H1N2亚型猪流感病毒NS1的原核表达及抗原性分析

为了进一步监控猪流感病毒对猪群的感染情况,研究对H1N2亚型猪流感病毒NS1基因进行RT-PCR扩增,并将其克隆到表达载体pET-30a(+)上构建重组质粒pET-NS1获得纯化产物,结果表明:NS1蛋白能够高效表达,与预期分子质量大小相符;经Western-blot分析,NS1蛋白能很好地与猪流感活病毒产生血清反应,而不能与灭活疫苗产生血清反应;被检血清稀释度为1∶640时,ELISA检测阳性血清的OD490值约为阴性血清的3倍,差异明显。说明NS1蛋白具有良好的血清学反应特异性。

Construction of Prokaryotic Expression Vectors of EBP1 Gene from Nervilia Fordii (Hance) Schltr.

[Objective] To construct prokaryotic expression vectors encoding gene Erb3binding protein （EBP1）, which plays important roles in regulating plant organ size from Nervilia fordii （Hance） Schltr. [Methods] PCR products of NfEBP1 with particular restriction sites and expression vectors, pET-28 and pET-16b were digested. Ligation, transformation and selection were performed to construct the recombinant plasmids pET-28-NfEBP1 and pET-16-NfEBP1. The recombinant plasmids were transformed into E. coli BL21 using heat -shock transformation. [Results] Recombinant plasmids pET-28-NfEBP1-1188 and pET-16-NfEBP1-1188 were constructed and transformed into expressional host cells, E. coli BL21, and validated by colony PCR, sequencing and double digestion. [Conclusion] Prokaryotic expression vectors of EBP1 gene from N. fordii were successfully constructed, which laid the foundation for characterization of the gene function.

Expression of Ferric Chelate Reductase Gene in Citrus junos and Poncirus trifoliataTissues

It has been hypothesized that under iron stress high ferric chelate reductase (FCR) activity in the absorptive root of plants tolerant to iron_deficiency will be induced and result in subsequent Fe 2+ transport across the plasmalemma. The activity of FCR and expression of FCR gene (FRO2) in Citrus junos Sieb. ex Tanaka tolerant to iron_deficiency and Poncirus trifoliata (L.) Raf. susceptible to iron_deficiency were determined to elucidate the physiological difference which causes the different tolerance of the two citrus rootstocks to iron stress. The activity of FCR was detectable in excised roots and was stimulated about 20_times in C. junos and only about 3_times in P. trifoliata under iron deficiency for four weeks. The FRO2 of Arabidopsis was used as a probe, the tissue print technique was used to ascertain the expression of the FCR gene in C. junos and P. trifoliata under iron stress. High_level transcripts were observed in the absorptive root, young green stem as well as new leaf of C. junos under iron stress for two weeks, and the transcripts were accumulated only slightly in P. trifoliata at the same time. The results showed that the obvious increase of FCR activity was an important reason for the tolerance of C. junos to iron_deficiency, and the regulation of FCR activity seemed to be at the transcriptional level, and the expression of FRO2 occurred in the root, stem and leaf.

High Frequency of GFP Gene Transient Expression in Electroporated Zygotes and Early Proembryos of Wheat

Green fluorescent protein (GFP) gene was successfully transferred into the isolated zygotes and early proembryos of wheat (Triticum aestivum L.) by electroporation. A frequency, as high as 46.7% of GFP gene transient expression in early proembryos, was achieved under 150 V/cm electric field strength, 25 muF capacitor, 200 mug/mL of linear plasmid DNA and an electroporation buffer at pH 7.2. Compared with five-day-old proembryos, the zygotes and early proembryos needed lower optimum strength of electric field. After culturing in KM8p medium, the electroporated early proembryos divided and GFP gene expression was observed in daughter cells and subsequent divisions. There was no mosaicism of gene expression in the zygotes and 2-, 4- and 8-celled proembryos.

THE COEXPRESSION OF THE preS1(1-42) AND THE CORE(1-144)ANTIGEN OF HBV IN E.coli

Objective.To study the therapeutic T cell vaccine for the treatment of chronic hepatitis B by improving the cellular immunization of HBsAg vaccine with the coexpression of the preS1(1-42)and the Core(1-144)anti-gen of HBV in E.coli.Methods.The genes of HBcAg (1-144)and preS1(1-42)were amplified and fused by PCR.This fused gene was inserted in the prokaryotic expression vector pET-11d and expre ssed in E.coli.Results.It was showed by SDS-PAGE that the pr otein molecular weight of the coexpr ession product was about 20kD,20%of all bacteria prote in.The monoclonal antibodies again st core and preS1antibody could re-act with this fused protein by Western-blot technique respectively.The fused gene was verified by sequencin g.Under the immune electron microscop y,this fused protein is typical particles of HBcAg but in an aggregated form.Conclusion.The results might aid for studying T c ell immunotherapeutic vaccine for c hronic hepatitis B.

Expression of Overlapping PCR-generated Shiga Toxin B Gene Fragment in E. Coli and Its Ascitic Polyclonal Antibody

The mature Shiga toxin B （StxB） gene was optimized and generated by overlapping PCR. Recombinant expression vector pQE40-DHFR/StxB was constructed when the gene was cloned into pQE fusion expression vector. Induced by Isopropyl β-D-thiogalactoside （IPTG）, the DHFR/StxB fusion protein was highly expressed to the level of 41.36% in E. coli MI5 cells. The 35 kDa fusion protein with a 6 His-tag was one-step purified from inclusion bodies using Ni-NTA affinity chromatography column under denaturing conditions, and was refolded by dialyzing with a decreasing urea gradient. Purified DHFR/StxB fusion protein was used to immunize Kunming mice for generating the ascitic polyclonal antibody against recombinant StxB protein by injecting sarcoma 180 cells and the titer ofascitic polyclonal antibody is up to 1： 1× 10^6 detected by the indirect enzyme linked immunosorbent assy （ELISA）. Western immunoblotting analysis revealed that the ascitic polyclonal antibody against StxB had a specific affinity for a 70 kDa shiga toxin protein of Shigella dysenteriae type 1. It is a new simple and quick method to produce a large amount of ascitic polyclonal antibody. The antibody is used to develop immunological method for detecting shiga toxin.

Effect of heme oxygenase-1 on renal function in rats with liver cirrhosis

AIM: To investigate the role of heme oxygenase-1 (HO-1) in pathogenesis of experimental hepatorenal syndrome (HRS). METHODS: Rats were divided into liver cirrhotic group, zinc protoporphyrin IX (ZnPP) treatment group, cobalt protoporphyrin (CoPP) treatment group and sham group. Biliary cirrhosis was established by bile duct ligation in the first three groups. Rats in the ZnPP and CoPP treatment groups received intraperitoneal injection of ZnPP and CoPP, respectively, 24 h before sample collection. Expression of HO-1 mRNA in kidney was detected by reverse-transcription polymerase chain reaction, while protein expression was determined by immunohis-tochemical analysis. Hematoxylin and eosin staining was performed to observe liver cirrhosis and renal structure. Renal artery blood flow, mean arterial pressure and portal vein pressure, 24 h total urinary volume, serum and urine sodium concentrations, and creatinine clearance rate (Ccr) were also measured.RESULTS: The HO-1 mRNA and protein expression levels in kidney, 24 h total urinary volume, renal artery blood flow, serum and urine sodium concentration and Ccr were lower in cirrhotic group than in sham group (P < 0.05). However, they were significantly lower in ZnPP treatment group than in cirrhotic group and significantly higher in CoPP treatment group than in cirrhotic group (P < 0.05). CONCLUSION: Low HO-1 expression level in kidney is an important factor for experimental HRS.

Changes in tumor-antigen expression profile as human small-cell lung cancers progress

Objective： Our group has previously observed that in patients with small-cell lung cancers （SCLCs）, the expression of a tumor antigen, glioma big potassium （gBK） ion channel, is higher at the time of death than when the cancer is first treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive profile analysis of tumor-antigen precursor protein （TAPP）. We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production. Methods： SCLC samples （eight surgical resections and three autopsy samples） and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets. Results： Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of PS3-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as confirmed by intracellular flow cytometry with a gBK-specific antibody. Conclusion： Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.

Exploring CTCF and cohesin related chromatin architecture at HOXA gene cluster in primary human fibroblasts

Spatial expression patterns of homeobox （HOX） genes delineate positional identity of primary fibroblasts from different topo- graphic sites. The molecular mechanism underlying the establishing or maintaining of HOX gene expression pattern remains an attractive developmental issue to be addressed. Our previous work suggested a critical role of CTCF/cobesin-mediated high- er-order chromatin structure in RA-induced HOXA activation in human teratocarcinoma NT2/D1 cells. This study investigated the recruitment of CTCF and cohesin, and the higher-order chromatin structure of the HOXA locus in fetal lung and adult foreskin fibroblasts, which display complementary HOXA gene expression patterns. Chromatin contacts between the CTCF-binding sites were observed with lower frequency in human foreskin fibroblasts. This observation is consistent with the lower level of cohesin recruitment and 5＇ HOXA gene expression in the same cells. We also showed that CTCF-binding site A56 （CBSA56） related chromatin structures exhibit the most notable changes in between the two types of cell, and hence may stand for one of the key CTCF-binding sites for cell-type specific chromatin structure organization. Together, these results im- ply that CTCF/cohesin coordinates HOXA cluster higher-order chromatin structure and expression during development, and provide insight into the relationship between cell-type specific chromatin organization and the spatial collinearity.