Abstract: Disclosed are cell lines that stably express CRISPR SAM complex which comprise a gRNA that specifically targets a promoter of a gene, wherein the gene is not normally expressed in said cell. Also disclosed are methods of measuring the ability of a vector to transfer a nucleic acid molecule into such cell lines.

Abstract: Nucleic acid constructs and compositions that allow insertion of a multidomain therapeutic protein (e.g., GAA fusion protein) coding sequence into a target genomic locus such as an endogenous ALB locus and/or expression of the multidomain therapeutic protein (e.g., GAA fusion protein) coding sequence are also provided. The nucleic acid constructs and compositions can be used in methods of integration of a multidomain therapeutic protein (e.g., GAA fusion protein) nucleic acid into a target genomic locus, methods of expression of a multidomain therapeutic protein (e.g., GAA fusion protein) in a cell, methods of reducing glycogen accumulation, methods of treating Pompe disease or GAA deficiency in a subject, and method of preventing or reducing the onset of a sign or symptom of Pompe disease in a subject, including neonatal cells and subjects.

Abstract: Non-human animal genomes, non-human animal cells, and non-human animals comprising a humanized albumin (ALB) locus and methods of making and using such non-human animal genomes, non-human animal cells, and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized albumin locus express a human albumin protein or a chimeric albumin protein, fragments of which are from human albumin. Methods are provided for using such non-human animals comprising a humanized albumin locus to assess in vivo efficacy of human-albumin-targeting reagents such as nuclease agents designed to target human albumin.

Abstract: Nucleic acid constructs and compositions that allow insertion of a FIX coding sequence into a target genomic locus such as an endogenous ALB locus and/or expression of the FIX coding sequence are provided. The nucleic acid constructs and compositions can be used in methods of introducing a F9 nucleic acid into a cell, methods of integration of a F9 nucleic acid into a target genomic locus, methods of expression of FIX in a cell, and in methods of treating hemophilia B or FIX deficiency in a subject.

Abstract: Non-human animal genomes, non-human animal cells, and non-human animals comprising a humanized albumin (ALB) locus and methods of making and using such non-human animal genomes, non-human animal cells, and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized albumin locus express a human albumin protein or a chimeric albumin protein, fragments of which are from human albumin. Methods are provided for using such non-human animals comprising a humanized albumin locus to assess in vivo efficacy of human-albumin-targeting reagents such as nuclease agents designed to target human albumin.

Abstract: The disclosure features compositions and methods for the treatment of sensorineural hearing loss and auditory neuropathy, particularly forms of the disease that are associated with a mutation in otoferlin (OTOF), by way of OTOF gene therapy. The disclosure provides a variety of compositions that include a first nucleic acid vector that contains a polynucleotide encoding an N-terminal portion of an OTOF isoform 5 protein and a second nucleic acid vector that contains a polynucleotide encoding a C-terminal portion of an OTOF isoform 5 protein. These vectors can be used to increase the expression of OTOF in a subject, such as a human subject suffering from sensorineural hearing loss.

Abstract: Provided herein are compositions and methods for adapting adeno-associated virus (AAV) particles comprising capsids of non-primate animal AAV, remote AAV, or a combination thereof. AAV adapted accordingly may be a viable gene therapy platform for the treatment of a patient in need thereof, and may be particularly useful in patients excluded from current treatment modalities involving current therapeutic AAV particles due to their high titer of antibodies against the current therapeutic AAV particles.

Abstract: The disclosure features compositions and methods for the treatment of sensorineural hearing loss and auditory neuropathy, particularly forms of the disease that are associated with mutations in otoferlin (OTOF), by way of OTOF gene therapy. The disclosure provides a variety of compositions that include a first nucleic acid vector that contains a polynucleotide encoding an N-terminal portion of an OTOF protein and a second nucleic acid vector that contains a polynucleotide encoding a C-terminal portion of an OTOF protein. These vectors can be used to increase the expression of OTOF in a subject, such as a human subject suffering from sensorineural hearing loss.

Abstract: The disclosure provides polynucleotides containing regions of the Myosin 15 (Myo15) promoter, as well as vectors containing the same, that can be used to promote expression of a transgene specifically in hair cells. The polynucleotides described herein may be operably linked to a transgene, such as a transgene encoding a therapeutic protein, so as to promote hair cell-specific expression of the transgene. The polynucleotides described herein may be operably linked to a therapeutic transgene and used for the treatment of subjects having or at risk of developing hearing loss or vestibular dysfunction.

Abstract: Non-human animal genomes, non-human animal cells, and non-human animals comprising a humanized albumin (ALB) locus and methods of making and using such non-human animal genomes, non-human animal cells, and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized albumin locus express a human albumin protein or a chimeric albumin protein, fragments of which are from human albumin. Methods are provided for using such non-human animals comprising a humanized albumin locus to assess in vivo efficacy of human-albumin-targeting reagents such as nuclease agents designed to target human albumin.

Abstract: Provided herein are compositions and methods for redirecting recombinant viral capsid particles via a specific protein:protein binding pair that forms an covalent, e.g., isopeptide, bond to display a targeting ligand on the capsid protein, wherein the targeting ligand specifically binds a cell surface marker expressed on the cell of interest.

Abstract: Provided herein are compositions and methods for retargeting recombinant viral capsid proteins/capsids/vectors, e.g., in vivo, with a multispecific binding molecule, such as a bispecific antibody, that specifically binds a heterologous epitope displayed by the capsid protein and a protein expressed on the cell of interest for the targeted delivery of a nucleotide of interest.