小鹅瘟病毒VP3基因疫苗的构建及其诱导小鼠和鹅中和抗体的初报

PCR扩增小鹅瘟病毒（GPV）CHv株VP3基因并克隆入pMD 18-T-Simple载体,亚克隆正向插入到真核表达质粒pcDNA3．1（＋）CMV启动子下游多克隆位点,经PCR和Hind与Bandt I双酶切鉴定表明成功构建了GPVVP3基因疫苗（pcDNA3．1．GPV—VP3）。该疫苗以200μg/只肌注免疫Balb／c小鼠和鹅,同时分别设肌注PBS和pcDNA3．1（＋）作为对照,于免疫后第30、45、60、75、90、105天应用鸭胚原代成纤维细胞（DEF）进行微量中和试验检测小鼠和鹅血清抗100TCID50GPV的抗体效价。结果表明,pcDNA3．1-GPV-VP3免疫小鼠第30天可检测到抗GPV的中和抗体,抗体效价缓慢上升至90天达到高峰（平均1：135．8）后下降,105天仍高于75天;免疫鹅的中和抗体效价呈现与小鼠类似的规律,第90天达到高峰（平均1：98．5）。因此,pcDNA3．1-GPV-VV3具有良好的免疫原性,肌注免疫小鼠和鹅后能够诱发产生抗GPV的中和抗体,有进一步开展临床研究和应用的前景。     

鸡贫血病毒VP3基因诱导人肺癌细胞SPC-A1凋亡的作用机制

探索了重组质粒pVVP3对人肺癌细胞SPC-A1的作用及机制.将pVVP3经脂质体介导转染人肺癌细胞SPC-A1,通过MTT方法检测了细胞活力;采用吖啶橙/溴化乙锭(AO/EB)染色分析了肿瘤细胞凋亡;采用罗丹明123和DCFA染色测定了线粒体跨膜电位(△Ψm)和活性氧水平变化;通过底物染色反应检测了Caspase-3活性.检测分析结果表明:重组质粒pVVP3转染人肺癌细胞SPC-A1后,细胞活力明显降低; AO/EB染色可见明显的细胞凋亡形态学变化;与空质粒对照相比,线粒体△Ψm下降(P＜0.01),活性氧水平升高(P＜0.05),Caspase-3活性增强(P＜0.01).以上结果提示,重组质粒pVVP3能够通过上调ROS水平,下调线粒体△Ψm,进而激活Caspase-3,最终诱导人肺癌细胞凋亡.     

淋巴囊肿病毒核酸疫苗在牙鲆体内的表达及免疫效果评价

将本试验室得到的牙鲆淋巴囊肿病毒(LCDV-cn)衣壳蛋白0.6kb片段重组质粒pEGFP-N2-LCDV-cn MCP0.6肌注入牙鲆体内,荧光显微观察及特异性RT-PCR检测其在牙鲆组织内的表达,并进一步测定牙鲆外周血、肠、脾脏、前肾的淋巴细胞增殖反应、呼吸爆发活性及抗体产生水平.研究结果表明, pEGFP-N2-LCDV-cn MCP 0.6可分布于牙鲆各组织内,并在一定时间内持续表达;免疫学检测表明,该重组质粒诱导了牙鲆特异性体液免疫和细胞免疫.本试验成果为淋巴囊肿病毒核酸疫苗的生产应用和产业化提供了重要的理论依据.     

共表达VP3与hIL-18基因真核重组质粒的构建及对人结肠癌细胞的影响

先将鸡贫血病毒VP3基因插入真核表达载体pVAXl的多克隆位点，再将pVAX1载体上的IRES启动子及新霉素基因一同切下插入pVAXl的VP3基因下游，然后切下新霉素基因，将pIRES1基因插入其中，构建成pVVP3IL-18，将pVVP3IL-18转染Heda细胞。间接免疫荧光表明，在细胞膜和细胞浆观察到了特异的黄绿色荧光，证明表达了hIL-18。pVVP3IL-18转染人结肠癌细胞HCY-116后，经AO／EB染色及电镜观察，可见大量细胞凋亡。说明真核重组质粒pVVP3IL-18可在HeLa细胞中表达，并可在体外诱导人结肠癌细胞HCT-116凋亡。     

鸡贫血病毒VP3基因对荷C6胶质瘤Weister大鼠的治疗

构建荷C6胶质瘤Weister大鼠的肿瘤模型,随机分组给予不同的处理给药,观察治疗期间及治疗后的肿瘤生长情况,通过病理组织学、超微结构分析,检测鸡贫血病毒VP3基因核酸疫苗在Weister大鼠体内的抗肿瘤作用。结果表明,pVVP3治疗组肿瘤生长速度明显受到抑制,其抑瘤率达85．57％。病理组织学观察可见化疗对照组肝组织有点状坏死,而pVVP3治疗组肝组织未见明显病变。肿瘤组织超微结构观察在pVVP3治疗组可见典型的凋亡特征。说明鸡贫血病毒VP3基因核酸疫苗对Weister大鼠C6胶质瘤生长有抑制作用,可诱导肿瘤细胞凋亡,且对肝组织无明显损伤。     

Suppression of Mn segregation in Ge/Mn5Ge3 heterostructures induced by interstitial carbon

Mn₅Ge₃ compound, with its room-temperature ferromagnetism and possibility to epitaxially grow on Ge, acts as a potential spin injector into group-IV semiconductors. It is shown that the realization of Ge/Mn₅Ge₃ heterostructures is highly hampered by Mn segregation toward the Ge growing surface. The Mn segregation length can be estimated in-situ and in real time by means of reflection high-energy electron diffraction. We present here an approach allowing to greatly reduce or even to prevent the Mn segregation, whose principle is based on filling the Mn₅Ge₃ lattice with interstitial carbon atoms. In addition, we show that interstitial carbon in Mn₅Ge₃ allows to enhance not only the Curie temperature of Mn₅Ge₃C_x layers but also in the whole Ge/Mn₅Ge₃/Ge heterostructures.     

Structural transition induced by the release of residual stress in the complex of cubic and monoclinic Gd2O3:Eu nanoparticles

The Photoluminescence (PL) spectra of Gd₂O₃:Eu composed of cubic and monoclinic structure were collected on November 2003 and June 2006, respectively. The results show that a portion of cubic Gd₂O₃ transforms into monoclinic after the sample was left as it is for two years; and the ⁵D₁-⁷F_J emission of Eu³⁺ in cubic host was enhanced in this released complex. Considering the high pressure behavior of Gd₂O₃, we think this structural transition is due to the sample that endures a process of press and release while the residual stress is released slowly.