286 results about "293t cell" patented technology

The invention discloses an LMNA gene knocked-out cell line. The cell line is a 293T cell line or a HePG2 tumor cell line. Cells to be knocked out are transfected by plasmid vectors constructed by twopairs of gRNA as shown in SEQ ID NO. 1-4 or two pairs of gRNA as shown in SEQ ID NO. 7-10 on the basis of a crispr-cas9 technology, and then are subjected to resistance screening to obtain the cell line. The LMNA gene knocked-out cell line can be used for intervention drug screening cell models for diseases such as dilated cardiomyopathy, fat metabolic disorder syndrome and premature aging syndromes.

The invention discloses a recombined chimeric antigen receptor with a photoinduction element. The chimeric antigen receptor comprises an antigen combining area, a transmembrane structure area, a co-stimulatory signal transduction area and T cell signal transduction area functional structure domains, wherein the photoinduction element is inserted at the N terminal or C terminal of the recombined chimeric antigen receptor or between the functional structure domains. According to the chimeric antigen receptor, photoinduction element LOV2 genes are cloned into plasmids Lenti-EF1alpha-CD19CAR with a molecular cloning method to establish a co-expression vector of the recombined chimeric antigen receptor with the photoinduction element, 293T cells are used for packaging to obtain a lentiviral vector with photoinduction CAR molecules. After the recombined chimeric antigen receptor is expressed in T cells through the lentiviral vector, the damage toxicity of T cells is reversely controlled by LOV2, and an importable approach is provided for improving the safety of CAR-T in treating cancer clinically.

The invention provides the construction for a farnesyl pyrophosphoric acid synthetase RNA (Ribonucleic Acid) interference recombinant lentivirus vector, which comprises the following steps of: sieving the most effective target sequence of an FDS (farnesyl diphosphate synthase) gene RNAi (RNA interference) in a tool cell 293T cell, synthesizing the double-stranded DNA of the most effective target sequence, connecting to a pGCSIL-GFP vector and successfully constructing the recombinant vector through enzyme cutting, sequencing and identification. Researches indicate that the constructed RNA interference vector LV-sh-FDS can downwards modulate the expression of an FDS mRNA (Messenger RNA) level in a neonatal rat cardiac myocyte, simultaneously can downwards modulate the expression of myocardial hypertrophy markers such as cell areas and marker genes beta-MHC (Myosin Heavy Chain) and BNP (Brain Natriuretic Peptide), additionally can effectively inhabit the activity of RhoA while downwards modulating the FDS, can be applied in preparing medicaments for treating myocardial hypertrophy diseases and also can be applied in preparing medicaments for cholesterol metabolic control.

The invention discloses a target quaternary ammonium salt cationic polymer lipid gene carrier, a preparation method and an application thereof. The target quaternary ammonium salt cationic polymer lipid genetic carrier is characterized in that: a polymeric quaternary ammonium salt and lipid are adopted for preparing a quaternary ammonium salt cationic polymer lipid genetic carrier according to a mass ratio, wherein the mass ratio of the polymeric quaternary ammonium salt to the lipid is 0.05-20:1; then a assembly method or a modification method is adopted for modifying to prepare a folic acid or EGFR antibody modified cationic polymer lipid gene carrier. Results of gene transfection experiments show that: gene transfection efficiencies of the target quaternary ammonium salt cationic polymer lipid gene carrier in 293T cells and NIH-3T3 cells are the same as the gene transfection efficiencies of positive control lipofectamine of lipofectamine<TM>2000 in the 293T cells and the NIH-3T3 cells; the gene transfection efficiencies of the EGFR antibody modified cationic polymer lipid genetic carrier in liver cancer Huh-7 cells and breast cancer MCF-7 cells are higher than the gene transfection efficiencies of the lipofectamine<TM>2000 in the liver cancer Huh-7 cells and the breast cancer MCF-7 cells. The cationic polymer lipid genetic carrier system provided by the present invention has good biocompatibility and low cytotoxicity, and can be as an excellent non-viral gene delivery carrier.

The invention discloses a Six2 genetic expression-inhibiting shRNA, a lentiviral expression vector and a construction method of the lentiviral expression vector. The Six2 genetic expression-inhibiting shRNA has a sequence of SEQ ID NO.2. The Six2 gene shRNA knockout lentiviral expression vector is obtained by inserting the shRNA into BamH I and EcoR I digestion sites of a vector plasmid pLVX-EF1alpha-IRES-Puro. The lentivirus pLV-shSix2 is obtained by transfecting the lentiviral vector plasmid and a packaging plasmid pLP1 and pLP/VSVG with a 293T cell. The screened shRNA which has a remarkable inhibiting effect on the Six2 genetic expression, and on the basis, the lentiviral expression vector and lentiviral, from which Six2 is knocked out, are successfully constructed, and a MES23.5 cell strain from which the Six2 gene is stably knocked out is obtained, thereby laying a good foundation for further researching the function of the Six2.

The invention relates to a building method of a cell strain for stably expressing NS1 (non-structural 1) protein. An NS1 gene is inserted in an EcoR I polyclone site of a pLenti-CMV-EGFP-3Flag-PGK-Puro carrier; a built pLenti-CMV-NS1-EGFP-3Flag-PGK-Puro recombinant plasmid and a virus packaging plasmid are used for 293T cell cotransfection; culture, toxin elimination, virus liquid supernatant collection and filtering are performed to obtain recombinant lentivirus liquid. Packaged recombinant lentivirus infection A549 cells are subjected to puromycin screening, immunofluorescence and Western blot identification to obtain the cell strain for stably expressing NS1 protein. A recombinant lentivirus system is used for preparing the cell strain fusing tag protein capable of stably expressing the NS1 protein. The cell strain provides a good tool for studying the biological function of the NS1 protein.

The invention relates to a method for building a model for collectively evaluating bioavailability and toxicity of cadmium accumulation in food for a human body, and the method comprises the following steps of (1) food sample digestion and determination liquid acquiring: a, grinding a food sample after the food sample is collected, and sequentially digesting the food sample by sequentially adopting gastric juice and intestinal juice; and b, centrifuging the digested mixed liquid, collecting supernate to be sterilized through high pressure; (2) independently culturing Caco-2 cells and 293T cells; (3) combined culture of Caco-2 cells and 293T cells: moving an insertion groove with the Caco-2 cells into a hexagonal-porous plate with the 293T cells to be continuously cultured for 24h; (4) evaluation of bioavailability and toxicity of cadmium: placing the food sample determination liquid on a Caco-2 cell layer of a combined culture model, simultaneously adding iso-osmotic incubation liquid on a 293T cell layer, and continuing the culture for 24h; in the chronic toxicity test, maximally collectively culturing the sample for 10d; and (5) detecting indexes. The method has characteristics of simpleness in operation, easiness in controlling test conditions, small pollution, economical efficiency, accurate result and the like, and also has the advantages for collectively evaluating the bioavailability and toxicity. The method is suitable for evaluating the safety of the cadmium accumulation in grains, vegetables and animal food.

The present invention relates to the preparation of a cell slide assembly for a CBA kit for detecting MOG-IgG, the CBA detection kit and its application. The preparation method of the cell slide assembly is as follows: S1: construction of MOG plasmid; S2: overexpression of MOG gene Lentiviral packaging; S3: Construction of a cell line (MOG-293T cell line) overexpressing the MOG gene; S4: Preparation of cell slide components. The kit includes cell slide assembly, anti-human IgG-FITC secondary antibody, blocking solution, PBS and mounting medium; the kit can be used for detection of MOG autoimmune IgG antibody in clinical samples. The kit of the invention has the advantages of simple operation, strong detection specificity, high sensitivity, good repeatability of experimental results, can be popularized and applied, and can be used for detection of MOG autoimmune IgG antibody in clinical samples.

The invention belongs to the field of biotechnology and particularly relates to a method for constructing a stable cell strain secreting an expression protein. The method comprises the following steps: with a recombinant lentiviral vector pCDH-S-His as a skeleton, constructing a target protein gene to the recombinant lentiviral vector pCDH-S-His to obtain a recombinant plasmid pCDH-S-P-His; co-transfecting the recombinant plasmid and helper plasmids pSPAX2 and pMD2.G with 293T cells by using a PEI transfection method to obtain a recombinant lentivirus; transducing the obtained lentivirus to the 293T cells, and performing puromycin screening to obtain a plurality of monoclonal cell strains; detecting the content of target protein in each cell supernatant by an Elisa method; determining a high-expression cell strain. Compared with a traditional plasmid transfection method, the method provided by the invention has the advantages of short experimental period, high positive rate and good stability of the cell strain.

The invention belongs to the technical field of cell research, and particularly relates to a method for constructing a laryngeal cancer cell line for stably expressing the green fluorescent protein. The method comprises the following steps: (1) designing and synthesizing a primer; (2) digesting the gene sequence of pLenti-puro carrier plasmids with BamHI and XhoI according to the gene sequence andpLenti-puro sequence of the green fluorescent protein, and connecting digested products to obtain a target carrier pLenti-puro-GFP; (3) verifying the carrier pLenti-puro-GFP with endotoxin extraction, digesting the pLenti-puro-GFP plasmids with BamHI and XhoI, and detecting the gene sequence by agarose gel electrophoresis, and sequencing the carrier pLenti-puro-GFP plasmids to detect the sequencesituation of the GFP-LC3; and (4) co-transfecting a 293T cell with the carrier pLenti-puro-GFP plasmids and a lentivirus package carrier, collecting virus supernatant, and transfecting a laryngeal cancer cell Hep-2 with the virus supernatant, infecting for 24 hours, then adding a culture medium containing puromycin, screening the cell, and observing under high content until a stable strain is obtained.

The invention discloses a mercaptyl-terminated (2-dimethylamino ethyl) polymethacrylic ester polymer, a self-assembled and modified nano-gold compound (PDMAEMAGNPs) of the polymer as well as a compound of the polymer and plasmid DNA; and the invention also discloses preparation methods of the polymer and the compounds as well as the application of all in carrier as genes. When the concentration ofthe compounds of PDMAEMAGNPs and GFP DNA (green fluorescent protein expression DNA) is 30Mug/mL, the transfection efficiency to HEK 293T cell is 30 percent, and the survival rate to HEK 293T cell, HeLa cell and 293 cell is more than 80 percent. The PDMAEMAGNPs/CpG ODN (human CpG oligodeoxynucleotide) compound has remarkable effects in gene therapy in vitro and in vivo. The suppression ratio to tumor growth of the PDMAEMAGNPs/p53 DNA (tumor suppressor gene) is 30-37 percent.

The invention discloses a cell line for stable expression of a peste des petits ruminants virus receptor Nectin-4 and a construction method of the cell line. According to the invention, by virtue of asynthetic Nectin-4 gene and on the basis of a lentiviral vector system, a recombinant plasmid pLOV-eGFP-Nectin-4 is constructed. The recombinant plasmid, together with pSPAX2 and pMD2.G plasmid, is applied to co-transfection of a 293T cell, so that retrovirus-like particles are obtained. A supernatant-infected MDBK cell is cultivated by virtue of cells containing the retrovirus-like particles, and puromycin screening and purifying are conducted, so that the MDBK cell for stable expression of Nectin-4 protein is obtained, and the MDBK cell is named as MDBK-Nectin-4. Through the construction ofthe cell line, an experimental material is provided for deep research of an interaction between PPRV and the receptor Nectin-4 and for the clinical rapid isolation of the PPRV is provided.

The invention provides a method for preparing a suspended 293T cell line cultured in low serum. The method includes the following steps: (1) resuscitating and cultivating mammalian cells to obtain theadherently cultured 293T cells, and digesting the 293T cells with trypsin; (2) culturing the adherently cultured 293T cells in a serum-free medium supplemented with a certain amount of serum, and continuously culturing the 293T cells to adapt to the serum-free medium supplemented with a certain amount of the serum; and (3) repeating the continuous cultivation procedure in the step (2) and gradually reducing serum addition amount in the serum-free medium until a serum concentration is 0 to obtain the suspension cultured 293T cell. The method of the invention has the advantages of simple operation, convenient use, low cost and good safety. An in vitro expansion culture method of 293T cell suspension culture requires no special equipment, and the operation is simple and feasible. The 293T cell suspension culture can has broad prospects in basic research and clinical applications.

The invention relates to the field of biotechnology, in particular to a monoclonal cell strain of a human embryo kidney cell 293T-C10 for packaging viruses as well as a screening method of the monoclonal cell strain. 293T cell mycoplasmas are removed, monoclonal screening is carried out during logarithmic growth period to obtain uniform monoclonal cells, different transfection and virus removal efficiencies are compared, and screening is carried out to obtain the monoclonal cell strain. Such cell strain has a collection number of CCTCC C201281, is very high in transfection efficiency and virus packaging stability, is remarkably improved in virus removal efficiency of 293T cells than that before screening, and can infect a majority of tumors and other cells to be infected without ultracentrifugation, so as to meet most of experimental demands.

The invention provides a respiratory syncytial virus pre-fusion F protein and application thereof, and belongs to the technical field of respiratory syncytial virus vaccines. The pre-fusion F proteinis formed in the way that the 106th, 108th and 109th amino acids of a wild-type F protein are mutated from Arg to Asn, the 104th amino acid is mutated from Asn to Cys, the 155th amino acid is mutatedfrom Ser to Cys, or the 58th amino acid is mutated from Thr to Cys, and the 190th amino acid is mutated from Ser to Cys. A first furin cleavage site of the mutant wild-type F protein makes the structure of Pre-F more stable, the expression amount is not decreased, and the pre-fusion epitope of M1-F expression in 293T cells is significantly increased. The second mutation of the amino acid site of the F protein forms a disulfide bond, achieves the more stable pre-fusion epitope compared to the wild type, and is suitable for other strains of human RSV. The protein is suitable for various vaccineforms with the RSV F protein as the antigen, such as nucleic acid vaccines, protein vaccines, vector vaccines and recombinant virus particle vaccines.

The present invention relates to a mediating method of RNAi (ribonucleic acid interference) utilizing a lentiviral vector. The method comprises the following specific steps of: firstly carrying out homology analysis on the nucleic acid sequence of relevant viruses to find out conserved regions and designing siRNA (small interfering ribonucleic acid) corresponding to the conserved regions of the related viruses; and cloning the siRNA to an expression plasmid pLVTH, then co-transfecting 293T cells together with pCMV-dR8.91 and pMD2.G, collecting the supernatant of the transfected cells, carrying out ultracentrifugation, purification and concentration to obtain a high-titer lentiviral vector expressing the siRNA, then carrying out cotransduction into target cells together with LV-tTR-KRAB, and strictly controlling the acting time and dose of siRNA drugs utilizing tetracycline analogue DOX. Because of high transduction rate and a stringent control system, the mediating method can actually evaluate the in-vivo antiviral action of the siRNA and can track the whole process of drug interference action, thus having clinical application prospects.

The invention aims to provides a preparation method of a gene mutation and fusion gene positive reference. The preparation method comprises the following steps: with a lentivirus or a retrovirus, usedfor integrating a foreign gene in a cell genome, as a vector, preparing a sequence meeting different gene mutations or fusion genes, and after the sequencing validation is error-free, embedding in the cell genome through the virus, screening out a monoclonal cell line with gene mutation or fusion gene from a drug, thereby obtaining the continual positive reference. The cell line is preferably 293T cell line, the mutation can be conducted at a single mutation site of a single gene, multiple site mutations of a single gene and multiple site mutations of multiple genes, and the fusion gene canbe a single fusion gene,and can also be multiple fusion genes connected in series. The preparation method has the advantages of being rapid, accurate, simple, low in cost, high in sensitivity, and capable of realizing mass production, and application and popularization in the markets are facilitated.