VPS34蛋白抑制剂PIKⅢ体外广谱抗冠状病毒作用研究

为了寻找有效抗冠状病毒感染的治疗靶点,用CCK-8法和结晶紫法检测VPS34蛋白抑制剂PIKⅢ对细胞的敏感性,通过CCK-8法检测PIKⅢ抗病毒活性,通过病毒滴度及RT-PCR检测PIKⅢ对冠状病毒复制的影响。结果显示,PIKⅢ可以抑制多种冠状病毒对细胞的杀伤作用,提高细胞活性并且减少冠状病毒复制。VPS34蛋白抑制剂PIKⅢ对SARS-CoV-2、PEDV和TGEV 3种冠状病毒感染具有抑制作用,可以减少病毒复制,PIKⅢ可能是一种有效的抗冠状病毒药物。

猪源IFN-λ3的克隆、表达及抗病毒活性分析

为了解猪源IFN-λ3的体外抗病毒活性,本研究利用RT-PCR技术从猪肺巨噬细胞(CRL2845)中扩增获得猪源IFN-λ3基因(pIFN-λ3),并将pIFN-λ3基因克隆至真核表达载体pcDNA3.1,构建重组质粒pCDNA3.1-pIFN-λ3,利用脂质体转染293细胞。48 h后通过Western blot分析pIFN-λ3瞬时表达情况,取转染后上清分别作用于PK15、MDCK细胞进行pIFN-λ3抗病毒活性分析。结果显示,本研究成功扩增获得pIFN-λ3基因,并在293细胞内成功表达;瞬时表达能够抑制表达绿色荧光蛋白的重组水泡性口炎病毒(Vesicular stomatitis virus-green fluorescent protein,VSVG)在PK15、MDCK细胞上的增殖。本研究结果为深入研究猪源IFN-λ3在宿主抗病毒免疫和黏膜免疫中的作用机理及其应用提供参考和依据。

小反刍兽疫流行状况及分子诊断技术研究现状

小反刍兽疫(PPR)是一种主要感染山羊和绵羊的传染病,病原为副黏病毒科麻疹病毒属的小反刍兽疫病毒(PPRV)。PPRV基因组由6个基因组成,依据N和F基因可将PPRV分为4个谱系或者基因群,我国流行的PPRV属于谱系Ⅳ。2007年我国首次报道发生PPR疫情,在2014年大流行后,农业农村部加强了PPR的防疫措施。目前,国内的PPR疫情基本得到了控制,主要风险来自于境外输入和野生动物。PPRV分子检测是防疫措施的重要一环,目前已经建立了多种针对PPRV不同基因的检测方法。将新型技术应用于PPRV分子检测,开发小型化、快速化、高通量的PPRV检测方法将是未来的发展方向。

Inhibition of Dual Specific Oncolytic Adenovirus on Esophageal Cancer via Activation of Caspases by a Mitochondrial-dependent Pathway

We investigated the anti-tumor effects of dual cancer specific-oncolytic adenovirus Ad-VP on esophageal cancer（EC）. The anti-tumor activity of Ad-VP was compared with that of the control recombinant adenoviruses （Ad-GP, Ad-Apoptin, Ad-EGFP） in human esophageal cancer cell EC-109 and human normal liver cell L02 in vitro. In 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） assays, the growth of EC-109 cells was slightly inhibited by Ad-GP, Ad-Apoptin and Ad-EGFE However, Ad-VP induced a significant cytotoxic effect. Infection of EC-109 cells with Ad-VP resulted in a significant induction of apoptosis of them in vitro, detected by 4＇,6-diamidino-2-phenylindole（DAPI） or acridine orange and ethidium bromide staining. The results of Western blot and flow cytometric assay indicate the loss of mitochondrial membrane potential（Aψm）, the release of eytochrome c and the activation of caspase-3, 6 and 7 in Ad-VP infected EC-109 cells. In contrast, all these assays show almost no effects of the recombinant adenoviruses on L02 cells. These results demonstrate that the treatment of tumors with Ad-VP selectively inhibits tumor growth and induces apoptosis of esophageal cancer cells. Ad-VP may provide a novel and powerful strategy for cancer gene therapy.

Activity of T Cells Stimulated by Hemagglutinin-neuraminidase of Newcastle Disease Virus in vivo

To investigate the stimulated activity of T cells and the anti-tumor properties of hemagglutinin-neuraminidase（HN） of Newcastle disease virus（NDV） strain Changchun（NDVcc）, the expression of HN gene in hepatoma cells（human HepG-2 and mouse H22 cells） infected with the recombinant adenovirus（Ad-HN） was identified by Western blot analysis and flow cytometry. Sialidase activity of NDVcc HN expressed by Ad-HN was assayed by the periodate-resorcinol method. The in vivo anti-tumor effects of NDVcc HN were evaluated in the H22 solid tumor model. Regional lymph nodes of the mouse model treated with Ad-HN were removed to harvest T lymphocytes and evaluating the specific cytotoxicity of cytotoxic T lymphocyte（CTL） and natural killer（NK） cells by an L-lactate dehydrogenase（LDH） assay, in the mean time, the secretion of cytokines was analyzed by enzyme linked immunosorbent assays（ELISA）. The results show that NDVcc HN was effectively expressed by Ad-HN in HepG-2 and H22 cells. The sialidase activity assay showed that Ad-HN significantly reduced sialic acid level of the hepatoma cells compared with the cells infected the empty adenovirus vector（Ad-mock）. When treated with Ad-HN, the growth of subcutaneous H22 primary tumors in C57BL/6 mice was suppressed, and the mean mice survival increased. In addition, the treatment of Ad-HN elicited strong NK and CTL responses, and high levels of Th1 cytokines, such as IL-2 and IFN-γ. In conclusion, NDVcc HN effectively elicits T cell-mediate anti-tumor cytotoxicity via sialidase activity and may be a novel strategy for cancer immunotherapy.

Anti-tumor Effects of a Recombinant Fowlpox Virus Expressing Apoptin on Human Cervical Carcinoma in Vivo and in Vitro

Apoptin is a chicken anemia virus-derived,p53-independent,bcl-2-insensitive apoptotic protein with the ability to specifically induce apoptosis of various human tumor cells,but not of normal diploid cells.To explore the application of apoptin in tumor gene therapy,we used a recombinant fowlpox virus expressing apoptin protein （vFV-Apoptin） to investigate the anti-tumor effectes of vFV-Apoptin on human cervical carcinoma（HeLa） cells in vivo and in vitro through 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide（MTT） assay,acridine orage/ethidium bromide（AO/EB） and annexin V staining test,respectively.The results show that vFV-Apoptin inhibites the proliferation of HeLa cells in vitro through inducing the apoptosis of HeLa cells,and the inhibition effect of vFV-Apoptin has a dose-effect and time-effect relationship.The results of animal models show that vFV-Apoptin significantly inhibits tumor growth,extends the lifespan of animals and improves the mean survival.Experimental results indicate that vFV-Apoptin has a potential application in the tumor gene therapy.

Adjuvant Effects of Dual Co-stimulatory Molecules on Cellular Responses to HIV Multiple-epitope DNA Vaccination

Designing adjuvants that can induce strong cytotoxic T cell responses is largely required for preparing DNA vaccines. In this study we explored dual costimulatory molecules 4-1BBL and OX40L as adjuvants to improve the efficiency of the HIV multiple-epitope DNA vaccine. When explored in the human dendritic cell-T cell based coculture system, dual costimulatory molecules significantly enhanced the anti-HIV T cell response of the HIV multiple-epitope DNA vaccine, as detected by intracellular cytokine staining to HIV antigens, cytokines accumulation in the cultures, and antigen-specific cytotoxic T lymphocyte responses. These results suggest that dual costimulatory molecules 4-1BBL and OX40L can effectively increase the potential of the HIV multiple-epitope antigen DNA vaccine and may provide an exciting approach for HIV therapy.

非侵入性血流检测法辅助卒中后抑郁模型的建立

卒中后抑郁是脑卒中患者发病率最高的精神障碍性疾病,其发病机制复杂,缺乏有效治疗性药物。为了建立更高效的小鼠动物模型,以研究该病发生机制、评估药物疗效,通过改良手术方案,并用激光散斑血流成像系统对造模试验进行非侵入性血流检测法辅助构建卒中后抑郁小鼠模型。结果表明,该方法可在造模过程中,实时、准确判断给药位置及药物作用效果,经过蔗糖偏好试验、悬尾试验等行为学检测方法,证明激光散斑血流成像系统辅助方法能够有效监控手术过程,提升卒中后抑郁Balb/c小鼠模型建立的成功率。

Expression and Characterization of a Recombinant Truncated Capsid Protein of Hepatitis E Virus in Pichia pastoris

Hepatitis E is an enterically transmitted viral disease caused by infection with hepatitis E virus（HEV）. HEV is a nonenveloped virus that bas been classified in the family of Caliciviridae. The virus appears to be a polya-denylated, positive-stranded RNA virus with three major open reading frames（ORFs）. The capsid protein of HEV is encoded by the open reading frame 2（ORF2）. We attempted to produce a truncated capsid protein, designed p293, in Pichia pastoris. The p293 gene encoding amino acids（aa） 382-674 of HEV ORF2 was designed based on the full length of HEV ORF2, cloned into the yeast vector pPIC9K, and expressed in P. pastoris strain GS 115. SDS-PAGE and Western blotting demonstrated that the recombinant protein p293 could well be expressed in P pastoris. Under optimized conditions （culture medium pH, 6.0-6.5; methanol concentration added daily, 3.0%; inoculum density, OD600=60; induction time point, 72-96 h）, the yield of soluble p293 was approximately 80 mg/L. We also observed p293 secretory expressed in P. pastoris to be 30 nm viral like particles by using electron microscopy. These results show that the p293 may has utility in the analysis of cell specific factors in the protein processing and assembly of HEV, and serve as a useful antigen for both diagnostic and vaccine purposes.

尼帕病毒全球流行态势解析

尼帕病毒(Nipah Virus,NiV)是一种严重威胁人类与动物健康以及公共卫生安全的人兽共患病原体,可通过直接接触或气溶胶的形式进行传播,导致人或动物感染甚至死亡。本文总结了自1998年马来西亚发生第一例感染者至今,NiV暴发和流行过的国家和地区,并分析了NiV的主要传播方式。调查研究发现,NiV在西太平洋地区和东南亚地区的流行呈上升趋势,且我国的广西、云南等南方地区属于NiV流行的高危区域,虽然目前没有相关病例报告,但应当加强预警与流行病学研究,时刻监测该病毒对我国的入侵。

Molecular Design and Immunogenicity of a Multiple-epitope FMDV Antigen and DNA Vaccination

This article reports the design and construction of a multiple-epitope foot and mouth disease virus （FMDV） antigen, designated as OAAT. This recombinant antigen consists of the structural protein VP1 genes from serotypes A and O FMDV, five major VP1 immunodominant epitopes from two genotypes of Asial serotype, and three Th2 epitopes originating from the nonstructural protein, three ABC gene and structural protein VP4 gene. Expressions of target gene from these plasmids in HeLa cells were verified by Western-blot. BALB/c mice were immunized intramuscularly with the DNA vaccines thrice every two weeks. We found that pA could induce simultaneously specific antibodies against serotypes A, Asial, and O FMDV. Compared to those of the controls, the spots of FMDV-specific IFN-7 and cytotoxic activity from mice immunized with pA were significantly increased, pA provided full protection in 2/4 guinea pigs from challenge with FMDV O/NY00 and Asial/YNBS/58, respectively. The results show that although pA did not give full protection in 100% immunized guinea pigs from challenge with type O and Asial FMDV, respectively, OAAT may be potential immunogen against FMDV and pA may be potential DNA vaccines against FMDV.

表达BTV-16 VP2蛋白重组痘苗病毒的构建与筛选

为了构建并筛选表达16型蓝舌病病毒(BTV-16)VP2蛋白的重组痘苗病毒rVTT-VP2,本研究通过同源重组的方法构建重组痘苗病毒,以TK基因缺失和EGFP绿色荧光为筛选标记,通过噬斑纯化法在BHK-21细胞中纯化10次,并连续传代20次来验证重组痘苗病毒遗传稳定性。PCR鉴定结果显示,VP 2基因已整合到重组痘苗病毒基因组中,且未扩增出TK基因。荧光显微镜镜下观察,噬斑处均为表达绿色荧光蛋白的病变细胞。本研究成功构建了表达BTV-16 VP2蛋白重组痘苗病毒rVTT-VP2,为后期疫苗的研究奠定了基础。

Expression and Activities Experiment of DNA Transduction Motif Based on GAL4 in Pichia Pastoris

The genes encoding DNA-binding domain（BD） designed based on the yeast transcriptional activator GAL4 and protein transduction domain of HIV-1 Tat protein were fused via soft linker peptide sequence, and cloned into yeast expression vector pPIC9k. The resulted plasmid pTG was linearized and transfected into Pichia pastoris strains GS 115 by electroporation. High copies of transformants were obtained with Muts and HIS＋ phenotype identi- fication, PCR amplification and screening of G418. After flask culture and expression induced by methanol, the target protein named TG was well expressed and analyzed by SDS-PAGE and Western blot. Under optimized conditions, the yield of soluble recombinant protein was approximately 39.7 mg/L. DNA binding activity and cell transduction property of TG were analyzed by gel eleetrophoresis and fluorescent microscopy. The results show that the recombinant protein could bind strongly to the plasmid containing upstream activating sequence（UAS）. The cell experiments revealed that TG could deliver the binding plasmid into HEK-293 cells effectively. In summary, the work presented here suggests that TG is specific toward UAS containing plasmid and has the potential for use as nonviral DNA delivery agent.

Induction of Effective Antitumor Immune Response by Combined Administration of hIL-18 and NDV HN

To analyze the antitumor potential and mechanism of action of simultaneous Newcastle disease virus （NDV） hemagglutinin-neuraminidase（HN） and human interleukin 18（hIL-18） gene transfer in C57BL/6 mice with H22 hepatoma,the mouse model with H22 hepatoma was established in C57BL/6 mice, and the antitumor effects of the combined application of NDV HN and hIL-18 were evaluated in vivo. The results show that the growth of established tumors in mice immunized with adenovirus（Ad）-HN in conjunction with Ad-hIL-18 was significantly inhibited compared with that in mice immunized with Ad-HN, Ad-hIL-18 alone, or the empty vector（Ad-mock）. Furthermore, the immunization of mice with Ad-HN in conjunction with Ad-hIL-18 elicited strong natural killer activity and H22 tumor-specific cytotoxic T lymphocyte（CTL） responses in vivo. In addition, T cells from the lymph nodes of mice immunized with Ad-hIL-18 or Ad-HN＋Ad-hIL-18 secreted high levels of the Th1 cytokine IL-2 and interferon-γ （IFN-γ）, indicating that the regression of tumor cells is related to a Th1-type dominant immune response. These results demonstrate that vaccination with NDV HN together with hIL-18 may be a novel and powerful strategy for cancer immunotherapy.

重组猪源IFN-λ1植物乳杆菌的构建与表达验证

为构建猪源3型干扰素(pIFN-λ1)的重组植物乳杆菌并进行验证。通过PCR方法扩增含有植物乳杆菌锚定信号肽的猪源IFN-λ1基因(pIFN-λ1),插入到pSIP411表达载体电转入到中间克隆宿主菌NZ3900中,获得重组质粒pSIP-pIFN-λ1;再次电转入到表达宿主植物乳杆菌Lp18获得重组植物乳杆菌;制备重组植物乳杆菌并验证其表达。结果显示,成功扩增出650bp目的条带,电转入植物乳杆菌Lp18中成功构建重组Lp18:pSIP-pIFN-λ1。WesternBlot、免疫荧光和流式细胞分析等方法验证重组蛋白pIFN-λ1的表达,获得阳性结果,阳性率为22.96%,且进一步证明其展示并锚定在植物乳杆菌表面。本试验成功构建了1株能稳定表达猪源IFN-λ1蛋白的重组植物乳杆菌,为猪源IFN-λ1的开发应用研究提供理论基础。

寨卡病毒E蛋白的原核表达及鉴定

目的应用原核表达载体pET-28a表达ZIKV主要结构蛋白E蛋白,并对反应条件进行优化,为ZIKV亚单位疫苗的研究奠定基础。方法从GenBank检索ZIKV基因组,合成E基因并进行密码子优化,以提高原核表达效率。设计引物,以合成的E基因为模板PCR扩增ZIKV E基因,用BamHI和HindIII进行双酶切后连接表达载体pET-28a,构建原核表达重组质粒pET28a-ZIKV E,转化大肠埃希菌BL21(DE3)进行目的蛋白的表达,并对最适IPTG诱导浓度进行优化。结果 pET28a-ZIKV E经酶切及测序鉴定均构建正确。用重组质粒转化DE3,当加入IPTG终浓度为2mmol/L,成功表达出分子质量单位(Mr)为56×103重组ZIKV E蛋白,与理论分子质量相符合。Western blot检测重组蛋白可被His标签抗体识别。结论成功构建原核重组载体pET-28a-ZIKV E,表达的重组蛋白具有免疫反应性,为ZIKV亚单位疫苗的研制奠定了基础。

PRRSV YN-LQ株的全基因序列测定及遗传进化分析

从云南省某发病猪场分离到1株猪繁殖与呼吸综合征病毒（PRRSV），将该毒株命名为YN—LQ株。为了研究该毒株的遗传变异及分子生物学特征，根据PRRSV标准毒株NCBI登录号KC422728设计10对引物，对YNI。Q株全基因进行扩增及测序，将测序结果依次拼接获得YN—LQ株的全基因序列，并进行序列的比对分析。结果显示：PRRsVYN—LQ株基因组全长为15320bp；将YN—LQ株与经典PRRSV病毒株Nsp2、GP5及全基因进行比对分析，发现YN—LQ株与JXAl的同源性最高。Nsp2基因序列同源性为99．0％，其氨基酸序列有15个位点发生了改变；GP5基因序列同源性为97．7％，其氨基酸序列有9个位点发生了改变；全基因的同源性为98．7％。证实该毒株为JXA1变异株，为深入研究该病毒株的遗传与变异及其与生物学特性的关系奠定了基础。

广西JXA1-like谱系PRRSV分离株的致病性研究

目的探讨广西地区猪繁殖与呼吸综合征的流行毒株特征,了解JXA1-like谱系猪繁殖与呼吸综合征病毒的致病特性。方法取广西分离的JXA1-like谱系PRRSV毒株17-10-PI接种于4周龄健康仔猪,观察其临床表现、体温变化和病毒血症,并进行细胞因子检测和病理组织学分析,了解该毒株的致病性。结果17-10-PI组试验仔猪出现典型的病毒感染症状,体温在攻毒后6~10 d体温持续高于40.0℃,9 d时达到峰值40.8℃,15 d时有1头试验仔猪死亡。17-10-PI株能在试验仔猪体内快速复制引起病毒血症,相关细胞因子不同程度升高,以IFN-α和IL-2升高更为显著。剖检和病理学检查显示,17-10-PI株可致明显的间质增生性肺炎和炎性细胞大量浸润等病理损伤。结论17-10-PI株具有较强的致病性,能引起相关细胞因子升高和肺组织损伤。该研究可为JXA1-like谱系毒株的防控与疫苗的研发提供理论基础。

人IFN-λ1的克隆表达及其在不同种属细胞中的抗病毒活性分析

目的测定IFN-λ1在CaCo2、Vero、BHK-21、MDCK等4种不同种属来源细胞中的抗病毒活性。方法利用RT-PCR技术从人结直肠腺癌细胞(CaCo2)中扩增获得人IFN-λ1 (HuIFN-λ1)基因,然后克隆至真核表达载体pCDNA3.1-Flag-HA中,通过质粒转化、阳性菌落筛选、质粒提取及测序,获得重组质粒pCDNA3.1-HuIFN-λ1;利用脂质体将其转染293细胞,48 h后通过Western blot检测HuIFN-λ1瞬时表达情况,取转染后上清分别作用于CaCo2、Vero、BHK-21、MDCK等四种不同种属来源细胞进行HuIFN-λ1抗病毒活性分析。结果从人结直肠腺癌细胞中扩增获得HuIFN-λ1基因,大小为600 bp,并在293细胞内成功表达HuIFN-λ1,表达产物能抑制VSVG在CaCo2、Vero、BHK-21、MDCK中的增殖,流式细胞仪检测经HuIFN-λ1处理的上述细胞荧光率分别为73.69%、80.12%、71.73%、69.47%。结论重组表达的人IFN-λ1蛋白对4种不同种属来源的细胞均存在一定的抗病毒活性,为研究人IFN-λ1在宿主抗病毒免疫和黏膜免疫中的作用机制及其应用奠定了基础。

PDCoV和PEAV二重RT-PCR检测方法的建立及初步应用

猪德尔塔冠状病毒(PDCoV)和猪肠道α冠状病毒(PEAV)是两种新发现的猪传染性冠状病毒,临床上均以腹泻症状为主,症状相似,临床上难以快速诊断。为建立一种快速、准确区分PDCoV和PEAV的二重RT-PCR方法,本研究根据PDCoV和PEAV N基因序列,分别设计2对特异性引物,以阳性质粒为模板,对二重RT-PCR反应条件进行优化,并进行特异性、敏感性试验。结果显示,所建立的方法能够扩增出PDCoV和PEAV的特异性片段,大小分别为690 bp和208 bp,且对猪流行性腹泻病毒(PEDV)、猪传染性胃肠炎病毒(TGEV)、猪轮状病毒(PRV)和猪圆环病毒2型(PCV2)无扩增条带;对PDCoV和PEAV的最低检测量分别为5.13×102copies/μL、4.73×101copies/μL。对60份临床腹泻样本病料进行检测,结果PDCoV的检出率为21.6%,未检测出PEAV。本研究所建立的二重RT-PCR方法可用于临床流行病学监测,为快速诊断PDCoV和PEAV提供理论依据和技术支持。