25 January 2007, Volume 27 Issue 1

    

• Select all
  |

• Select
  Activity study of ciliary neurotrophic factor (CNTF)mutant

  China Biotechnology. 2007, 27(1): 1-5.

  Abstract ( )   Knowledge map   Save

  To study furderly the activity of CNTF mutant designed by computer molecular modling,this study used the methods of dissociated cultures of chick dorsal root ganglion、TF-1 prolification and the normal mice′weight loss tests.The results indicated that the mutant protein promoted the survival of dorsal root ganglion、induced TF-1 prolification and made the normal mice lose weight,decrease appetite and reduce fat index.The weight loss effect was dependant with its administration dosage,ED50 was 150.986?g/kg/d.To TF-1,the specific activity reached 2.0×106U/mg against international reference reagent.In a word,CNTF mutant had excel bioactivity.So our study provided cluds for its development and application.
• Select
  Generation of the Antibody against the schistosoma japonicum antigen Sj22 with genetic immunization

  China Biotechnology. 2007, 27(1): 6-10.

  Abstract ( )   Knowledge map   Save

  To study the genetic immunization effectiveness, 16 6-week-old female BALB/C mice were immunized with recombinant plasmids with or without CpG adjuvant, and then boosted with the same recombinant plasmids or the recombinant protein of Schistosoma Japonicum antigen Sj22 in four experimental groups. Mice in group A were immunized with 100μg of plasmid pVAX1-sj22. Mice in group B were immunized with 50μg plasmid pVAX1-sj22 and 20μg CpG adjuvant simultaneous. Mice in group C and D were immunized with pcDNA3.1-sj22. All the mice were immunized at the 0, 3rd, and 6th week by i.m. injection and boosted with recombinant Sj22 protein except group D boosted with the plasmid pcDNA3.1-sj22 at the 9th week. Blood was collected at the 0, 9th and 10th week, and the titer of the serum was detected by ELISA, the specificity of the antibody was examined by Western blot. In conclusion, the antiserum specified to Sj22 protein was obtained by genetic immunization. And the study shows that the application of CpG adjuvant can reduce the amount of the plasmid and the DNA prime-boost protein strategy can improve the effectiveness of immunization reaction in genetic immunization.
• Select
  High Level Prokaryotic Expression of Thymosin α1 by Gene Repeats

  China Biotechnology. 2007, 27(1): 11-15.

  Abstract ( )   Knowledge map   Save

  A new thymosin α1(Tα1) gene [SD-His.tag-EK- Tα1] named SD-Tα1 was synthesized, consecutively consisting of SD sequence, sequence encoding His.tag, enterokinase recognition site and Tα1 cDNA. This gene monomer was multiplied up to 8-tandems using Isocaudamer XbaI and SpeI. These different repeats of SD-Tα1 were inserted into plasmind pET-32a(+) respectively and then transformed into E. coli BLR(DE3) to achieve a series of genetic bacteria E. coli BLR(DE3) containing 1~8 copies of SD-Tα1.PCR analysis and the sequencing showed that 1~8 copies of SD-Tα1 were all correctly cloned into pET-32a(+) vector. Furthermore, the reporter gene lacZ with its own SD sequence (SD-lacZ) was added as a tail of SD-Tα1 tandems to verify the translation efficiency of the fusion gene through blue-white clone screening. The expected blue clones were obtained such as genetic E. coli BLR(DE3)strain containing pET32a-1Tα1-LacZ、pET32a-3Tα1-LacZ、pET32a-5Tα1-LacZ and pET32a-8Tα1-LacZ. The results implied that each SD-Tα1 repeat can be authentically transcribed and submitted for translation. Fermentation and SDS-PAGE analysis indicated that Tα1 peptide was expressed in a soluble form in all the genetic bacterial strains containing 1~8 repeats of SD-Tα1. In conclusion, a series of multiple repeats of Tα1 gene has successfully been constructed and expressed in E. coli with a new construction method. Also, a platform of high prokaryotic expression of small peptides was established.
• Select
  Construction of OTX1 lentiviral vector and overexpression research

  China Biotechnology. 2007, 27(1): 16-21.

  Abstract ( )   Knowledge map   Save

  OTX1 gene is one of the pivotal transcriptional factors involved in the neurogenesis. In order to overexpress the OTX1 gene in distinct cell types and find out its contribution to the proliferation and differentiation of stem cells in vitro, OTX1 cDNA was subcloned into lentiviral vectors. The resulting constructions pDUET－OTX1、pDUET－GFP－OTX1 and pDUET-GFP were packaged in 293 cells producing viral particles to transduce 293T cells、SY5Y cells、mouse embryonic stem cells and E15 neural stem cells. It was proved that the transferred OTX1 gene was located in the nuclei of the transduced cells in stead of plasma. Lentivirus is an ideal vector delivering gene to different cells. The overexpression of OTX1 in transduced 293T cells were validated by Western blot and immunofluorescence.
• Select
  Agrobacterium -mediated Transformation of Several Turfgrass Cultivars

  China Biotechnology. 2007, 27(1): 22-27.

  Abstract ( )   Knowledge map   Save

  It is very important to improve stress characteristics of turfgrass such as drought, cold, hot and sanity by genetic engineering approach. But, the transformation system of Agrobacterium mediated turfgrass has not been set up completely. More research on it is still needed for perfection. Embryonic calli derived from the mature embryos of four turfgrass cultivars including Accent, Quest, Tengyue and Goalkeeper were used as target materials to be infected by Agrobacterium harboring nptII selectable gene and GUS report gene. Some calli were tested by histochemical staining for GUS gene transient expression after three days co-cultivation. And the remaining calli was transferred onto G418 10.0-25.0mg/l containing medium for selection and regeneration. The resistant plantlets to the antibiotics were identified by ELISA, PCR and X-Gluc staining for the integration and expression of the foreign genes. The results indicated that the frequency of GUS gene transient expression in the four cultivars varied from 8.6% to 46.9%, the highest in Accent, the lowest in Quest, and the medium in other two genotypes. In 144 total regeneration plants, 45 plantlets were conformed to be positive, in which the expression of nptII gene was suggested by ELISA, and among which the expression of GUS gene in 43 plants and the silence in 2 plants were demonstrated by histochemical staining. Regeneration frequency of resistant plantlets to the antibiotics from the four cultivars was 0-43.5%, and transformation efficiency of the four genotypes was 0-21.5%. The results also suggested that the both frequencies transient expression and stable transformation of the alien gene were not coincident in turfgrass, and the former frequency cannot be used to evaluate the transformation ability of turfgrass for Agrobacterium.
• Select
  Construction of SSR genetic Map and its QTL analysis of agronomic traits with sequenced varieties

  China Biotechnology. 2007, 27(1): 28-34.

  Abstract ( )   Knowledge map   Save

  A F2 population, included 90 lines, which derived from the cross between the completely sequenced japonica variety Nipponbare and the indica variety GuangLuAi-4, was applied to construct a genetic linkage framework map. The map covered 1737.81cM，of total genomic length, and included 148 SSR loci; an average distance of 11.90 cM。The phenotypic values of 6 agronomic traits including number of tillers (Tn), number of panicle (Pn), number of effective tillers (Etn), main panicle length (Mpl), plant height (Ph), and flag length (Fl) were surveyed with three replication (Table 1 and Fig.1). Correlation coefficients between these traits were calculated by means of the software of Excel 2000 were found to be similar to other research conclusions (Table 2). was applied to detect QTLs with Mapmaker/QTL1.1b. Under the condition that LOD>2.2 and P＜0.005, 29 QTLs were detected, which distributed on all rice chromosomes. The phenotypic variations (V.E.) explained by individual QTL were ranged from 11.1% to 42.9%, among which 11 QTLs explained V.E. by more than 20%(Table 3 and Fig.2). The molecular basis of inheritance and the applications of QTL for rice agronomic traits with sequenced rice materials as mapping parents were discussed.
• Select
  Construction and identification of recombinant adenovirus coexpression PRRSV GP5 gene and porcine interferon-γ gene

  China Biotechnology. 2007, 27(1): 35-40.

  Abstract ( )   Knowledge map   Save

  In this study, the GP5 gene of PRRSV and the porcine IFN-γ were amplified by PCR, and ligated by IRES sequence ,then cloned into the transfer vector pAdenoVator-CMV5-IRES-GFP.After co-transformation of PmeI-linearized recombinant plasmid plRES-GP5-IFN-γ and the bone vector pAdEasy-1 into Escherichia coli bacteria strain BJ5183, recombinant plasmid containing GP5 gene and IFN-γ(pAd-GP5- IFN-γ) was obtained and identified with PCR.Upon transfection of PacI-linearized plasmid pAd-GP5- IFN-γ in 293 cell line, a recombinant adenovirus was obtained and named as rAd- GP5- IFN-γ with viral titer of 2×109 TCID50/ml. The expression of the E protein and IFN-γ in the 293 cells infected with rAd- GP5- IFN-γ was confirmed with specific antibodies to E protein and IFN-γ byWestern blotting. It indicated that a stable and safety replication defective recombinant adenovirus rAd-GP5-IFN-γ was produced successfully The recombinant adenovirus might be an attractive candidate vaccine for preventing the disease of PRRS.
• Select
  Gene Cloning and Eukaryotic Expressist Vector Constructing of Porcine lnterleukin-18

  China Biotechnology. 2007, 27(1): 41-46.

  Abstract ( )   Knowledge map   Save

  Interleukin18 (IL-18) is a novel potent inducer of IFN-γproduction. One pair of primers were designed according to porcine IL-18 gene sequence published in GenBank. Porcine IL-18 gene was amplified by RT-PCR from porcine splenocytes total RNA extracts and then was cloned and sequenced. The result suggested that the full length of porcine IL-18 gene is consisted of 579bp,and encodes 192 amino acids. The homology of the nucleotides compared to ABO10003 is 99.8%,and at 550 base the nucleotide changed from A to G. The homology of the amino acids compared to ABO10003, AF176949, AY262109, NM1997 are 99%, 98.5%,99.8% and 99%.Then,got pIL-18 gene, and subcloned it into the eukaryotic expressing plasmid vector pcDNA3.1 and transformed into host E.colistrain JM109 for identification.The result showed that the recombinant plasmid of pcDNA-ILl8m was constructed correctly,which paved the way of nucleotide vaccine.
• Select
  Exogenous Alanine Enhances the Expression of Spidroin2 cDNA of Spider Dragline Silk Protein in Escherichia coli

  China Biotechnology. 2007, 27(1): 47-51.

  Abstract ( )   Knowledge map   Save

  Abstract Expression in vitro of the natural genes of spider silk protein is limited by many factors. Based on the cloning of Spidroin2 cDNA of Nephila clavipes (Genbank Accession No. AF441245), we constructed a prokaryotic expression vector pET-28b(+)-Sp by double digestion. The recombinant plasmids pET-28b(+)-Sp were then transferred into the competent expression host strain BL21(DE3) E. coli. Expression of the native gene Spidroin2 cDNA was induced by the addition of different concentrations of IPTG, followed by extension of induction time, culture temperature and addition of exogenous alanine to increase the expression of interest gene. The recombinant protein was identified by SDS-PAGE and Western blot in which the polyclonal antiserum of dragline silk protein was used as the first antibody. Sequencing result of recombinant expression plasmid showed that Spidroin2 cDNA was inserted into the prokaryotic expression vector pET-28b(+) with a correct read frame. An interest protein with a molecular weight of 31 kDa was observed on SDS-PAGE gel in the condition of alanine addition, which can be specifically immunoblotted with a polyclonal antibody targeted at spider silk protein. We concluded that the Spidroin2 cDNA of Nephila clavipes can be expressed in prokaryotic expression system, and addition of exogenous alanine plays important role in the promotion of expression of the naive gene of spider silk protein.
• Select
  A Secretive Pichia pastoris Expression Vector Capable of Direct PCR Product Cloning

  China Biotechnology. 2007, 27(1): 52-58.

  Abstract ( )   Knowledge map   Save

  It is difficult to obtain N-terminus-authentic recombinant protein in secretive expression system, for cloning of the objective gene through restriction and ligation inevitably introduces additional amino acids between the objective protein and the secretive signal peptide. This work proposed a novel approach to address this problem in the Pichia pastoris secretive expression system through construction and application of an expressive T-vector. A randomly selected fragment was PCR amplified with properly designed primers, such that Xho⒐and Eam1105⒐ restriction sites were included in the 5ˇ end of the amplified product, and Eam1105⒐ and Xba⒐ restriction sites were included in the 3ˇ end. The PCR amplified product was inserted into the P. pastoris expression plasmid pPICZ冄A through Xho⒐ and Xba⒐ restriction sites. The resultant plasmid was digested with Eam1105⒐, and the big fragment was recovered, generating the P. pastoris expressive T-vector pPICZT. The gene of cellobiohydrolase ⒑of T. reesei was expressed in P. pastoris with this expressive T-vector. The results indicated that the constructed expression T-vector was convenient for PCR product cloning, and was effective for heterolgous protein expression in P. pastoris. On the other hand, application of the expression T-vector avoided the introduction of additional amino acids in the N-terminus of the expressed protein, an event that generally occurred when normal expression vectors were used in secretive expression system.
• Select
  Disruption of hom gene encoding for homoserine dehydrogenase of Corynebacterium glutamicum

  China Biotechnology. 2007, 27(1): 59-63.

  Abstract ( )   Knowledge map   Save

  In this research the hom gene encoding for homoserine dehydrogenase was amplified from the genomic DNA of Corynebacterium glutamicum ATCC 13032. After the kanamycin-resistant gene (Km) cassette from plasmid pET28a was inserted into the center of hom, the hom::Km cassette was then electroporated into the competent cell of C. glutamicum ATCC 13032. And kanamycin-resistant clones were obtained. PCR was performed to confirm whether the Km gene was integrated into the hom gene of these clones and the recombinant strains of hom-disrupted were screened out. Fermentation results showed that the lysine yield of the hom-disrupted strain C.g-hom::Km-8 reached 4.7 g/L, which was 6.7 times that of C. glutamicum ATCC 13032.
• Select
  Effect of culture conditons on Jarosite for immobilized Acidothiobacillus ferrooxidans

  China Biotechnology. 2007, 27(1): 64-68.

  Abstract ( )   Knowledge map   Save

  With Ca(NO3)2 (1%~5%) solution as crosslinking agent, Acidithiobacillus ferrooxidans was immobilized by the complex of PVA solution and sodium alginate solution. Continuous culture of immobilized Acidithiobacillus ferrooxidans can be used to remove H2S and SO2. In order to reduce the negative effect of jarosite which formed during the oxidation of Fe2+ by immobilized cells, the changing of initial pH and the ingredient in 9K medium were tried. The results showed: among the three methods, decreasing the concentration (NH4)2SO4 was more feasible than two others. By decreasing the concentration of (NH4)2SO4 from 3 g/L to 0.5 g/L in batch culture, the forming rate of jarosite was decreased by 50%, while Fe2+ oxidation rate was hardly affected. Based on the results from batch culture, a modified 9K medium containing less ammonium sulfate was used to develope an immobilized bioreactor system in which long-term continuous ferrous iron oxidation for about 96h of operation at dilution rates of 0.4 h-1, were successfully achieved with a small amount of jarosite which has many negative effects and a high Fe2+ oxidation rate of 3.75 g/L.h .
• Select
  Effect of overexpression of NAD+-Dependent Malic Enzyme on Anaerobic Mixed Acid Fermentation of E.coli FMJ39

  China Biotechnology. 2007, 27(1): 69-74.

  Abstract ( )   Knowledge map   Save

  In order to investigate the effect of malic enzyme on anaerobic mixed acid fermentation, the gene encoding NAD+-dependent malic enzyme was amplified from E.coli DH5α genome by using PCR and cloned into vector pTrc99a to give an expression vector pTrc99a-sfcA. Malic enzyme was over-produced by E.coli FMJ39（ldh，pfl）harboring pTrc99a-sfcA under the condition of IPTG inducement, so a weak metabolic pathway was constructed and strengthened in anaerobic mixed acid fermentation. The results of anaerobic fermentation indicate overexpression of malic enzyme would have influence on the pathway of formate, acetate and succinate in FMJ39. The concentration of formate and acetate were 17.58% and 15.27% higher than FMJ39, the succinate concentration was reduced by 26.87%. No obvious change on citrate concentration. The fact that high L-Thr and L-Ser concentration would induce the Tdc operon to convert pyruvate into formate and acetate even when pfl gene encoding the pyruvate formate lyase had been inactivated. The experimental results lay the foundation for further modifying and utilizing FMJ39.
• Select
  AOT/Isooctane reverse micellar extraction by adding ethanol Chen Lin-Jie, Cao Xue-Jun

  China Biotechnology. 2007, 27(1): 75-84.

  Abstract ( )   Knowledge map   Save

  Proteins denaturation or precipitation is a big problem during AOT-isooctane reverse micellar extraction due to strong electrostatic interaction between AOT-proteins molecules. In this paper, it has been resolved by adding ethanol into reverse micellar system, and no denaturation was observed. The phase separation time was shortened significantly. It is only 10 minutes or less to reach phases separation after forward and backward extraction. If this method can be applied in industry, efficiency will be greatly improved. In this study, trypsin was extracted from crude material of pig pancreas by using AOT/isooctane reversed micellar system. Forward and backward extraction recovery of trypsin reached almost 90% and neared 100%, respectively. Finally, about 88% of total yield was obtained, and the specific activity of trypsin was increased to over 1800U/mg with purification factor of 5 times more.
• Select
  Clone and Sequence Analysis of Antheraea pernyi Nucleopolyhedrovirus PstⅠ-B and C fragments

  China Biotechnology. 2007, 27(1): 85-85.

  Abstract ( )   Knowledge map   Save

  Antheraea pernyi nucleopolyhedrovirus (ApNPV) PstⅠ-B and C fragments were cloned and sequenced. ApNPV PstⅠ-B was 7406 bp long, contained seven open reading frames (orfs)/genes, including p87, he65, pnk/pnl, odv-ec43 and Orgyia pseudotsugata multicapsid nucleopolyhedrovirus (OpMNPV) orf107, orf108 homologue, on either strands of genomic DNA. ApNPV PstⅠ-C was 6663 bp long, contained eleven orfs/genes, including pk-1, orf1629, polh, lef-2, ptp-2, ctl-1, ptp-1 and OpMNPV orf5, orf7, orf8, orf11 homologue, on either strands of genomic DNA. ApNPV was the third baculovirus found contain pnk/pnl gene, the fourth baculovirus found contain both ptp-1 and ptp-2 gene.
• Select
  Correction of a mutation in a synthetic gene by DREAM technique, a site-directed mutagenesis

  China Biotechnology. 2007, 27(1): 86-92.

  Abstract ( )   Knowledge map   Save

  Objective: To develop a simple and efficient way to perform site-directed mutagenesis. Methods: DNA sequence to be mutated was reversely translated into degenerate codons, which contains large sum of silent mutations and accordingly carries various restriction enzyme sites. A silent mutant sequence with appropriate restriction enzyme was selected as the template. Two outwards primers containing the restriction enzyme were synthesized, with only one harboring the aimed mutation. Then two polymerase chain reactions were carried out with the above primers to amplify the fragments at both sides of the site to be mutated, with only one fragment carrying the site. The amplified fragments were then joined by restriction enzyme cut and ligation, resulting in the wanted mutation. Results: A two-base deletion in a synthetic gene (namely soluble human tissue factor) was successfully corrected in this way. Conclusion: This is an easy-to-use technique for site-directed mutagenesis which can be easily adopted in any molecular biology research settings. This strategy has several variations, including a universal design which uses one of the restriction enzymes cutting outside the recognition site, such as BsaI and SapI. In this universal design, the reverse translation and search for restriction enzyme are omitted. This technique is designated as DREAM: Designed Restriction Enzyme Assisted Mutagenesis.
• Select
  Preparation and Characteristic of Monoclonal Antibodies to tag of FLAG and Its Primary Application

  China Biotechnology. 2007, 27(1): 93-97.

  Abstract ( )   Knowledge map   Save

  Monoclonal Antibodies against FLAG, which was conjugated with BSA by EDC, were produced using conventional cell fusion technology.Five high affinity hybridoma lines were screened for specificity to FLAG by ELISA ，their ascites titers were higher than 1：106.Those monoclonal antibodies didn’t have cross reactivity with other antibiotics, and were implied in Immuno-affinity Chromatography successfully .It may be applicated in purification and research of syncretic protein with tag.
• Select
  Effect of flow cytometrically-sorted sperm on chromosomes of bovine blastocysts produced in vitro

  China Biotechnology. 2007, 27(1): 98-101.

  Abstract ( )   Knowledge map   Save

  The chromosome abnormalities of blastocysts (6 d ~ 8 d ) produced by IVF(in vitro fertilization) with flow cytometrically-sorted, stained and unsorted sperm from 3 bulls were investigate in this study, which determine if the sorting procedure and staining cause the chromosomal abnormality of embryos. The results revealed that there were no significant differences in chromosomal abnormality (mosaic) rates of blastocysts derived from sorted, stained unsorted and unsorted sperm (40.7%, 59/145; 35.8%, 40/106 and37.0%,37/100, respectively); Chromosomal abnormality rates were variant among bulls (30.0% vs 44.6%; p<0.05); These results indicated that: 1) neither sorting procedure nor staining affect the chromosomal composition of embryos; The chromosomal abnormality rates of embryos were variable among bulls.
• Select
  Selection of Liquid Media for High-Density Fermentation of Recombinant E.coli for Production of Plasmids

  China Biotechnology. 2007, 27(1): 102-105.

  Abstract ( )   Knowledge map   Save

  In order to decrease the cost of media for recombinant bacterial fermentation and plasmid DNA production, 10 different liquid media were prepared using home-made reagents and tested at small-scale for growth of recombinant E.coli. By mornitoring the bacterial density (OD600), plasmid yield and replication stability, a cost-effective medium was selected. The growth curve of pEGFPC3, pcDNAlacZ and pcDNKLYZ plasmid-harboring E.coli DH5α and JM109 were plotted in the new medium. At the mid-log growth phase, the growth temperature was shifted from 37℃ to 42℃ and cultivation was continued for 12h. Quantitative analysis showed that the plasmid yields were significantly increased, with 20% increase in JM109 than in DH5α. These data demonstrated that the new medium selected in this study could be used cost-effectively for fermentation of recombinant E.coli for preparation of recombinant plasmids.
• Select
  Studies on Bacteriostatic Effect of Honggumycin

  China Biotechnology. 2007, 27(1): 106-109.

  Abstract ( )   Knowledge map   Save

  Honggumycin, which was a bioactive compound obtained by the fermentation broth of Streptomyces 702, showed a significant antibacterial activity. The antibacterial activity of honggumycin against Bacillus subtilis and Escherichin coli was determined in culture medium. The result showed that the minimal inhibitory concentration (MIC) of honggymycin against Bacillus subtilis and Escherichin coli were 0.08mg/L and 40mg/L, respectively. A better bacterial growth inhibition by honggumycin was observed during the lag phase than that during other phases. Honggumycin has stability to heating and UV irradiation. Furthermore, the bacteriostatic effect of honggumycin was better than other preservatives by evaluating the antibacterial activities of honggumycin and other preservatives.
• Select
  The Study and Design Methods of Serum-Free Medium for Animal Cells

  China Biotechnology. 2007, 27(1): 110-114.

  Abstract ( )   Knowledge map   Save

  With the expanding scale of animal cell culture and increasing demand of biopharmaceutical, the development of serum-free medium based on cell lines and products has become a major task in the field of cell engineer. Identifying and optimizing the sera substitute and the base medium is the most important work in the study of serum-free medium. The interactions among medium components, the high intrinsic variance in cell culture assays and restriction on numbers of conditions per experiment can be studied by using statistical method. By using microarray and proteomic analysis, we can identify the receptors for growth factors, hormones and cytokines, cell adhesion molecules and other components of cell signaling pathway. Thus the additive components can be determined as regulating molecules (largely ligands) of medium. The aim of this review is to provide some idea for serum-free medium study through systematically summarizing the newly and commonly used serum-free medium study and design approaches and their characteristics.
• Select
  Research on antimicrobial peptides and their function

  China Biotechnology. 2007, 27(1): 115-118.

  Abstract ( )   Knowledge map   Save

  Antimicrobial peptides are a recently discovered type of cationic antimicrobial activity peptides and are widely distributed in nature. More and more evidence indicates they are important host-defense molecules of innate immunity and play a major role in innate and adaptive immunity. Continuing researches are developing clearer understanding of these cationic antimicrbial peptides. In this review, we firstly describe their properties briefly, then focus on their direct antibacterial activities and the function of immunomodulating. Furthermore, the article introduces research on applied foreground for antibacterial peptides.
• Select
  Research Progress on Hepatitis C Virus Multi-epitope DNA Vaccine

  China Biotechnology. 2007, 27(1): 119-125.

  Abstract ( )   Knowledge map   Save

  Hepatitis C virus (HCV) is the major etiology of non-A, non-B hepatitis. At present, neither a vaccine nor any effective therapy is available. Multi-epitope DNA vaccine (minigenes/epigenes) is a novel nucleic acid vaccine which can induces high effective cellular and humoral immune responses and has good perspective in clearing Hepatitis C virus through screening and assembling optimal antigen epitope genes(T cell、B cell epitope included). It is advanced in covering more HCV subtypes, inducing comprehensive anti-HCV immune responses and reducing the negative influence caused by irrelevant, disturbing and suppressive sequence as far as possible through selecting the most potential protective epitopes in DNA vaccine design. The recent research progress on HCV compound multi-epitope DNA vaccine and future prospects were reviewed.
• Select
  Recombinant baculoviruses as mammalian cell gene-delivery vectors: a review

  China Biotechnology. 2007, 27(1): 126-130.

  Abstract ( )   Knowledge map   Save

  The baculovirus expression system has been used extensively for the expression of recombinant proteins in insect cells. Recently, recombinant baculoviruses containing mammalian cell-active promoter element have been used to transduce a broad spectrum of primary and established mammalian cells, including non-hepatic cells. Recombinant baculoviruses have been used successfully for transient or stable gene delivery in mammalian cells in vitro, while the efficiency of delivering gene in vivo is inhibited obviously by complements, but efforts have been made to overcome the problems, for instance, VSV-G-pseudotyped baculoviruses display complement resistance. The mechanism of the transduction is still not clearly understood, though many researchers have been done. The baculovirus is able to replicate only in insect cells, but it is incapable of initiating replication cycle in mammalian cells, which guarantees high biosafety of this gene delivery system. In addition, this system is easily manipulated and able to carry large inserts. These attributes will undoubtedly lead to the increased application and continued development of this system for highly effective gene delivery into mammalian cells.
• Select
  Ferment Engineering and Validation Ideas

  China Biotechnology. 2007, 27(1): 131-136.

  Abstract ( )   Knowledge map   Save

  ABSTRACT:The ferment is science technology , The validation is science management. The technology can not part from the management , The management can not part from the technology too . If the technique want to fly more steady and more higher, then it must put on the wing of the management.This text fuse the idea of the validation into the ferment technology ,set up the idea of the validation of the ferment system .set forth the whole process of the validation of the ferment system from personal qualification ,working-out procotol,validation implement to sum-up report . Fact proof, Implementing validation and constructing validation system throughout ferment process is indispensable for completing a successful ferment. the validated ferment system is just dependable system, the validated ferment technics is just stable technics.