鸡新城疫强毒分离株SC01的分子特性及与La Sota和F48E8的交叉保护

对NDV四川分离鸡源强毒株SC01的F基因进行克隆测序,克隆的SC01 F基因片段长1600bp,编码的F蛋白裂解位点序列为112R-R-Q-K-R-F117,具有强毒株序列特征,聚类分析属基因Ⅶe型;F基因与国内外NDV代表株的核苷酸同源性为75.4 %～95.4 %,其中与鹅源毒株JS501Go 的同源性高达95.4%,与F48E8同源性为84.3%,与La Sota 的同源性为82%;La Sota弱毒活疫苗及F48E8灭活疫苗免疫小鸡2周后,对SC01的致死性攻击能提供完全保护.     

Construction and anti-tumor effects of recombinant fowlpox virus expressing Newcastle disease virus hemagglutinin-neuramidinase gene

Hemagglutinin-neuramidinase (HN), a Newcastle disease virus-derived protein, not only mediates receptor recognition but also possesses neuraminidase (NA) activity, the ability to cleave a component of those receptors, N-acetylneuraminic acid (NAcneu, sialic acid). It is known that this protein in mammalian species, including human beings, has interesting anti-neoplastic as well as immune stimulating properties. To explore the use of the HN gene in cancer gene therapy, we constructed a recombi-nant fowlpox virus expressing the HN protein (vFV-HN) and compared the anti-tumor activity of the recombinant virus with that of wild-type fowlpox virus (FPV) in vivo and in vitro. Here we found that although B16 cells were somewhat resistant to the basal cytotoxic effect of wild-type fowlpox virus, infection with vFV-HN caused a pronounced cytotoxic effect and, the survival of tumor-bearing mice immunized with vFV-HN was significantly increased compared with the survival of mice immunized with the FPV alone. Furthermore, the immunization of mice with vFV-HN elicited a B16 tumor-specific cytotoxic T lymphocyte (CTL) response and clonal expansion of both CD4 and CD8 T cell populations in vivo. In addition, T cells from lymph nodes of mice vaccinated with vFV-HN secreted high levels of the Th1 cytokine IL-2 and IFN-γ, indicating that the regression of tumor cells is related to a Th1-type dominant immune response. These results demonstrate that vaccination with vFV-HN may be a potential strategy for cancer gene therapy.     

NDV-Lasota毒株在鸡胚成纤维细胞上的增殖特性

为探讨NDV-Lasota株在鸡胚成纤维细胞(CEF)上的增殖特性,采用细胞病变观察、空斑技术、红细胞吸附试验和血凝试验等方法对Lasota株在CEF上的感染特性及其增殖动力学进行检测。结果表明:NDV-Lasota株在添加外源性胰蛋白酶的条件下,可在CEF上有效复制,细胞维持液中胰蛋白酶浓度为25μg/mL时,病毒感染细胞24 h后,红细胞吸附试验呈阳性;30 h后培养上清液血凝效价大于22;48 h后出现明显的细胞病变;72 h后细胞单层上形成边界清晰、圆形的小空斑。     

鹌鹑新城疫人工发病及其病理形态学观察

应用 A 株、F_(48)E_8株新城疫病毒对不同日龄鹌鹑人工发病试验,结果表明:不同日龄鹌鹑对两毒株均有较强的易感性;随日龄增加到成年鹌鹑时则易感性降低。A 株和 F_(48)E_8株病毒所致的病变在各日龄基本相似,但 A 株比 F_(48)E_8株病毒对神经系统的损伤为重。     

GaAs/AlAs弱耦合掺杂超晶格中存在电流自激振荡的掺杂和电压条件

结合宏观和微观模型 ,对GaAs AlAs弱耦合掺杂超晶格的纵向输运问题进行模拟计算 ,并给出产生电流自激振荡时的掺杂浓度和固定偏压的范围 .计算结果与实验数据基本吻合     

我国新城疫病毒疫苗通过重组影响病毒进化

许多商业新城疫活疫苗被广泛用来阻止我国新城疫病毒的感染.然而,疫苗在我国新城疫病毒群进化过程中所起的作用鲜为人知.为了确定在我国广泛应用的新城疫疫苗是否对该病毒进化进程产生影响,在本研究中,我们对在我国流行的新城疫病毒进行了系统发生和重组分析,获得了一系列NDV株间同源重组的证据.一些重组株的部分遗传物质被发现可能来自疫苗株,这些结果证实疫苗可能通过同源重组影响我国新城疫病毒的进程.由于疫苗与流行株之间的重组可能导致出现疫苗接种失败的后果,因此,在临床上应当尽可能避免疫苗与野生株之间的重组.故在NDV防治过程中,应该采用合适的免疫程序避免这种重组的发生.     

嗜神经型新城疫病毒野毒株的电镜观察

采用钼酸铵负染色方法，电镜观察一株野外分离的嗜神经型新城疫病毒。分离的毒株接种ＳＰＦ鸡胚后，收集尿囊液，在电镜下看到大量圆形或扁圆形，直径２００￣３００ｎｍ的病毒颗粒，并且，部分病毒粒子囊膜及纤突清晰可见。     

NDV核心抗原重组杆状病毒转移载体的构建

F和HN蛋白是新城疫病毒(NDV)中两种具有抗原性的表面糖蛋白．对NDV中国强毒株F48E8的F和HN基因进行了全长核苷酸序列分析．F基因的长度为1662bp，编码553个氨基酸，糖基化位点与已知的其他株系的位点相同；HN基因全长1904bp，编码571个氨基酸，其中第5个糖基化位点(第500～502个氨基酸)由NPT突变成NPV．为了便于在杆状病毒中表达，将F和HN基因的核心抗原区通过PCR扩增，并成功地克隆进杆状病毒转移栽体中，为利用杆状病毒表达系统生产抗新城疫病毒的基因工程疫苗打下基础．     

Feasibility Study of Aluminum Hydroxide Sol as Adjuvant to Prepare Stable Vaccine Using Newcastle Disease Virus as a Model

Aluminum hydroxide sol (consisting of aluminum hydroxide nano-particles) prepared by a hydrothermal method was used as nano-aluminum adjuvant adsorbed the inactived Newcastle disease virus (NDV). The zeta potential of aluminum hydroxide colloidal particles,the inactivated NDV and the nano-aluminum adjuvant NDV are +48.16 mV,?13.8 mV and +39.97 mV,respec-tively. The nano-aluminum adjuvant vaccine was transparent and stable without precipitate,whereas the conventional aluminum ad-juvant vaccine was turbid and a white precipitate was visible soon. The hemagglutination inhibition (HI) titers of the nano-aluminum adjuvant group were generally higher than those of the conventional aluminum group except the titer on day 29. The results show that the nano-aluminum adjuvant has better stability and higher levels of antibodies for a longer time than the conventional aluminum adjuvant.     

Antibodies against analogous heptad repeat peptide HR212 of Newcastle Disease Virus inhibit virus-cell membrane fusion

Membrane fusion is a key step in enveloped virus entry. Highly conserved heptad repeat regions (HR1 and HR2) of Newcastle disease virus (NDV) fusion protein (F) are critical functional domains for viral membrane fusion. They display different conformations in the membrane fusion states and are viewed as candidate targets for neutralizing antibody responses. We previously reported that an analog of heptad repeat peptides HR2-HR1-HR2(HR212) and HR2 could inhibit NDV induced cell-cell membrane fusion. Here, we show that HR212 can induce the production of highly potent antibody in immunized rabbits, which could recognize full length peptides of both HR1 and HR2, and inhibit NDV hemagglutination and NDV entry. These suggest that either HR212 or its antibody could be an inhibitor of virus-induced cell-cell membrane fusion.