Some aspects of this disclosure provide compositions, methods, systems, and kits for controlling the activity of RNA-programmable endonucleases, such as Cas9, or for controlling the activity of proteins comprising a Cas9 variant fused to a functional effector domain, such as a nuclease, nickase, recombinase, deaminase, transcriptional activator, transcriptional repressor, or epigenetic modifying domain. For example, the inventive proteins provided comprise a ligand-dependent intein, the presence of which inhibits one or more activities of the protein (e.g., gRNA binding, enzymatic activity, target DNA binding). The binding of a ligand to the intein results in self-excision of the intein, restoring the activity of the protein.

The present disclosure provides RNA-guided CRISPR-Cas effector proteins, nucleic acids encoding same, and compositions comprising same. The present disclosure provides ribonucleoprotein complexes comprising: an RNA-guided CRISPR-Cas effector protein of the present disclosure; and a guide RNA. The present disclosure provides methods of modifying a target nucleic acid, using an RNA-guided CRISPR-Cas effector protein of the present disclosure and a guide RNA. The present disclosure provides methods of modulating transcription of a target nucleic acid.

Systems and methods to genetically modify B cells to express selected antibodies are described. The systems and methods can be used to: obviate the need for classical vaccinations; provide protection against infectious agents for which no vaccinations are currently available; provide protection against infectious agents when patients are otherwise immune-suppressed; and/or provide a benefit provided by a therapeutic antibody, such as in the treatment of autoimmune disorders.

Genetically modified cells that are compatible with multiple subjects, e.g., universal donor cells, and methods of generating said genetic modified cells are provided herein. The universal donor cells comprise at least one genetic modification within or near a gene that encodes one or more MHC-I or MHC-II human leukocyte antigens or a component or a transcriptional regulator of a MHC-I or MHC-II complex, wherein genetic modification comprises an insertion of a polynucleotide encoding a tolerogenic factor and/or survival factor. The universal donor cells may further comprise at least one genetic modification within or near a gene that encodes a survival factor, wherein said genetic modification comprises an insertion of a polynucleotide encoding a second tolerogenic factor and/or a different survival factor.

Compositions and methods for treatment of CEP290 related diseases are disclosed.

Compositions and methods for editing, e.g., introducing double-stranded breaks, within the TTR gene are provided. Compositions and methods for treating subjects having amyloidosis associated with transthyretin (ATTR), are provided.

Systems and methods for targeted gene modification, targeted insertion, perturbation of gene transcripts, and nucleic acid editing. Novel nucleic acid targeting systems comprise components of CRISPR systems and non-LTR retrotransposon elements.

Compositions and methods are provided for production of cells useful in regenerative therapies.

Embodiments of the disclosure encompass improvements on cell therapies by allowing the cells to be more effective for cancer treatment, including in a solid tumor microenvironment. In specific cases, the cells are modified to have reduced or inhibited levels of expression of T-Cell Death Associated Gene 8 (TDAG8), such as by CRISPR gene editing. In specific cases, the cells are further modified to express, for example, one or more engineered receptors, one or more cytokines, and optionally a suicide gene.

The present disclosure provides compositions, methods, and systems related to genome editing technology. In particular, the present disclosure provides a novel CRISPR-based genome editing technology that involves the generation of abasic sites to facilitate genetic recombination, without the need for breaks in the DNA. The compositions, methods, and systems described herein address many of the drawbacks of currently available approaches, including off-target effects and cellular toxicity.