重组杆状病毒表达的EIAV Env蛋白与含有env基因重组痘苗病毒的联合免疫

目的：构建新型的马传染性贫血病毒(EIAV)的候选疫苗：方法：利用BAC—To—BAC杆状病毒表达系统，将中国马传贫驴白细胞弱毒疫苗(EIAV DLV)及其亲本株(EIAV LN)env基因导入到杆状病毒基因组中。转染昆虫细胞后，得到的重组病毒用SDS—PAGE和Western blot检测表达产物。以本实验室构建的含有EIAV env基因的重组痘苗病毒，单独或与重组杆状病毒表达的EIAV Env蛋白联合免疫小鼠。结果：构建的重组杆状病毒能正确表达全长Env蛋白。与单独免疫组相比，联合免疫组免疫应答显著增强，其中中和抗体的滴度提高5～9倍。结论：含有EIAV env基因的重组痘苗病毒与Env蛋白抗原联合免疫，能够诱导高滴度的中和抗体。     

中国呼吸道合胞病毒地方株G蛋白在重组痘苗病毒中的表达

目的　构建表达中国呼吸道合胞病毒 (RSV)地方株G蛋白基因的重组痘苗病毒 ,以用于RSV感染防治的研究。方法　用基因克隆技术将中国RSV地方株G蛋白基因插入到痘苗病毒载体中 ,与痘苗病毒共感染获得重组病毒。用免疫印迹、ELISA、蚀斑减少试验等方法检测表达产物的免疫原性及生物活性。结果　RSV地方株G蛋白在痘苗病毒中获得较好的表达 ,表达产物的糖基化程度较高 ,且该重组病毒免疫家兔可诱发特异性抗体产生。蚀斑减少试验证明 ,用该表达产物制备的抗血清具有中和病毒的活性。结论　重组病毒表达的中国RSV地方株G蛋白具有较好的抗原性、免疫原性等生物活性     

利用重组痘苗病毒表达人CD20基因

目的获得重组人 CD2 0分子并研究编码人 CD2 0的基因在痘苗病毒中的表达。方法从 p GEM- T- EASY/ CD2 0载体上酶切下编码人 CD2 0分子的 c DNA,亚克隆到 p JSA1175载体上 ,重组质粒与野生痘苗病毒共转染 TK- 143细胞。结果APAAP检测到重组病毒感染的细胞表面有 CD2 0分子表达 ,富集后病毒滴度约为 1× 10 9pfu/ ml。结论人 CD2 0基因在痘苗病毒中表达 ,为研究其功能以及研制单克隆抗体奠定了基础     

Expression of herpes simplex virus type 1 DNA polymerase by recombinant vaccinia virus

We have studied expression of the catalytic subunit of a phosphonoacetic acid-resistant (PAA^r) DNA polymerase (Pol) of herpes simplex virus type 1 (HSV-1) strain ANG by recombinant vaccinia virus (VV) engineered with the dominant Ecogpt selection system. In agreement with the vector construction recombinant Pol expression was regulated like a VV late function. De novo-synthesis of the 136-kDa Pol polypeptide was detectable as early as 6 h postinfection, peaked between 10 and 12 h, and correlated with specific polymerase activity. Compared with HSV-1 lytic infection, the recombinant Pol protein exhibited a reduced stability with a half-life of 7 h. Whereas the Pol-associated exonuclease activities, determined from lysates of recombinant VV- and HSV-1-infected cells, were almost identical, the polymerizing activity of recombinant Pol ceased after 10 min of incubation, in correlation with the fact that Pol depends on its cofactor for optimal chain elongation. Kinetics of cellular localization, tracked by a monospecific Pol antibody, revealed that the catalytic subunit initially assembled to a few dot-like nuclear sites, reminiscent of HSV-1 DNA replication compartments. Later during infection, the localization of recombinant Pol matched with that found in lytically HSV-1-infected cells. This study demonstrates that nuclear transport and localization of the Pol subunit is independent of herpesviral functions, and neither requires the presence of herpesviral DNA sequences. Recombinant VV provides a promising alternative to explore protein interactions of the herpesviral replication machinery in their authentic cellular environment.     

Comparative sequence analysis of the M gene among rabies virus strains and its expression by recombinant vaccinia virus

Nucleotide sequences and the deduced amino acid sequences of the gene encoding the matrix (M) protein of the Nishigahara and the CVS strains of rabies virus have been determined. The M gene is 609 nucleotides long and is capable of coding for a peptide composed of 202 amino acids. Sequence comparison of these M genes with those of other stains [Pasteur (PV), ERA, Avol] revealed that there is 89.7–91.5% homology at the nucleotide level, and 90.1–92.1% homology at amino acid level, between almost all combinations of these strains. However, in the combinations of the PV and ERA strains, and the virulent CVS and the avirulent CVS-derived Avol strains, much higher homology was observed both at the nucleotide and amino acid levels. The predicted secondary structure and hydropathy profiles also exhibited similar features. Recombinant vaccinia virus containing the M gene was constructed. Sodium dodecyl sulfate (NaDodSO₄)-polyacrylamide gel electrophoresis of the precipitates obtained by immune reaction of the recombinant virus-infected cell lysate with a monoclonal antibody against the M protein revealed that electrophoretic mobility of the expressed protein is indistinguishable from that of the authentic M protein from rabies virions.The nucleotide sequence data of the M genes of the CVS and Nishigahara (RCEH) strains reported in this paper will appear in the DDBJ, EMBL, and GenBank Nucleotide Sequence Databases under the accession numbers D90450 and D90451.     

丙型肝炎病毒结构蛋白在痘苗病毒中的表达

为研究中国丙型肝炎病毒（ＨＣＶ）的抗原性及在细胞内的加工，将丙型肝炎病毒（ＨＣＶ）５’非编码区（ＮＴＲ）和结构基因（Ｃｏｒｅ＋Ｅ１＋Ｅ２／ＮＳ１）插入痘苗病毒表达载体ｐＪＳＡ１１７５中，转染ＴＫ－１４３细胞，经纯化得到丙型肝炎（ＨＣＶ）重组痘苗病毒ｖＪＳＡ１１７５ＣＥ株。Ｓｏｕｔｈｅｒｎｂｌｏｔ杂交表明，ＨＣＶ结构基因存在于痘苗病毒之中。Ｗｅｓｔｅｒｎｂｌｏｔ分析发现，ｖＪＳＡ１１７５ＣＥ表达蛋白带位于９０ｋＤａ，为一多聚蛋白；此蛋白为分泌型，分泌量与细胞裂解物内量大致相同     

表达GFP的重组减毒鼠伤寒沙门氏菌体内感染抗原呈递细胞的动态变化

目的：阐明重组减毒鼠伤寒沙门氏菌在体内早期感染抗原呈递细胞(APC)的动态变化规律。方法：用一定剂量的表达绿色荧光蛋白(GFP)的重组减毒鼠伤寒沙门氏菌X4550(pY．AG-FP)口服接种BALB／c小鼠。3d后，取腹腔巨噬细胞培养24h，用荧光显微镜观察。另以该细菌静脉注射小鼠，于感染后3、6和12h，制备脾脏、肝脏低浮密度细胞。用流式细胞术检测巨噬细胞和树突状细胞的感染率。结果：巨噬细胞感染X4550(pYAGFP)的百分率，腹腔中约为50％，肝脏和脾脏中约为20％～40％。树突状细胞感染X4550(pYAGF、P)的百分率，脾脏中约为4％～10％，肝脏中约为10％～20％。巨噬细胞的吞噬能力明显高于树突状细胞。结论：感染早期，重组减毒鼠伤寒沙门氏菌在体内已被APC所摄取，为诱导有效的免疫应答提供了先决条件。     

用流式细胞术检测胃癌p53蛋白的表达

目的：检测并比较胃癌及癌前病变p53蛋白表达水平,探讨p53蛋白在胃癌发病中的意义。方法;采用间接免疫荧光标记,流式细胞术分析。以DNA指数、增殖指数、荧光指数为分析指标。结果：胃癌、不典型增生及肠上皮化生的荧光指数（FI）值与正常胃粘膜相比差异均有显著性（P＜0．05）,前三者与浅表性胃炎相比差异也都有显著性（P＜0．05）。不同病变间的比较,可见胃癌FI高于不典型增生及肠上皮化生（P＜0．05）。不典型增生p53蛋白阳性率为27％,胃癌为68％,在不典型增生及胃癌病例中,其异倍体的FI值、增殖指数（PI）值和p53蛋白阳性率与二倍体者相比差异都有显著性（P＜0．05）。结论：胃癌组织p53蛋白的表达水平高于癌前病变及正常胃粘膜组织,随病变向恶性转化,p53蛋白、PI及异倍体率均增高。检测p53蛋白表达水平对胃癌的诊断具有一定意义。     

Binding of human C-reactive protein to monocytes: analysis by flow cytometry.

An opsonic role has been proposed as a major function of C-reactive protein (CRP) in humans. In support of this hypothesis, recent radiolabelled ligand binding studies have provided evidence for the presence of specific receptors for soluble human CRP on human phagocytic cells, including neutrophils and monocytes. In order to confirm specific binding of CRP to monocytes and to quantify the percentage of such cells capable of expressing binding sites, we employed a sensitive biotin-avidin fluorescence assay to study the CRP-monocyte interaction. It was observed that 67% of monocytes bound biotinylated CRP in a dose-dependent manner, that the binding was calcium dependent, and that it could be inhibited by 60% in the presence of a greater than 20-fold excess of competing native CRP. In other experiments, neither IgG nor heat-aggregated IgG inhibited the binding of CRP to monocytes; and no significant binding to lymphocyte population could be detected. These studies confirm the ability of human CRP to bind to a majority of human monocytes in a calcium-dependent and specific manner, and provide further support for a biologically important interaction of this acute-phase protein with phagocytic cells.     

Methodology of using vaccinia virus to express foreign genes in tissue culture

Summary A basic technique is described for inserting any foreign gene into poxvirus by in vitro recombination. Also described is a method for identifying and plaque-purifying recombinant poxvirus containing the foreign gene using nitrocellulose filters and DNA hybridization. Immunologic techniques are presented for analyzing expression of the foreign gene, either on the surface membrane or inside infected cells.     

人CD19基因在痘苗系统中的表达

目的 在痘苗系统中表达人ＣＤ１９基因,为研究ＣＤ１９分子的豚研制抗ＣＥ１９的单克隆抗体（ｍＡｂ）打下基础。方法 用ＰＣＲ技术扩增人ＣＤ１９全长基因,并 组人克隆载体ｐＧＥＭ－Ｔ,进行序列测定。将ＣＤ１９全长基因克隆人痘苗表达载体ｐＪＳＡ１１７５中,用脂 本介导的方法,与野生 人转染ＴＫ－１４３细胞。运用蓝斑筛选获避人ＣＤ１９全长基因的重组痘苗病毒,并用此重组病毒感染ＴＫ－１４３细胞,以ＡＰＡＡＰ法     

Characterization of spontaneous metastasis in an aggressive breast carcinoma model using flow cytometry

Studies of metastasis can be accelerated and provide more mechanistic information using cell lines which reproducibly and aggressively metastasize, and which are accurately and easily detected in tissues at all stages of the metastatic process. Although reporter proteins such as green fluorescent protein (GFP) and β-galactosidase have improved the tracking of tumor cells in vivo, their measurement has often been limited to visual observation and manual counting. In this study, we exploited the highly sensitive and objective quantitation provided by flow cytometry to characterize, in detail, the sequence of events associated with orthotopic metastasis in a highly aggressive mouse model. Following stable transfection of the MDA-MB-435 breast carcinoma cell line with GFP, we utilized an in vivo selection process to isolate a variant exhibiting increased primary tumor growth and metastasis. As few as one fluorescent tumor cell per 200,000 host cells could be accurately detected in dissociated tissues by flow cytometry, allowing us to demonstrate that metastatic cells migrate to the lungs of SCID mice very early after orthotopic implantation. Tumor burden in lungs increased in a smooth continuous manner, until death approximately eight weeks later. Levels of circulating tumor cells in blood were also detectable at an early timepoint, but remained relatively low throughout the course of secondary tumor development in the lungs. Surgical removal of the primary tumor at various times after inoculation significantly affected lung tumor burden, supporting the concept that circulating tumor cells in blood inefficiently initiate distal metastases. Furthermore, the continuing contribution to metastasis by the primary tumor was independent of tumor mass. The combined characteristics of enhanced orthotopic metastasis and quantitative detection in blood and tissues will make this a useful new model for the characterization of the multi-stage progression of cancer, and the preclinical evaluation of anti-neoplastic therapies. This revised version was published online in July 2006 with corrections to the Cover Date.     

应用RNAi抑制细胞中绿色荧光蛋白的表达

目的 在293T和Mel细胞中研究RNA干扰（RNA interference，RNAi）对绿色荧光蛋白（enhanced green fluorescent protein，eGFP）表达的沉默作用。方法 以巢式PCR方法从人胚肾293T细胞中克隆出依赖于RNA聚合酶Ⅲ的H1启动子，并用于驱动RNAi片段的合成；构建能抑制eGFP特异性表达的RNAi载体（TRl）。将eGFP载体和RNAi干扰载体共转染293T和Mel两类细胞中，应用荧光显微镜观察、逆转录-PCR、荧光辅助细胞分选技术和定量逆转录-PCR方法分析上述细胞中RNAi对eGFP表达的抑制情况。结果 RNAi载体能有效地使293T和Mel细胞中红系特异的eGFP表达量均降低约50％以上。结论 本文构建的RNAi载体能有效的抑制目的基因eGFP在细胞中的表达。     

Expression and regulation of the vaccinia virus thymidine kinase gene in non-permissive cells

The expression and regulation of the vaccinia virus (VV) thymidine kinase (tk) gene was examined in two non-permissive cell lines, CHO and MDBK, which restrict VV development at different stages of the viral replication cycle. The VV tk gene was expressed in these two cell lines with kinetics similar to a fully permissive cell line BSC40. These results are consistent with the hypothesis that inhibition of tk mRNA translation by another viral early gene product is a normal component of the overall strategy employed to express and regulate the VV tk gene during a productive infection.     

Interleukin-5 expressed by a recombinant virus vector enhances specific mucosal IgA responses in vivo

Several in vitro studies have shown that murine interleukin-5 (mIL-5) enhances IgA production by activated mucosal B cells. To date, however, there is no evidence that this factor significantly up-regulates mucosal IgA responses in vivo. Here, we show that expression of the gene for mIL-5 in a recombinant vaccinia virus vector markedly increases IgA responses to co-expressed heterologous antigen in the lungs of mice given intranasal inocula of the virus. The elevated local IgA responses to vectors expressing mIL-5 peaked at a fourfold higher level than those elicited by control virus at 14 days after infection and were sustained for at least 4 weeks. Increased IgA responses were abrogated in mice treated with monoclonal antibody against mIL-5 and were not detected in systemic lymphoid tissue. No enhancement of specific IgG levels was found either locally or systemically. Our results indicate that mIL-5 selectively enhances the development of mucosal IgA responses in vivo and suggest that expression of this factor in mucosal vaccine vectors may stimulate local immune reactivity.     

应用痘苗病毒载体表达的重组甲肝抗原特性的研究

目的 探讨以痘苗病毒载体表达的甲肝病毒培养合适的细胞系和重组病毒灭活以及甲肝病毒抗原保存条件.方法 将构建成功的表达甲肝抗原的重组痘苗病毒分别接种于K4、143、HEL、Hep-2和Vero等细胞,用ELISA测定重组甲肝抗原的表达产量和不同方法灭活重组病毒后的抗原活性.结果 在K4、143和HEL细胞表达重组甲肝抗原的产量略优于Hep-2和Vero细胞,重组病毒经β-丙内酯和甲醛灭活后,甲肝抗原活性不变,制备的重组甲肝抗原稳定性好.结论 痘苗病毒表达载体可以提高甲肝抗原表达效率,具有十分广阔的应用前景.     

Application of flow cytometry for biomarker-based cervical cancer cells detection

The Pap test used for cervical cancer screening is subjective, labor-intensive, and has relatively low sensitivity and specificity for the detection of underlying clinically significant lesions. The objective of this study is to develop a biomarker/flow cytometry-based approach for cervical cancer screening. Immunofluorescence technology to quantify cervical cell expression of two biomarkers p16(INK4A) and Mcm5 was developed and evaluated by both microscopy and flow cytometry. The capability of using biomarker/flow cytometry approach to detect rare-event dysplastic cells in a large background of benign epithelial and inflammatory cells was evaluated. The results indicate that flow cytometry could detect 0.01% dysplastic cells in a background of normal cervical epithelial cells with the combination of the two biomarkers. Thirty-two clinical specimens were used to test the biomarker/flow cytometry-based approach and the results were compared with the liquid-based cervical cytology. The experiment yielded 100% sensitivity and 93% specificity with reference to the liquid-based cervical cytology. This study indicates the promise of using multi-color fluorescence flow cytometry for biomarker-based cervical cancer screening. This molecular-based, potentially high-throughput and automated method is expected to provide an alternative/auxiliary means of cervical cancer screening.     

Intracellular processing and immunogenicity of the envelope proteins of human T-cell leukemia virus type I that are expressed from recombinant vaccinia viruses

Two types of recombinant vaccinia viruses (VVs) expressing the env gene of the human T-cell leukemia virus type I (HTLV-I) were reported previously. One recombinant VV, WR-proenv1, synthesized the authentic env protein. In the other recombinant VV, WR-env17, the env gene was inserted within the signal sequence of the VV hemagglutinin (HA) gene, so that the reading frame for the env gene was in phase with that for the HA gene. Comparative studies were performed on the mode of expression and processing of the env proteins in relation to their immunogenicity. In WR-env17-infected cells, translation was initiated exclusively from the initiation methionine of the HA to produce nascently the chimeric env protein, including the altered HA signal peptide. Both this altered HA signal peptide and the internalized env signal peptide functioned as insertion signals for the endoplasmic reticulum. Although about half of the nascent chimeric protein was cleaved at the carboxyl terminus of the internalized env signal peptide to produce the authentic env protein, the other half was cleaved at the carboxyl terminus of the altered HA signal peptide alone to synthesize the chimeric protein. These events led to a less efficient transport of the env protein produced by WR-env17 from the rough endoplasmic reticulum to the Golgi apparatus than that of the authentic env protein synthesized by WR-proenv1. The efficiency of the processing and transport of the env protein affected the immunogenicity of these two recombinant VVs.     

应用痘苗病毒载体表达的重组甲肝抗原特性的研究

目的 探讨以痘苗病毒载体表达的甲肝病毒培养合适的细胞系和重组病毒灭活以及甲肝病毒抗原保存条件.方法 将构建成功的表达甲肝抗原的重组痘苗病毒分别接种于K4、143、HEL、Hep-2和Vero等细胞,用ELISA测定重组甲肝抗原的表达产量和不同方法灭活重组病毒后的抗原活性.结果 在K4、143和HEL细胞表达重组甲肝抗原的产量略优于Hep-2和Vero细胞,重组病毒经β-丙内酯和甲醛灭活后,甲肝抗原活性不变,制备的重组甲肝抗原稳定性好.结论 痘苗病毒表达载体可以提高甲肝抗原表达效率,具有十分广阔的应用前景.