467 results about "Slow virus" patented technology

The invention belongs to the field of pharmaceutical and biological engineering, and relates to a CRISPR/Cas9 recombinant lentiviral vector for human immunodeficiency virus gene therapy and a lentivirus of the CRISPR/Cas9 recombinant lentiviral vector. The recombinant lentiviral vector is prepared by carrying out enzyme digestion on a lentiviral vectorlentiCRISPR by BsmBI and connecting into a BsmBI cohesive end-containing CXCR4 specific target sequence to recombine; the obtained CRISPR/Cas9 recombinant lentiviral vector is capable of mutating gene sequences at four different loci of ahuman immunodeficiency virusco-receptor CXCR4 and themutatuin rate is high and up to 25-75%. The cells transformed by the recombinant lentiviral vector cannot be infected by the human immunodeficiency virus. Compared with theRNAi-Knockdown, ZFN and TALEN technologies, the method has higher efficiency of suppressing the human immunodeficiency virus replication; the system is rapid to construct, simple and low in cost, is capable of preventing the invasion of the human immunodeficiency virus and is suitable for human immunodeficiency virus gene therapy.

The invention belongs to the field of allogenic mesenchymal stem cells, and particularly relates to a preparation method of allogenic mesenchymal stem cells by CRISPR (clustered regularly interspaced short palindromic repeats) technique editing and IGF (insulin-like growth factor) optimization and application of the allogenic mesenchymal stem cells in treating myocardial infarction. The preparation method comprises the following steps: carrying out separation by density gradient centrifugation to obtain allogenic single karyocytes, and carrying out adherent culture to obtain mesenchymal stem cells; designing a mesenchymal stem cell surface antigen B2M-gRNA and an inflammatory factor TNF-alpha-gRNA; establishing recombinant slow virus particles, and transfecting the mesenchymal stem cells; optimizing the mesenchymal stem cells by using IGF-1; and preparing drugs for treating myocardial infarctions by using the modified and optimized mesenchymal stem cells. The CRISPR/Cas9 technique is utilized to remove the antigens capable of causing immunological rejection and the inflammatory factors capable of causing inflammatory reaction on the mesenchymal stem cell surface, and the IGF-1 is utilized to enhance the apoptosis resistance of the mesenchymal stem cells and promote the homing of the mesenchymal stem cells, thereby providing a new technical scheme for preparing drugs for treating cardiovascular diseases in clinic. The prepared allogenic mesenchymal stem cells can not cause immunological rejection after cell transplantation.

A modified polypeptide corresponding to an envelope glycoprotein of a primate lentivirus is described. The polypeptide has been modified from the wild-type structure so that it has at least two of the glycosylation sites proximal to the CD4 binding site or chemokine receptor site altered so that the alteration prevents glycosylation at that site or where glycosylation sites distal to these sites have been derivatized with a molecular adjuvant, while retaining the overall 3-dimensional structure of a discontinuous conserved epitope of the wild-type protein. Preferably, the polypeptide has both changes. Preferably, the primate lentivirus is HIV, and the protein is HIV-1 gp 120.

The invention discloses a targeted-FTO-gene-knockout sgRNA (small guide ribonucleic acid) and CRISP (clustered regularly interspaced short palindromic repeats)/Cas9 slow virus system and application thereof. The sgRNA is selected from FTOsgRNAsp2 or FTOsgRNAsp3 with the following DNA sequence. The sgRNA has high cutting efficiency for the FTO gene. When the sgRNA-containing CRISPR/Cas9 slow virus system is used for transfecting SV-HUC-1, the FTO protein expression level of the obtained cell strain is obviously lowered. Therefore, the sgRNA disclosed by the invention can effectively implement targeted FTO gene knockout; and after the sgRNA is established into the CRISPR/Cas9 slow virus system, the system can knock out the FTO gene to obtain the FTO-gene-knockout cell strain, thereby being beneficial to researching the action mechanism of FTO in the cell strain.

The invention discloses a CRISPR (clustered regularly interspaced short palindromic repeat)/Cas9 recombinant lentiviral vector containing gRNA sequence specifically targeting CCR5 and application thereof. A lentivirus of the CRISPR/Cas9 recombinant lentiviral vector containing gRNA sequence specifically targeting CCR5 gene Delta 32 region is constructed that the lentivirus can introduce cells into a CRISPR/Cas9 system specific to CCR5, double-chain breakage occurs to a specific site of CCR5 gene, a random mutation is introduced to a breakage site after repairing by means of nonhomogeneous recombinant terminal binding, and the mutation rate reaches 90% and above. As gRNA is a nonhomogeneous region of CCR5 and CCR2, detection shows that the missing efficiency of the two gRNAs is lower than 0.2%. Cells modified via the recombinant lentivirus have significantly decreased efficiency of HIV (human immunodeficiency virus) infection. The system is quick to construct, simple and low in price, and is applicable to gene therapy of acquired immune deficiency syndrome.

The invention provides a method for efficiently inducing multipotential stem cells, six inducible factors such as Oct4 (POU5f1), Sox2, c-Myc, Klf4, UFT1, Rex1 (ZFP42), and the like and p53 gene inhibitor are induced into the cells by utilizing a slow virus carrier, thereby the method can efficiently induce and produce the multipotential stem cells.

The invention discloses a low-expression CYP7A1 hepatic cell and a constructing method thereof. A method for inhibiting the CYP7A1 expression level of the hepatic cell comprises the step of introducing an encoding gene of small-interference RNA which is used for inhibiting the CYP7A1 gene expression into the hepatic cell so as to inhibit the CYP7A1 expression level of the hepatic cell. A slow virus vector system can be used for introducing the encoding gene of small-interference RNA which is used for inhibiting the CYP7A1 gene expression into the hepatic cell. An experiment proves that the method of the invention can obviously regulate the expression level of the CYP7A1 gene of the hepatic cell in an mRNA level and a protein level downwards and can further effectively reduce the secretoryvolume of total bile acid. The Low-expression CYP7A1 hepatic cell and the constructing method thereof can be used for the fundamental research and the clinical application of biologic artificial liver supporting treatment and have a wide application prospect.

A pseudo-virus packaging system of coronaviruses comprises a vesicular stomatitis virus (VSV) vector with a Fluc and EGFP double reporter gene replacing a GP gene and an assembly cell expressing coronavirus spike protein S. The double reporter gene is selected from luciferase and fluorescent protein, and the luciferase reporter gene is preferably a Fluc gene. The fluorescent protein reporter geneis preferably an EGFP gene, and the assembly cell is preferably 293T. The invention further relates to a one-step packaging method of the packaging system; a pseudo-virus with single-cycle infection,low background value and high titer can be quickly packaged through simple, convenient and rapid operation, and the packaging system has the characteristic of being rapid in detection compared with aslow virus mediated pseudo-virus system; the one-step packaging method can be used for researching COVID-19, SARS, MERS and other coronaviruses and other viruses, provides a powerful screening tool for evaluation of antiviral preparations and vaccine, and has wide application value.

The invention belongs to the fields of genetic engineering and cell engineering, pertaining to a human T-lymphocytic series model for screening and reactivating latent infection HIV-1 compound and a preparation method thereof. The invention discloses a T lymphocyte used for screening and activating latent infection HIV-1 drug, and the T lymphocyte is a Jurkat stable strain that is infected by but not expresses HIV slow virus carrying reporter gene. The preservation number of the T lymphocyte is CCTCC NO.C200821. The invention also provides a preparation method for the T lymphocyte, including infecting human T-lymphocytic series Jurkat with the HIV-1 slow virus carrying EGFO reporter gene, and carrying out cell sorting and HIV integration test so as to obtain the clone with HIV integration while not expressing EGFP. The invention is the cell model for the virus preservation library to control drug screening.

The invention discloses a double-reporter-gene skeleton vector. Double reporter genes of the double-reporter-gene skeleton vector are selected from luciferase and fluorescein, the fluorescein reportergene is preferably an mGFP gene, and the luciferase reporter gene is preferably a Fluc gene. A double-reporter-gene four-plasmid pseudovirus packaging system comprises the double-reporter-gene skeleton vector and three eukaryotic expression packaging plasmids which are respectively integrated with a slow virus gag-pol gene, a slow virus rev gene and an envelope protein gene containing a target virus. A packaged COVID-19 pseudovirus comprises the double-reporter-gene four-plasmid pseudovirus packaging system and a host cell, wherein the host cell is preferably selected from 293T-hACE2 cells. According to the invention, SARS-CoV-2 is specifically implemented, the pseudovirus with single-cycle infection and higher safety can be rapidly packaged, and the vector and the system can be used forresearching coronaviruses such as SARS-Cov2 and the like, provide a powerful screening tool for evaluation of antiviral preparations and vaccines, and have wide application value.

The invention relates to a method of inducing a human fibroblast to reprogram the human fibroblast into an osteoblast by utilization of Runx2 and a low-molecular-weight compound, particularly relates to a method of inducing a human fibroblast to transdifferentiate the human fibroblast into an osteoblast under the existence of dexamethasone by utilization of Runx2 gene expression, a low-molecular-weight compound CHIR99021 and/or a low-molecular-weight compound forskolin, and belongs to the fields of cytobiology and tissue engineering. The method includes: constructing a human skin fibroblast infected by a slow virus carrying Runx2-GFP, performing transdifferentiation of the human fibroblast under the existence of the dexamethasone by utilization of the low-molecular-weight compound CHIR99021 having a concentration of 5-10 muM and the low-molecular-weight compound forskolin having a concentration of 10 muM, changing into an osteoblast inducing liquid after 7-15 days, and inducing, and the fibroblast can be induced into the osteoblast after 5-20 days. The method can obtain osteoblasts simply and rapidly and can be used for cell therapy for bone metabolic disease, fracture, and the like. A pharmaceutical composition provided by the invention can be used for research, development and production of tissue-engineered bone, brings convenience to fundamental research and brings a prospect for clinical application.

The invention discloses an immortalized human liver cell line, a preparation method and an application thereof. The immortalized human liver cell line has the main function of primarily cultured humanliver cell. The preparation method comprises the following steps of: transferring SV40T antigen and human telomerase catalyzed subunit gene into primarily cultured separated human normal liver cell by slow virus carrier; and sieving in a cloning way to obtain the immortalized human liver cell line. The immortalized human liver cell line also can be extrinsically amplified in large scales in a microcarrier way. The immortalized human liver cell line can be used for preparing a biological artificial liver support system and preparing the medicament for curing the liver failure.

The invention belongs to the biomedicine field, and aims at providing an expression vector for stably indicating cell autophagy activities, an establishing method and an application method thereof. By constructing a slow-virus expression plasmid containing an EGFP-LC3 autophagy reporter gene and adopting a four-plasmid system, the invention establishes a slow-virus expression vector capable of enabling cells to stably express an EGFP-LC3 gene. By using the expression vector to infect a host cell, the EGFP-LC3 gene can be stably integrated in a genome of the host cell, and the host cell can stably and efficiently express the EGFP-LC3 and indicate cell autophagy changes. A stable autophagy indicating cell can be established by using the expression vector, and the cell autophagy changes are quickly and quantitatively analyzed by an image analysis method based on Top-hat operators and morphological filtration. The invention has the characteristics of stable and reliable autophagy indication, real-time sensitivity, quick and accurate autophagy quantification, simply and convenient operation and the like, greatly facilitates autophagy observation and analysis, and can be widely used for autophagy-correlated researches.

The invention discloses a CD 123-targeting replication-defective recombinant lentivirus CAR-T transgenic vector. The CD 123-targeting replication-defective recombinant lentivirus CAR-T transgenic vector comprises a prokaryotic replicor pUC Ori sequence used for plasmid duplication; an amicillin resistance gene AmpR sequence used for amplification of a large number of target strains; a virus replicor SV40 Ori sequence used for enhancing the replication in eukaryocytes; a lentivirus packaging cis element used for lentivirus packaging; ZsGreen 1 green fluorescent protein used for green fluorescence expression of eukaryocytes; an IRES ribosome binding sequence used for co-transcription and co-expression of protein; a human EF1 alpha promoter used for eukaryotic transcription of genes of a chimeric antigen acceptor; the chimeric antigen acceptor used for forming second-generation CAR or third-generation CAR integrating recognition, delivery and promoting; an eWPRE element used for enhancing the expression efficiency of transgenes. In addition, the invention further discloses a construction method and applications of the vector. With the vector, the secretion of the cell factors and the in-vitro lethal effect of the CAR-T cells can be obviously improved, and the effect in treatingacute myelogenous leukemia (AML) clinically is outstanding.

The invention relates to a preparation method of a cytotoxic T lymphocyte (CTL) targeting to multiple KRAS mutant antigen epitopes. The method comprises the steps: cloning a new artificial antigen coding sequence formed by series combination of 7 main KRAS mutant antigen epitope sequences into a lentivirus expression vector, transfecting DC, stimulating the proliferation and differentiation of activated CD8+T cells, and making the finally prepared cytotoxic T lymphocyte (CTL) having the specificity of targeting to seven main KRAS mutant antigen epitopes. The prepared KRAS mutant antigen specific cytotoxic T lymphocyte (CTL) has the advantages of high targeting specificity, no side effects and not easily causing of immune escape, and has great application prospects in treatment of KRAS mutant tumors.