特异性干扰ICP27基因的siRNA对HSV-1病毒复制的影响

针对单纯疱疹病毒1型(herpes simplex virus 1,HSV-1)的ICP27基因和其他疱疹病毒相关基因的高度保守区设计小干扰RNA(small interfering RNA,siRNA),研究其抑制病毒复制的效果。首先构建相应的小发夹RNA(small hairpin RNA,shRNA),然后通过病毒滴度测定、real-time PCR和细胞致病变效应(cytopathic effect,CPE)检测所设计的siRNA抑制病毒复制的能力。结果显示,所设计的shRNA-2(靶序列起始位置815)和shRNA-3(靶序列起始位置1 367)具有明显地抑制病毒复制的效果。尤其是shRNA-3,抑制病毒复制的效果更明显,在病毒滴度实验中,与阴性对照相比,其抑制倍数为81,同时可以下调ICP27基因的mR NA表达水平。实验结果表明shRNA-3能够显著抑制HSV-1病毒复制的能力,可以作为HSV-1感染性疾病的补充治疗手段,其对应的靶序列可以作为抗HSV-1新的靶标。     

靶向ICP4的小干扰RNA对HSV-1病毒复制能力的影响

HSV-1是一种嗜神经病毒,能引起一系列神经系统严重症状,然而目前抗HSV-1药物易反弹、不能完全清除潜伏的病毒。ICP4对HSV复制、转录起主要调节作用,决定着溶细胞型感染或潜伏状态的平衡点。为了探寻新的抗病毒策略,本课题以HSV-1ICP4基因为靶点,设计合成2对siRNA,并构建重组真核慢病毒表达质粒pL-KO-puror-hU6-siRNA,通过脂质体转染和嘌呤霉素筛选建立靶向ICP4的4个siRNA单克隆细胞系,Real-timePCR法检测细胞系中ICP4的mRNA表达水平,TCID50法检测siRNA对HSV-1病毒复制能力的影响。结果显示靶向siRNA能有效抑制单克隆细胞系中的ICP4表达,并且抑制ICP4的表达后HSV-1病毒复制能力明显减弱,表明靶向ICP4的siRNA对HSV-1复制有明显抑制作用,且多位点siRNA联合干扰对病毒复制有协同抑制效果,有望应用于生物抗病毒药物的制备。     

SiRNA干扰HSV-1即刻早期基因α22效应的初步分析

以HSV1即刻早期基因α22为靶点,应用T7 RNA聚合酶体外合成siRNA-1和siRNA-2序列,脂质体转染法将其导入Hep-2或KMB17细胞,再接种HSV1病毒,通过细胞形态和病毒滴度的测定,初步探索了siRNA干扰α22基因的的效应.结果表明,在Hep-2中,转染siRNA的实验组与对照组的细胞病变时间相同,子代病毒的生长曲线也没有显著差异;而分别转染或共同转染siRNA-1和siRNA-2 于"限制"性细胞KMB-17中,接种病毒后,ICP22特异的siRNA对HSV1的复制则表现了相应的干扰作用,细胞病变慢,子代病毒的最高滴度峰值出现较晚.     

SiRNA干扰HSV-1即刻早期基因α22效应的初步分析

以HSV1即刻早期基因α22为靶点,应用T7RNA聚合酶体外合成siRNA1和siRNA2序列,脂质体转染法将其导入Hep2或KMB17细胞,再接种HSV1病毒,通过细胞形态和病毒滴度的测定,初步探索了siRNA干扰α22基因的的效应。结果表明,在Hep2中,转染siRNA的实验组与对照组的细胞病变时间相同,子代病毒的生长曲线也没有显著差异;而分别转染或共同转染siRNA1和siRNA2于“限制"性细胞KMB17中,接种病毒后,ICP22特异的siRNA对HSV1的复制则表现了相应的干扰作用,细胞病变慢,子代病毒的最高滴度峰值出现较晚。     

我国单纯疱疹病毒I型168株糖蛋白D基因的克隆及其在痘苗病毒天坛…

将我国单纯疱疹病毒Ｉ型１６８株基因组ＤＮＡ中扩增出的糖蛋白Ｄ基因,插入痘苗病毒ｐ７．５启动子下游,使其在痘苗病毒天坛株表达,免疫荧光分析表明,产生的重组病毒糖蛋白Ｄ能被运到被重且病毒感染的１４３细胞表面表达,表达的产物经Ｗｅｓｔｅｎｂｌｏｔ鉴定为分子量约５０ｋＤ的多肽,Ｓｏｕｔｈｅｒｎｂｌｏｔ证明重组病毒基因组中整合有ＨＳＶ－１１６８株糖蛋白基因片段,重组病毒免疫家兔后,产生了高滴度的ＨＳＶ特异性     

HSV-2gD重组腺病毒疫苗的构建及免疫原性分析

Ⅱ型单纯疱疹病毒(Herpes simplex virus 2,HSV-2)是引起生殖器疱疹(Genital herpes,GH)的主要病原体,研制有效的HSV-2疫苗是控制病毒传播的有效途径,本研究通过穿梭载体pDC316将糖蛋白D2(Glucoprotein D2,gD2)基因连接到腺病毒载体上,制备HSV-2重组腺病毒rAd-gD2,经PCR和Western blot的方法在基因和蛋白水平上鉴定正确后,分别于第0、2、4周免疫小鼠,以PBS和空白腺病毒载体(AdV)为对照,第7周取血,通过检测小鼠血清中gD2特应性IgG和中和抗体评价体液免疫应答,检测Th1/Th2型细胞因子评价细胞免疫应答。结果显示经过3次免疫,小鼠产生了高水平的gD2特应性IgG和较高水平的中和抗体,Th1型细胞因子IFN-γ和IL-2明显高于对照组,Th2型细胞因子IL-4、IL-5和IL-10均高于对照组,P0.01,具有显著的统计学意义。本研究制备的rAd-gD2既可以刺激小鼠产生体液免疫应答,也可以产生细胞免疫应答,与预期设想一致,为未来HSV-2疫苗的研发提供了数据基础。     

单纯疱疹病毒2型糖蛋白D成熟肽基因毕赤酵母表达载体的构建及序列分析

构建单纯疱疹病毒2型包膜糖蛋白D成熟肽基因毕赤酵母表达载体,并对序列进行分析,为进行高抗原性的真核表达重组gD蛋白奠定基础。采用PCR扩增HSV2-gD成熟肽基因,将该段基因克隆于pGEM-T克隆载体,转化鉴定后,与巴斯德毕赤酵母表达载体(pPIC9K)酶切连接,转化大肠杆菌DH5α,筛选测序确定构建了pPIC9K?gD的真核表达载体,对克隆的序列进行分析,预测表达产物的理化特性及抗原性。结果显示,获得的重组的酵母表达载体pPIC9K-gD,测序结果证实为HSV2-gD成熟肽基因,序列分析其高度保守,预测蛋白分子量40.63kD,等电点pI为7.15,包含完整成熟肽分值达1.7的多个抗原决定簇。成功构建了HSV2-gD成熟肽基因的毕赤酵母表达载体。     

细胞水平狂犬病病毒感染的RNA干扰

以质粒pSilencer2.1-U6 Hygro为基础,设计并构建了针对狂犬病病毒(RV)糖蛋白和核蛋白mRNA的共9个siRNA表达载体,转染BHK-21细胞系后,在潮霉素-B的筛选压力下,获得9个稳定转录相关siRNA的BHK-21细胞株。1000TCID50的RV分别感染24孔板内的上述9株细胞,48h后以直接免疫荧光法检测各株细胞上RV的增殖,结果显示,在经不同siRNA表达载体转染的BHK-21细胞中,RV增殖水平有不同程度下降,RV增殖水平最低者为对照细胞的1%,即RNA干扰效应最高可阻断99%RV的感染。针对其中阻断水平超过90%的靶序列G69和N19,人工合成其双链siRNA,瞬时转染BHK-21细胞后,仍可达到80%以上的感染阻断率。本试验为有效阻断RV早期感染提供了新选择,为通过RNAi研究RV的基因组功能提供了新的依据。     

Expression and immunogenicity of recombinant glycoprotein D of herpes simplex virus 1 in Drosophila S2 cells

Herpes simplex virus type 1 (HSV-1) is responsible for cold sores in the general population, but also contributes to the development of other more serious diseases in some circumstances. The viral glycoprotein D (gD) is essential for virus entry into host cells. In the present study, the Drosophila melanogaster Schneider 2 (S2) expression system (DES) was evaluated for the expression of recombinant gD1. The DNA sequences encoding the full-length gD1 (369aa, FLgD1) and a truncated gD1 form corresponding to the ectodomain (314aa, EgD1) were cloned into S2 expression vector pMT/BiP/V5-HisA to generate pMT-EgD1 and pMT-FLgD1, respectively. Two forms of gD1 gene were fitted with a hexahistidine tag to facilitate their purification. Cell populations expressing the highest gD1 levels were selected by using a limiting dilution assay. Western blot, flow cytometry (FACS), and confocal immunofluoresence assay demonstrated that the full-length form is restrained in the lipid membranes of the cell and the ectodomain form is secreted into the medium. Recombinant ectodomain gD1 was scaled up and purified from the culture medium using nickel nitrilotriacetic acid affinity chromatography, and a maximum production level of 56.8 mg/L of recombinant gD1 was obtained in a shake-flask culture of S2 cells after induction with 5 µM CdCl2 for 4 days. Mice were then immunized with recombinant purified gD1 and produced high titers of antibody measured by enzyme-linked immunosorbent assay (ELISA; 1:5,120,000) as well as high plaque neutralization titer (1:320). Overall, the data indicated that stable expression in S2 cells is a practical way of synthesizing gD1 for use in structural and functional studies in the further study.     

Specific Deposition of Passively Transferred Monoclonal Antibodies against Herpes Simplex Virus Type 1 in Rat Brain Infected with the Virus

The kinetics of human monoclonal antibody (anti-gB) to herpes simplex virus type 1 (HSV-1) were investigated after intravenous injection of anti-gB into an HSV-1 encephalitis animal model. Immunohistochemical study revealed specific deposition of passively tansferred anti-gB in the hippocampus and thalamus of the infected rat brain, and it bound to the same neurons in which HSV-1 antigen was positively stained. To examine the macroscopic distribution of anti-gB in the infected brain, we undertook an ¹²⁵I-labeled anti-gB injection study, and the same distribution of ¹²⁵I-labeled anti-gB deposition was observed by brain semimicroautoradiography as in the immunohistochemical study. These results suggest that anti-gB easily permeates the capillary wall and is deposited in the inflammatory site where HSV-1-specific antigen is detectable. The use of radioisotope-labeled anti-gB injection and external brain imaging could lead to a noninvasive diagnostic tool for the early detection of HSV-1 antigen in cases of suspected HSV-1 encephalitis.     

DJ-1基因siRNA对三阴性乳腺癌细胞侵袭和迁移影响的研究

目的:探讨DJ-1基因siRNA对三阴性乳腺癌细胞体外侵袭和迁移能力的影响。方法:设计DJ-1基因的小分子干扰RNA(siRNA)片段,脂质体介导转染入三阴性乳腺癌细胞株MAD-MB-23l,转染分3个组:A组(空白对照control组)、B组(转染非特异性对照Scramble组)、C组(转染si DJ-1组)。应用Western blotting免疫印迹法检测转染前后DJ-1表达水平;运用细胞迁移和侵袭实验检测细胞迁移和侵袭能力的变化。结果:C组DJ-1蛋白的表达强度弱于A组和B组(t=9.831,P0.05),而A组与B组比较,DJ-1蛋白表达水平则无明显差异(t=1.629,P0.05)。细胞迁移实验中,A组细胞为(218.37±12.75);B组的细胞为(214.46±11.38);C组的细胞为(129.65±8.59),C组细胞明显少于A组和B组(t=10.927,9.984,P0.05),而A组与B组之间,差异无统计学意义(t=0.512,P0.05)。细胞侵袭实验中,A组细胞为(127.28±12.65);B组的细胞为(123.06±13.08);C组的细胞为(52.85±9.58),C组穿过人工基底膜的细胞明显少于A组和B组(t=7.927,8.643,P0.05),而A组与B组之间,差异无统计学意义(t=0.627,P0.05)。结论:DJ-1基因siRNA可抑制三阴性乳腺癌细胞侵袭和迁移。     

Herpes simplex virus type 1 dysregulates anti‐fungal defenses preventing monocyte activation and downregulating toll‐like receptor‐2

We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP‐1 monocytic cell line is first infected with HSV‐1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV‐1‐infected THP‐1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL‐12 production was also observed. Cytofluorimetric analysis showed that HSV‐1‐infected monocytes exhibit: (i) downregulated TLR‐2 and TLR‐4, critical structures in fungal recognition; (ii) reduced expression of CD38 and CD69, known to be important markers of monocyte activation; and (iii) enhanced expression of apoptosis and necrosis markers, in the absence of altered cell proliferation. Overall, these findings imply that HSV‐1 infection prevents monocyte activation, thus leading to a significant dysfunction of the monocyte‐mediated anti‐Candida response; HSV‐1 induced apoptosis and necrosis of monocytes further contribute to this impairment.     

单纯疱疹病毒Ⅰ型糖蛋白D在酵母中的表达

从提取的HSV-1基因组中扩增得到编码gD蛋白胞外区1～314aa的基因gDt,将其插入毕赤酵母表达质粒pPIC9K的醇氧化酶(AOX1)启动子下游,构建携带gDt的重组载体,经电转化GS115菌株和G418筛选,得到了高效分泌表达gD蛋白的毕赤酵母菌株,表达量达到250mg/L,该目的蛋白可被gD单抗(1-I-9)特异性识别.表达产物经离子交换、金属螯合、分子筛柱层析纯化后得到纯度较高的重组蛋白.重组gD蛋白免疫BALB/c小鼠可诱生一定水平的特异性抗体,表明该蛋白具有较好的免疫原性,能够诱导小鼠产生体液免疫应答.     

单纯疱疹病毒糖蛋白D的表达及免疫学鉴定

单纯疱疹病毒(herpes simplex virus,HSV)是TORCH综合征的病原体之一.新生儿可通过宫内、产道和出生后等多种途径感染,大部分患儿呈现症状,如皮炎、角膜炎、口唇疱疹,也可发生涉及多个器官的播散性感染,严重者出现疱疹性脑膜炎,并常导致婴幼儿死亡.目前尚无全身用的特效药物和有效的防范措施.HSV包膜糖蛋白D(glycoprotein D,gD)是极为保守的免疫原性蛋白,在体内可诱导高滴度的中和抗体,因此gD基因成为近些年来诊断研究的靶基因.本文尝试将gD蛋白在酵母菌中表达,并分析其抗原性,为建立快速易行的重组抗原诊断试剂盒奠定基础.此外,利用该表达系统表达的HSV gD蛋白,可为HSV基因工程重组疫苗的研制提供依据,对优生优育、提高人口出生质量具有重要的理论及实际意义.