我国散发性戊型肝炎病毒细胞培养分离株的鉴定

我国散发性戊型肝炎病毒细胞培养分离株的鉴定１００８５０北京军事医学科学院微生物流行病研究所苑锡同，李晓萸，黄如统，李德荣关键词肝炎病毒，戊型；病毒细胞培养；病毒鉴定；聚合酶链反应；核酸杂交中国图书资料分类号Ｑ９３９．４我国戊型肝炎存在着流行和散发两种...

诺如病毒实验室诊断现状与展望

诺如病毒是引起非细菌性急性胃肠炎的主要病因,常常引起严重的公共卫生与食品安全问题。诺如病毒基因组的多样性及其它们不断的进化和变异为临床诊断及疫苗研制带来了挑战。本文就诺如病毒实验室诊断方法的研究进展作一综述,包括从传统经典的核酸检测到应用纳米、芯片等高新技术的多重核酸定量检测和高通量测序平台,以及体外成功培养的报道等等。这些新技术的成功运用将推动诺如病毒实验室诊断的新发展,以满足临床诊疗及疫苗研制的新需求。

2008至2011年美国CAP病毒培养室间质量评价及结果分析

传统病毒细胞培养及鉴定技术因为花费大、操作繁琐、周期长且实验室技术要求高，一般临床实验室较少开展。但是，病毒培养技术仍然是临床实验室高水平的标志，其结果许多情况下仍被视为“金标准”[1]。病毒培养特异度是100％，虽然敏感度低于100％，但2009年的甲型流感病毒大流行，病毒培养敏感度远高于POCT等免疫学方法[2]。

Development of an Inactivated Iridovirus Vaccine Against Turbot Viral Reddish Body Syndrome

Turbot(Scophthalmus maximus L.) reddish body iridovirus(TRBIV) was propagated in turbot fin cells(TF cells) and inactivated as the TRBIV vaccine with its protection efficiency evaluated in this study.TF cells were cultured in 10% bovine calf serum(BCS)-containing MEM medium(pH7.0) at 22℃,in which TRBIV propagated to a titer as high as 105.6 TCID50 mL-1.The TRBIV was inactivated with 0.1% formalin and formulated with 0.5% aluminum hydroxide.The inactivated vaccine caused neither cytopathogenic effect(CPE) on TF cells nor pathogenic effect on turbots.After being administered with the vaccine twice via muscle injection,the turbot developed high-tittered TRBIV neutralizing antibodies in a dose-dependent manner.The vaccine protected the turbot from dying with an immunoprotection rate of 83.3% as was determined via subcutaneous vaccination in the laboratory and 90.5% via bath vaccination in turbot farms,respectively.The inactivated vaccine was very immunogenic,efficiently preventing tur-bot from death.It holds the potential of being applied in aquaculture.

Hepatitis B virus infection and replication in primarily cultured human fetal hepatocytes

AIM: To investigate the infection and replication of hepatitis B virus (HBV) in primarily cultured human fetal hepatocytes (HFHs). METHODS: The human fetal hepatocytes were cultured in serum-free medium, HBV-positive serum was added into the medium to study the susceptibility of hepatocytes to HBV infection. The supernatant was collected for ELISA assay of HBsAg and HBeAg, and quantitative fluorescence PCR for HBV-DNA assay daily. Albumin and HBcAg, CK8 and CK18 expressions were detected by immunohistochemistry in cultured hepatocytes. Content of lactate dehydrogenate (LDH) was measured to find out the integrity of the cell membrane. RESULTS: A stable hepatocyte culture system was established. HBV could infect the hepatocytes and replicate, and HBcAg expression could be detected by immunohistochemistry in hepatocyte-like cells. HBV- DNA in the supernatant could be detected from d 2 to d 18 and HBsAg and HBeAg were positive on d 3-d 18 after HBV infection. HBV in medium increased from d 0 to d 6 and subsequently decreased as the cells were progressively loosing their hepatocyte phenotypes. CONCLUSION: HBV could infect human fetal hepato- cytes and replicate. This in vitro model allowed a detailed study on early events associated with human HBV entry into cells and subsequent replication.

The Antiviral Action of Polyhexamethylene Guanidine Derivatives

Although the PHMG （polyhexamethylene guanidine） and other oligomer guanidines are known as highly efficient biocides against a broad spectrum of microorganisms and eukaryotic cells, the cell protection by PHMG derivatives has been established firstly in this study. The antiviral protection was also exhibited after 15 min pretreatment of different cell cultures with low-concentration of PHMG salts. Monolayers of the continuous bovine tracheal cells culture （TCC） and primary culture of chicken embryo fibroblasts （FCE） were treated with aqueous solutions of PHMG chloride salts or PHMG succinate. The molecules of PHMG polycation adhered to the plasma membrane of the cells tested as they were treated with PHMG for 15-30 min. The viral material was added to the cell cultures after the wash-out carried out twice to rid of unbound PHMG. The viruses of Equine herpesvirus type 1, Rhinotracheitis infectious bovine and Equine infectious anemia virus were used. The protective effect from the cytopathic action of herpes and retroviruses was exhibited after 15 min pretreatment of cell monolayer with PHMG chloride at the TCC concentrations of 10^-3 - 10^-2% and FCE concentrations of 10^-5 - 10^-4%. The unique antiviral properties of PHMG salts represented in our research had never been shown before.

Complete Genomic Sequence of Transmissible Gastroenteritis Virus TS and 3' End Sequence Characterization Following Cell Culture

The complete genome sequence of transmissible Gastroenteritis virus (TGEV) strain TS, previously isolated from Gansu province, was cloned and compared with published sequence data from other TGEV strains. Phylogenetic tree analysis based on the amino acid and nucleotide sequences of the S gene showed that the TGEV strains were divided into 3 clusters. TGEV TS showed a close evolutionary relationship to the American Miller cluster but had a 5' non-translated region (NTR) sequence closely related to the American Purdue cluster. Continued culture in different cell types indicated that TGEV TS virulence could be attenuated after fifty passages in Porcine kidney (PK-15) cells, and that the Porcine kidney cell line IB-RS-2 (IBRS) was not suitable for culture of the TGEV strain TS.

Transactivating effect of complete S protein of hepatitis B virus and cloning of genes transactivated by complete S protein using suppression subtractive hybridization technique

AIM: To investigate the transactivating effect of complete S protein of hepatitis B virus (HBV) and to construct a subtractive cDNA library of genes transactivated by complete S protein of HBV by suppression subtractive hybridization (SSH) technique and to clone genes associated with its transactivation activity, and to pave the way for elucidating the pathogenesis of hepatitis B virus infection. METHODS: pcDNA3.1(-)-complete S containing full-length HBV S gene was constructed by insertion of HBV complete S gene into BamH I/Kpn I sites. HepG2 cells were cotransfected with pcDNA3.1(-)-complete S and pSV-lacZ. After 48 h, cells were collected and detected for the expression of β-galactosidase (β-gal). Suppression subtractive hybridization and bioinformatics techniques were used. The mRNA of HepG2 cells transfected with pcDNA3.Incomplete S and pcDNA3.1(-) empty vector was isolated, and detected for the expression of complete S protein by reverse transcription polymerase chain reaction (RT-PCR) method, and cDNA was synthesized. After digestion with restriction enzyme RsaI, cDNA fragments were obtained. Tester cDNA was then divided into two groups and ligated to the specific adaptors 1 and 2, respectively. After tester cDNA had been hybridized with driver cDNA twice and underwent nested PCR twice, amplified cDNA fragments were subcloned into pGEM-Teasy vectors to set up the subtractive library. Amplification of the library was carried out within E. coli strain DH5α. The cDNA was sequenced and analyzed in GenBank with BLAST search after polymerase chain reaction (PCR) amplification. RESULTS: The complete S mRNA could be detected by RT-PCR in HepG2 cells transfected with the pcDNA3.1(-)-complete S. The activity of β-gal in HepG2 cells transfected with the pcDNA3.1(-)-complete s was 6.9 times higher than that of control plasmid. The subtractive library of genes transactivated by HBV complete S protein was constructed successfully. The amplified library contains 86 positive clones. Colony PCR showed that 86 clones contained DNA inserts of 200-1 000 bp, respectively. Sequence analysis was performed in 35 clones randomly, and the full length sequences were obtained with bioinformatics method and searched for homologous DNA sequence from GenBank, altogether 33 coding sequences were obtained. These cDNA sequences might be target genes transactivated by complete S protein of HBV. Moreover, two unknown genes were discovered, full length coding sequences were obtained by bioinformatics techniques, one of them was named complete S transactivated protein 1 (CSTP1) and registered in GenBank (AY553877). CONCLUSION: The complete S gene of HBV has a transactivating effect on SV40 early promoter. A subtractive cDNA library of genes transactivated by HBV complete S protein using SSH technique has been constructed successfully. The obtained sequences may be target genes transactivated by HBV complete S protein among which some genes coding proteins are involved in cell cycle regulation, metabolism, immunity, signal transduction, cell apoptosis and formation mechanism of hepatic carcinoma.

The adenoviral E1A protein relieves gene repression by receptors in v/vo displaces corepressors and unliganded thyroid hormone

The human adenovirus type 5 early region 1A （E1A） is one of two oncogenes present in the adenovirus genome and functions by interfering with the activities of cellular regulatory proteins. The E1A gene is alternatively spliced to yield five products. Earlier studies have revealed that E1A can regulate the function of thyroid hormone （T3） receptors （TRs）. However, analysis in yeast compared with transfection studies in mammalian cell cultures yields surprisingly different effects. Here, we have examined the effect of E1A on TR function by using the frog oocyte in vivo system, where the effects of E1A can be studied in the context of chromatin. We demonstrate that different isoforms of E1A have distinct effects on TR function. The two longest forms inhibit both the repression by unliganded TR and activation by T3-bound TR. We further show that E1A binds to unliganded TR to displace the endogenous corepressor nuclear receptor corepressor, thus relieving the repression by unliganded TR. On the other hand, in the presence of T3, E1A inhibits gene activation by T3-bound TR indirectly, through a mechanism that requires its binding domain for the general coactivator p300. Taken together, our results thus indicate that E1A affects TR function through distinct mechanisms that are dependent upon the presence or absence of T3.

Cell culture systems for the hepatitis C virus

Since the discovery of HCV in 1989, the lack of a cell culture system has hampered research progress on this important human pathogen. No robust system has been obtained by empiric approaches, and HCV cell culture remained hypothetical until 2005. The construction of functional molecular clones has served as a starting point to reconstitute a consensus infectious cDNA that was able to transcribe infectious HCV RNAs as shown by intrahepatic inoculation in a chimpanzee. Other consen- sus clones have been selected and established in a hu- man hepatoma cell line as replicons, i.e. self-replicating subgenomic or genomic viral RNAs. However, these repli- cons did not support production of infectious virus. Inter- estingly, some full-length replicons could be established without adaptive mutations and one of them was able to replicate at very high levels and to release virus particles that are infectious in cell culture and in vivo. This new cell culture system represents a major breakthrough in the HCV field and should enable a broad range of basic and applied studies to be achieved.

EFFECT OF VERAPAMIL ONCa^（2＋） INFLUX ANDCVB3－RNA REPLICATION IN CULTURED NEONATALRAT HEART CELLS INFECTED WITH CVB3

The effect of verapamil on Ca2+ influx across the myocardial plasma membrane and coxsackie virus B3 ( CVB3)-RNA replication in cultured neonatal rat heart cells infected with CVB3 was investigated. It was found that the Ca2+ influx could be inhibited significantly (P<O. 01) by verapamil (1 μmol/L) after infection of heart cells for 48h. However, when the cultured heart cells infected with CVB3 and treated with verapamil (Iμmol/L and 10 nmo/L) at the same time for 48h, the amounts of CVB3-RNA in myocytes were significantly higher than that in infected control group (P<O. 05). These phenomena suggest that the increase of Ca2+ influx of cultured heart cells infected with CVB3 could be inhibited by some calcium antagonists, e. g. verapamil at the early stage. On the other hand, verapamil might accelerate viral replication in myocardium. Thus, although verapamil could be beneficial for decreasing the secondary Ca2+ damages and improve the myocardial electric activity, it isn’t a sensible choice for therapy in early stage of virus infection with cardiac symptoms.

In vitro incubation of cytokine-induced killer cells from patients with and without hepatitis B virus and a cell subset analysis

Objective The aim of the study was to explore the difference between immune cell subsets during the incubation of cytokine-induced kill cells （CIKs） from patients with and without hepatitis B virus （HBV）. Methods Peripheral blood samples were extracted from 50 tumor patients, and were divided into two groups according to the presence or absence of HBV. The proliferation rate and activity of CIK cells were examined based on counts on days 1, 5, 7, 9, 11, 13, and 15 of culture. Additionally, the CD3＋, CD4＋, CD8＋, CD3＋CD8＋, C＋）3＋CD4＋, and CD3＋CD56＋ T cell populations were analyzed by flow cytometry on days 5, 7, 10, 13, and 15 of culture. Results Proliferation over a 15-day period was higher in the HBV-positive group than in the negative group （280-fold vs. 180-fold increase, respectively）, but there was no significant difference between the two groups at each time point. The frequencies of CD3＋, CD8＋ T, CD3＋CD8＋, and CD3＋CD56＋T cells increased over time, while those of CD4＋ and CD3＋CD4＋ T cells decreased over time, and these changes were greater in the positive group than in the negative group. The differences in CD8＋ T cells and CD3＋CD4＋ T cells between the two groups were significant （P 〈 0.05）. Conclusion The proliferative capacity of CIK cells was higher for patients in the HBV-positive group than those in the HBV-negative group, and immune cell subsets were more favorable in the HBV-positive group than the neaative arouD.

Epitope variation in the Newcastle disease virus HN gene under antibody immune selective pressure in cell culture

The influence of antibody immune selective pressure on Newcastle disease virus (NDV) HN and F gene mutations was studied in cell cultures.NDV field strain TZ060107 was inoculated into chicken embryo fibroblast cells and continuously passaged with (group A) or without (group B) anti-NDV monospecific serum.Each group contained three independent passage series.HN and F genes were amplified and sequenced for the 10th,20th,30th,40th and 50th generations of each serial passage,and compared with the original strain.The results demonstrated that increased HN gene mutations were observed in group A with the antibody than in group B without the antibody.The nonsynonymous (NS) to synonymous (S) mutations ratio was 6 for group A,significantly higher than 3.4 in group B.In group A with the antibody,there were five stable NS mutations in HN gene,three of which (related to aa#353,521 and 568) were related to known epitopes.There were two stable NS mutations in F gene in group A,but no stable NS mutations in group B.The NS/S ratios of F gene were less than 2.5 for both groups A and B.Our results suggested that the antibody strongly influenced HN gene mutations,while the F gene was less influenced by the same antibody.