We disclose dumbbell-shaped vectors adapted for efficient expression in mammalian cells. We also disclose a novel method allowing the efficient synthesis of dumbbell-shaped vectors at low cost for delivery of recombinant DNA and RNA into host cells; and the use of dumbbell-shaped vectors for transient expression in, for example, primary human cells.

The purpose of the present invention is to provide a method for producing a very stable, cyclized mutant protein such that high cyclization efficiency is achieved while the number of amino acids added is minimal and the biological properties of an original protein are maintained. In view of conformational information about the original protein, secondary structure-free regions at N/C terminal portions are deleted. Then, a protein database is screened for proteins with secondary structures similar to those of N/C terminal residues of a secondary structure-forming portion after the deletion. The screening results are used to determine the amino acid length of a loop structure through which the N-terminus and the C-terminus of the secondary structure-forming portion of the original protein are to be connected. A cyclized mutant protein is finally produced having a loop structure with the determined amino acid length.

Novel intron fragments are provided. The intron fragments can increase gene expression to levels equal to or higher than those achieved by the full-length intron while maintaining their ability to increase gene expression even when combined with various types of promoters and splicing donors. Particularly, the intron fragments enable loading of larger transgenes when used in genetic information delivery systems whose size is limited, for example, adeno-associated viruses (AAVs) and rhabdoviruses. Therefore, the use of the intron fragments is expected to extend the range of therapeutic genes.

The present invention relates to constructs, vectors, relative host cells and pharmaceutical compositions which allow an effective gene therapy, in particular of genes larger than 5 Kb.

Novel intron fragments are provided. The intron fragments can increase gene expression to levels equal to or higher than those achieved by the full-length intron while maintaining their ability to increase gene expression even when combined with various types of promoters and splicing donors. Particularly, the intron fragments enable loading of larger transgenes when used in genetic information delivery systems whose size is limited, for example, adeno-associated viruses (AAVs) and rhabdoviruses. Therefore, the use of the intron fragments is expected to extend the range of therapeutic genes.

Provided herein are methods and compositions for expressing Otoferlin, e.g., utilizing adeno-associated viral (AAV) particles. Such methods and compositions may be useful for treatment of diseases such as Deafness, Autosomal Recessive 9 (DFNB9).

Provided herein are synthetic RNA molecules for reconstitution of RNA molecules, including compositions and methods of using these molecules. For example, such molecules can be used to deliver a protein coding sequence over two or more viral vectors (such as AAVs), resulting in reconstitution of the full-length protein in a cell. Such methods can be used to deliver a therapeutic protein, for example to treat a genetic disease or cancer.

Provided herein are methods and compositions for expressing Otoferlin, e.g., utilizing adeno-associated viral (AAV) particles. Such methods and compositions may be useful for treatment of diseases such as Deafness, Autosomal Recessive 9 (DFNB9).

Provided herein are compositions and methods related split prime editors.