1.Quantitative Analysis for Telomerase Activity in Rice
Xiao-Chuan LIU ; Yong-Heng LIANG ; Bo CHEN ;
China Biotechnology 2006;0(05):-
The Telomeric Repeat Amplification Protocol(TRAP)and its modified versions change the size and/or the ratio of the telomerase products in the amplification stage of the assay.Based on TRAP,a useful method was developed for detecting telomerase activity in rice.A special precursor primer and a special reverse primer and conducted two steps of PCR cycles were designed.GENE Genius? Bio-imaging System was applied for this quantitative analysis for exploring telomerase activity and its optimal reaction conditions.The method ensured that the optimal reaction conditions for the telomerase was 19℃,13minutes,at a concentration of 0.28 u g/? l.A quantitative analysis method was established for detecting telomerase activity in rice.With this method,we detected telomerase activity in roots,young leaves and young panicles of six parental lines of hybrid rice.The results show that young panicles have the highest telomerase activity,demonstrating that telomerase activity is closely related to the cell vitality in plants.
2.Development of human antibodies against the Gn protein of severe fever with thrombocytopenia syndrome virus.
Suhua CHEN ; Lina SUN ; Yang LIU ; Chuan LI ; Lin LIU ; Mifang LIANG ; Peihong QIU
Chinese Journal of Virology 2015;31(1):24-29
To obtain human antibodies against the Gn protein of Severe fever with thrombocytopenia syndrome virus (SFTSV) with phage display technology, this study aimed to screen anti-Gn protein antibodies from an anti-SFTSV Fab human phage display library. Antibody genes were identified by sequence analysis and the specificity of antibodies was confirmed by ELISA. The Fab antibody genes were cloned into the HL51-14 vector and expressed in a mammalian cell expression system. IgG antibodies were then purified by protein A affinity chromatography,and the results were further confirmed by ELISA,IFA,western blotting assays and micro-neutralization tests. The results showed that, after three rounds of panning, there were 390 human Fab antibodies against SFTSV particles, of which 364 were specific for nucleoprotein. Coated with the Gn protein, eight different Fab antibodies specific for Gn protein were obtained after the determination of the subtype and subclass of antibodies by gene sequencing; five of these antibodies were from the Lambda library and three were from the Kappa library. The eight IgG antibodies could specifically bind to Gn protein according to the ELISA, IFA and Western blotting assays. The micro-neutralization test showed that these eight antibodies had no neutralizing activity,but they could still provide a reference for research in human monoclonal antibodies against SFTSV.
Antibodies
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genetics
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immunology
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Bunyaviridae Infections
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genetics
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immunology
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virology
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Cell Line
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Cloning, Molecular
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Humans
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Immunoglobulin Fab Fragments
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genetics
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immunology
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Immunoglobulin G
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genetics
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immunology
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Neutralization Tests
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Phlebovirus
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genetics
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immunology
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Viral Proteins
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genetics
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immunology
3.Effect of Different Purification Technology on Physical and Chemical Properties of Water Extract of Ophio-pogonin
Yanni LIANG ; Zhishu TANG ; Ying TIAN ; Chuan GU ; Shijun LIU ; Hongbo LIU
China Pharmacist 2016;19(3):430-433
Objective:To explore the effect of different separation and purification technology on the physical and chemical proper-ties of water extract of ophiopogonin. Methods:The water extraction process of total ophiopogon saponins was optimized by an orthogo-nal test. The macroporous resin adsorption and membrane separation technology were adopted to purify the ophiopogonin water extract. The physical and chemical parameters, such as electrical conductivity, pH value, viscosity and turbidity, and the contents of total sap-onins, proteins, tannins and polysaccharides were determined. Results:The optimum water extraction technology of total saponins was as follows:6-fold amount of water was added, boiling 3 times with 90 min for each time. The electrical conductivity, pH value and vis-cosity of different purified liquid of total saponins had no significant differences, while the contents of total saponins and the three kinds of macromolecules showed significant differences. Conclusion: The content of macromolecules can be used as the reference index of purification process of total saponins water extract. Compared with macroporous resin separation, membrane separation technology is more suitable for the separation and purification of total saponins water extract.
4.Optimization of Water Extraction Process for Glycyrrhiza by Central Composite Design/Response Surface Methodology
Chuan GU ; Jing WU ; Yanni LIANG ; Zhongxing SONG ; Hongbo LIU ; Shijun LIU
China Pharmacist 2015;(8):1253-1255
To optimize the water extraction process for glycyrrhiza. Methods: HPLC was used to determine the con-tents of glycyrrhizic acid and liquiritin. The comprehensive index included the contents of glycyrrhizic acid and liquiritin and the yield of dry extract. The water amount and the extraction time were selected as the independent variables, and the comprehensive index was set as the dependent variable. Design-expert 8. 06 software was used to fit multivariate linear or quadratic multinomial models for the experimental values. Response surface methodology was used to optimize the water extraction process. The prediction was carried out through comparing the observed and predicted values. Results:The regression coefficient of binomial fitting complex model was as high as 0. 979 7. The optimum conditions of extraction process were as follows:12-fold amount of water, extracting 3 times with 90 min for each time. The deviation between the observed and predicted values was -1. 72%. Conclusion: Central composite design-response surface methodology is convenient and highly predictive in optimizing the water extraction process for glycyrrhiza, which can be applied in the further membrane separation and purification.
6.Study of baicalin in inducing prostate cancer cell line DU145 apoptosis in vitro.
Zheng-Qin GU ; Ying-Hao SUN ; Chuan-Liang XU ; Yi LIU
China Journal of Chinese Materia Medica 2005;30(1):63-66
OBJECTIVEThe purpose of the present study was to investigate the in vitro effects of baicalin on induction of apoptosis in human prostate cancer cell line DU145.
METHODHuman prostate cancer cell line DU145 was treated with different concentration of baicalin in vitro. The apoptosis rate was determined by FACS analysis, cell cycle distribution was detected by flow cytometry, morphological changes and protein analysis were determined by means of electron microscope techniqueand immunohistochemical techniquerespectively.
RESULT50micromol x L(-1) and 125 micromol x L(-1) of baicalin dose-dependently induced apoptosis and inhibited the proliferation of prostate cancer cell DU145 in a dose and time-dependent manner. DNA flow cytometric analysis indicated that baicalin induced a arrest in G1 phase, showing a typical apoptosis peak. Electron microscopy detected a characteristic appearance of the apoptotic cells morphology. Immunohistochemical analysis revealed that induction of apoptosis by ways of inhibition of the bcl-2, loss of the Bax, and upregulation of Fas.
CONCLUSIONThe results indicate that baicalin may induce apoptosis and inhibit proliferation of prostate cancer cells, and has direct anti-tumor effects on human prostate cancer cells.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Dose-Response Relationship, Drug ; Flavonoids ; isolation & purification ; pharmacology ; G1 Phase ; Humans ; Male ; Plants, Medicinal ; chemistry ; Prostatic Neoplasms ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Scutellaria ; chemistry ; bcl-2-Associated X Protein ; fas Receptor ; metabolism
7.Purification and Preliminary Research on the Immunogenicity of Inactivated Severe Fever with Thrombocytopenia Syndrome Bunyavirus.
Aqian LI ; Lin LIU ; Shuo ZHANG ; Chuan LI ; Quanfu ZHANG ; Mifang LIANG ; Dexin LI
Chinese Journal of Virology 2015;31(3):239-244
To understand the immunogenicity of purified inactivated severe fever with thrombocytopenia syndrome bunyavirus (SFTSV), concentration by ultrafiltration as well as molecular-sieve chromatography (MSC) were used for purification of inactivated SFTSVs. Inactivated viruses in purified samples were analyzed and identified by western blotting and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), the glycoprotein (GP) and nucleoprotein (NP) antigen titers of which were detected using a double-sandwich enzyme-linked immunosorbent assay (ELISA). Purified inactivated SFTSVs were enriched and observed by electron microscopy, and the total protein concentration detected using the bicinchoninic acid assay. Purified inactivated SFTSVs were applied to New Zealand rabbits via two immunization programs to evaluate immunogenicity and to compare the immune effect. After SFTSVs were inactivated and concentrated by ultrafiltration, MSC revealed two typical elution peaks. The sample of one peak was identified as inactivated virions, in which GP and NP were detected by SDS-PAGE, western blotting and ELISA. Main corponent of the other peak was NP. After concentration by ultrafiltration, purified inactivated SFTSVs with purity >90% and total protein concentration of 1. 1 mg/mL were obtained, and the typical electron microscopy of bunyavirus was observed. In the sera of animals immunized with purified inactivated SFTSVs, SFTSV-specific IgG antibody and neutralizing antibody were detected at high titers. However, antibody titers were affected by the immunization program. Effect of immunization on days 0, 14 and 28 was significantly better than that on days 0, 7 and 28. Our work revealed that cultivation of SFTSVs contained intact virus particles and large amounts of free NP. Using MSC, purified inactivated SFTSVs of high purity could be obtained. Purified inactivated SFTSVs induced high titers of neutralizing antibody and virus-specific IgG antibody showing satisfactory immunogenicity, which provides important clues for further study on a vaccine for the inactivated virus.
Animals
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Antibodies, Neutralizing
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immunology
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Antibodies, Viral
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immunology
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Bunyaviridae Infections
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immunology
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virology
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Humans
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Neutralization Tests
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Phlebovirus
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classification
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genetics
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immunology
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isolation & purification
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Rabbits
8.Preparation and functional analysis of the monoclonal antibodies against severe fever with thrombocytopenia syndrome bunyavirus structural proteins.
Aqian LI ; Lin LIU ; Shuo ZHANG ; Chuan LI ; Quanfu ZHANG ; Mifang LIANG ; Dexin LI
Chinese Journal of Virology 2015;31(1):18-23
To prepare monoclonal antibodies (mAbs) against structural proteins of severe fever with thrombocytopenia syndrome bunyavirus (SFTSV), BALB/c mice were immunized using purified inactivated SFTSV virions as the antigens. Subsequently, hybridoma cell lines that secreted monoclonal antibodies against nucleoprotein (NP) and glycoproteins (GP) were obtained using a hybridoma technique. The antigen specificities of prepared mAbs were examined by indirect immunofluorescence and immunoprecipitation assays. Functional analyses were then performed,including the detection of IFA antibody titers,the levels of neutralizing activity and antibody affinities. After cell fusion and cloning,13 hybridoma cell lines secreted mAbs specifically against SFTSV-GP and 7 hybridoma cell lines secreted mAbs specifically against SFTSV-NP. Immunofluorescence and immunoprecipitation assays showed that the mAbs had high levels of antigen specificity. Among the 13 anti-SFTSV-GP mAbs,6 recognized Gn,whereas the others reacted with Gc. IFA titers of most anti-SFTSV-GP mAbs were between 1,280 and 20,480, and four anti-SFTSV-Gn mAbs showed neutralizing activity. Seven of the obtained anti-SFTSV-NP mAbs reacted specifically with NP,of which the IFA titers ranged from 5,120 to 20,480 with no observed neutralizing activity. Furthermore, two anti-SFTSV-GP mAbs, 1C8 and 1G8, showed high levels of affinity via a non-competitive ELISA. Our study lays the foundation for the development of further diagnostic assays and basic research into SFTSV.
Animals
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Antibodies, Monoclonal
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immunology
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Antibodies, Viral
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immunology
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Antibody Specificity
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Bunyaviridae Infections
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immunology
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virology
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Female
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Humans
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Hybridomas
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immunology
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Mice
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Mice, Inbred BALB C
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Phlebovirus
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immunology
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Viral Structural Proteins
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immunology
9.Structure and function of 3'- untranslated region in picornavirus.
Rui-Ying LIANG ; Chuan-Feng LI ; Chun-Chun MENG ; Zong-Yan CHEN ; Guang-Qing LIU
Chinese Journal of Virology 2014;30(4):463-469
Both sides of the picornavirus genome have 5'-untranslated region (5'UTR) and 3'- untranslated region (3'UTR). This study demontrated that both the 5'-and 3'-UTR can form complex structures, such as stem-loop, clover and pseudoknot structure, These structures play an important role in the regulaton of the replication and translation of the viruses. This article reviewed the progress of research on the structure and function of picornavirus' 3'-UTR over recent years.
3' Untranslated Regions
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Animals
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Humans
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Nucleic Acid Conformation
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Picornaviridae
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chemistry
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genetics
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metabolism
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Picornaviridae Infections
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virology
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RNA, Viral
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chemistry
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genetics
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metabolism
10.Research of Human-mouse Chimeric Antibodies Against Ebola Virus Nucleoprotein.
Rongping ZHOU ; Lina SUN ; Yang LIU ; Wei WU ; Chuan LI ; Mifang LIANG ; Peihong QIU
Chinese Journal of Virology 2016;32(1):14-18
The Ebola virus is highly infectious and can result in death in ≤ 90% of infected subjects. Detection of the Ebola virus and diagnosis of infection are extremely important for epidemic control. Presently, Chinese laboratories detect the nucleic acids of the Ebola virus by real-time reverse transcription-polymerase chain reaction (RT-PCR). However, such detection takes a relatively long time and necessitates skilled personnel and expensive equipment. Enzyme-linked immunosorbent assay (ELISA) of serum is simple, easy to operate, and can be used to ascertain if a patient is infected with the Ebola virus as well as the degree of infection. Hence, ELISA can be used in epidemiological investigations and is a strong complement to detection of nucleic acids. Cases of Ebola hemorrhagic fever have not been documented in China, so quality-control material for positive serology is needed. Construction and expression of human-mouse chimeric antibodies against the nucleoprotein of the Ebola virus was carried out. Genes encoding variable heavy (VH) and variable light (VL) chains were extracted and amplified from murine hybridoma cells. Genes encoding the VH and VL chains of monoclonal antibodies were amplified by RT-PCR. According to sequence analyses, a primer was designed to amplify functional sequences relative to VH and VL chain. The eukaryotic expression vector HL51-14 carrying some human antibody heavy chain- and light chain-constant regions was used. IgG antibodies were obtained by transient transfection of 293T cells. Subsequently, immunological detection and immunological identification were identified by ELISA, immunofluorescence assay, and western blotting. These results showed that we constructed and purified two human- mouse chimeric antibodies.
Animals
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Antibodies, Monoclonal
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genetics
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immunology
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Cloning, Molecular
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Ebolavirus
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genetics
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immunology
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Hemorrhagic Fever, Ebola
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immunology
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virology
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Humans
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Immunoglobulin Heavy Chains
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genetics
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immunology
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Mice
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Nucleoproteins
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genetics
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immunology
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Viral Proteins
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genetics
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immunology