68 results about "Host gene" patented technology

The invention relates to an infectious arenavirus particle that is engineered to contain a genome with the ability to amplify and express its genetic information in infected cells but unable to produce further infectious progeny particles in normal, not genetically engineered cells. One or more of the four arenavirus open reading frames glycoprotein (GP), nucleoprotein (NP), matrix protein Z and RNA-dependent RNA polymerase L are removed or mutated to prevent replication in normal cells but still allowing gene expression in arenavirus vector-infected cells, and foreign genes coding for an antigen or other protein of interest or nucleic acids modulating host gene expression are expressed under control of the arenavirus promoters, internal ribosome entry sites or under control of regulatory elements that can be read by the viral RNA-dependent RNA polymerase, cellular RNA polymerase I, RNA polymerase II or RNA polymerase III. The modified arenaviruses are useful as vaccines and therapeutic agents for a variety of diseases.

The invention provides a screening method for methylated protective strain expressing restriction endonuclease SacI. The method comprises steps: screening and culturing recombinant expression plasmidpBAD-R. SacI transformed competence cells with correct sequencing to obtain a recombinant expression strain of restriction endonuclease SacI by establishment of recombinant expression strain of methyltransferase M. AluI, recombinant expression of restriction endonuclease SacI, and other steps; and performing enlarging cultivation on the strain, and inducing with arabinose to obtain the recombinantprotein of restriction endonuclease SacI. For the method disclosed by the invention, the efficient recombinant expression of the restriction endonuclease SacI can be achieved; the recombinant expression of the restriction endonuclease SacI is carried out by strict control of an arabinose operon expression system on background expression; the method is stable and efficient against digestion of therestriction endonuclease SacI on a host genome DNA; and an M. AluI methylated protection strain is also applicable to recombinant expression of other restriction endonucleases with similar recognition sites.

The invention discloses a method for high-flux screening of host genes essential for plant virus copying, belongs to the technical field of gene engineering and aims to solve the problem that at present, an infective cloning construction method is low in virus infection efficiency and make gene expression difficult to control. The method for high-flux screening of host genes essential for plant virus copying specifically comprises the steps that an inducible promoter is utilized to establish inducible virus infection cloning, transgenic plants are used for constructing a mutant library throughagrobacterium tumefaciens-mediated transformation plants, an inducer is utilized to induce virus infection after mutants germinate, the mutants are screened to obtain mutant plants which cannot be induced by viruses, and the host genes essential for plant virus copying are positioned and cloned by cooperating with a map-based cloning and whole genome sequencing method.

The invention discloses a metagenome extraction method for specifically reducing or removing a host genomic DNA based on a CRISPR-Cas system composition. The invention aims to provide a technique forreducing a host genomic DNA background in metagenome sequencing and improving effective sequencing data of other microorganisms. The CRSIPR-Cas system in the method comprises a plurality of crRNA or crRNA/tracrRNA derivatives, as well as a biotin-labeled Cas protein or variant protein with endonuclease activity deficiency. The sequence of the crRNA or crRNA/tracrRNA derivatives is complemented with a repetitive sequence Alu element region (target sequence) in the host genomic DNA, so that the binding of the Cas protein or the variant thereof with endonuclease activity deficiency is guided to be bonded on the host genomic DNA, the CRISPR-Cas system and the bonded host DNA are captured by adding magnetic beads coated with streptavidin, and thus the concentration of the host genomic DNA in asample solution is reduced and the abundance of nucleic acids of other non-host genomic DNA is improved.

The invention discloses a multi-gene stacking knockout method for bacillus. The multi-gene stacking knockout method includes: inserting homologous arm gene segments of upstream and downstream of multiple genes to be knocked out of the bacillus into thermo-sensitive type plasmids to convert the bacillus, forcing homologous single-crossover to happen to knockout plasmids in the bacillus and genome DNA (deoxyribose nucleic acid) of the knockout plasmids through high-temperature culture, and screening double-crossover bacterial strains through high-temperature subculture; extracting the genome DNAs of the multiple bacterial strains successful in gene single-crossover, performing double-crossover screening, stacking the bacterial strains successful in knockout as host strains for the nest round of stacking knockout, and sequentially stacking to finally realize multi-gene knockout of the bacillus. Traceless gene knockout of the bacillus is realized with the thermo-sensitive type plasmids, conversion efficiency can be improved by using the single-crossover hose genome DNAs to convert the bacillus, restoration of the knockout genes in the host strains can be effectively avoided, and multi-gene stacking knockout efficiency is remarkably improved.

Contemplated antiviral/cancer treatments comprise analysis of neoepitopes from viral DNA that has integrated into the host genome, and design of immunotherapeutic agents against such neoepitopes.

The invention provides a double-sgRNA traceless gene editing plasmid as well as a preparation method and application thereof. The plasmid comprises a Cas9 protein expression cassette and a double-sgRNA expression cassette, wherein the double-sgRNA expression cassette comprises host gene editing sgRNA and plasmid gene editing sgRNA. The plasmid containing the double-sgRNA is designed to perform gene editing on a host, one sgRNA of the double-sgRNA is used for performing gene editing on the host, and the other sgRNA is used for eliminating the plasmid, so that the aim of eliminating the gene editing plasmid while performing gene editing on the host is achieved, the off-target rate is not increased due to continuous expression of Cas9 protein, and subsequent experiments are not influenced. The plasmid is transformed into saccharomyces cerevisiae for gene editing, so that the traceless editing efficiency of the saccharomyces cerevisiae is obviously improved.

The invention discloses a Cas9 system for efficiently editing a bombyx mori genome and an application of the Cas9 system. The system comprises a bombyx mori transgenic expression vector for expressing a Cas9 gene and bombyx mori nuclear polyhedrosis virus packaging virion containing an expression cassette U6-sgRNA expressed by a U6 promoter regulating sgRNA. A bombyx mori nuclear polyhedrosis virus (BmNPV) genome is used as a vector, the U6-sgRNA expression cassette is recombined to the virus genome through Bac-to-Bac transposition, a recombinant virion is constructed, a Cas9 cell line or Cas9 bombyx mori is infected with the recombinant virus, and a target gene can be effectively edited. The established Cas9 system does not need a transfection process, is high in transfection efficiency and good in safety, can stably and efficiently edit a target gene, and can be suitable for research on functions of viral genes and related host genes, a baculovirus expression system and the like.

The invention discloses a primer for inhibiting sequence-specific amplification of 18S rDNA of shrimps and oysters. The primer mainly comprises base sequences as shown in SEQ ID NO.1, five deoxyhypoxanthines inserted among the base sequences AG, and C3 spacers at the tail ends of the base sequences. The primer can effectively inhibit the amplification of host genes and enhance the amplification effect of 18S rDNA of other eukaryotes (such as protozoa, algae and fungi) in host bodies. The invention further discloses the application of the primer in preparing a reagent with the effect of inhibiting the sequence-specific amplification of 18S rDNA of the shrimps and oysters.

The invention provides a polypeptide and application thereof in preparation of an immunomodulatory drug. The functional polypeptide is a novel polypeptide PEP20 which is coded by a host gene of a long-chain non-coding RNA LINC01871; the polypeptide can specifically target CD8 < + > T cells in an inflammatory environment, inhibit differentiation of the CD8 < + > T cells to Tc17 cells, and inhibit over-differentiation and over-proliferation of the Tc17 cells and over-expression of IL-17A. The invention has an immune regulation function and can be used for preventing or treating autoimmune diseases, such as psoriasis, rheumatoid arthritis and multiple sclerosis. The PEP20 disclosed by the invention is small in molecular weight and can easily enter cells to play a role; the invention can be synthesized by a chemical method, is easy to prepare in a large scale, has good stability, and is lower in price and safer compared with the existing antibody for treating autoimmune inflammatory diseases such as psoriasis.

The invention discloses a construction method and application of an annular RNA overexpression system for a protoplast of a secondary xylem of a poplar, belonging to the technical field of genetic engineering. The construction method comprises the following steps: carrying out molecular biological verification on annular RNA; constructing an overexpression recombinant plasmid of annular RNA; converting the protoplast of the poplar by virtue of a PEG-mediated recombinant plasmid; and carrying out molecular biological detection on the overexpression condition of annular RNA in the protoplast ofthe converted recombinant plasmid. The overexpression system can be applied to the regulation and control of the expression condition after the transcription of a host gene.

The invention discloses a screening method of influenza virus related host gene mutants, and belongs to the technical field of random mutation. In order to screen out host genes related to influenza viruses, the invention provides a screening method. The screening method comprises the following steps: 1) transfecting a human lung cancer cell strain with CAG-tTA plasmids to obtain a Tel-off cell strain of a transcription activator stably expressed and regulated by tetracycline; co-transfecting the Tel-off cell strain with a gene search vector and plasmids that effectively express transposase toobtain a whole-genome pulmonary epithelial cell gene mutation library; 2) infecting the mutation library obtained in the step 1) by using the H1N1-WSN influenza virus; and 3) extracting the genome DNA of the cell strain, resisting the H1N1-WSN influenza virus, obtained in the step 2), and carrying out sequencing by Splinkette PCR to obtain the influenza virus related host gene mutants. The screening method can be used for screening the influenza virus related host gene mutants.

The invention relates to functions of genes of pseudomonas aeruginosa and an application of the genes, wherein the gene BN889_05221, the gene PA0243, the gene PA3808, the gene PA1993 and the gene PA1115 of pseudomonas aeruginosa are the necessary host genes of phage infection, and are used for screening the relevant medicines for inhibiting the phage infection. According to the invention, through the study on the relevant host genes of phage infection, a molecular mechanism for the interaction between phage and host bacteria can be well understood, therefore, a theoretical basis is provided for the treatment on the phage, meanwhile, new target genes related to virus infection can be found, and assistance is provided for screening antiviral drugs.