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2005 Vol.20(4)

Research Article

Predominance of Th2 Cytokine Response at Acute Phase in 95 Patients with SARS and its Clinical Significance

HUANG Jia-ling, DUAN Zhao-hui, LUO Xiao-hong, WU Li-zhi, TAN Wei-ping, MIN Jun, HUANG Jian, LIU Ran-yi, HUANG Bi-jun, LI Yan, ZENG Yi-xin, HUANG Wen-lin

2005, 20(4): 341

This study was designed to investigate dynamics of cytokines in acute and convalescent patients with Severe acute respiratory syndrome (SARS). The serum levels of cytokines (IL-2, IL-4, IL-8, interleukin-10, IFN-γ, TNF-β and TGF-β) in 95 healthy workers with SARS in our hospital were measured by ELISA. Phenotypes of peripheral lymphocytes were analyzed by flow cytometry in acute phase, compared with those of healthy volunteers. The results showed that serum level of IFN-γ showed no significant change during the whole period of SARS-CoV attack, and IL-2 level did not changed obviously within the first 2 months but decreased during month 3 and 5, while IL-4 levels were undetectable in both healthy subjects and the patients, and expression of TNF-β was diminished within the first week and the second month. In contrast, IL-10 and TGF-β were continuously overproduced for the entire SARS development. These changes are not correlative with the usage of corticosteroids (P0.05). In patients with SARS at acute phase,

Construction and Characterization of SHIV Carrying HIV-1 Capsid

ZHU Yi-xin, LIU Chang, QIAO Wen-tao, CHEN Qi-min, GENG Yun-qi, ZENG Yi

2005, 20(4): 346

SHIV (SIV/HIV chimeric virus) proviral DNA carrying Human immunodeficiency (virus) type1 (HIV-1 HXBc2) capsid was constructed on the backbone of Simian immunodeficiency (virus) (SIVmm239). The gene expression of chimeric virus could be detected in 293T cells transfected by SHIV proviral DNA. Chimeric SHIV virions were also obtained in the supernatant of transfected 293T cells. These virions have complete structures,including genomic RNA, reverse transcriptase, core proteins and envelope with glycoproteins. The chimeric Gag precursor could be appropriately cleaved and lead to the conformation of spindle core in the mature virus particles. They could Absorb and enter into MT4 cells and complete the course of reverse transcription. (witbout) repication.

Immune Response Induced by Recombinant Adenoviruses Expressing Serotype G2 or G3 VP7 of Group A Human Rotavirus in Mice

ZHANG Cai-hong, JIANG Xiu-li, WANG Min, ZHANG Yan-ming, WANG Jian-wei, HONG Tao

2005, 20(4): 352

In order to clarify the feasibility of adenovirus vector-based multivalent genetic engineering vaccine of Rotavirus (RV), we investigated the immune responses induced by the adenoviruses expressing serotype G2 or G3 VP7 of group A rotavirus on the basis of our previous reports. Balb/c mice were immunized with recombinant adenovirus rvAdG2VP7 or rvAdG3VP7, which expressing G2 or G3 type VP7,respectively, via intranasal or oral route for 3 times and serum antibodies, mucosal antibodies as well as the level of related cytokines were determinated. The results demonstrated that immunizing with the adenoviruses expressing serotype G2 or G3 RV VP7 intranasally or orally could induce strong rotavirus-specific immune response in mice, including humoral immunity, cell-mediated immunity, mucosal immunity as well as protective neutralizing antibody. The results also implied that Th2-like response triggered by the immunization is probably the primary response compared to Th1-like response. In summary, this study laid a fo

Compavison of JEV E-Hsp70 and E-Bindingdomain Fusion Protein on Immune Responses in Mice

GE Fei-fei, QIU Ya-feng, YANG Yao-wu, CHEN Fu-yan

2005, 20(4): 357

Further investigation of this interesting adjuvant-free carrier effect is necessary to ascertain whether peptide-binding portion alone can replace the whole M.tuberculosis Hsp70 acting as carrier. In our study, we selected a portion of E protein with higher index of antigenic determinants dependent on analysis of computer software and con-structed two chimeric vectors of pPICZα-E-Hsp70 and pPICZα-E-BD. Vectors were transformed into yeast X-33 by electroporation. Expression of fusion protein in yeast was induced by the addition of methanol every 24 hours and analysed by SDS-PAGE and Western blotting. We produced E-Hsp70 fusion protein at a yield of 33 mg per litter of culture and E-Bindingdomain fusion protein at a yield of 97 mg per litter of culture in methylotrophic yeast Pichia pastoris.with specific antigenicitys. To compare the immune response induced by E-Hsp70 fusion protein with that induced by E-bindingdomain, mice were immunized i.p. on day 0 and day 21. Mice immunized with E-bindingdomain had highe

Inhibition of Herpes Simplex Virus Infection by a GLP Isolated from Mycelium of Ganoderma lucidum

LIU Jing, YANG Fan, LI Shan-shan, WANG Yu-hua, YANG Xiao-jun, WU Zheng-hui, GAO Jin-rong, YE Lin-bo

2005, 20(4): 362

We reported here that a Ganoderma lucidum polysaccharide (GLP), one of the components extracted and purified from the liquid fermentation of mycelium of Ganoderma lucidum, was active against HSV-1infection in Vero cells. The CC_{50} (50% cytotoxic concentration) value of GLP for Vero cells growth was more than 2000μg/mL The EC_{50} (50% effective concentration) of GLP for virus yield reduction assay was 4.6μg/mL and 11μg/mL when virus or Vero cells were pre-mixed with GLP, 17μg/mL when virus and GLP were added into the cell culture simultaneously, and 50μg/mL when GLP was added after virus infection. Meanwhile, the selective index (SI, ratio of CC_{50} to EC_{50}) of GLP were more than 435, 182, 118 and 40, respectively. There was no significant antiviral activity to be detected when the GLP was presented in the culture after beginning infection and before progeny virus release. Quantitative real-time PCR of the infective supernatant further confirmed that the GLP blocked HSV-1 infection at early stages of th

Studies on the Inhibitory Effects of HNP1,3 on HSV1 Infection in vitro

LIU Juan, SUN Yong-tao, WANG Shao-yang, SHI Meng-yuan, ZHUANG Yan, ZHAI Song

2005, 20(4): 366

In order to evaluate the effect of human neutrophil peptide_{1,3}(HNP_{1,3})and acyclovir (ACV) on Herpes simplex virus type 1 (HSV-1) infection, Vero cells were inoculated with HSV-1. Antiviral activity was evaluated by reduction in cytopathic effect and HSV-1 envelop glycoprotein antigen,which determined by sandwich ELISA 48h after infection when drug~3 were interacted with free virus particles and infected vero cells(group A: inactivation of viruses, group B: inhibition of viral replication). Their cytoxicity were also measured by MTT assay. The results showed HNP_{1,3} reversed HSV-1 induced cytopathic effect and inhibited the antigen expression in group A, their 50% efficiency concentrations ( EC_{50}) were 8.1μg/mL、10.03μg/mL;In group B,ACV can lessen HSV-1 induced cytopathicity effects and reduced the antigen secretion whose EC_{50} was 0.68μg/mL. No cytotoxic effects of HNP_\{1,3\} were found by MTT assay. These findings confirmed that HNP_{1,3}, previously showed active to bacterium and human immunod

Sequence Analysis of HIV-1 Infected Individuals Found in Shenyang City

GUAN Qi, WANG Su-fen, MA Xiao-guang, LI Ming-xin, WANG Yan

2005, 20(4): 370

RNA were extracted from plasma samples collected from 10 HIV-1 positive patients in Shenyang city, RT-PCR and nest-PCR were carried out , PCR products of HIV-1 gag p17/p24 region were used for sequencing. Sequences of samples were compared with reference sequences of different HIV-1 genetic subtypes. HIV-1 genetic subtypes of samples in this test were then compared with that identified by the method of nested multiplex PCR with subtype-specific primers. Results showed that HIV-1 genetic subtypes of 10 samples were B’,CRF07-BC and CRF01-AE, respectively. ks/ka ratio is statistically below 1.0 in p17 region, and ks/ka ratio is significantly above 1.0 in p24 region. Gene homology in p24 region is higher than that in p17 region. More diversity of genetic sequences in gag p17 region than that in p24 region was observed. It is suggested that the p24 genetic region of HIV-1 genetic subtype B’, CRF07-BC and CRF01-AE is more suitable for development of HIV-1 vaccine.

Hepatitis C Virus Non-structural Protein 4B Induces Unfolded Protein Response

ZHENG Yi, GAO Bo, KONG Ling-bao, YANG Xiao-jun, WU Zheng-hui, YE Yin-bai*

2005, 20(4): 374

The unspliced and spliced forms of XBP1 stably expressing NS4B in HeLa cells, the transcriptional levels of ATF6, Grp78 and caspase-12, and the luciferase activity in XBP1 and Grp78 promoter reporter assays in HeLa and Huh-7 cells expressing NS4B were detected. The results showed that the two forms of XBP1 were detected NS4B in HeLa cells, moreover, ATF6 and Grp78 transcription levels and the luciferase activity in XBP1 and Grp78 promoter assays in cells expressing NS4B increased compared with that of cells without NS4B expression due to XBP1 binding to their promoter sites. Collectively, the results imply the possibility that NS4B induces UPR through ATF6 or IRE1-XBP1 pathways upon ER stress, and maybe play some roles in HCV pathogenesis, in particular, in chronic hepatitis, even hepatocellular carcinoma.

Prophylaxtic Efficacy of Recombinant Fowl-pox Virus and DNA Vaccine Against Foot-and-Mouth Disease Virus in Guinea Pigs

ZHENG Min, JIN Ning-yi, ZHANG Hong-yong, LI Chang, TIAN Ming-rao, MA Ming-xiao, JIA Lei-li

2005, 20(4): 379

A recombinant Fowlpox virus (vUTAL3CP1) containing FMDV capsid, P1-2A, and viral 3C protease coding regions,and another plasmid DNA (pVIRIL18P1) encoding P1-2A gene and swine interleukin-18 (IL-18) cDNA,were constructed. guinea pigs were inoculated intramuscularly twice at a 28-day interval with vUTAL3CP1 and pVIRIL18P1 alone, respectively, or vUTAL3CP1 priming and pVIRIL18P1 boosting. To evaluate the prophylaxtic efficacy of these vaccine candidates, anti-FMDV antibodies, neutralizing antibodies and T cell proliferation were detected. All of Guinea pigs were challenged with 250ID_{50} FMDV. The results indicated that both vaccines could elicit specific humoral immune and cellular immune responses. Compared with conventional inactivated vaccines, vUTAL3CP1 elicited not only similar FMDV antibody level but also stronger T cell proliferation. Three in four guinea pigs immunized by vUTAL3CP1 were protected completely from the FMDV infection, while other recombinant vaccines inoculated groups had much lower prote

Expression of the VP2 Gene Fragment of Goose Parvovirus in Prokaryotic System and Preparation of its Antiserum

HOU Qiu-lian, WANG Jing, LIU Sheng-wang, KONG Xian-wang, HAN Zong-xi, RAN Duo-liang

2005, 20(4): 383

A 969bp fragment at the 5′- end of the vp2 gene of Goose parvovirus isolate HG5/82 was subcloned into the Nco I site of prokaryotic expression vector pPROEX~{TM}HTb. The recombinant plasmid was transformed into E.coli DH5α and induced with IPTG. SDS-PAGE analysis showed an induced product band about 36kDa, which was corresponding to the size of the fragment. The amount of the recombiant protein was evaluated by densitometric scanning. It indicated that the product was 21.4% of total bacterial protein.The induced bacteria was solubilized by 6mol/L Guanidine hydrochloric acid and purified by ProBond~{TM} Resin. The antiserum against the recombinant protein was obtained by injecting the rabbit with fusion protein. We successfully expressed and purified the fusion protein from E.coli and obtained the antiserum against it, and laid a foundation for future studies on the bioactivity of GPV.

Construction and Confirmation of Plasmids Transcripting and Expressing Genes from Avian Influenza Virus H9N2 Subtype

LU Jian-hong, SHAO Wei-xing, LONG Jin-xue, LIU Yu-liang, SHI Huo-ying, LIU Xiu-fan*

2005, 20(4): 388

Eight full-length cDNAs of H9N2 Avian influenza virus (AIV) genes were amplified and separately cloned into the transcription/expression vector, pHW2000.A total of three genetic tags of silent mutations were introduced into PB2, PB1 and NA genes,respectively. Six 3+5 reassortants were generated by reverse genetics, each containing three genes, HA, NA and any one of the internal genes, from the H9N2 virus, and the remaining five internal genes from A/WSN/33. Thereby, the six transfectants were all designed as H9N2 subtypes. The results showed that influenza A virus could obtain one or more gene segments from another virus which was remotely related, and suggested that the surface genes and a single internal gene were not enough to exhibit host range restriction for the H9N2 virus on COS-1 mammalian cells. The results also showed that each of the eight constructs worked efficiently. This reverse genetics system would be a useful tool for further studies on the structure and function of H9N2 influenza virus gene

The Mutation Tendency of the gp85 Gene of Chinese Field Strains of ALV-J from 1999 to 2003

2005, 20(4): 393

Fourteen field strains of J Avian leukosis virus Subgroup(ALV-J)was isolated from farms with suspected diseased chickens and identified by inoculating the samples into embryo fibroblast, indirect immunofluorescence assay (IFA) and PCR amplification To observe the antigenic variants of the GP85 protein, the env gene of 14 field strains were cloned and sequenced. The induced amino acid sequences of the GP85 protein of the isolated field strains were compared with HPRS-103. The results indicated that the GP85 protein of ALV-J had multiple changes,and those changes clustered in the regions of hr1, hr2 and vr3 .The identity of the amino acid of the GP85 protein among different ALV-J strains differs from 86.6% to 100%. The ratio of NS/S in Gp85 and its variable regions indicated that these variable regions may be the most likely targets for immune selective pressure.

Cloning of DHBV Complete Genome from Guangdong Brown Ducks and Finding of a New ORF

HE Jin-yang, GE Wen-hua, ZHU Yu-tong, GUO Xing-bo, YANG Rui-yi, FENG Li-ling, ZHANG Feng-xue, CHEN Hong-shan

2005, 20(4): 399

3 samples of Duck hepatitis B virus (DHBV) positive serum from Guangdong brown ducks were chosen to be experimental samples. One pair of primers named Q1 and Q2 were designed to amplify the DHBV complete genome. Following the DHBV complete genomes from the 3 DHBV positive serum samples were amplified and cloned, these DHBV complete genomes were sequenced and then analyzed through related software and related molecular biology methods. The results showed that all the 5 complete genomes from Guangdong brown ducks were 3027 nucleotides long. After submitting to the GenBank, the accession Number were attained as: AY433937, AY521226, AY521227(from DHBV positive serum Number 1.);AY392760, AY536371(from DHBV positive serum Number 2 and 3 respectively). One single nucleotide mutation was occurred in the PreS/S ORF of AY521227. A new ORF was found in the upper reaches of PreC/C ORF and named as HORF temporarily. The HORF also exists in the other 8 DHBV complete genomes from Genbank. Phylogenetic analyze indicated that

Co-expression and Construction of Eukaryote Plasmid of pp38 and pp24 of Marek’s Disease . Virus

JIANG Shi-jin, DING Jia-bo, MENG Shan-shan, CUI Zhi-zhong, YANG Han-chun

2005, 20(4): 404

pp38 gene and pp24 gene of MDV Md11 strain were cloned into pBudCE(4.1) vector respectively. The pBudCE(4.1)-pp38 and pBudCE(4.1)-pp24 eukaryotic expressing plasmids were transfected into CEF respectively by lipofectamine reagent. 24, 48, 72 hours after transfection, the expression of pp38 was testified with Mab H19, and pp24 with the antiserum of pp24 expressed in E.coli.pp38 gene and pp24 gene were cloned into pBudCE(4.1) vector which can express two different genes at the same time. After transfection,the co-expression of PP38 and PP24 was testified by IFA and by Western-blotting with Anti-GST-pp24 sera.

Attenuation of a Highly Virulent Strain SD0210 of Infectious Bursal Disease Virus

CUI Yan-shun, LI Jian-liang, LIU Xing-huo, JIANG Shi-jin, SUN Shu-hong, CUI Zhi-zhong, ZHANG Yan-ming

2005, 20(4): 408

A very virulent strain SD0210 of Infectious bursal disease virus (vvIBDV) was adapted to chicken embryo fibroblast cell (CEF) after propagating in SPF chicken embryo for 10 generations and CEF for 18 generations. The test of pathogenicity, virulent stability and immunogenicity in chickens showed that the cell-adapted virus kept the immunogenicity of paternal virus, while its virulence did not reverse. The change pattern of deduced amino acid sequences in VP2 hypervariable region during the adaptation to CEF and transform from high pathogenicity to low pathogenicity has been obtained. When the virus was passed to the 18th generation, it began to adapt CEF and cause cell pathological effect (CPE). To 21th generation, the virus still kept its paternal immunogenicity and had no pathogenicity to SPF chickens even it was propagated to 15th generation in SPF chicken bodies.

Complete Genome Sequencing and Molecular Structure Prediction of C81 Attenuated Strain of CSFV

XU Zhuo-fei, QIAN Ping, LI Xiang-min, GUO Dong-chun, YAO Qing-xia, CHEN Huan-chun*

2005, 20(4): 413

Seven pair of primers covering the whole genome of Classical swine fever virus(CSFV) attenuated strain were devised according to the published sequences . 7 cDNA fragments were amplified by RT-PCR from PK-15 cell infected by CSFV attenuated strain. The amplifid fragments were further sequenced after cloned into the pMD18-T vector. The whole genome sequence of C81-strain was assembled by DNASIS (GenBank: AY663656). The genome is 12310 nucleotides in length and contains one large open reading frame encoding a polyprotein of 3898 amino acids. Sequence comparison with other CSFV strains revealed major differences in the open reading frame,84.4%~99.6% identities at the nucleotide level and 91.6%~99.4% identities at the amino acid level.26 ORF phylogenetic trees of CSFV strain were also protracted. The nucleotide sequence and secondary structure of CSFV 5′-untranslated region (5′-UTR) were compared and deduced, and found the major difference exists among diverse virus strains. Furthermore, functional domains and 3-D structure of CSFV/ C81 polyprotein were predicted.

Transfer of the AaIT Gene of a Recombinant Helicoverpa armigera Nucleopolyhedrovirus to its Surrounding Organisms

SUN Xin-cheng, CHENG Guo-ying, ZHOU Ming-zhe, HU Zhi-hong, SUN Xiu-lian

2005, 20(4): 420

To test if the foreign gene of a recombinant baculovirus can be transferred to organisms in the same ecological niche, two experiments were performed. First, the fungus Verticillium dahliae Lleb. was cultivated for up to 90 days in laboratory in the presence of BV,ODV and DNA of recombinant Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus which contains an insect-selective toxin (AaIT) (HaSNPV-AaIT). At 30, 60 and 90 days, the genomic DNA of Verticillium dahliae was isolated and analyzed for the presence of AaIT sequences by dot-blot hybridization. The results show that no positive signal was detected. Second, ladybeetles (Propylaea japonica thunberg) were collected from cotton fields which had been treated several times with a HaSNPV-AaIT formulation. After rearing on healthy aphids (Rhopalosiphum pseudobrassicae Davis) for 3-4 days, DNA samples were extracted from the surface of ladybeetle bodies treated or untreated with alkaline solution and Dnase. PCR products specific for HaSNPV-AaIT were f

Sequence Analysis of RpL 13 Gene from HzAm1 Cells and Effect of HaSNPV Infection on the Transcription of RpL13

DAI Wen-tao, DENG Fei, HU Zhi-hong

2005, 20(4): 424

The cDNA and genomic DNA of ribosomal protein L13 (RpL13) gene were cloned from Helicoverpa zea cells(HzAM1). Sequence analysis indicated that the open reading frame of rpL13 was composed of 666bp without intron,encoding a protein of 25 kDa. The sequence was used to construct phylogentic trees with other known sequences of 15 animal rpL13s. The result suggested it has similar topology with the classical taxonomy. Quantitative RT-PCR assay revealed that the transcription level of rpL13 declined in the HzAm1 cells infected by Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HaSNPV). At 96 hours post infection, the mRNA copies of rpL13 were about 8% to that of healthy cells.

Detection for CMV,LSV,LMoV Infected Lily with DNA Microarry Techniques

WANG Jin-zhong, JIA Hui, WEN Si-yuan, WANG Shen-qi, ZHANG Min-zhao, ZHAO Xiang-yun, DONG jin-gao

2005, 20(4): 429

Specific primers and probes were designed according to conservative and specific DNA sequence of CMV,LSV and LMoV.The probes were spotted on glass slides to form microarrays The Cy3-labled single strand DNA fragments prepared by dissymmetical RT-PCR were hybridized with the probes on the glass slides .The microarrays were scanned and analyzed with a scanner. DNA microarray could detect different typed DNA of CMV,LSV and LMoV with adequate specificity and sensitivity . Microarray techniques establish a rapid,sensitive and specific diagnostic assay for lily viruses. The successfully developed DNA microarray and techniques might be a very useful method for diagnosis and prevention ,and widely applied in specific pathogen detection of diseases such as lily virus.

Detection for CMV,LSV,LMoV Infected Lily with DNA Microarry Techniques

ZHU Chang-xiang, SONG Yun-zhi, WANG Mei-mei, WANG Xiu-fang, WEN Fu-jiang

2005, 20(4): 434

Coat protein (CP) gene of Tobacco ringspot virus (TRSV) Shandong isolate 1 was cloned by reverse transcription-polymerase chain reaction (RT-PCR), and was subcloned into the pET-22b(+) prokaryotic expression vector. The recombinant vector was transformed into E.coli strain BL21. Sequence analysis revealed that the cp gene was 1548 nucleotides in length,encodes a coat protein of 515 amino acids, and shares 90.7%~94.6% nucleotides and amino acid homology with TRSV cp genes registered in GenBank. The target fusion peptide with a molecular weight of 58kDa was expressed under the condition of 23-25℃ and induced by IPTG at a final concentration of 1mmol/L. Rabbit was immunized using the expressed target peptide as antigen, and the antiserum was obtained. The antiserum had a titer of 1/1024 with high specificity to TRSV.

Expression,Purification and Antigenicity Analysis of the HDV Antigen

XIE Li, HUANG De-zhuang, HE Li-xiang, ZHOU Yu-sen

2005, 20(4): 444

Amplified HDV fragment by RT-PCR was cloned into T vector and PQE_{31} plasmid, which established a prokaryotic expression vector in E coli M_{15} The recombinant protein was purified by Ni-NTA column affinity chromatography, and identified by Western blot and ELISA: HDV antigen was expressed efficiently and had a well antigenicity character. It can be used in HDV clinical diagnosis and epidemiology survey.

Genotypes Investigation of Hepatitis B Virus in Population in Xianning, Hubei Province

WANG Ming, HU Wen-qian, ZHANG Li, LEI Wen-lan, ZHOU Jian-ping, CHEN Hui, WANG Han-zhong

2005, 20(4): 447

Epidemiological characteristics of Hepatitis B virus in population in Xianning of Hubei province were investigated by ELISA, conventional PCR detection as well as specific genotyping system by PCR. Blood specimens were detected by ELISA and conventional PCR, the results indicated that 177(11.1%) of 1596 were HBV positive. Comparing with ELISA, conventional PCR is a sensitive, specific method for HBV DNA detection in serum. Positive serum specimens of 53 were identified and differentiated by specific genotyping system by PCR, the results demonstrated that HBV B genotype was found only in population in Xianning and that genotyping system based on PCR using type-specific primers could effectively differentiate HBV genotypes, indicating that this assay system is considered to be a useful tool for the molecular diagnosis of HBV and for large-scale survey of HBV.
Brief Reports

Isolation and Identification of Porcine Circovirus Type 2 from Sichuan Province and Sequence Analysis of ORF2 Gene

WANG Xin, GUO Wan-zhu*, ZHU Ling, XU Zhi-wen, YAN Qi-gui, WANG Yin, WANG Xiao-yu, LUO Yan, ZHOU Ting

2005, 20(4): 438

The PCV-2 positive tissues by PCR-restriction fragment length polymorphism (PCR-RFLP) were inoculated to the PK-15 cells not contaminated by PCV. The viral particles were observed in the infected PK-15 cells by eletronmicroscope .It was concluded that the isolate was PCV-2 and was named SCH-A strain.The capsid protein gene(cp) in ORF2 was amplified from PK-15 cell line infected with SCH-A strain by PCR, and was cloned and sequenced.The nucleotide sequences of ORF2 gene of the SCH-A strain was compared with other porcine circovirus isolates.The results showed that the homologies of nucleotides were between 90.5% and 96.7% in comparision with the PCV-2 reference strains,but the homologies of nucleotides were only about 67% with the PCV-1 reference strains. SCH-A strain displayed the highest nucleotide homology((96.7)%) with the reference strain Hunan .Phylogenetic tree analysis showed ORF2 gene of the SCH-A isolate belongs to PCV-2 .

Preliminary Studies of Prokaryotic Expression of GP5 of Porcine Reproductive and Respiratory Syndrome Virus

CHEN Yong-jun, SU Xin-ming, GAO Xiao-fei, ZHENG Sheng-qi, YU Chun-mei, CAO Rui-bing, ZHOU Bin, CHEN Pu-yan*

2005, 20(4): 441

The envelope glycoprotein (GP5) is one of the major structural proteins of Porcine reproductive and respiratory syndrome virus (PRRSV). In this report, the N-terminal hydrophobic sequence of envelope glycoprotein gene (orf5) was deleted by PCR. The gene was subcloned into prokaryotic expressing vector pET-28 a(+) , the recombinant plasmid named pET-GP5 was transformed into E.coli cell BL21. SDS-PAGE and Western-blot indicated that the orf5 gene was expressed successfully and the recombinant fusion protein, which was about 20.8kDa, had immunologically reactive activity. The studies lay foundations for further study on the development of vaccines for PRRSV.
Review

Molecular Basis of Pathogenesis and Immunity of Swine Vesicular Disease Virus

SUN Shi-qi, GUO Hui-chen, LIU Xiang-tao*, XIE Qing-ge

2005, 20(4): 450

Advances on Vaccine of Human Cytomegalovirus

WANG Ben-xu, LIU Chuan*, SHAO Ning-sheng, SHEN Bei-fen

2005, 20(4): 455