3 results about "Homologous recombination" patented technology

The invention discloses a physiological general CAR-T cell which enables expression of CAR to be controlled by an endogenous promoter and a preparation method and application thereof. A TCR constant region gene is knocked out by utilizing a CRISPR / Cas9 gene editing technique, and the CAR gene is inserted into a TCR constant region precisely by using an AAV-mediated homologous recombination technique. Therefore, the general CAR-T enabling the CAR expression controlled by the endogenous promoter and enabling the expression level of CAR be controlled within a normal physiological range can be obtained. The general CAR-T cell has the characteristics of being allogeneically infused, the expression of CAR is at the physiological level and uniform and consistent, no significant cytokine storm exists, and the cell is safer. The invention also relates to application of the CAR-T cell on anti-tumor aspect.

The invention provides an ORF074 (Open Reading Frame 074) gene deleted strain of an infectious spleen and kidney necrosis virus as well as a preparation method and application thereof. The ORF074 genedeleted strain is an attenuated viral strain prepared after the ORF074 gene is deleted from an infectious spleen and kidney necrosis viral strain. The invention also provides a selection marker carrying ORF074 gene deleted strain of the infectious spleen and kidney necrosis virus as well as a preparation method and application thereof. The selection marker carrying ORF074 gene deleted strain is an attenuated viral strain prepared after the ORF074 gene is deleted from the infectious spleen and kidney necrosis virus and further a selection marker gene is inserted into a gene deleted position through homologous recombination. The ORF074 gene deleted strain of the infectious spleen and kidney necrosis virus, which is provided by the invention, is an ORF074 knocked-out recombinant gene engineering vaccine, is lower in virulence, and is used for greatly reducing the morbidity and lethality of an immunized fish; the obvious immunization effect can be achieved by adopting immersion immunization; the injection is not needed, and the application value is extremely high.

The invention discloses a method for improving absorption and utilization capacities of brewer's yeast xylose. According to the method, DNA homologous recombination is adopted for inserting DNA sequences containing selection marker genetic expression frames on the RGT1 genetic expression open reading frame region of a brewer's yeast chromosome, so as to destroy the expression of the RGT1 genes, obtain the brewer's yeast strain having the transcription factor gene RGT1 knocked off and containing the xylose transformation path, and improve the absorption and utilization capacities of the brewer's yeast xylose. The experiment shows that through the RGT1 deficiency method, the expression levels of hexose transporter proteins HXT1 and HXT2 in the brewer's yeast under the condition of xylose are improved by 17.32 times and 3.75 times compared with the prior art, the utilization efficiency of xylose is improved to 0.34g / L / h from the prior art of 0.23g / L / h, which is improved by 47.8%, and thus the method is contemplated to have extremely great application prospect in the production.