Described herein are methods and compositions for improving the genome-wide specificities of targeted base editing technologies. Herein, we describe dimeric base editing (BE) technologies that use split deaminases (sDA) that are functional when brought into close proximity to each other, one fused to a ZF and one to an nCas9-UGI protein comprising one or more UGIs, so as to limit the ability of the deaminase domain from deaminating at off-target ssDNA target sites independent of nCas9 R-loop formation. Thus, provided herein are fusion proteins comprising: (i) a first portion of a split deaminase (sDAI) enzyme fused to a programmable DNA-binding domain; or (ii) a second portion of a split deaminase (sDA2) fused to an nCas9 protein. The present invention also includes the vectors and cells comprising the vectors, as well as kits comprising the proteins and nucleic acids described herein.

Genetically programmed microorganisms, such as bacteria or virus, pharmaceutical compositions thereof, and methods of modulating and treating cancers are disclosed.

Provided herein are fusion proteins useful in a bipartite cytosine base editor system comprising: (i) a first fusion protein comprising a non-R-loop-forming programmable DNA binding domain, preferably a transcription-activator-like effector (TALE) or zinc finger array (ZF), fused to a deaminase enzyme, or an active portion thereof, optionally with a linker therebetween, or (ii) a second fusion protein comprising an R-loop-forming Cas9 protein that lacks nuclease activity or is a nickase, but can interact with a guide RNA and target DNA, fused to a Uracil glycosylase inhibitor (UGI), optionally with a linker therebetween. Additionally, provided are methods for targeted deamination of one or more selected cytosines in a nucleic acid.

Provided are: a composition for DNA double-strand breaks (DSBs), comprising (1) a cytosine deaminase and an inactivated target-specific endonuclease, (2) a guide RNA, and (3) a uracil-specific excision reagent (USER); a method for producing DNA double-strand breaks by means of a cytosine deaminase using the composition; a method for analyzing a DNA nucleic acid sequence to which base editing has been introduced by means of a cytosine deaminase; and a method for identifying (or measuring or detecting) base editing, base editing efficiency at an on-target site, an off-target site, and/or target specificity by means of a cytosine deaminase.

Provided nucleic acid-based expression construct for the target cell-specific production of a therapeutic protein, such as a pro-apoptotic protein, within a target cell, including a target cell that is associated with aging, disease, or other condition, in particular a target cell that is a senescent cell or a cancer cell. Also provided are formulations and systems, including fusogenic lipid nanoparticle (LNP) formulations and systems, for the delivery of nucleic acid-based expression constructs as well as methods for making and using such nucleic acid-based expression constructs, formulations, and systems for reducing, preventing, and/or eliminating the growth and/or survival of a cell, such as a senescent cell and/or a cancer cell, which is associated with aging, disease, or other condition as well as methods for the treatment of aging, disease, or other conditions by the in vivo administration of a formulation, such as a fusogenic LPN formulation, comprising an expression construct for the target cell-specific production of a therapeutic protein, such as a pro-apoptotic protein, in a target cell that is associated with aging, disease, or other condition, in particular a target cell that is a senescent cell or a cancer cell.

Described herein are DNA-editing complexes, particularly DNA-editing complexes that specifically alter a single base pair in target DNA sequence as well as methods of making and using these DNA-editing complexes.

Provided herein are systems, compositions, and methods for the incorporation of unnatural amino acids into proteins via nonsense suppression or rare codon suppression. Nonsense codons and rare codons may be introduced into the coding sequence of a protein of interest using a CRISPR/Cas9-based nucleobase editor described herein. The nucleobase editors are able to be programmed by guide nucleotide sequences to edit the target codons in the coding sequence of the protein of interest. Also provided are application enabled by the technology described herein.

Some aspects of this disclosure provide strategies, systems, reagents, methods, and kits that are useful for the targeted editing of nucleic acids, including editing a single site within the genome of a cell or subject, e.g., within the human genome. In some embodiments, fusion proteins comprise a Gam protein, a napDNAbp, and a cytidine deaminase. In some embodiments, the fusion proteins further comprise a UGI domain. In some embodiments, methods for targeted nucleic acid editing are provided. In some embodiments, reagents and kits for the generation of targeted nucleic acid editing proteins, e.g., fusion proteins of a Gam protein, a cytidine deaminase and nucleic acid editing proteins or domains, are provided.

Provided herein are systems, compositions, kits, and methods for the suppression of pain (e.g., chronic pain). Genes encoding ion channels (e.g., SCN9A) responsible for the propagation pain signals in neurons (e.g., DRG neurons) may be edited using a genome editing agent (e.g., a nucleobase editor). In some embodiments, loss-of-function ion channel mutants are generated, leading to pain suppression. In some embodiments, the genome editing agent is administered locally to the site of pain or to the nerves responsible for propagation of the pain signal.

The invention provides pluripotent cells that are used therapeutically for regenerating tissues but avoid rejection by subjects that receive them. In particular, the invention provides hypo-immunogenic pluripotent cells that avoid host immune rejection. The cells lack major immune antigens that trigger immune responses and are engineered to avoid phagocytic endocytosis. The invention further provides universally acceptable off-the-shelf pluripotent cells and derivatives thereof for generating or regenerating specific tissues and organs.