转位肽/粒酶B融合蛋白基因的构建、表达及对细胞生长的抑制作用

目的：研究转位肽／粒酶B融合蛋白对细胞生长的抑制作用。方法：采用重组PCR法，将绿脓杆菌外毒素(PE)部分转位肽编码序列与活性型粒酶B(GrBa)基因相融合，构建PE Ⅱ-GrBa融合蛋白基因，以粒酶活性中心丝氨酸突变的PE Ⅱ—mGrBa作为阴性对照。将所获重组基因克隆入真核表达载体pcDNA3和pIRES2-EGFP中，以脂质体法瞬时转染Hela等细胞系，通过与GFP共表达，用MTT比色、TUNEL及间接免疫荧光染色，检测PE Ⅱ—GrBa基因的表达对转染细胞的形态和生长的影响。结果：表达PE Ⅱ—GrBa融合蛋白的细胞的细胞骨架发生异常，细胞生长受到抑制，部分细胞呈现凋亡特征。结论：PE Ⅱ—GrBa融合蛋白的表达可抑制细胞生长。     

B型流感病毒B/Guangzhou/01/2007株HA基因重组3型腺病毒的构建

目的:构建包含有B型流感病毒B/Guangzhou/01/2007株血凝素(HA)基因的重组3型腺病毒.方法:用PCR方法扩增得到HA基因, 酶切后克隆至3型腺病毒穿梭质粒pSK-CMV, 构建重组穿梭质粒pSK-CMV-HA, 然后在大肠杆菌BJ5183内进行经 Not I和 Eco R V线性化的pSK-CMV-HA和经 Rsr Ⅱ线性化的骨架质粒pBRAdV3△E3的同源重组, AsiS I酶切线性化重组腺病毒质粒pBRAdV3△E3-HA后脂质体法转染HEp-2细胞, 进行病毒包装和增殖后得到重组腺病毒rAdV3△E3-HA, 并且通过病变观察、扫描电镜、 RT-PCR、免疫细胞化学方法对基因组的包装和HA基因的表达进行检测.结果:将HA基因克隆入pSK-CMV获得重组穿梭质粒pSK-CMV-HA, 线性化的pSK-CMV-HA与pBRAdV3△E3同源重组后获得pBRAdV3△E3-HA, 线性化的pBRAdV3△E3-HA转染HEp-2细胞观察到细胞病变和HA基因的表达.结论:成功构建了带有HA基因的重组腺病毒rAdV3△E3-HA, 为B型流感病毒-3型腺病毒二联活苗的研究提供了依据.     

截短型BAP31/GST基因重组质粒的构建及融合蛋白的表达、纯化和鉴定

目的构建编码截短型肿瘤抗原BAP31(△BAP31)与GST融合基因的原核表达载体,在大肠杆菌中表达并对融合蛋白(△BAP31/GST)进行纯化和初步鉴定。方法 PCR扩增编码△BAP31的基因片段,上下游分别引入EcoR I及Xho I酶切位点,亚克隆至含有GST标签的原核表达载体pGEX4T-1中,构建重组表达载体pGEX4T1-△BAP31,将该载体转化大肠杆菌DH5α,IPTG诱导表达△BAP31/GST,用GST亲和层析分离纯化原核表达的△BAP31/GST,表达产物分别用SDS-PAGE和West-ern blot进行鉴定。结果重组质粒经限制性内切酶EcoR I和Xho I双酶切鉴定和IPTG诱导表达△BAP31/GST的SDS-PAGE分析表明,表达产物的相对分子质量为40 000,与理论值相符,并主要以可溶性蛋白形式存在;经过对融合蛋白表达条件的优化,在IPTG浓度为1 mmol/L,诱导6 h目的蛋白表达量最高;灰度扫描分析发现,融合蛋白表达量占菌体蛋白总量的70.6%,纯化产物的纯度最高可达94.5%,Western blot证实该△BAP31/GST可与抗GST单克隆抗体(mAb)发生特异性结合反应,分子量为△BAP31与GST分子量之和,提示为融合蛋白。结论成功构建了编码△BAP31基因原核表达载体pGEX4T1-△BAP31,利用大肠杆菌表达系统和GST亲和层析,获得了较高纯度的△BAP31/GST融合蛋白,为进一步研究肿瘤抗原BAP31的功能及开发以BAP31作为靶点的肿瘤疫苗提供了试验基础。     

抗人Lipocalin型前列腺素D合酶单链抗体基因的构建与表达

利用RT-PCR技术,从稳定分泌抗人Lipocalin型前列腺素D合酶(Lipocalin-typeprostaglandinDsynthase,L-PGDS)单克隆抗体的鼠杂交瘤细胞中获得抗体可变区基因;通过一柔性连接短肽[(Gly)4Ser]3,SOEPCR法将此重、轻链可变区拼接成完整的抗人L-PGDS单链抗体基因,并装入表达载体pET-28a(+),在BL21宿主菌中进行表达。经SDS-PAGE检测显示,在低剂量0.02mmol/LIPTG诱导和较低温度25℃或28℃条件下培养,重组菌表达了一定量的可溶性单链抗体。后经Ni-NTA亲和层析柱纯化,得率为2mg/100ml,纯度达92%;双夹心ELISA和免疫荧光竞争抑制实验证实,纯化后的单链抗体具有较好的亲和力和特异性。     

抗B7-H4-scFv / PE38KDEL 重组免疫毒素的表达和功能性检测

目的:构建基于抗B7-H4 单链抗体(scFv)的重组毒素anti-B7-H4-scFv-PE38KDEL,检测毒素蛋白的抗肿瘤作用。方法:通过重叠延伸PCR(SOE-PCR )技术将anti-B7-H4-scFv 基因和毒素PE38KDEL 基因进行连接,重组基因克隆到原核表达载体pET28a(+)中表达,蛋白经变复性和镍柱亲和层析(Ni-NTA)纯化后进行Western blot 鉴定;间接ELISA 和流式分析技术进行特异性鉴定。利用MTT 法和皮下移植瘤模型实验,检测毒素对体外、内肿瘤细胞的抑制作用,并对肿瘤组织进行HE染色和免疫组化分析。结果:酶联后得到重组表达载体pET28a-anti-B7-H4-scFv-PE38KDEL,纯化后的毒素蛋白对肿瘤细胞具有一定杀伤力,并且在肿瘤模型实验中能抑制体内肿瘤的生长。结论:成功构建了基于抗B7-H4 单链抗体的重组毒素表达体系,经鉴定重组毒素蛋白有良好的生物学功能活性和抗肿瘤活性。     

人颗粒酶B真核表达载体的构建与表达分析

目的:构建能在Hep2细胞中表达的颗粒酶B的表达质粒pVAX1-GrB。方法:用淋巴细胞分离液分离肿瘤组织中的淋巴细胞,并抽提RNA,用RT-PCR方法扩增其分泌蛋白颗粒GrB的全部外显子片段,利用基因重组技术将其定向插入pVAX1多克隆位点。脂质体介导转染Hep2细胞,用间接免疫荧光法观察目的蛋白在细胞中的表达。结果:限制性内切酶酶切和DNA测序分析证实成功获得GrB基因片段,GrB准确克隆入pVAX1的多克隆位点,未改变读码框架。转染Hep2细胞后,检测到目的蛋白的表达。结论:成功构建了pVAX1-GrB,并在Hep2细胞中得到表达。     

人颗粒酶B基因的克隆、蛋白纯化及表达分析

TIL具有抗肿瘤的活性 ,其中颗粒酶B在杀伤肿瘤细胞的过程中起了最重要的作用。本实验拟扩增GrB全序列 ,构建GrB的原核表达载体 ,从而建立其原核表达体系 ,获得高效表达的重组GrB ,纯化蛋白。用淋巴细胞分离液分离肿瘤组织中的淋巴细胞 ,并抽提RNA ,RT PCR方法获得GrB的全长 ,并重组到pGEX 4T 1中 ,用限制性内切酶酶切和DNA测序法进行鉴定 ,IPTG诱导pGEX GrB转化的BL2 1菌 ,大量纯化表达产物 ,并通过SDS PAGE、Westernblot分析表达产物 ,用MTT法体外检测GrB对Hep2细胞的作用。结果 :限制性内切酶酶切和DNA测序分析证实成功获得GrB基因片段 ,GrB准确克隆入pGEX 4T 1 ,成功的构建pGEX GrB ,经诱导表达出与GST融合的蛋白 ,经凝血酶酶切后获得与GrB相符的条带 ,并能与GrB特异性抗体结合。体外实验表明 ,GrB能抑制Hep2细胞的增殖。成功构建了pGEX GrB ,并成功表达、大量纯化GrB蛋白 ,其能够抑制Hep2细胞的增殖。     

人IκBα基因原核表达质粒的构建及TrxA/IκBα融合蛋白的制备

目的利用基因重组技术构建人IκBα基因原核表达质粒,制备TrxA/IκBα融合蛋白,以便进一步研究IκBα的生物学功能和制备相应抗体. 方法以重组质粒pGEM-T-IκBα为模板,利用PCR方法扩增出带有BamHⅠ和HindⅢ酶切位点的人IκBα基因cDNA,经相应酶切后插入原核表达载体pET-32a(+).重组表达质粒pET32a(+)-IκBα转化大肠杆菌BL21(DE3),经IPTG诱导表达TrxA/IκBα融合蛋白.Western blot试验鉴定表达蛋白.超声波破菌后采用Ni-NTA树脂对TrxA/IκBα融合蛋白进行纯化. 结果酶切鉴定证实人IκBα基因cDNA已插入原核表达载体pET-32a(+).重组表达质粒pET32a(+)-IκBα在大肠杆菌BL21(DE3)中成功地表达了TrxA/IκBα融合蛋白,其相对分子质量(Mr)约为56×103,表达量约占细菌总蛋白的25%.Western blot试验显示TrxA/IκBα融合蛋白与兔抗IκBα多克隆抗体呈特异性免疫反应.经Ni-NTA树脂纯化后,TrxA/IκBα融合蛋白的纯度可高达95%以上. 结论人IκBα基因原核表达质粒的构建及TrxA/IκBα融合蛋白的制备为进一步研究IκBα的生物学功能和制备相应抗体奠定了物质基础.     

诱导表达人活性型颗粒酶B的Hela细胞系的建立

目的 :构建人颗粒酶B基因的可诱导表达载体 ,并将其在Hela细胞中诱导表达 .方法 :用PCR法获取人活性型颗粒酶B基因序列 ,克隆入pIND诱导表达载体中。将其与辅助质粒pVgRXR通过脂质体法共转染Hela细胞后 ,用G4 18和zeocin筛选建系。通过免疫细胞化学染色法 ,确定蜕皮激素A最佳的诱导浓度及诱导时间 ,并通过MTT比色法检测及细胞骨架染色等方法观察 ,表达的活性型颗粒酶B对Hela细胞形态和生长的影响。结果 :获得可诱导表达人活性型颗粒酶B基因的Hela细胞系。免疫细胞化学染色表明 ,30 μmol/L蜕皮激素诱导 5d时目的蛋白表达最强 ,同时观察到Hela细胞的形态发生变化 ,出现多核大细胞及固缩小细胞 ,并且细胞生长受到抑制。骨架分析进一步显示 ,多核大细胞的骨架发生异常。结论 :活性型颗粒酶B的可诱导表达系统的建立 ,为进一步研究颗粒酶B的生物学效应功能奠定了基础     

High expression of NKG2A/CD94 and low expression of granzyme B are associated with reduced cord blood NK cell activity

Human umbilical cord blood （CB） has recently been used as a source of stem cells in transplantation. NK cells derived from CB are the key effector cells involved in graft-versus-host disease （GVHD） and graft-versus-leukemia （GVL）. It was reported that the activity of CB NK cells was lower than that of adult peripheral blood （PB） NK cells. In this study, we analyzed the expression of some NK cell receptors and cytotoxicity-related molecules in CB and PB NK cells. The expressions of activating NK receptors, CD16, NKG2D and NKp46, did not show significant difference between CB and PB NK cells. But the expression of inhibitory receptor NKG2A/CD94 was significantly higher on CB NK cells. As to the effector function molecules, granzyme B was expressed significantly lower in CB NK cells, but the expressions of intracellular perforin, IFN-γ, TNF-α and cell surface FasL and TRAIL did not show difference between CB and PB NK cells. The results indicated that the high expression of NKG2A/CD94 and low expression of granzyme B may be related with the reduced activity of CB NK cells.     

穿孔素与颗粒酶B在鼻NK/T细胞淋巴瘤诊断中的意义

目的　检测鼻NK/T细胞淋巴瘤中的穿孔素、颗粒酶B表达分布情况 ,为临床治疗和预后判断提供依据。方法　运用免疫组化S P法检测 11例鼻NK/T细胞淋巴瘤中穿孔素、颗粒酶B的表达和分布情况 ;同时与组织芯片中其他类型淋巴瘤进行比较研究 ,10例淋巴组织反应性增生作为对照。结果　 11例鼻NK/T细胞淋巴瘤中均见穿孔素和颗粒酶B过度表达。以 6 0例淋巴瘤制成组织芯片的 4 2例B细胞淋巴瘤中见 11例少许穿孔素和 14例少许颗粒酶B阳性表达细胞散在分布于瘤细胞间 ,10例外周T细胞淋巴瘤中 8例少许表达穿孔素和 9例少许表达颗粒酶B。 2例间变性大细胞淋巴瘤见少许穿孔素和颗粒酶B阳性表达细胞。 2例霍奇金淋巴瘤阴性。NK/T细胞淋巴瘤的穿孔素和颗粒酶B表达程度与T、B淋巴瘤比较 ,差异有显著性 (P <0 0 1)。结论　穿孔素和颗粒酶B是鉴定活化的细胞毒性细胞的免疫标记物 ,可作为NK/T细胞淋巴瘤的诊断性标记物 ;其在外周T细胞淋巴瘤和B细胞淋巴瘤中的表达 ,反映了机体存在抗肿瘤的免疫反应机制。     

抗绿脓杆菌毒素A单克隆抗体杂交瘤细胞系的建立

本文采用绿脓杆菌外毒素A免疫BALB/c小鼠取脾细胞与Sp2/0细胞融合,建立了6株分泌单克隆抗体的杂交瘤,分别命名为14F10,23B9,23F1,23C12,,24A6及24B5。其中,23F1及24A6在传代培养中逐渐丧失了分泌抗体的能力,其余4株可稳定地分泌抗体。它们的Ig亚类鉴定;14F10为IgM,23B9为IgC1,23C12为JgG2b,24B5为JgG1。注射入同系小鼠腹腔,可产生高滴度抗体,在夹心ELISA试验中己证实均为抗绿脓杆菌外毒素A特异性的。此外,文中还讨论了在间接ELISA初次筛选中出现的假阴性及假阳性的原因及其排除方法。     

Co-exposure of lipopolysaccharide and pseudomonas aeruginosa exotoxin A-induced multiple organ injury in rats

Pseudomonas aeruginosa Exotoxin A (PEA) induces hepatotoxicity in experimental animals. Lipopolysaccharide (LPS) interacts synergistically with xenotoxics to induce severe organ injury. We examined the combination of non-injurious doses of LPS and sub-hepatotoxic PEA in the induction of multiple organ injury (MOI). Rats treated with 20 or 40 μg/kg LPS plus 10 μg/kg PEA developed severe liver, kidney, and lung injury; elevation of TNF-α, IFN-γ, and IL-2; and high mortality. Depletion of Kupffer cells or T-cells by pretreatment with Gadolinium Chloride or FK506, respectively, attenuated MOI. Thus LPS + PEA acted synergistically on Kupffer and T-cells to induce proinflammatory cytokines contributing to MOI.     

Increase in granzyme B+ lymphocytes and soluble granzyme B in bronchoalveolar lavage of allergen challenged patients with atopic asthma

Asthma has been linked to a chronic, T-cell-mediated bronchial inflammation. Because other T-lymphocyte-mediated, chronic inflammatory disorders have been associated with elevated granzyme B (grB) expression we tested the hypothesis that atopic asthma might be associated with elevated grB levels in the bronchoalveolar compartment. Therefore we performed intracellular grB staining in lymphocytes from bronchoalveolar lavage (BAL) collected 42 h after segmental allergen provocation (SAP) in allergic patients with bronchial asthma. There was a significant increase in CD3(+), CD8(+), and CD16/56(+) lymphocytes expressing grB in BAL 42 h after SAP as compared to saline challenged controls. However, compared to peripheral blood the percentages of these lymphocyte subsets detected as grB(+) in BAL remained significantly lower. Measurement of extracellular grB in BAL fluids by a particle immunoassay revealed significantly elevated grB levels in the allergen challenged bronchoalveolar compartment 42 h following SAP in six of the eight patients (range, <1.0-348.1 pg/ml) as compared to saline challenged controls (range, <1.0-70.5 pg/ml). We conclude that total cell numbers of grB(+) lymphocyte subsets increase 42 h after SAP in the lower respiratory tract. In addition there is evidence to suggest that grB is released into the airways of asthmatic patients. This suggests a role for grB in the pathophysiological processes following SAP but its definitive role in allergic bronchial asthma needs to be established.     

铜绿假单胞菌外毒素衍生物PE38KDEL的原核表达载体构建及其鉴定

目的 构建铜绿假单胞菌外毒素衍生物(PE38KDEL)的原核表达载体并对其表达的蛋白进行鉴定.方法 采用PCR方法扩增本实验所需要的PE38KDEL基因片段,再通过酶切及连接反应构建原核表达载体pGEX-4T-1-PE38KDEL,重组载体经过限制性内切酶酶切、PCR扩增鉴定及DNA序列测定证实插入片段正确后,转化感受态大肠杆菌BL21,经IPTG诱导表达,表达产物经SDS-PAGE电泳后及蛋白免疫印迹法分别测定其大小和特异性.结果 经鉴定证实原核表达载体pGEX-4T-1-PE38KDEL构建成功,且在大肠杆菌BL21中获得了PE38KDEL与GST的融合表达,且表达蛋白产物的分子质量大小与预期值一致,并可被PE的特异性抗体所识别.结论 PE38KDEL在大肠杆菌中获得了高效的融合表达,为下一步研究其功能奠定了基础.     

Expression of Epstein-Barr virus and granzyme B in cytologic smears of histiocytic necrotizing lymphadenitis

Histiocytic necrotizing lymphadenitis (HNL) is a non-neoplastic disease of the lymph nodes that is self-limiting in its clinical course. In this study, the expression of Epstein-Barr virus (EBV), granzyme B, and other phenotypic markers of HNL was investigated in fine needle-aspirated (FNA) cytologic smears obtained from 38 patients with HNL. The smear were subjected to immunohistochemical staining for granzyme B, CD3, CD4, CD8, CD20, and CD68 in addition to in-situ hybridization for EBV to determine whether marker expression could be correlated with disease pathogenesis. The mean age of 28 female and 10 male patients was 22.8 years. CD8-positive cytotoxic T cells were noted in 65.0% of the smears (13/20 cases), whereas CD4 and CD68 were rarely observed. Granzyme B reactivity was seen in lymphocytes, especially in apoptotic areas, and in histiocytes, with positive rates of 25.0% (9/36) and 11.1% (4/36), respectively. Most FNA smears showed immunoreactivity to both CD3 and CD20, with a predominance of CD3-positive cells. In-situ hybridization for EBV was positive in 22.9% (8/35) of the cases. The immunohistochemical staining and EBV in-situ hybridization results obtained in bleached FNA smears were similar to those in histologic sections. Overall, our results implicate that even though EBV positivity and granzyme B immunoreactivity are noted in HNL, they do not appear to have any apoptosis-associated role.