of cord blood CD34+ cells expands progenitor cell numbers, preserves engraftment capacity in nonobese diabetic/severe combined immunodeficient mice, and enhances retroviral transduction efficiency

Ex vivo culture of hematopoietic stem/progenitor cells could potentially improve the efficacy of human placental/umbilical cord blood (CB) in clinical hematopoietic stem cell (HSC) transplantation and allow gene transduction using conventional retroviral vectors. Therefore, we first examined the effects of a 7-day period of ex vivo culture on the hematopoietic capacity of CB CD34+ cells. Medium for the ex vivo cultures contained either serum and six recombinant human hematopoietic growth factors (GFs), including Flt-3 ligand (FL), Kit ligand (KL = stem cell factor), thrombopoietin (Tpo), interleukin 3 (IL-3), granulocyte colony-stimulating factor (G-CSF), and interleukin 6 (IL-6), or a serum-free medium containing only FL, KL, and Tpo. After culture under both ex vivo conditions, the total numbers of viable cells, CD34+ cells, colony-forming cells (CFCs), and long-term culture initiating cells (LTC-ICs) were increased. In contrast, the severe combined immunodeficiency (SCID) mouse engrafting potential (SEP) of cultured cells was slightly decreased, as compared with fresh cells. Nevertheless, cultured human CB CD34+ cells were able to generate engraftment, shown to persist for up to 20 weeks after transplantation. We next tested the efficacy of retroviral transduction of cultured cells. Transduced cultured human cells were able to engraft in NOD/SCID mice, as tested 4 weeks after transplantation, and EGFP+CD34+ cells and EGFP+ CFCs were isolated from the chimeras. Thus, although additional improvements in ex vivo culture are still needed to expand the numbers and function of human HSCs, the current conditions appear to allow gene transduction into hematopoietic SCID engrafting cells, while at least qualitatively preserving their in vivo engraftment potential.