Identification of amino acid residues important to the neuraminidase activity of the HN glycoprotein of Newcastle disease virus

Monoclonal antibodies (MAbs) to three overlapping antigenic sites (designated 12, 2, and 23) on the hemagglutinin-neuraminidase glycoprotein (HN) of Newcastle disease virus (NDV) were previously shown to inhibit neuraminidase activity (NA) on neuraminlactose (R. M. Iorio and M. A. Bratt, 1984a, J. Immunol. 133, 2215-2219; R. M. Iorio et al., 1989, Virus Res. 13, 245-262). However, a competitive inhibitor of NA blocks the binding of only MAbs to site 23, suggesting that the domain they recognize may be closely related to the NA site. Antigenic variants selected with site 23 MAbs have single amino acid substitutions at HN residues 192, 193, or 200. Virions of variants, which have a substitution at residue 193 or 200, have alterations in NA which are not attributable to a commensurate change in HN content. A revertant of a temperature-sensitive mutant, which has markedly diminished NA relative to the wild type, has an amino acid substitution at residue 175. A second step revertant having partially restored NA has an additional substitution at residue 192 identical to that in one of the site 23 variants, which, in turn, also makes the revertant resistant to neutralization by site 23 MAbs. Thus, an amino acid substitution at residue 175, 193, or 200 of the HN of NDV can have marked effects on the NA of the protein. The amino acids in the region around residue 175 are highly conserved between the HNs of NDV and other paramyxoviruses, suggesting that this domain is important to the integrity of the NA site in this group of viruses.     

Monoclonal antibodies identify a strain-specific epitope on the HN glycoprotein of Newcastle disease virus strain Australia-Victoria

A panel of monoclonal antibodies raised against the hemagglutinin-neuraminidase glycoprotein (HN) of the Australia-Victoria strain of Newcastle disease virus has been used to compare that strain and eight other strains of the virus. The ability of the antibodies to neutralize infectivity, inhibit hemagglutination and neuraminidase, and bind to purified virions in solid-phase radioimmunoassays was determined for each strain. Of the four antigenic sites delineated by these antibodies on the HN of the homologous strain, site 1 (that with the greatest neutralizing susceptibility), is apparently conserved in all the strains tested as revealed by neutralization assays. The least neutralizing site, number 4, is also conserved in most of the strains tested. Site 2, which lies at or near the neuraminidase site, appears to be conserved in the avirulent strains but not in the virulent strains. An antibody to site 3 is unable to bind to a significant extent to any of the heterologous strains tested, and thus recognizes a strain-specific epitope. Inhibition of hemagglutination and neuraminidase by antibodies to each site were also examined and the results suggest that antibodies to sites 1 and 2 may distinguish virulent and avirulent strains at least with respect to these functions.     

Crystallization of Newcastle disease virus hemagglutinin-neuraminidase glycoprotein

The hemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus was isolated by cleaving HN (cHN) from reconstituted virosome with chymotrypsin. N-terminal sequence analysis of the purified cHN showed that chymotrypsin cleavage had occurred at amino acid 123, freeing the C-terminal 454 amino acids. The purified cHN retained its neuraminidase and receptor binding activities and reacted with specific monoclonal antibodies, showing that the isolated cHN was biologically and antigenically functional. The crystals of the cHN were obtained in acetate buffer (pH 4.6) containing polyethylene glycol 3350 and ammonium sulfate and belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimension of approximately a = 72 A, b = 78 A, and c = 198 A. Crystals of cHN grown in the presence of sialic acid (Neu5Ac) were grown in HEPES buffer (pH 6.2) containing polyethylene glycol 3350 and belong to the hexagonal space groups P6(1) or P6(5) with unit cell dimensions of a = b = 137.5 A and c = 116.6A. The orthorhombic crystals produced in this study diffract X rays to at least 2.0-A resolution, thereby setting the stage for the solution of the three-dimensional structure of the HN glycoprotein of a paramyxovirus.     

Temperature-sensitive mutants of Newcastle disease virus altered in HN glycoprotein size, stability, or antigenic maturity

It has been suggested that the 11 group B, C, and BC temperature-sensitive (ts) mutants of Newcastle disease virus (NDV), strain Australia-Victoria (AV-WT), have lesions in the gene for the hemagglutinin/neuraminidase glycoprotein (HN), and that complementation between groups B and C is intracistronic. Virions produced by these mutants even at permissive temperature contain greatly reduced amounts of HN, and the accompanying hemagglutinating and neuraminidase functions. To explore the basis for decreased HN incorporation into virions and the temperature sensitivity of these mutants, infected chick embryo cells were examined for changes in HN characteristics. The HN of two of the mutants was clearly altered in electrophoretic migration rates in both virions and infected cells. The migrational differences were not due to differences in glycosylation because altered migration rates were also observed in the presence of tunicamycin. In all cases, cells infected by these mutants produced as much HN as did AV-WT-infected cells, but the HN of six of these mutants was metabolically unstable. All of the mutants, including those with metabolically stable HN, exhibited greatly restricted ability to convert HN to an antigenically reactive form, indicating an early block in processing. For most of these mutants, the neuraminidase activities of infected cells were somewhat temperature sensitive, but the production of hemadsorbing activities on cell surfaces was not temperature sensitive. In contrast, the hemadsorbing and neuraminidase activities of cells infected by one mutant, BC2, were temperature sensitive, probably a reflection of the previously described extreme thermolability of the HN of this mutant. The relationship between these mutant characteristics, their temperature sensitivity and the virion phenotypes, is discussed. The data presented here confirm the assignment of these 11 group B, C, and BC mutants to defects in HN and begin to separate them into groups with different characteristics.     

Intracellular processing of the vesicular stomatitis virus glycoprotein and the Newcastle disease virus hemagglutinin-neuraminidase glycoprotein

The kinetics of intracellular transport of the vesicular stomatitis virus (VSV) glycoprotein (G) and the Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) glycoprotein in chicken embryo cells were compared. To assay for the appearance of pulse-labelled glycoprotein at the cell surface, an antibody-binding assay was developed which allowed the precipitation of only those molecules on the outside surfaces of infected cells. Using this assay, it was found that pulse-labelled VSV G protein appeared at the cell surface with a half-time of approximately 27 min, while pulse-labelled NDV HN glycoprotein reached the cell surface with a half-time of approximately 78 min. To determine the transit time of these glycoproteins to trans-Golgi membranes, the kinetics of the acquisition of endoglycosidase H resistance was analyzed. The half-time of the transit of the G protein to the trans-Golgi membranes was found to be approximately 13 min while that of the HN glycoprotein was found to be approximately 60 min. Since the G protein migrates to the trans-Golgi membranes with a half-time of 13 min, and the cell surface with a half-time of 27 min, the half-time for the transit between the trans-Golgi membrane and the plasma membrane must be approximately 14 min. In a similar analysis, the half-time for the transit of the HN glycoprotein from the trans-Golgi membrane to the plasma membrane must be approximately 18 min, a time not significantly different from that of the G protein. Thus the difference in the kinetics of the intracellular transport of these two glycoproteins resides primarily in the transit from the rough endoplasmic reticulum to the trans-Golgi membranes. These results argue against a non-selective mechanism for the transport of plasma membrane glycoproteins to the cell surface.     

Effects of the HN gene C-terminal extensions on the Newcastle disease virus virulence

The hemagglutinin-neuraminidase (HN) of Newcastle disease virus (NDV) is a multifunctional protein that has receptor recognition, neuraminidase, and fusion promotion activities. Sequence analysis revealed that the HN gene of many extremely low virulence NDV strains encodes a larger open-reading frame (616 amino acids, aa) with additional 45 aa at its C-terminus when compared with that (571 aa) of virulent NDV strains. Therefore, it has been suspected that the 45 aa extension at the C-terminus of the HN may affect the NDV virulence. In this study, we generated an NDV mesogenic strain Anhinga-based recombinant virus with an HN C-terminal extension of 45 aa (rAnh-HN-ex virus) using reverse genetics technology. The biological characterization of the recombinant virus showed that the rAnh-HN-ex virus had similar growth ability to its parental virus rAnh-wt both in embryonating chicken eggs and DF-1 cells. However, the pathogenicity of this recombinant virus in embryonating chicken eggs and day-old chickens decreased, as evidenced by a longer mean death time and lower intracerebral pathogenicity index when compared with the parental virus. This is consistent with our previous finding that the recombinant LaSota virus with a 45-aa extension at its HN C-terminal was attenuated in chickens and embryonating eggs. These results suggest that the HN protein C-terminal extension may contribute to the reduced virulence in some low virulence NDV strains.     

HN protein of Newcastle disease virus causes apoptosis in chicken embryo fibroblast cells

Newcastle disease virus (NDV), an avian paramyxovirus, induces apoptosis in chicken embryo fibroblast (CEF) cells. In the present investigation, the ability of haemagglutinin-neuraminidase (HN) protein of NDV to cause apoptosis in CEF cells was examined. The results revealed that cells expressing the HN protein demonstrated decreased DNA content, phosphatidylserine exposure and increased cytoplasmic vacuolation. Up-regulation of caspase-1, -9, -8, -3, loss of mitochondrial transmembrane potential and an increase in oxidative stress were also observed in cells expressing the HN protein. Based on the above results it can be concluded that HN protein of NDV causes apoptosis in CEF cells.     

新城疫病毒HN基因对肿瘤抗原诱导的抗肿瘤免疫的增强作用

目的 了解新城疫病毒HN基因增强肿瘤抗原诱发的抗肿瘤免疫反应的作用。并对其作用机制进行探讨。方法 将构建的HN基因-癌胚抗原（CEA）cDNA共表达质粒（pcD-CEA/HN)免疫小鼠,通过淋巴细胞增殖实验,NK细胞活性检测了解HN对抗CEA免疫反应的影响,并以免疫组化的手段追踪HN质粒表达产物在体内组织的分布,以及HN质粒对荷瘤小鼠肿瘤生长,抗肿瘤免疫反应的影响。结果 （1）共表达质粒pcD-CEA/HN免疫小鼠获得了较其他对照组强的淋巴细胞增殖指数及NK细胞活性。（2）HN质粒在肌肉,肿瘤组织有明显的表达。（3）HN质粒对肿瘤长生具有一定的抑制作用。并能增强荷瘤小鼠的抗肿瘤免疫。结论 新城疫病毒HN基因对肿瘤抗原诱导的抗肿瘤免疫具有增强作用。     

HN gene C-terminal extension of Newcastle disease virus is not the determinant of the enteric tropism

The hemagglutinin-neuraminidase (HN) protein of Newcastle disease virus (NDV) plays an important role in virus pathogenicity and tissue tropism. Sequence analysis revealed that the HN gene of many asymptomatic enteric NDV strains encodes a larger open reading frame (616 amino acids, aa) with additional 39 aa at its C-terminus when compared with that (577 aa) of respirotropic NDV strains. Therefore, it has been suspected that the HN C-terminal extension may contribute to the enteric tropism. In the present study, we generated a NDV respirotropic strain LaSota-based recombinant virus with a HN C-terminal extension of 39 aa derived from an enterotropic NDV strain using reverse genetics technology. The biological characterization of the recombinant virus, rLS-HN-ex, showed that the HN C-terminal extension slightly attenuated the virus pathogenicity in embryonated eggs and in day-old chicks when compared to the parental LaSota virus. However, the HN C-terminal extension did not alter virus tissue tropism. In infected chickens, the recombinant virus was detected and re-isolated from the tracheal tissue, but not from the intestinal tissue, exhibiting a similar respirotropic tissue preference as its parental LaSota strain. These results demonstrated that the HN protein C-terminal extension of NDV is not the determinant of the virus enteric tropism.     

Functional and neutralization profile of seven overlapping antigenic sites on the HN glycoprotein of Newcastle disease virus: monoclonal antibodies to some sites prevent viral attachment

We have previously identified five antigenic sites on the hemagglutinin-neuraminidase (HN) glycoprotein of the Australia-Victoria isolate of Newcastle disease virus (Iorio and Bratt, J. Virol. 48, 440-450; Iorio et al., J. Gen. Virol. 67, 1393-1403). Two additional sites (designated 12 and 23) are now described, bringing to a total of seven the number of antigenic sites defined by our panel of neutralizing anti-HN antibodies. Competition antibody binding and additive neutralization assays reveal that each of these newly-identified sites overlaps two previously-defined ones. The seven HN antigenic sites thus form a continuum in the three-dimensional conformation of the molecule. Studies on the inhibition of hemagglutination (HA), neuraminidase (NA) and the attachment of virus to chick cell monolayers have been used to construct a functional profile of each antigenic site. Monoclonal antibodies (mAbs) to three overlapping sites (12, 2 and 23) inhibit HA and NA and prevent viral attachment to chick cell monolayers. These findings are consistent with the domains recognized by these mAbs being close to the NA and receptor-binding sites. MAbs to two other overlapping sites, 14 and 1 (which in turn, overlap site 12), inhibit HA quite effectively, and attachment to a lesser extent. Sites 14 and 1 probably identify a second domain involved in receptor recognition. MAbs to the two remaining sites (3 and 4), though neutralizing, are negative in all three assays, thus recognizing domains not involved in HA or NA or attachment to chick cells.     

Safety and efficacy of water-in-oil-in-water emulsion vaccines containing Newcastle disease virus haemagglutinin-neuraminidase glycoprotein

Subunit vaccines containing haemagglutinin-neuraminidase (HN) glycoprotein of Newcastle disease virus (NDV), formulated as water-in-oil-in-water (W/O/W) emulsions, were prepared. First, the suitable constituents of a W/O/W emulsion adjuvant were investigated with polyvalent vaccines using NDV, infectious bronchitis virus and Haemophilus paragallinarum. The W/O/W emulsion adjuvant, composed of the antigen in phosphate-buffered saline (PBS), liquid paraffin, squalene, diglyceryl monooleate, polysorbate 80 and PBS in a 30:25:10:5:2:28 ratio, induced a good antibody response with less adverse local reactions. HN protein of NDV was expressed by an improved baculovirus expression vector, a hybrid nucleopolyhedrovirus (HyNPV) between Autographa californica NPV and Bombyx mori NPV,and was prepared from silkworm pupae infected with the recombinant baculovirus, HyNPV-HN. Then, the W/O/W emulsion vaccine containing HN protein was prepared using the aforementioned constituents. Chickens showed 100, 100 and 80% protection against challenge exposure to virulent NDV at 4 weeks after vaccination with W/O/W emulsion vaccines containing 30, 6 and 3% of HyHPV-HN-infected pupae, respectively. The vaccines containing HN protein did not induce adverse local reactions at the site of injection. The subunit vaccine for NDV containing HN protein expressed in the recombinant baculovirus-infected pupae, formulated as a W/O/W emulsion vaccine composed of the antigen in PBS, liquid paraffin, squalene, diglyceryl monooleate, polysorbate 80 and PBS in a 30:25:10:5:2:28 ratio, was therefore found to be safe and effective.     

Recombinant haemagglutinin neuraminidase antigen-based single serum dilution ELISA for rapid serological profiling of Newcastle disease virus

A recombinant haemagglutinin neuraminidase (HN) antigen-based single serum dilution enzyme linked immuno-sorbent assay (ELISA) was developed to measure the specific antibody in sera of chickens against Newcastle disease virus. A linear relationship was found between the predicted antibody titres at a single working dilution of 1:1000 and the corresponding observed serum titres as determined by the standard serial dilution method. Regression analysis was used to determine a standard curve from which an equation was derived that allowed the demonstration of this correlation. The equation was then used to convert the corrected absorbance readings of the single working dilution directly into the predicted ELISA antibody titres. The assay proved to be sensitive, specific and accurate as compared to the standard haemagglutination inhibition (HI) test.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的构建定位表达于细胞不同部位的新城疫病毒HN（hemagglutinin—neuraminidase）基因。方法应用反转录聚合酶链反应（RT—PCR）技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3．1（＋）中,经过定向插入组织凝血酶原激活物（tPA）的前导序列和／或A型流感病毒血凝素（HA）基因跨膜区（TM）片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒。结果所有重组质粒经酶切和测序鉴定插入正确。经过体外转染真核细胞,间接免疫荧光和SDS．PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外。结论成功构建了定位表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型。     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.     

新城疫病毒HN基因真核细胞定位表达的重组质粒的构建

目的 构建定位表达于细胞不同部位的新城疫病毒HN(hemagglutinin-neuraminidase)基因.方法 应用反转录聚合酶链反应(RT-PCR)技术,以新城疫病毒D90株RNA为模板,分别扩增出含有HN基因全长和不含终止子的HN基因片段,将克隆的HN基因片段经双酶切后定向插入真核表达质粒pcDNA3.1(+)中,经过定向插入组织凝血酶原激活物(tPA)的前导序列和/或A型流感病毒血凝素(HA)基因跨膜区(TM)片段进行修饰分别构建胞浆型、跨模型和分泌型DNA质粒.结果 所有重组质粒经酶切和测序鉴定插入正确.经过体外转染真核细胞,间接免疫荧光和SDS-PAGE蛋白质电泳检测,证明构建的新城疫病毒HN基因定位表达于真核细胞的胞浆、胞膜和细胞外.结论 成功构建了定位DOI:10.3760/cma.j.issn.1673-4394.2009.04.003作者单位:150040,哈尔滨医科大学附属肿瘤医院内科(隋红,李乐静,白玉贤);150001 中国农业科学院哈尔滨兽医研究所兽医生物技术国家重点实验室/猪病研究室(李曦,张永欣,肖晶,符芳)通信作者:李曦,E-mail:lx2005@126.com表达于细胞不同部位的HN蛋白的DNA质粒即胞浆型、跨模型和分泌型.