125 results about "Suicide gene" patented technology

The present invention is directed to universal T cells and their use in treating diseases and other physiological conditions. More specifically, the present invention is directed to universal T cells and their use in treating treating B-lineage acute lymphoblastic leukemia (B-ALL) in particular and malignancy in general. The universal T cells contain (i) nucleic acid encoding a chimeric antigen receptor (CAR) to redirect their antigen specificity and effector function and (ii) nucleic acids encoding shRNA and/or siRNA molecules to down-regulate cell-surface expression of T cell classical HLA class I and/or II genes to avoid recognition by recipient T cells. The universal T cells may also contain a nucleic acid encoding a non-classical HLA gene, such as an HLA E gene to enforce expression of HLA E genes and/or an HLA G gene to enforce expression of HLA G genes, to avoid recognition by recipient NK cells. The universal T cells may further contain a nucleic acid encoding a selection-suicide gene.

The invention discloses a method of packaging a CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat-associated 9) system by using a temperate phage vector. The method comprises the steps of: (1) constructing suicide genes, target spot sequences bound with specific gRNA (guide ribonucleic acid), and downstream PAM (protospacer adjacent motif) sequences into pSTK (protein serine threonine kinase) plasmids, (2) transforming the pSTK plasmids into escherichia coli host bacteria, (3) transforming CRISPR-Cas9 sequence recombination template double-chain DNA (deoxyribonucleic acid) linear fragments carrying phage sequence homologous arms at the two ends into the host bacteria, (4) inducing expression of homologous recombination related enzymes and the suicide genes SacB, (5) screening the host bacteria subjected to homologous recombination, and (6) inducing temperate phages to crack the host bacteria, and harvesting the recombined temperate phages packaging the CRISPR-Cas9 system, wherein chromosomes of the escherichia coli host bacteria are integrated with the temperate phages; and plasmids capable of expressing the homologous recombination related enzymes are transformed into the escherichia coli host bacteria. According to the packaging method, a secondary recombination step of deleting a resistance marker is removed, and the technical support is provided for the phage vector presenting CRISPR-Cas9 system to resist drug-resistance bacteria efficiently and quickly.

Embodiments of the present disclosure concern therapeutic vectors and cells that target certain cancer cells but do not other cells having the same antigen. In specific embodiments, the methods and compositions of the disclosure concern cells having a CD138-specific chimeric antigen receptor whose expression is under the control of environment-specific regulation. In specific embodiments the environment is hypoxia. In some cases, the compositions comprise a suicide gene.

The invention relates to a chimeric antigen receptor (CAR) immune cell provided with a safety switch as well as a preparation method and an application of the CAR immune cell. The CAR immune cell carrying the safety mechanism (the safety switch) comprises a CAR coding nucleotide sequence, wherein the structure of the nucleotide sequence comprises a receptor structural domain for recognizing tumor-specific antigen or tumor-associated antigen, a transmembrane-stimulation structural domain, a CD3[zeta] stimulating signal transduction region and a suicide gene region. The CAR immune cell can be obtained as different immunological effect cells are amplified and a CAR sequence carrying a suicide mechanism is transduced; corresponding antigens of tumor cells are recognized by virtue of CAR; and the CAR immune cell can generate a specific killing effect on the tumor cells. The CAR immune cell, when used, is infused in a gradient mode and dynamic change in related cell factor levels is monitored; in case of need, a suicide gene can be started by virtue of drugs to scavenge the immunological effect cells, so that optimal balance between safety and a curative effect is achieved; therefore, the safety of the technology applied to the treatment of tumors in the clinical field is guaranteed to the greatest extent.

Mesenchymal stem cells expressing a suicide gene show excellent and highly selective anticancer effects against cancer tissues through the selective conversion of a prodrug of an anticancer agent to the anticancer agent at around the cancer. Also disclosed herein are a pharmaceutical composition for treating a cancer comprising the mesenchymal stem cell; a kit for treating a cancer comprising an expression vector comprising the suicide gene, the mesenchymal stem cell and the prodrug; and a method for treating a cancer patient, which comprises successively administering the mesenchymal stem cell and the prodrug to the patient.

The invention provides an engineering immune cell with a suicide gene switch of targeting human mesothelin (MSLN). Particularly, the invention provides a chimeric antigen receptor T cell of the targeting human mesothelin, a CAR (Chimeric Antigen Receptor) structure of the cell comprises a cell suicide element, and the expression of a PD1 gene in the cell is silent. Particularly, the CAR structurecomprises a CAR basic structure and the cell suicide element at the same time, the CAR basic structure and the cell suicide element are independent of each other, and the corresponding functions of the CAR basic structure and the cell suicide element are non-interfering. In addition, the silent expression of the PD1 gene in the cell has a synergistic effect with the CAR structure, the tumor killing effect is strengthened, and the disease does not relapse easily.

The invention provides an establishing method of a recoverable immortalized hepatic cell line. The establishing method comprises the following steps: separating a hepatic progenitor cell from liver in a mouse which is 12.5-14.5 days old in an embryonic period; guiding a retrovirus containing genes SV40T and HSV-TK into the hepatic progenitor cell; screening a monoclonal cell strain having a hepatic progenitor cell marker and having a function of differing to a mature hepatic cell; then guiding a retrovirus containing CD gene into the cell strain so as to obtain recoverable immortalized hepatic cell carrying double suicide genes. The cell strain can multiply in vitro to obtain the phenotype and functions of a normal hepatic cell, the safety of the immortalized cell becomes adjustable through controllable modes such as locus recombination and drug screening; when the cell is used in a human body, the biological safety of the immortalized cell is ensured to the greatest extent and the dangerousness of the immortalized cell is reduced; therefore, a reliable, safe and ideal hepatic cell material is provided for bioartificial liver technology.

The present invention provides a feeder cell for target cell induction, wherein the feeder cell is transduced with an immortalizing gene and a suicide gene; and a production process for a target cell sheet using the feeder cell for target cell induction.

The invention relates to a plasmid vector and a method for building a plant population by using the plasmid vector. The plasmid vector contains, at a replication origin, a gene expression box for expressing Cas9 protein, a first promoter, nucleotide sequences containing suicide gene sequences, a gRNA scaffold element and a termination signal, and at least one first enzyme cutting site located on the nucleotide sequence 5' end containing the suicide gene sequence and at least one second enzyme cutting site located at the nucleotide sequence 3' end containing the suicide gene sequence; furthermore, no first enzyme cutting site and no second enzyme cutting site exist in other positions of the plasmid vector. The first promoter is located at the upstream of the termination signal; the nucleotide sequences containing suicide gene sequences and the gRNA scaffold element are all located between the first promoter and the termination signal.

The invention relates to the technical field of medicine, and provides a nano drug-carrying system. The nano drug-carrying system comprises a magnetic-mesoporous silicon dioxide nanorod carrier, a pro-drug GCV (ganciclovir) carried on the carrier, and a graft copolymer PLL-g-PEG (poly-L-lysine graft polyethylene glycol) formed by PLL and PEG, wherein the PLL-g-PEG also carries a suicide gene TK. The magnetic-mesoporous silicon dioxide nanorods are used as the magnetic targeted carrier to carry the suicide gene TK/pro-drug GCV to enter cells, thereby implementing the time and space consistency of the suicide gene and pro-drug transfer, and further implementing accurate drug release. The magnetic-mesoporous silicon dioxide silicon dioxide nanorods and suicide gene/pro-drug treatment method are effectively combined, thereby enhancing the combined treatment effect on the liver cancer. The preparation method of the nano drug-carrying system is simple in technique and suitable for large-scale industrial production.

The invention provides a method for rapidly screening a bacterial quorum sensing inhibitor (QSI) by utilizing a suicide gene. The method is characterized in that under natural light, bacteria not infected with a phage do not turn blue and bacteria infected with the phage turn blue; induced by an added lethal condition inducer, a specific polypeptide with the function of inhibiting QS does not start expression of the suicide gene because of inhibiting the activities of QS molecules, so the bacteria survive; a non-specific polypeptide can not inhibit the QS molecules, so the suicide gene starts lethal; then survival candidate clones are picked out, functional verification is further carried out and finally a DNA (deoxyribonucleic acid) sequence corresponding to a specific polypeptide sequence is obtained by a method of DNA sequencing, thus obtaining an efficient and specific QSI polypeptide. The method is simple in steps, and multiple QSI candidate polypeptides can be obtained only within three days to about one weak, so that the method has very obvious advantages.

The invention provides a kind of transgenic inhuman mammal by producing klone gene without mouse model. Roll outside self murder gene into the mammal. The expression box contains promoter, self murder gene relation with promoter and termination codon. The natural masculine gene will express in testes organize after transgenic animal builds system. The transgenic animal can provide blastosphere for eliminating gene technic to improve the efficiency of the technic and to solve the problem that mouse genetic background is impure.

The invention discloses a recombinant slow virus vector, a recombinant slow virus and a stem cell containing recombinant slow virus, belonging to the field of medical molecular biology. The recombinant slow virus vector is characterized in that: a Survivin prompter, an Apoptin gene and a SV40Poly A sequence are sequentially inserted into a plurality of cloning sites of the slow virus vector; and the slow virus vector is FG-12. Due to the application of the recombinant slow virus, such as transfection applied to a transplanted stem cell, the stem cell transplanted into the body of a patient is under the monitoring of the promoter of the recombinant slow virus vector. Once the transplanted stem cell is transformed severely, the expression of a suicide gene Apoptin in the recombinant slow virus is started immediately, so that the severely-transformed cell is dead by apoptosis. During clinical application, the recombinant slow virus plays a role in specifically pre-warning, reacting, tracing and clearing the transformed stem cell.

The present invention relates to cytosine deaminase protein and cDNA from various species of the yeast genus Dekkera/Brettanomyces. Compared to yeast cytosine deaminase the novel cytosine deaminases are more efficient and have a higher stability. The invention also relates to the field of suicide gene therapy based on activation of a non-toxic prodrug, 5-fluorocytosine to a toxic drug 5-fluorouracil based on the enzymatic activity of novel cytosine deaminses. Finally the invention provides use of 5-fluorocytosine for controlling the growth of Dekkera/Brettanomyces yeast.

The invention relates to the field of biotechnology and discloses a high-proliferation specific recombination eucaryotic cell promoter PCNATAI; an eucaryotic cell operating system PCNATAI-LoxP-stop-LoxP taking a PCNATAI as a core transcription initiator and a LoxP-stop-LoxP as a transcriptional repression element; and a set of general scheme for eliminating the repression effect of the LoxP-stop-LoxP to the transcription process of the PCNATAI promoter through a Cre recombinase provided by a tumor cell specific dependent model trans form and enabling the downstream exogenous tumor suppressor gene or the suicide gene to be effectively and specifically expressed in the malignant tumor cell in a tumor cell specific pattern and a proliferation specific pattern. The scheme not only can remarkably improve the tumor inhibition rate during the gene therapy of the malignant tumor or the expression efficiency of the suicide gene in the malignant tumor cell, but also can ensure the security of the gene therapy.

The invention provides a packaging cell line for production of diphtheria toxin (DT) expressing, non-replicating adenovirus for use in suicide gene therapy of cancer cells, as well as production of immunotoxins. Also provided are methods for producing diphtheria toxin (DT) expressing, non-replicating adenovirus, methods for producing immunotoxins, and adenovirus and immunotoxins produced by those methods. Further provided are methods for making a cell resistant to diphtheria toxin.

The invention discloses a construction scheme of artificially transforming human type 5 adenovirus (Ad5), and a specific application of a novel oncolytic adenovirus construct obtained by the scheme in tumor treatment, and belongs to the technical field of medical genetic engineering. A recombinant adenovirus construct obtained by PCR amplification site-directed deletion, enzyme digestion, ligation, cloning, homologous recombination, transfection, adenovirus monoclonal purification, etc., its technical characteristics are: Ad5 genome E1A conserved sequence 2 27 bases were deleted in the (CR2) region; 29477-29714nt of the ADP gene in the E3 region was deleted; and the full-length coding sequence (1131bp) of the HSV-TK gene was inserted in the deleted region. This construct is a new type of oncolytic adenoviral vector with higher tumor selective replication ability, which utilizes the suicide gene function of HSV-TK and the double killing effect of oncolytic virus to dissolve tumor cells, and has great potential in the biological treatment of tumors. Unique practical value.

The invention discloses an ROBO1 CAR-NK cell carrying a suicide gene as well as a preparation method and application of the ROBO1 CAR-NK cell. In order to improve the safety and controllability of theCAR-NK therapy, a suicide gene switch element is integrated into a genome through a lentiviral transfection technology on the basis of the current ROBO1 CAR-NK cell to form the CAR-NK with the suicide gene. By adding the suicide gene, the CAR-NK cells can be better controlled, and the clinical safety is further improved.

A DNA comprising a 609 bp base sequence from -559 to +50 when the first base sequence of exon 1 of the midkine gene, a human retinoic acid-responsive growth/differentiation factor was set as +1, or a DNA comprising a 251 bp base sequence from -213 to +38 when the transcription initiation point of the c-erbB-2 gene belonging to the EGF receptor family and having a tyrosine kinase activity was set as +1 has a tumor-specific transcription activity, and the promoter activity thereof is high, and therefore is very important as a tumor-specific promoter for use in the suicide gene therapy that combines the use of a gene for a drug metabolizing enzyme and a prodrug for cancer therapy, the gene therapy of cancer using an expression vector that contains a gene encoding a cytokine, and the gene therapy of cancer using an oncolytic virus that exhibits cytotoxic effects only on tumor cells, etc.