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1.
Article in Chinese | WPRIM | ID: wpr-880076

ABSTRACT

OBJECTIVE@#To construct an acute myeloid leukemia cell line stably expressing CD123-CLL1 so as to provide an "in vitro" model for studying the role of CD123 and CLL-1 in leukemia and the treatment targeting CD123 and CLL-1.@*METHODS@#The recombinant plasmid of lentivirus was constructed by synthesizing CD123 and CLL-1 sequences and PCR homologous recombination. The lentivirus vector was packaged by three-plasmid packaging system. After collecting the supernatant of lentivirus, the virus titer was determined by quantitative PCR. K562 leukemia cells were collected and transtected with virus supernatant. Leukemia cell line stably expressing the target gene were screened by purinomycin. The expression levels of CD123 and CLL-1 were detected by RT-PCR and flow cytometry.@*RESULTS@#The lentiviral vector was successfully constructed, and identified by agarose gel electrophoresis and gene sequencing, then the virus titer of the supernatant was up to 5.81×10@*CONCLUSION@#Lentiviral vector expressing CD123-CLL1 has been successfully constructed, and K562 leukemia cell line stably expressing CD123 and CLL-1 has been successfully obtained.


Subject(s)
Cell Line, Tumor , Genetic Vectors , Humans , Interleukin-3 Receptor alpha Subunit , K562 Cells , Lentivirus/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Plasmids , Transfection
2.
Chinese Journal of Biotechnology ; (12): 321-330, 2021.
Article in Chinese | WPRIM | ID: wpr-878565

ABSTRACT

To construct a prokaryotic promoter report system with wide applicability, a series of pFGH reporter vectors based on lacZ gene and pUC replicon were constructed from plasmid pFLX107 through the replacement of multiple cloning sites and sequence modifications. The plasmid with the lowest background activity was selected as the final report system with the lacZ gene deletion strain MC4100 as the host bacterium, following by testing with inducible promoter araBAD and the constitutive promoter rpsM. The background activity of pFGH06 was significantly lower than that of other plasmids of the same series, and even lower than that of reference plasmid pRCL at 28 °C (P<0.01). Further evaluation tests show that the plasmid pFGH06 could be used to clone and determine the activity of inducible promoter or constitutive promoter, and the complete recognition of the target promoter could be achieved through blue-white selection in the simulation test of promoter screening. Compared with the reported prokaryotic promoter report systems, pFGH06 has the advantages of smaller size, more multiple clone sites, adjustable background activity, high efficiency of promoter screening and recognition, thus with a wide application prospect.


Subject(s)
Cloning, Molecular , Escherichia coli/genetics , Genes, Reporter/genetics , Genetic Vectors/genetics , Lac Operon/genetics , Plasmids/genetics , beta-Galactosidase/genetics
3.
Mem. Inst. Oswaldo Cruz ; 115: e190347, 2020. tab, graf
Article in English | LILACS, SES-SP | ID: biblio-1135231

ABSTRACT

BACKGROUND Bacillus Calmette-Guérin (BCG) is considered a promising live bacterial delivery system. However, several proposals for rBCG vaccines have not progressed, mainly due to the limitations of the available expression systems. OBJECTIVES To obtain a set of mycobacterial vectors using a range of promoters with different strengths based on a standard backbone, previously shown to be stable. METHODS Mycobacterial expression vectors based on the pLA71 vector as backbone, were obtained inserting different promoters (PAN, PαAg, PHsp60, PBlaF* and PL5) and the green fluorescence protein (GFP) as reporter gene, to evaluate features such as their relative strengths, and the in vitro (inside macrophages) and in vivo stability. FINDINGS The relative fluorescence observed with the different vectors showed increasing strength of the promoters: PAN was the weakest in both Mycobacterium smegmatis and BCG and PBlaF* was higher than PHsp60 in BCG. The relative fluorescence observed in a macrophage cell line showed that PBlaF* and PHsp60 were comparable. It was not possible to obtain strains transformed with the extrachromosomal expression vector containing the PL5 in either species. MAIN CONCLUSION We have obtained a set of potentially stable mycobacterial vectors with a arrange of expression levels, to be used in the development of rBCG vaccines.


Subject(s)
Animals , Female , Mice , BCG Vaccine/immunology , Mycobacterium smegmatis/immunology , Green Fluorescent Proteins/immunology , Escherichia coli/immunology , Genetic Vectors/immunology , Mycobacterium bovis/immunology , Escherichia coli/genetics , Genetic Vectors/genetics , Mice, Inbred BALB C
4.
Braz. j. med. biol. res ; 53(7): e9207, 2020. tab, graf
Article in English | LILACS, ColecionaSUS | ID: biblio-1132533

ABSTRACT

The objective of this study was to investigate the relationship between PI3K/mTOR/RhoA signaling regulated cytoskeletal rearrangements and phagocytic capacity of macrophages. RAW264.7 macrophages were divided into four groups; blank control, negative control, PI3K-RNAi, and mTOR-RNAi. The cytoskeletal changes in the macrophages were observed. Furthermore, the phagocytic capacity of macrophages against Escherichia coli is reported as mean fluorescence intensity (MFI) and percent phagocytosis. Transfection yielded 82.1 and 81.5% gene-silencing efficiencies against PI3K and mTOR, respectively. The PI3K-RNAi group had lower mRNA and protein expression levels of PI3K, mTOR, and RhoA than the blank and negative control groups (Р<0.01). The mTOR-RNAi group had lower mRNA and protein levels of mTOR and RhoA than the blank and the negative control groups (Р<0.01). Macrophages in the PI3K-RNAi group exhibited stiff and inflexible morphology with short, disorganized filopodia and reduced number of stress fibers. Macrophages in the mTOR-RNAi group displayed pronounced cellular deformations with long, dense filopodia and an increased number of stress fibers. The PI3K-RNAi group exhibited lower MFI and percent phagocytosis than blank and negative control groups, whereas the mTOR-RNAi group displayed higher MFI and percent phagocytosis than the blank and negative controls (Р<0.01). Before and after transfection, the mRNA and protein levels of PI3K were both positively correlated with mTOR and RhoA (Р<0.05), but the mRNA and protein levels of mTOR were negatively correlated with those of RhoA (Р<0.05). Changes in the phagocytic capacity of macrophages were associated with cytoskeletal rearrangements and were regulated by the PI3K/mTOR/RhoA signaling pathway.


Subject(s)
Humans , Animals , Rats , Phagocytosis/physiology , Cytoskeleton/metabolism , Phosphatidylinositol 3-Kinases/metabolism , rhoA GTP-Binding Protein/metabolism , TOR Serine-Threonine Kinases/metabolism , Macrophages/metabolism , Transfection , Signal Transduction , Blotting, Western , Gene Silencing , RNA Interference , Real-Time Polymerase Chain Reaction , RAW 264.7 Cells , Genetic Vectors
5.
Protein & Cell ; (12): 707-722, 2020.
Article in English | WPRIM | ID: wpr-827023

ABSTRACT

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.


Subject(s)
Adoptive Transfer , Alveolar Epithelial Cells , Pathology , Animals , Apoptosis , Betacoronavirus , Body Fluids , Metabolism , CD4-Positive T-Lymphocytes , Allergy and Immunology , Clinical Trials as Topic , Coinfection , Therapeutics , Coronavirus Infections , Allergy and Immunology , Disease Models, Animal , Endothelial Cells , Pathology , Extracorporeal Membrane Oxygenation , Genetic Therapy , Methods , Genetic Vectors , Therapeutic Uses , Humans , Immunity, Innate , Inflammation Mediators , Metabolism , Lung , Pathology , Mesenchymal Stem Cell Transplantation , Methods , Mesenchymal Stem Cells , Physiology , Multiple Organ Failure , Pandemics , Pneumonia, Viral , Allergy and Immunology , Respiratory Distress Syndrome , Allergy and Immunology , Pathology , Therapeutics , Translational Medical Research
6.
Chinese Journal of Biotechnology ; (12): 622-631, 2020.
Article in Chinese | WPRIM | ID: wpr-827006

ABSTRACT

Small interfering RNA (siRNA) has been used to treat various skin diseases. However, siRNA is limited in application due to its electronegativity, strong polarity, easy degradation by nuclease and difficulty in breaking through the skin barrier. Therefore, safe and efficient siRNA delivery vector is the premise of effective treatment of skin diseases by siRNA. In recent years, with the deepening of research on siRNA, great progress has been made in the development of delivery systems based on lipids, polymers, peptides and nanoparticles, some new transdermal delivery vectors of siRNA have emerged, such as liposomes, dendrimers, cell penetrating peptides, and spherical nucleic acid nanoparticles. This review will focus on the recent advance in siRNA transdermal delivery vectors.


Subject(s)
Administration, Cutaneous , Genetic Vectors , Humans , RNA, Small Interfering , Skin Diseases , Therapeutics
7.
Chinese Journal of Biotechnology ; (12): 792-800, 2020.
Article in Chinese | WPRIM | ID: wpr-826897

ABSTRACT

Stomatal density is important for crop yield. In this paper, we studied the epidermal pattern factors (EPFs) related to stomatal development. Prokaryotic expression vectors were constructed to obtain EPFs. Then the relationship between EPFs and hydrogen sulfide (H2S) was established. First, AtEPF1, AtEPF2 and AtEPFL9 were cloned and constructed to pET28a vectors. Then recombinant plasmids pET28a-AtEPF1, pET28a-AtEPF2 and pET28a-AtEPFL9 were digested and sequenced, showing successful construction. Finally, they were transformed into E. coli BL21(DE3) separately and induced to express by isopropyl β-D-galactoside (IPTG). The optimized expression conditions including IPTG concentration (0.5, 0.3 and 0.05 mmol/L), temperature (28 °C, 28 °C and 16 °C) and induction time (16 h, 16 h and 20 h) were obtained. The bands of purified proteins were about 18 kDa, 19 kDa and 14.5 kDa, respectively. In order to identify their function, the purified AtEPF2 and AtEPFL9 were presented to Arabidopsis thaliana seedlings. Interestingly, the H2S production rate decreased or increased compared with the control, showing significant differences. That is, EPFs affected the production of endogenous H2S in plants. These results provide a foundation for further study of the relationship between H2S and EPFs on stomatal development, but also a possible way to increase the yield or enhance the stress resistance.


Subject(s)
Arabidopsis , Genetics , Metabolism , Arabidopsis Proteins , Genetics , Metabolism , Escherichia coli , Genetics , Genetic Vectors , Genetics , Hydrogen Sulfide , Metabolism , Plasmids , Genetics , Seedlings , Metabolism
8.
Chinese Journal of Biotechnology ; (12): 1232-1240, 2020.
Article in Chinese | WPRIM | ID: wpr-826854

ABSTRACT

Overlap extension PCR is a common method for site-directed mutagenesis. As objective gene sequence growing longer, it is often difficult to obtain the target product in the second round of PCR, and it is highly possible to introduce unexpected mutations into a long gene fragment by PCR. To circumvent these problems, we can only amplify a small gene fragment which contain the target mutation by overlap extension PCR, and then ligate it with vector to get target plasmid. If the restriction site at the end of the amplified fragment was not a single one on plasmid vector, double fragments ligation method could be used to construct target plasmid. Partial amplification, combined with double fragments ligation, could solve lots of problems in long gene mutagenesis. Taking retinoblastoma gene 1 S780E mutagenesis as an example, it is difficult to amplify whole retinoblastoma gene 1 by overlap extension PCR because of long fragment interfering the overlapping extension of second round PCR. However, it is relatively easy to amplify the F3 (1 968-2 787) fragment which contains target mutation S780E. There is a Nhe I site which can be used for ligation on 5' end of F3 fragment, but another Nhe I site on the plasmid restrained from doing so directly. In order to circumvent this obstacle, we ligated F3 fragment, combining with F2 (900-1 968) fragment which was digested from wild type plasmid, with the vector which contain F1 (1-900) fragment of the gene. That double fragments ligated with one vector at the same time, though less efficient, can recombine into a complete plasmid. The sequences of the two selected recombinant plasmids were consistent with the target mutation, which verified the feasibility of this scheme. As an improvement of overlap extension PCR, partial amplification and double fragments ligation methods could provide solutions for site directed mutagenesis of many long genes.


Subject(s)
Base Sequence , Cloning, Molecular , Genetic Vectors , Genetics , Mutagenesis, Site-Directed , Methods , Nucleic Acid Amplification Techniques , Plasmids , Polymerase Chain Reaction
9.
Chinese Journal of Biotechnology ; (12): 1269-1276, 2020.
Article in Chinese | WPRIM | ID: wpr-826850

ABSTRACT

Human adenoviruses are widespread causative agent that induces respiratory diseases, epidemic keratoconjunctivitis and other related diseases. Adenoviruses are commonly used in experimental and clinical areas. It is one of the most commonly used virus vectors in gene therapy, and it has attracted a lot of attention and has a high research potential in tumor gene therapy and virus oncolytic. Here, we summarize the biological characteristics, epidemiology and current application of adenovirus, in order to provide reference for engineering application of adenovirus.


Subject(s)
Adenovirus Infections, Human , Epidemiology , Virology , Adenoviruses, Human , Genetics , Genetic Engineering , Methods , Genetic Vectors , Humans , Oncolytic Virotherapy , Oncolytic Viruses , Genetics , Virus Replication
10.
Braz. arch. biol. technol ; 63: e20190223, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132217

ABSTRACT

Abstract Gene subcloning, a process in which the nucleotide sequence of interest is excised from on plasmid and inserted into another, seems to be an easy task to done. However, not all subcloning attempts are successful, even when the insert sequence and the double digested target plasmid are successfully purified form agarose gel and thought to be ready for subsequent ligation. In the current study we introduce a reliable, easy, and time consuming method for gene subcloning and also truncation. The stages are all carried out in a single microtube without any running on a gel, making it possible to accomplish a successful gene subcloning or truncation even with low concentrations of DNA molecules. Summarily, subcloning is achieved by mixing the plasmids of interest in a microtube and subjecting to restriction enzymes whose restriction sites flank the segment that is going to be subcloned. Digestion mixture is precipitated in the same microtube using isopropanol and the resultant DNA molecules are allowed to take part in a ligation reaction. The recombinant plasmids of interest are screened by colony PCR. Truncation is achieved by double- digestion of the plasmid of interest using a restriction enzyme whose restriction site flanks the segment that is going to be cut out.


Subject(s)
Plasmids/genetics , Cloning, Molecular/methods , Genetic Vectors , Polymerase Chain Reaction
11.
Chinese Journal of Biotechnology ; (12): 1395-1404, 2020.
Article in Chinese | WPRIM | ID: wpr-826837

ABSTRACT

By inserting microRNAs into the intron of EF1α promoter, we constructed a novel lentiviral vector knocking down PD-1 gene via microRNA and applied it to CAR-T cells. Lentiviral transduction efficiency and PD-1-silencing efficiency were detected by flow cytometry. PD-1 expression was detected by Western blotting. Relative expression of microRNA was measured by Q-PCR. Cytotoxicity of CAR-T cells based on this vector was tested by luciferase bioluminescence and flow cytometry. Compared with lentiviral vector with microRNA transcribed by U6 promotor, the transduction efficiency of lentiviral vector with microRNA which was inserted into the intron of EF1α promoter was more significant, and the knockdown rate of PD-1 was more than 90%, which was validated by flow cytometry and Western blotting. And the relative expression level of microRNA in Jurkat cells transduced with this novel lentiviral vector was shown by Q-PCR. Compared with normal CAR-T cells, CAR-T cells based on this vector showed stronger cytotoxicity against PD-L1 positive Raji cells. We successfully constructed a novel lentiviral vector that knocked down PD-1 via microRNA and verified the superiority of its transduction efficiency and knockdown efficiency of PD-1. CAR-T cells based on this vector can exert a more powerful cytotoxicity, thus providing theoretical support for the subsequent treatment of PD-L1 positive tumors.


Subject(s)
Cell Line, Tumor , Gene Knockdown Techniques , Genetic Vectors , Genetics , Humans , Lentivirus , Genetics , MicroRNAs , Metabolism , Programmed Cell Death 1 Receptor , Promoter Regions, Genetic , Genetics
12.
Protein & Cell ; (12): 707-722, 2020.
Article in English | WPRIM | ID: wpr-828750

ABSTRACT

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.


Subject(s)
Adoptive Transfer , Alveolar Epithelial Cells , Pathology , Animals , Apoptosis , Betacoronavirus , Body Fluids , Metabolism , CD4-Positive T-Lymphocytes , Allergy and Immunology , Clinical Trials as Topic , Coinfection , Therapeutics , Coronavirus Infections , Allergy and Immunology , Disease Models, Animal , Endothelial Cells , Pathology , Extracorporeal Membrane Oxygenation , Genetic Therapy , Methods , Genetic Vectors , Therapeutic Uses , Humans , Immunity, Innate , Inflammation Mediators , Metabolism , Lung , Pathology , Mesenchymal Stem Cell Transplantation , Methods , Mesenchymal Stem Cells , Physiology , Multiple Organ Failure , Pandemics , Pneumonia, Viral , Allergy and Immunology , Respiratory Distress Syndrome , Allergy and Immunology , Pathology , Therapeutics , Translational Medical Research
13.
Protein & Cell ; (12): 707-722, 2020.
Article in English | WPRIM | ID: wpr-828586

ABSTRACT

The 2019 novel coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has occurred in China and around the world. SARS-CoV-2-infected patients with severe pneumonia rapidly develop acute respiratory distress syndrome (ARDS) and die of multiple organ failure. Despite advances in supportive care approaches, ARDS is still associated with high mortality and morbidity. Mesenchymal stem cell (MSC)-based therapy may be an potential alternative strategy for treating ARDS by targeting the various pathophysiological events of ARDS. By releasing a variety of paracrine factors and extracellular vesicles, MSC can exert anti-inflammatory, anti-apoptotic, anti-microbial, and pro-angiogenic effects, promote bacterial and alveolar fluid clearance, disrupt the pulmonary endothelial and epithelial cell damage, eventually avoiding the lung and distal organ injuries to rescue patients with ARDS. An increasing number of experimental animal studies and early clinical studies verify the safety and efficacy of MSC therapy in ARDS. Since low cell engraftment and survival in lung limit MSC therapeutic potentials, several strategies have been developed to enhance their engraftment in the lung and their intrinsic, therapeutic properties. Here, we provide a comprehensive review of the mechanisms and optimization of MSC therapy in ARDS and highlighted the potentials and possible barriers of MSC therapy for COVID-19 patients with ARDS.


Subject(s)
Adoptive Transfer , Alveolar Epithelial Cells , Pathology , Animals , Apoptosis , Betacoronavirus , Body Fluids , Metabolism , CD4-Positive T-Lymphocytes , Allergy and Immunology , Clinical Trials as Topic , Coinfection , Therapeutics , Coronavirus Infections , Allergy and Immunology , Disease Models, Animal , Endothelial Cells , Pathology , Extracorporeal Membrane Oxygenation , Genetic Therapy , Methods , Genetic Vectors , Therapeutic Uses , Humans , Immunity, Innate , Inflammation Mediators , Metabolism , Lung , Pathology , Mesenchymal Stem Cell Transplantation , Methods , Mesenchymal Stem Cells , Physiology , Multiple Organ Failure , Pandemics , Pneumonia, Viral , Allergy and Immunology , Respiratory Distress Syndrome , Allergy and Immunology , Pathology , Therapeutics , Translational Medical Research
14.
Article in Chinese | WPRIM | ID: wpr-781353

ABSTRACT

OBJECTIVE@#To construct a PA28γ overexpression cell line and determine its effects after infecting an oral squa-mous cell carcinoma (OSCC) cell line.@*METHODS@#The PA28γ gene was cloned into the pLOV.CMV.cherry.2A.EF1a.PuroR lentiviral vector by polymerase chain reaction (PCR), and PCR and DNA sequencing alignment analysis were used for identification. Then, 293T cells were used to package viral diseases. Infected OSCC cells were used to construct a cell line with stable PA28γ overexpression. Finally, the level of PA28γ expression in the OSCC cell line was detected through Western blot.@*RESULTS@#The successful construction of PA28γ recombinant lentiviral vectors was confirmed by DNA sequencing. The results of immunofluorescence showed that the PA28γ overexpression lentivirus successfully infected the OSCC cells and showed cherry red fluorescence. The results of Western blot demonstrated that the constructed cells with stable PA28γ overexpression significantly increased the expression of PA28γ.@*CONCLUSIONS@#The PA28γ overexpression lentiviral vector can significantly increase its protein expression in OSCC cells. We provide a stable OSCC cell line for further study on the effect of PA28γ in OSCC.


Subject(s)
Autoantigens , Carcinoma, Squamous Cell , Cell Line, Tumor , Genetic Vectors , Humans , Lentivirus , Mouth Neoplasms , Proteasome Endopeptidase Complex , Transfection
15.
Chinese Journal of Biotechnology ; (12): 1135-1142, 2019.
Article in Chinese | WPRIM | ID: wpr-771814

ABSTRACT

PLCζ is a new isoenzyme of the PLC family which plays an important role in activating mammalian oocytes. In recent years, large-scale expression and purification of active PLCζ protein in vitro for structural biology research has not been successful. In this study, the recombinant human PLCζ protein was expressed and purified in the baculovirus expression system. First, the full length of human PLCζ gene was cloned into the pFastBac-HTA plasmid to form the recombinant donor plasmid that was further transformed into DH10Bac Escherichia coli cells to construct the recombined bacmid by the site-specific transposition that was screened by resistance and blue-white spots. Then the bacmid was transfected to Sf9 insect cells via cellfectin to package the recombinant baculovirus. After the amplification of the recombinant baculovirous, the recombinant protein was expressed from the cells transduced by the recombinant baculovirus and was purified by Ni-NTA resin. Purified protein was identified by Western blotting and time-of-flight mass spectrometry and the enzyme activity was determined. The results showed that the recombinant PLCζ protein in the Sf9 cells was achieved at 72 hours after baculovirus infection and expressed in secreted form in cell culture medium. The recombinant protein purified by Ni²⁺ affinity column was identified as PLCζ by Western blotting and ionization time-of-flight mass spectrometry and the enzyme activity was up to 326.8 U/mL. The experimental results provide a reference for the large-scale production and biological application of recombinant human PLCζ protein.


Subject(s)
Animals , Baculoviridae , Genetic Vectors , Humans , Recombinant Proteins , Sf9 Cells , Spodoptera
16.
Chinese Journal of Biotechnology ; (12): 1307-1316, 2019.
Article in Chinese | WPRIM | ID: wpr-771798

ABSTRACT

Gene therapy is a rapidly developing field. The most widely used technique for foreign gene transfer is lentiviral-mediated gene therapy. Lentiviral vector has been developed from the first generation to the third generation in terms of safety. The preparation of lentiviruses with high titer remains difficult. In this study, a Fibra-Cel sheet carrier was used as an HEK293T cell carrier matrix, and several sterile cell culture spinners were combined and cultured on a roller bottle machine to scale up the adherent cells. The virus titer was maximized by screening the factors to optimize the lentivirus titer in the third-generation lentivirus packaging process one by one. Fibra-Cel sheet vector was successfully used as the matrix of HEK293T cell adhesion to culture adherent cells at large scale. The optimal conditions for large-scale preparation of the third-generation lentivirus by bottle roller were screened and three batches of lentiviruses were produced on pilot scale. The production time of lentivirus was shortened from 120 hours to 54 hours from plasmid transfection to virus collection; in terms of cost, a rolling bottle machine was used instead of a bioreactor, leading to lower cost and no need for repeated sterilization during the whole process. The safe, effective and low-cost operation of successful production will provide a technical base for the large-scale preparation of lentivirus and thus lay a firm foundation for its clinical application.


Subject(s)
Genetic Vectors , HEK293 Cells , Humans , Lentivirus , Transduction, Genetic , Transfection
17.
Chinese Journal of Biotechnology ; (12): 1463-1468, 2019.
Article in Chinese | WPRIM | ID: wpr-771783

ABSTRACT

We studied the construction of fusion protein TAT-RIG-I-GFP prokaryotic expression vector and verified the function of TAT in transmembrane delivery. First, four pairs of specific primers were designed, and the RIG-I gene of Mallard Duck (Anas platyrhynchos) was cloned. Then, the pET-TAT-RIG-I-GFP and pET-RIG-I-GFP prokaryotic expression vectors were constructed. Meanwhile, they were converted to E. coli BL21 (DE3), which were induced to be expressed after culture. After the purification of His-60 nickel affinity chromatography column and the identification of SDS-PAGE, the purified TAT-RIG-I-GFP and RIG-I-GFP proteins were incubated to DF-1 cells. Finally, fluorescence microscopy was used to observe whether the corresponding fluorescence was produced in DF-1 cells. The results showed that pET-TAT-RIG-I-GFP fusion with TAT showed obvious green fluorescence in DF-1 cells. However, the pET-RIG-I-GFP without TAT cannot display green fluorescence. This shows that TAT-fused protein have successfully delivered DF-1 cells and play a key role in transmembrane delivery. In conclusion, these results provide a solid material basis for further study of antiviral drugs in poultry.


Subject(s)
Cell Membrane , DNA Primers , Escherichia coli , Gene Expression , Gene Products, tat , Genetic Vectors , Recombinant Fusion Proteins
18.
Chinese Journal of Biotechnology ; (12): 577-588, 2019.
Article in Chinese | WPRIM | ID: wpr-771351

ABSTRACT

Baculovirus expression vector system (BEVS) has been successfully applied to the over-expression of various proteins, thus providing sufficient materials for vaccine research. Compared to other systems, BEVS has many advantages: baculovirus solely being parasitic in invertebrates, the resultant products conferring high safety to mammalian, high expression level of recombinant proteins, preferable folding for eukaryotic protein, proper post-translational modification required for biological function, suitable for multiple genes co-expression and large-scale production with serum-free culture media. To better understand the advantages and prospective of BEVS for the vaccine research, this article will review the development of BEVS and its application on vaccine research.


Subject(s)
Animals , Baculoviridae , Genetic Vectors , Prospective Studies , Recombinant Proteins , Vaccines
19.
Chinese Journal of Biotechnology ; (12): 892-900, 2019.
Article in Chinese | WPRIM | ID: wpr-771321

ABSTRACT

To investigate the effect of miR-331-3p on the proliferation of porcine renal epithelial cells (PK15) and its mechanism, the pcDNA 3.1(+) overexpression vector of miRNA-331-3p (pcDNA 3.1(+)-miR-331-3p) was constructed. PK15 cells were divided into four groups, including experimental group, experimental control group, inhibitor group and inhibitor control group. Experimental group and experimental control group were transfected with pcDNA 3.1(+)-miR-331-3p and pcDNA 3.1(+), respectively. Inhibitor group and inhibitor control group were transfected with miR-331-3p inhibitor and miR-331-3p negative control (miR-331-3p NC), respectively. Above all, CCK-8 reagent was used to plot the cell proliferation curve and Propidium (PI) staining was used to detect the proportion of cell stages. Secondly, its expression change were detected by quantitative real-time PCR that included the growth inhibitory protein family member 5 (ING5), cyclin-dependent kinase 2 (CDK2), cyclin-dependent kinase 3 (CDK3), cyclin-dependent kinase 4 (CDK4), Cyclin B and cyclin-dependent kinase inhibitor 1A (CDKN1A). The results showed that the expression of miRNA-331-3p was significantly increased in the experimental group. The cell proliferation curve showed that the number of cells in experimental group was significantly higher than that in experimental control group or inhibitor control group at 48 h and 72 h (P<0.05). Simultaneously, Inhibitor group was significantly lower than experimental control group or inhibitor control group in the number of cells at 48 h and 72 h (P<0.05), but there was no significant difference between the experimental group and the control group. Compared with the experimental control group, the proportion of cells of experimental group in G0/G1 phase decreased, the proportion of S phase and G2/M phase increased, and the inhibitor control group showed the opposite trend. Simultaneously, the expression levels of CDK2, CDK3, CDK4 and Cyclin B genes in the experimental group were significantly increased, while ING5 and CDKN1A genes inhibiting proliferation showed a significant downward trend. These results demonstrate that the miR-331-3p overexpression vector was successfully constructed, and miR-331-3p has the ability to promote the proliferation of PK15 cells. The study lays a solid foundation for further research for its role in pig growth and development.


Subject(s)
Animals , Cell Line , Cell Proliferation , Genetics , Epithelial Cells , Cell Biology , Genetic Vectors , MicroRNAs , Genetics , Swine
20.
Journal of Experimental Hematology ; (6): 1812-1819, 2019.
Article in Chinese | WPRIM | ID: wpr-781535

ABSTRACT

OBJECTIVE@#To construct a eukaryotic expression vector of human tissue factor pathway inhibitor-2 (TFPI-2) and to investigate the effect of TFPI-2 gene on the growth of acute monocytic leukemia cell line (SHI-1).@*METHODS@#The cDNA of TFPI-2 was obtained by genetic chemical synthesis, the TFPI-2 gene and the linear vector fragment were ligated and inserted into the multiple cloning site of PEGFP-N1 vector, and the eukaryotic expression vector PEGFP-N1-TFPI-2 was transfected SHI-1 cells, then the obtained SHI-1 cells was observed by fluorescence microscopy; MTT assay was used to detect the effect of TFPI-2 gene on the relative growth rate of SHI-1 cells at the different time-point; RT-PCR was used to detect TFPI-2 mRNA expression levels in the cells of each group before and after TFPI-2 transfection; TFPI-2 protein expression was detected by Western blot. The cells which successfully transfected with PEGFP-N1-TFPI-2 vector were named as SHI-1-TFPI-2 (experimental group), and the cells transfected with the empty vector pEGFP-N1 and the untransfected cells were named as SHI-1-V and SHI-1-P and used as the control group.@*RESULTS@#The human TFPI-2 gene eukaryotic expression vector PEGFP-N1-TFPI-2 was successfully constructed, then the transfected into SHI-1 cells, observed by fluorescence microscopy 24 hours later, as a result, the PEGFP-N1-TFPI-2 was successfully transferred into SHI-1 cells, and the number of fluorescent cells increased after 48 h and 72 h. RT-PCR showed that the gray scale ratio of TFPI-2 gene to β- actin in the experimental group was higher than that in the control group. The gray scale ratio was 0.51±0.04 in SHI-1-V group, 0.52±0.03 in SHI-1-P group, 0.87±0.08 in SHI-1-TFPI-2 group, and the difference between SHI-1-TFPI-2 and SHI-1-V, SHI-1-P group was statistically significant (P<0.05).@*CONCLUSION@#The expression of TFPI-2 gene in PEGFP-N1-TFPI-2 can inhibit the growth of SHI-1 cells, which provides a research direction for gene therapy of leukemia in the future.


Subject(s)
Eukaryota , Genetic Vectors , Glycoproteins , Metabolism , Green Fluorescent Proteins , Humans , Transfection
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