A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will b...A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will be the most useful and practical for DNA vaccines in different species. This report examines the use of five expression vectors with different promoters and Kozak sequence to express the same hemagglutinin (HA) protein of an H6N2 avian influenza virus for DNA vaccination in chickens. Although intramuscular vaccination with seven DNA constructs elicited no or limited measurable H6 HA antibody responses in Hy-Line chickens, variable reduction in virus shedding for either oropharyngeal or cloacal swabs post-virus challenge were observed. This indicated that all DNA constructs generated some levels of protective immunity against homologous virus challenge. Interestingly, lower dose (50 or 100 μg) of plasmid DNAs consistently induced better immune response than higher dose (300 or 500 μg). In the transfection experiments there appeared to be a hierarchy in the in vitro expression efficiency in the order of pCAG-optiHAk/ pCAG-HAk > pCI-HAk > VR-HA > pCI-HA > pCI-neo-HA > pVAX-HA. Since the level of in vitro expression correlates with the level of immune response in vivo, in vitro expression levels of the DNA constructs can be used as an indicator for pre-selection of plasmid vaccines prior to in vivo assessment. Moreover, our results suggested that the Kozak sequence could be used as an effective tool for DNA vaccine design.展开更多
Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed ...Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed in- cluded the coding regions for the core protein (pC) and for the core, E_1 and E_2 together (pCE_1E_2), IL- 12 p35 and p40. These plasmids were transfected into mammalian cells to test their protein expression and were injected into the quadriceps muscles of BALB/ C mice for measurement of specific antibodies and cytotoxic T-lymphocyte (CTL) responses. Results: All the recombinant plasmids were shown to express specific antigens stably in mammalian cells. Codelivery of pIL-12 expression cassettes with pC and pCE_1E_2 in mice resulted in the enhancement of Ag-dependent CTL responses and the reduction of specific Ab response. The CTL activity was: pC= 18.65%±5.71%, pCE_1E_2=20.07%±11.11%, pC +pIL-12=60.11%±17.37%, pCE_1E_2+pIL-12= 67.48%±15.57%, respectively. The average A val- ues of anti-HCV were pC=0.415±0.127, pCE_1E_2= 0.358±0.096, pC+pIL-12=0.210±0.086, pCE_1E_2 +pIL-12=0.258±0.125. Conclusion: Codelivery of pIL-12 with plasmid DNA can enhance the efficacy of immune responses and shift the type of immune responses.展开更多
We sought to construct the adenoviral vector carrying the gene encoding mouse telomerase reverse transcriptase(mTERT),as well as detect its expression and effect on the proliferation of neuronal stem cells.mTERT was...We sought to construct the adenoviral vector carrying the gene encoding mouse telomerase reverse transcriptase(mTERT),as well as detect its expression and effect on the proliferation of neuronal stem cells.mTERT was am-plified by RT-PCR and then the eukaryotic expression vector of pDC-EGFP-TERT was constructed.After DNA sequence analysis,we detected that there were 293 cells transfected with pDC-EGFP-TERT and helper adenovirus plasmid pBHG lox ΔE1,and three Cre using Lipofectamine 2000 mediation,named Ad-mTERT-GFP,to pack-age adenoviral particles.The Ad-mTERT-GFP was used to infect neuronal stem cells and then the expression and activity of mTERT were detected.In addition,Bromodeoxyuridine labeling test identified the impact of mTERT overexpression on proliferation of neuronal stem cells.The recombinant adenoviral vector confirmed that mTERT was successfully constructed.Overexpression of mTERT stimulated the proliferation of neuronal stem cells both in vitro and in vivo.mTERT overexpression via adenoviral vector carrying mTERT cDNA upregulated the ability of proliferation in neuronal stem cells.展开更多
To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths ...To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EFP, pCDNA3.1 (Zeo+) respectively.The recombinants were cotransfected into HeLa cells.After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6.The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence.The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS.It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR).After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR.The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell.Neither single H1b nor H1b and H2c could bind ASOR.In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established.The new split variant H1b has no effect on ASGPR binding to ASOR.ASGPRH1b alone can’t bind to ASOR, it yet can’t form functional complex with ASGPRH2c.展开更多
DNA vaccines encoding a viral protein have been shown to induce antiviral immune responses and provide pro-tection against subsequent viral challenge. The present article deals with the efficacy of a DNA vaccine great...DNA vaccines encoding a viral protein have been shown to induce antiviral immune responses and provide pro-tection against subsequent viral challenge. The present article deals with the efficacy of a DNA vaccine greatly im-proved by the simultaneous expression of HBsAg and interferon-T gene. We constructed a dual expression vector pHIN encoding the HBsAg of Hepatitis B virus and murine IFN-T which are connected with Internal Ribosome Entry Site(IRES). Mice immunized with this dual expression DNA vaccine exhibited the enhancement of cellular immune response and increased the production of anti-HBV surface antibody, compared with the mice of single gene expres-sion control. Taken together, these results demonstrate that the application of a cytokine gene in a DNA vaccine for-mulation as an adjuvant can improve its immunigenicity.展开更多
High yield,high quality,stable yield,adaptability to growth period,and modern mechanization are the basic requirements for crops in the 21st century.Soybean oleic acid is a natural unsaturated fatty acid with strong a...High yield,high quality,stable yield,adaptability to growth period,and modern mechanization are the basic requirements for crops in the 21st century.Soybean oleic acid is a natural unsaturated fatty acid with strong antioxidant properties and stability.Known as a safe fatty acid,it has the ability to successfully prevent cardiovascular and cerebrovascular disorders.Improving the fatty acid composition of soybean seeds,can not only speed up the breeding process of high-quality high-oil and high-oleic soybeans,but also have important significance in human health,and provide the possibility for the development of soybean oil as a new energy source.Hence,the aim of this study was to analyze the high oleic acid elated gene GmSAM22 in soybean.In this research the soybean oleic acid-related gene GmSAM22 was screened out by Genome-wide association analysis,a 662 bp fragment was acquired by specific PCR amplification,and the pMD18T cloning vector was linked by the use of a seamless cloning technique.Bioinformatics analysis of the signal peptide prediction,subcellular localization,protein hydrophobicity,transmembrane region analysis,a phosphorylation site,protein secondary and tertiary structure and protein interaction analysis of the protein encoded by the SAM22 gene was carried out.The plasmid of the gene editing vector is pBK041.The overexpression vector was transformed from pCAMBIA3301 as the base vector,and overexpression vector were designed.Positive plants were obtained by genetic transformation by the pollen tube channel method.Fluorescence quantitative PCR was performed on the T2 generation plants to detect the relative expression levels in different tissues.Southern Blot was used to detect the presence of hybridization signal.Screening genes BAR,35S,and NOS in plants were identified by conventional PCR.10 seeds with high and low oleic acid content were chosen for quantitative PCR identification,and finally,the concentration and morphology of soybean fatty acids were identified by nearfar infrared spectroscopy.On 10 seeds with an upper and lower oleic acid content,a quantitative fluorescence analysis was done.In Southern blot hybridization,the SAM22 gene was integrated into the recipient soybean plant in hands of a sole copy.Fluorescence quantitative PCR appeared that the average relative expression of the SAM22 gene in roots,stems,leaves,and seeds was 1.70,1.67,3.83,and 4.41,respectively.Positive expression seeds had a 4.77%increase in oleic acid content.The level of oleic acid in the altered seeds was reduced by 4.13%when compared to CK,and it was discovered that the GmSAM22 gene could be a regulatory and secondary gene that promotes the conversion of stearic acid to oleic acid in soybean.There has not been a discussion of gene cloning or functional verification.The cloning and genetic transformation of the soybean SAM22 gene can effectively increase the content of oleic acid,which lays a foundation for the study of soybean with high oleic acid.展开更多
Objective:PR domain is responsible for the tumor suppressing activity of RIZ1.The study aimed to construct human PR domain eukaryotic expression vectors,transfect human esophageal cancer cells (TE13),and evaluate t...Objective:PR domain is responsible for the tumor suppressing activity of RIZ1.The study aimed to construct human PR domain eukaryotic expression vectors,transfect human esophageal cancer cells (TE13),and evaluate the anticancer activity of PR domain on human esophageal cancer TE13 cells.Methods:First,mRNA was extracted from human esophageal cancer tissue by RT-PCR,then reversetranscribed to cDNA.After amplifying from the DNA template,PR domain was linked to T vector.Second,after extraction,PR domain was cut using enzyme and linked to pcDNA3.1(+).Then,the plasmid was transfered to Trans1-T1 phage resistant competent cells,following by extracting the ultrapure plasmid,and transfecting into TE13 cells.In the end,the protein expression of pcDNA3.1(+)/PR domain in TE13 was detected by Western blot,and the apoptosis of TE 13 by technique of flow cytometry.Results:More than 5,000 bp purposed band of pcDNA3.1(+)/PR domain plasmid was found by agarose gel electrophoresis.After transfection,the PR domain (molecular weight of about 28 Da) was found only in 3,4 and 5 groups by Western blot.Flow cytometry assay showed apoptosis in experimental group was significantly more than that in the control group (P<0.05).Conclusions:The PR domain eukaryotic expression vector was constructed successfully.The protein of the PR domain could be expressed in esophageal cancer TE13 cells firmly after transfection,and a single PR domain could promote apoptosis of TE13 cells.展开更多
BACKGROUND: The proliferation and metastasis of cancers depend on angiogenesis. This property provides the feasibility for the treatment of cancer by inhibition of angiogenesis, and many angiogenic inhibitors have bee...BACKGROUND: The proliferation and metastasis of cancers depend on angiogenesis. This property provides the feasibility for the treatment of cancer by inhibition of angiogenesis, and many angiogenic inhibitors have been demonstrated to effectively inhibit angiogenesis and consequently the growth of solid cancer. As for the newly identified angiogenesis inhibitor, arresten, some studies have found its high activity on restrainting tumor vessel. This study was to assess the anti-angiogenic activity of arresten. METHODS: The arresten gene was obtained from a healthy puerpera's placenta tissue by the reverse transcriptase-polymerase chain reaction (RT-PCR) method, and molecular cloning to prokaryotic expression plasmid pBV220 by recombination strategy. The prokaryotic expression plasmid pBV220/arr was identified by restriction enzyme digestion and sequenced. The pBV220/arr was transformed into E. coli JM109, DH5α, BL21 and BL21 (DE3) by the CaCl_2 transformation method. The arresten expression level was detected by SDS-PAGE. The expressed product was purlfled, re-naturalized and detected for its biological activity of inhibiting the angiogenesis of chorioallantoic membrane (CAM). RESULTS: The arresten gene was cloned and pBV220/arr was constructed. The arresten expression level of protein was highly increased after pBV220/arr was transformed into E. coli BL21 (DE3). SDS-PAGE showed that the expressed arresten proteins were mainly inclusion bodies and had a molecular weight of 26 kDa. The expressed arresten protein showed evident biological activities. CONCLUSIONS: The successful construction of recombinant plasmid pBV220/arr and the effective expression in E. coil have laid a foundation for further study of its anti-angiogenic function and may pave the way for future antitumor application.展开更多
Thenoggin gene is present in the central nervous system in embryonic and postnatal mammals, and plays an important role in maintaining nervous system development and physiological function A 0.76-kb sequence of human ...Thenoggin gene is present in the central nervous system in embryonic and postnatal mammals, and plays an important role in maintaining nervous system development and physiological function A 0.76-kb sequence of human noggin gene was cloned by polymerase chain reaction with the digestion site of Hind Ill and Xba I on the 5' end. The cloned fragment was reversely inserted into pCS2+[Tal]-GFP plasmid, an neural cell-specific antisense eukaryotic expression vector. The plasmid expresses antisense for human noggin specifically in neurons, which may facilitate understanding of the physiological function of noggin.展开更多
Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin (PLFN). A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the cha...Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin (PLFN). A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the characters of translational fusions from gene and expression vector plasmid. A 1 077 bp fragment of the gene from PLF was cloned from mammary gland tissue of the lactating sow on the third day by RT-PCR; the gene was connected with the vector plasmid pPG612.1 and transformed into the host strain JM109. The recombinant expression vector plasmid pPG612-PLFN was created and identified by using plasmid extraction, PCR, restriction enzyme digestion and sequence analysis. The recombinant plasmid was transformed into Lactobacillus casei ATCC393, Lactobacillus plantarum KLDS 1.0344, Lactobacillus paracasei KLDS 1.0652 and Lactobacillus pentosus KLDS 1.0413 by electroporation, and produced the recombinant strains of pPG612-PLFN/L, casei, pPG612-PLFN/L, plantarum, pPG612-PLFN/ L. paracasei and pPG612-PLFN/L, pentosus, respectively. The results indicated that PLFN gene had inserted into the expression vectors and achieved multiple Laetobacillus expression systems. It electes the base for the expression and production of recombinant porcine lactoferrin in Lactobaeillus展开更多
By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-my...By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-mycobacteria shuttle expression plasmid PBCG-8000 was constructed. The PBCG-8000 was able to replicate in both E. Coli and mycobacteria (including BCG) systems, and to confer stable kanamycin resistance upon transformants. The study should facilitate the development of BCG and other mycobacteria into multivalent vaccine vectors.展开更多
Objective: To investigate the inhibitory effects of RNAi ( RNA interference, RNAi) expression vector on CXCR4 expression in prostate carcinoma cell lines. Methods: Small interference RNA (siRNA) expression vecto...Objective: To investigate the inhibitory effects of RNAi ( RNA interference, RNAi) expression vector on CXCR4 expression in prostate carcinoma cell lines. Methods: Small interference RNA (siRNA) expression vectors for CXCR4 gene were constructed and transfected into prostate carcinoma cell lines(PC-3m and LNCaP)with liposomes. T expression of CXCR4 was detected by RT-PCR and western blot. Results: T expression of CXCR4 mRNA and protein in the PC-3m and LNCaP cells was reduced by RNAi expression vectors. The inhibitory rate of CXCR4 mRNA expression in the PC-3m cells was 87.81% ± 10.20% ,56.10% ± 9.32% at the 24th hour and the 48th hour, compared with 56.93% ±8.78% ,49.24% ± 11.23% in LNCaP cells. The inhibitory rate of the expression of CXCR4 protein was 64.71% ± 6.68% ,58.66% ± 11.56% respectively. Conclusion: The expression of CXCR4 gene can effectively be inhibited by RNAi expression vectors.展开更多
AIM: To generate recombinant adenoviral vector con-taining calreticulin (CRT)-hepatitis B surface antigen (HBsAg) fusion gene for developing a safe, effective and HBsAg-specific therapeutic vaccine.METHODS: CRT and HB...AIM: To generate recombinant adenoviral vector con-taining calreticulin (CRT)-hepatitis B surface antigen (HBsAg) fusion gene for developing a safe, effective and HBsAg-specific therapeutic vaccine.METHODS: CRT and HBsAg gene were fused using polymerase chain reaction (PCR), endonuclease diges-tion and ligation methods. The fusion gene was cloned into pENTR/D-TOPO transfer vector after the base pairs of DNA (CACC) sequence was added to the 5′ end. Adenoviral expression vector containing CRT-HBsAg fusion gene was constructed by homologous recombinan-tion. The human embryo kidney (HEK) 293A cells were transfected with linearized DNA plasmid of the recombi-nant adenoviral vector to package and amplify recombi-nant adenovirus. The recombinant adenovirus titer was characterized using the end-dilution assay. The expres-sion of the CRT/HBsAg fusion protein in Ad-CRT/HBsAg infected 293A cells was detected by Western blotting.RESULTS: The CRT-HBsAg fusion gene was char-acterized by PCR and sequencing and its length and sequence were confirmed to be accurate. The CRT-HB-sAg fusion gene recombinant pENTR/D-TOPO transfer vector was constructed. The recombinant adenoviral vector, Ad-CRT/HBsAg, was generated successfully. The titer of Ad-CRT/HBsAg was characterized as 3.9 × 1011 pfu/mL. The CRT-HBsAg fusion protein was ex-pressed by HEK 293A cells correctly. CONCLUSION: CRT/HBsAg fusion gene recombinant replication-defective adenovirus expression vector is constructed successfully and this study has provided an experimental basis for further studies of Hepatitis B vi-rus gene therapy.展开更多
Being a major class of single-stranded DNA viruses, geminiviruses are mostly studied due to their catastrophic infectious effect on crops. These DNA viruses are characteristic for their ability in quickly multiplying ...Being a major class of single-stranded DNA viruses, geminiviruses are mostly studied due to their catastrophic infectious effect on crops. These DNA viruses are characteristic for their ability in quickly multiplying viral genetic materials without integrating into the genome of plants, which makes them ideal for developing viral vectors for plants bioengineering. Geminivirus-derived vectors can be classified into expression vectors and virus-induced gene silencing(VIGS) vectors. Details of the design, construction, application and improvements of these geminivirus vectors are summarized and discussed.展开更多
To study the therapeutic effects of herpes simplex virus thymidine kinase gene transferred by the EBV based expression vector on experimental hepatocellular carcinoma, pDR2 TK gene was delivered into human hepatoc...To study the therapeutic effects of herpes simplex virus thymidine kinase gene transferred by the EBV based expression vector on experimental hepatocellular carcinoma, pDR2 TK gene was delivered into human hepatocellular carcinoma cell line SMMC 7721 by using liposome mediated transfection technique,and then gene expression was detected by RT PCR, and the killing effects were examined through MTT method. In the nude mice hepatoma model,the antitumor effects of pDR2 TK /GCV system was evaluated in terms of tumor growth. MTT results showed that the pDR2 TK /GCV had cytotoxic effect and about 70 % SMMC 7721 cells were killed when GCV was at 1000 μmol/L. In vivo experiment showed that the tumor size in nude mice with transferred pDR2 TK gene was significantly smaller than that in control group . On the 10th day the tumor in 3 mice (60 %) disappeared completely after GCV treatment. It is concluded that the pDR2 TK/GCV system has marked killing effects on the experimental hepatocellular carcinoma.展开更多
The aim of this article is to successfully express the Bt (Bacillus thuringiensis) toxin receptor protein located on the internal membrane of larval midgut of cotton bollworm (Helicoverpa armigera Hübner) wit...The aim of this article is to successfully express the Bt (Bacillus thuringiensis) toxin receptor protein located on the internal membrane of larval midgut of cotton bollworm (Helicoverpa armigera Hübner) within eukaryotic expression system, which is one of the key links for clarifying the relationship between receptor and Bt resistance. The fragments of aminopeptidase N1 (APN1) gene without signal peptide in the susceptible and the resistant H. armigera were cloned separately using PCR method, and were separately cloned into pUC 19 vector. After sequencing the gene, the fragments encoding for APN1 without signal peptide were cloned into the Bac-to-Bac baculovirus expression system with transfer vector pFastBacHTB under the polyhedron gene promoter. The recombinant transposing plasmid pFastBacHTB/APN1 was screened and then transformed into Escherichia coli DH10Bac. It was cultured in LB medium, which contained Te, Kan, Ge, X-gal, and IPTG. The resulting recombinant bacmid was transfected into cells of the insect Trichoplusia ni and recombinant baculoviruse was obtained. The lysate of cells infected with recombinant baculoviruse was analyzed by SDS-PAGE and blot analysis. The results showed that the recombinant baculoviruse was fully capable of expressing APN1. The APN1 gene successfully expressed in T. ni cell established the base for continuing the research on its function and relationshio of resistance with Bt.展开更多
A full-length cDNA sequence of xyloglucan endotransglycosylase gene (XET), abundantly expressed in the cambium of Anthocephalus chinensis was cloned by conserved PCR, rapid-amplification of cDNA ends and by chromoso...A full-length cDNA sequence of xyloglucan endotransglycosylase gene (XET), abundantly expressed in the cambium of Anthocephalus chinensis was cloned by conserved PCR, rapid-amplification of cDNA ends and by chromosome walking. Analytical results of the DNA sequence show that a 912 bp complete open reading frame (ORF) encoded a 303-amino acid protein was in the 1205 bp full cDNA sequence. The deduced amino acid sequence of AcXET, which contained the conserved specific EIDFE catalytic site sequence to XETs was homologous to the other known XET proteins. In order to study the gene function of AcXET and obtain transgenic plants, a plant expression vector pBIAcXET was constructed by recombinating the AcXET fragment from the cloning vector pMD19AcXET and the binary vector pBI121 between the XbaI and SmaI sites. The fragment ofAcXET gene was inserted between the CaMV 35S promotor and the coding region of the GUS gene in pBI121. The identification results show that the plant expression binary vector pBIAcXET was constructed successfully. These results lay the foundation for studying the molecular mechanism ofAcXET gene during wood formation.展开更多
文摘A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will be the most useful and practical for DNA vaccines in different species. This report examines the use of five expression vectors with different promoters and Kozak sequence to express the same hemagglutinin (HA) protein of an H6N2 avian influenza virus for DNA vaccination in chickens. Although intramuscular vaccination with seven DNA constructs elicited no or limited measurable H6 HA antibody responses in Hy-Line chickens, variable reduction in virus shedding for either oropharyngeal or cloacal swabs post-virus challenge were observed. This indicated that all DNA constructs generated some levels of protective immunity against homologous virus challenge. Interestingly, lower dose (50 or 100 μg) of plasmid DNAs consistently induced better immune response than higher dose (300 or 500 μg). In the transfection experiments there appeared to be a hierarchy in the in vitro expression efficiency in the order of pCAG-optiHAk/ pCAG-HAk > pCI-HAk > VR-HA > pCI-HA > pCI-neo-HA > pVAX-HA. Since the level of in vitro expression correlates with the level of immune response in vivo, in vitro expression levels of the DNA constructs can be used as an indicator for pre-selection of plasmid vaccines prior to in vivo assessment. Moreover, our results suggested that the Kozak sequence could be used as an effective tool for DNA vaccine design.
文摘Objective: To demonstrate the utility of DNA vaccines for the tailored methods, the efficacy of enhanced immune responses, and the types of increased im- mune responses. Methods: Four recombinant plasmids constructed in- cluded the coding regions for the core protein (pC) and for the core, E_1 and E_2 together (pCE_1E_2), IL- 12 p35 and p40. These plasmids were transfected into mammalian cells to test their protein expression and were injected into the quadriceps muscles of BALB/ C mice for measurement of specific antibodies and cytotoxic T-lymphocyte (CTL) responses. Results: All the recombinant plasmids were shown to express specific antigens stably in mammalian cells. Codelivery of pIL-12 expression cassettes with pC and pCE_1E_2 in mice resulted in the enhancement of Ag-dependent CTL responses and the reduction of specific Ab response. The CTL activity was: pC= 18.65%±5.71%, pCE_1E_2=20.07%±11.11%, pC +pIL-12=60.11%±17.37%, pCE_1E_2+pIL-12= 67.48%±15.57%, respectively. The average A val- ues of anti-HCV were pC=0.415±0.127, pCE_1E_2= 0.358±0.096, pC+pIL-12=0.210±0.086, pCE_1E_2 +pIL-12=0.258±0.125. Conclusion: Codelivery of pIL-12 with plasmid DNA can enhance the efficacy of immune responses and shift the type of immune responses.
基金supported by grants from the Science and Technology Foundation of Nanjing Medical University(No.09NJMUZ15)from the Natural Science Foundation of Jiangsu Province(No.10KJB31008)
文摘We sought to construct the adenoviral vector carrying the gene encoding mouse telomerase reverse transcriptase(mTERT),as well as detect its expression and effect on the proliferation of neuronal stem cells.mTERT was am-plified by RT-PCR and then the eukaryotic expression vector of pDC-EGFP-TERT was constructed.After DNA sequence analysis,we detected that there were 293 cells transfected with pDC-EGFP-TERT and helper adenovirus plasmid pBHG lox ΔE1,and three Cre using Lipofectamine 2000 mediation,named Ad-mTERT-GFP,to pack-age adenoviral particles.The Ad-mTERT-GFP was used to infect neuronal stem cells and then the expression and activity of mTERT were detected.In addition,Bromodeoxyuridine labeling test identified the impact of mTERT overexpression on proliferation of neuronal stem cells.The recombinant adenoviral vector confirmed that mTERT was successfully constructed.Overexpression of mTERT stimulated the proliferation of neuronal stem cells both in vitro and in vivo.mTERT overexpression via adenoviral vector carrying mTERT cDNA upregulated the ability of proliferation in neuronal stem cells.
基金supported by grants from the National Major Science and Technology Special Project for Infectious Diseases of China (No.2008ZX10002-011)National High Technology Research and Development of China (Program 863) (No.2006AA02Z128)the National Natural Science Foundation of China (Nos.30700701,30571646)
文摘To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands’ binding ability, we established a functional cell line which expresses ASGPR.The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EFP, pCDNA3.1 (Zeo+) respectively.The recombinants were cotransfected into HeLa cells.After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6.The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence.The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS.It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR).After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR.The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell.Neither single H1b nor H1b and H2c could bind ASOR.In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established.The new split variant H1b has no effect on ASGPR binding to ASOR.ASGPRH1b alone can’t bind to ASOR, it yet can’t form functional complex with ASGPRH2c.
文摘DNA vaccines encoding a viral protein have been shown to induce antiviral immune responses and provide pro-tection against subsequent viral challenge. The present article deals with the efficacy of a DNA vaccine greatly im-proved by the simultaneous expression of HBsAg and interferon-T gene. We constructed a dual expression vector pHIN encoding the HBsAg of Hepatitis B virus and murine IFN-T which are connected with Internal Ribosome Entry Site(IRES). Mice immunized with this dual expression DNA vaccine exhibited the enhancement of cellular immune response and increased the production of anti-HBV surface antibody, compared with the mice of single gene expres-sion control. Taken together, these results demonstrate that the application of a cytokine gene in a DNA vaccine for-mulation as an adjuvant can improve its immunigenicity.
基金funded by the National Major Special Project for Breeding New Varieties of Genetically Modified Organisms(2016ZX08004-004)National Natural Science Foundation of China(31771817).
文摘High yield,high quality,stable yield,adaptability to growth period,and modern mechanization are the basic requirements for crops in the 21st century.Soybean oleic acid is a natural unsaturated fatty acid with strong antioxidant properties and stability.Known as a safe fatty acid,it has the ability to successfully prevent cardiovascular and cerebrovascular disorders.Improving the fatty acid composition of soybean seeds,can not only speed up the breeding process of high-quality high-oil and high-oleic soybeans,but also have important significance in human health,and provide the possibility for the development of soybean oil as a new energy source.Hence,the aim of this study was to analyze the high oleic acid elated gene GmSAM22 in soybean.In this research the soybean oleic acid-related gene GmSAM22 was screened out by Genome-wide association analysis,a 662 bp fragment was acquired by specific PCR amplification,and the pMD18T cloning vector was linked by the use of a seamless cloning technique.Bioinformatics analysis of the signal peptide prediction,subcellular localization,protein hydrophobicity,transmembrane region analysis,a phosphorylation site,protein secondary and tertiary structure and protein interaction analysis of the protein encoded by the SAM22 gene was carried out.The plasmid of the gene editing vector is pBK041.The overexpression vector was transformed from pCAMBIA3301 as the base vector,and overexpression vector were designed.Positive plants were obtained by genetic transformation by the pollen tube channel method.Fluorescence quantitative PCR was performed on the T2 generation plants to detect the relative expression levels in different tissues.Southern Blot was used to detect the presence of hybridization signal.Screening genes BAR,35S,and NOS in plants were identified by conventional PCR.10 seeds with high and low oleic acid content were chosen for quantitative PCR identification,and finally,the concentration and morphology of soybean fatty acids were identified by nearfar infrared spectroscopy.On 10 seeds with an upper and lower oleic acid content,a quantitative fluorescence analysis was done.In Southern blot hybridization,the SAM22 gene was integrated into the recipient soybean plant in hands of a sole copy.Fluorescence quantitative PCR appeared that the average relative expression of the SAM22 gene in roots,stems,leaves,and seeds was 1.70,1.67,3.83,and 4.41,respectively.Positive expression seeds had a 4.77%increase in oleic acid content.The level of oleic acid in the altered seeds was reduced by 4.13%when compared to CK,and it was discovered that the GmSAM22 gene could be a regulatory and secondary gene that promotes the conversion of stearic acid to oleic acid in soybean.There has not been a discussion of gene cloning or functional verification.The cloning and genetic transformation of the soybean SAM22 gene can effectively increase the content of oleic acid,which lays a foundation for the study of soybean with high oleic acid.
基金supported by National Natural Science Foundation of China(No.81201945)Science foundation of Tianjin medical University(No.2011KY08)
文摘Objective:PR domain is responsible for the tumor suppressing activity of RIZ1.The study aimed to construct human PR domain eukaryotic expression vectors,transfect human esophageal cancer cells (TE13),and evaluate the anticancer activity of PR domain on human esophageal cancer TE13 cells.Methods:First,mRNA was extracted from human esophageal cancer tissue by RT-PCR,then reversetranscribed to cDNA.After amplifying from the DNA template,PR domain was linked to T vector.Second,after extraction,PR domain was cut using enzyme and linked to pcDNA3.1(+).Then,the plasmid was transfered to Trans1-T1 phage resistant competent cells,following by extracting the ultrapure plasmid,and transfecting into TE13 cells.In the end,the protein expression of pcDNA3.1(+)/PR domain in TE13 was detected by Western blot,and the apoptosis of TE 13 by technique of flow cytometry.Results:More than 5,000 bp purposed band of pcDNA3.1(+)/PR domain plasmid was found by agarose gel electrophoresis.After transfection,the PR domain (molecular weight of about 28 Da) was found only in 3,4 and 5 groups by Western blot.Flow cytometry assay showed apoptosis in experimental group was significantly more than that in the control group (P<0.05).Conclusions:The PR domain eukaryotic expression vector was constructed successfully.The protein of the PR domain could be expressed in esophageal cancer TE13 cells firmly after transfection,and a single PR domain could promote apoptosis of TE13 cells.
基金This work was supported by a grant from Science and Technology Fund of Shanxi Province, China (No. 042082).
文摘BACKGROUND: The proliferation and metastasis of cancers depend on angiogenesis. This property provides the feasibility for the treatment of cancer by inhibition of angiogenesis, and many angiogenic inhibitors have been demonstrated to effectively inhibit angiogenesis and consequently the growth of solid cancer. As for the newly identified angiogenesis inhibitor, arresten, some studies have found its high activity on restrainting tumor vessel. This study was to assess the anti-angiogenic activity of arresten. METHODS: The arresten gene was obtained from a healthy puerpera's placenta tissue by the reverse transcriptase-polymerase chain reaction (RT-PCR) method, and molecular cloning to prokaryotic expression plasmid pBV220 by recombination strategy. The prokaryotic expression plasmid pBV220/arr was identified by restriction enzyme digestion and sequenced. The pBV220/arr was transformed into E. coli JM109, DH5α, BL21 and BL21 (DE3) by the CaCl_2 transformation method. The arresten expression level was detected by SDS-PAGE. The expressed product was purlfled, re-naturalized and detected for its biological activity of inhibiting the angiogenesis of chorioallantoic membrane (CAM). RESULTS: The arresten gene was cloned and pBV220/arr was constructed. The arresten expression level of protein was highly increased after pBV220/arr was transformed into E. coli BL21 (DE3). SDS-PAGE showed that the expressed arresten proteins were mainly inclusion bodies and had a molecular weight of 26 kDa. The expressed arresten protein showed evident biological activities. CONCLUSIONS: The successful construction of recombinant plasmid pBV220/arr and the effective expression in E. coil have laid a foundation for further study of its anti-angiogenic function and may pave the way for future antitumor application.
基金the Science and Technology Development Program of Shandong Province,No.2007GG10002017the Natural Science Foundation of Shandong Province,No.Y2008C63
文摘Thenoggin gene is present in the central nervous system in embryonic and postnatal mammals, and plays an important role in maintaining nervous system development and physiological function A 0.76-kb sequence of human noggin gene was cloned by polymerase chain reaction with the digestion site of Hind Ill and Xba I on the 5' end. The cloned fragment was reversely inserted into pCS2+[Tal]-GFP plasmid, an neural cell-specific antisense eukaryotic expression vector. The plasmid expresses antisense for human noggin specifically in neurons, which may facilitate understanding of the physiological function of noggin.
基金Supported by National Natural Science Foundation of China (30871809,31072057)Principal Fund of Northeast Agricultural University
文摘Lactobacillus was selected as a bacterial carrier for expression of N-lobe of porcine lactoferrin (PLFN). A pair of primers was designed with Oligo6.0 and used to amplify PLFN gene. It was in accordance with the characters of translational fusions from gene and expression vector plasmid. A 1 077 bp fragment of the gene from PLF was cloned from mammary gland tissue of the lactating sow on the third day by RT-PCR; the gene was connected with the vector plasmid pPG612.1 and transformed into the host strain JM109. The recombinant expression vector plasmid pPG612-PLFN was created and identified by using plasmid extraction, PCR, restriction enzyme digestion and sequence analysis. The recombinant plasmid was transformed into Lactobacillus casei ATCC393, Lactobacillus plantarum KLDS 1.0344, Lactobacillus paracasei KLDS 1.0652 and Lactobacillus pentosus KLDS 1.0413 by electroporation, and produced the recombinant strains of pPG612-PLFN/L, casei, pPG612-PLFN/L, plantarum, pPG612-PLFN/ L. paracasei and pPG612-PLFN/L, pentosus, respectively. The results indicated that PLFN gene had inserted into the expression vectors and achieved multiple Laetobacillus expression systems. It electes the base for the expression and production of recombinant porcine lactoferrin in Lactobaeillus
文摘By employing the pUC19 as a backbone,the regulatory and signal sequences which encode kanamycin resistance, and mycobacterial plasmid origin of replication (oriM) were cloned into the pUC19. The recombinant E. Coli-mycobacteria shuttle expression plasmid PBCG-8000 was constructed. The PBCG-8000 was able to replicate in both E. Coli and mycobacteria (including BCG) systems, and to confer stable kanamycin resistance upon transformants. The study should facilitate the development of BCG and other mycobacteria into multivalent vaccine vectors.
文摘Objective: To investigate the inhibitory effects of RNAi ( RNA interference, RNAi) expression vector on CXCR4 expression in prostate carcinoma cell lines. Methods: Small interference RNA (siRNA) expression vectors for CXCR4 gene were constructed and transfected into prostate carcinoma cell lines(PC-3m and LNCaP)with liposomes. T expression of CXCR4 was detected by RT-PCR and western blot. Results: T expression of CXCR4 mRNA and protein in the PC-3m and LNCaP cells was reduced by RNAi expression vectors. The inhibitory rate of CXCR4 mRNA expression in the PC-3m cells was 87.81% ± 10.20% ,56.10% ± 9.32% at the 24th hour and the 48th hour, compared with 56.93% ±8.78% ,49.24% ± 11.23% in LNCaP cells. The inhibitory rate of the expression of CXCR4 protein was 64.71% ± 6.68% ,58.66% ± 11.56% respectively. Conclusion: The expression of CXCR4 gene can effectively be inhibited by RNAi expression vectors.
基金Supported by Grants from National Natural Science Foundation of China, No. 30901344
文摘AIM: To generate recombinant adenoviral vector con-taining calreticulin (CRT)-hepatitis B surface antigen (HBsAg) fusion gene for developing a safe, effective and HBsAg-specific therapeutic vaccine.METHODS: CRT and HBsAg gene were fused using polymerase chain reaction (PCR), endonuclease diges-tion and ligation methods. The fusion gene was cloned into pENTR/D-TOPO transfer vector after the base pairs of DNA (CACC) sequence was added to the 5′ end. Adenoviral expression vector containing CRT-HBsAg fusion gene was constructed by homologous recombinan-tion. The human embryo kidney (HEK) 293A cells were transfected with linearized DNA plasmid of the recombi-nant adenoviral vector to package and amplify recombi-nant adenovirus. The recombinant adenovirus titer was characterized using the end-dilution assay. The expres-sion of the CRT/HBsAg fusion protein in Ad-CRT/HBsAg infected 293A cells was detected by Western blotting.RESULTS: The CRT-HBsAg fusion gene was char-acterized by PCR and sequencing and its length and sequence were confirmed to be accurate. The CRT-HB-sAg fusion gene recombinant pENTR/D-TOPO transfer vector was constructed. The recombinant adenoviral vector, Ad-CRT/HBsAg, was generated successfully. The titer of Ad-CRT/HBsAg was characterized as 3.9 × 1011 pfu/mL. The CRT-HBsAg fusion protein was ex-pressed by HEK 293A cells correctly. CONCLUSION: CRT/HBsAg fusion gene recombinant replication-defective adenovirus expression vector is constructed successfully and this study has provided an experimental basis for further studies of Hepatitis B vi-rus gene therapy.
基金supported by the National Natural Science Foundation of China (31672006 and 31390422)
文摘Being a major class of single-stranded DNA viruses, geminiviruses are mostly studied due to their catastrophic infectious effect on crops. These DNA viruses are characteristic for their ability in quickly multiplying viral genetic materials without integrating into the genome of plants, which makes them ideal for developing viral vectors for plants bioengineering. Geminivirus-derived vectors can be classified into expression vectors and virus-induced gene silencing(VIGS) vectors. Details of the design, construction, application and improvements of these geminivirus vectors are summarized and discussed.
文摘To study the therapeutic effects of herpes simplex virus thymidine kinase gene transferred by the EBV based expression vector on experimental hepatocellular carcinoma, pDR2 TK gene was delivered into human hepatocellular carcinoma cell line SMMC 7721 by using liposome mediated transfection technique,and then gene expression was detected by RT PCR, and the killing effects were examined through MTT method. In the nude mice hepatoma model,the antitumor effects of pDR2 TK /GCV system was evaluated in terms of tumor growth. MTT results showed that the pDR2 TK /GCV had cytotoxic effect and about 70 % SMMC 7721 cells were killed when GCV was at 1000 μmol/L. In vivo experiment showed that the tumor size in nude mice with transferred pDR2 TK gene was significantly smaller than that in control group . On the 10th day the tumor in 3 mice (60 %) disappeared completely after GCV treatment. It is concluded that the pDR2 TK/GCV system has marked killing effects on the experimental hepatocellular carcinoma.
基金supported by the grant(30200182)from the National Natural Science Foundation of Chinathe National Basic Research Program of China(2006CB102004)from the Ministry of Science and Technology of China.
文摘The aim of this article is to successfully express the Bt (Bacillus thuringiensis) toxin receptor protein located on the internal membrane of larval midgut of cotton bollworm (Helicoverpa armigera Hübner) within eukaryotic expression system, which is one of the key links for clarifying the relationship between receptor and Bt resistance. The fragments of aminopeptidase N1 (APN1) gene without signal peptide in the susceptible and the resistant H. armigera were cloned separately using PCR method, and were separately cloned into pUC 19 vector. After sequencing the gene, the fragments encoding for APN1 without signal peptide were cloned into the Bac-to-Bac baculovirus expression system with transfer vector pFastBacHTB under the polyhedron gene promoter. The recombinant transposing plasmid pFastBacHTB/APN1 was screened and then transformed into Escherichia coli DH10Bac. It was cultured in LB medium, which contained Te, Kan, Ge, X-gal, and IPTG. The resulting recombinant bacmid was transfected into cells of the insect Trichoplusia ni and recombinant baculoviruse was obtained. The lysate of cells infected with recombinant baculoviruse was analyzed by SDS-PAGE and blot analysis. The results showed that the recombinant baculoviruse was fully capable of expressing APN1. The APN1 gene successfully expressed in T. ni cell established the base for continuing the research on its function and relationshio of resistance with Bt.
基金supported by the National Natural Science Foundation of China (Grant No. 30901158)the Key Project of Chinese Ministry of Education (Grant No. 104243)
文摘A full-length cDNA sequence of xyloglucan endotransglycosylase gene (XET), abundantly expressed in the cambium of Anthocephalus chinensis was cloned by conserved PCR, rapid-amplification of cDNA ends and by chromosome walking. Analytical results of the DNA sequence show that a 912 bp complete open reading frame (ORF) encoded a 303-amino acid protein was in the 1205 bp full cDNA sequence. The deduced amino acid sequence of AcXET, which contained the conserved specific EIDFE catalytic site sequence to XETs was homologous to the other known XET proteins. In order to study the gene function of AcXET and obtain transgenic plants, a plant expression vector pBIAcXET was constructed by recombinating the AcXET fragment from the cloning vector pMD19AcXET and the binary vector pBI121 between the XbaI and SmaI sites. The fragment ofAcXET gene was inserted between the CaMV 35S promotor and the coding region of the GUS gene in pBI121. The identification results show that the plant expression binary vector pBIAcXET was constructed successfully. These results lay the foundation for studying the molecular mechanism ofAcXET gene during wood formation.