86 results about "Dna cleavage" patented technology

The present invention pertains to engineered T-cells, method for their preparation and their use as medicament, particularly for immunotherapy. The engineered T-cells of the invention are characterized in that the expression of beta 2-microglobulin (B2M) and / or class I I major histocompatibility complex transactivator (CIITA) is inhibited, e.g., by using rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding B2M and / or CIITA, or by using nucleic acid molecules which inhibit the expression of B2M and / or CIITA. In order to further render the T-cell non-alloreactive, at least one gene encoding a component of the T-cell receptor is inactivated, e.g., by using a rare-cutting endonucleases able to selectively inactivating by DNA cleavage the gene encoding said TCR component. In addition, expression of immunosuppressive polypeptide can be performed on those modified T-cells in order to prolong the survival of these modified T cells in host organism. Such modified T-cell is particularly suitable for allogeneic transplantations, especially because it reduces both the risk of rejection by the host's immune system and the risk of developing graft versus host disease. The invention opens the way to standard and affordable adoptive immunotherapy strategies using T-Cells for treating cancer, infections and auto-immune diseases.

The present invention relates to an Argonaute protein mutant which lacks DNA cleavage activity, but has DNA binding activity. The mutation of the mutant is located in a PIWI domain. The invention alsorelates to application of the protein mutant particularly in the enrichment of target DNA and in the construction of a sequencing library. Therefore, the present invention also relates to a method for enriching the target DNA. The method comprises the steps of: (a) designing a leader sequence for a specific sequence in the target DNA; (b) combining the mutant, the leader sequence and the target DNA according to the present invention to obtain a mutant-leader sequence-target DNA ternary complex; (c) capturing the mutant-leader sequence-target DNA ternary complex through a capture medium; and (d) isolating the target DNA from the captured mutant-leader sequence-target DNA ternary complex to obtain enriched target DNA.

The present invention provides a Cas9 platform to facilitate single-site nuclease gene editing precision within a human genome. For example, a Cas9 nuclease / DNA-targeting unit (Cas9-DTU) fusion protein precisely delivers a Cas9 / sgRNA complex to a specific target site within the genome for subsequent sgRNA-dependent cleavage of an adjacent target sequence. Alternatively, attenuating Cas9 binding using mutations to the a protospacer adjacent motif (PAM) recognition domain makes Cas9 target site recognition dependent on the associated DTU, all while retaining Cas9's sgRNA-mediated DNA cleavage fidelity. Cas9-DTU fusion proteins have improved target site binding precision, greater nuclease activity, and a broader sequence targeting range than standard Cas9 systems. Existing Cas9 or sgRNA variants (e.g., truncated sgRNAs (tru-gRNAs), nickases and FokI fusions) are compatible with these improvements to further reduce off-target cleavage. A robust, broadly applicable strategy is disclosed to impart Cas9 genome-editing systems with the single-genomic-site accuracy needed for safe, effective clinical application.