The present invention refers to a fusion protein or a protein complex comprising a DNA binding protein (DnaBP), a nucleobase modifying protein (NMP), and a Base Excision Repair associated protein (BERAP. Also, described herein are a method of replacing a cytosine with a guanine on a DNA strand in a cell and a method of treating a subject having or suspected of having a disease or disorder.

RNA-guided programmable cytosine and adenine base editors are a powerful class of genome editing tool for the introduction of localized base transitions without generating a double-stranded DNA break. Base editors (BE) have an optimal window of activity relative to the PAM recognized by the Cas9 enzyme and these constructs are strand selective. Here we demonstrate that fusion of a programmable DNA-binding domain (pDBD) or another Cas9 orthologue to spCas9-BE, we can produce an RNA-programmable Cas9-BE-pDBD chimera or Cas9-BE-Cas9 chimeras with dramatically improved activities and increased targeting range. Cas9-pDBD or Cas9-Cas9 fusion base editors display an expanded targeting repertoire and achieve highly specific genome editing, which can be tailored to achieve extremely precise genome editing at nearly any genomic locus.

The invention relates to peptide linkers and fusion proteins comprising linkers designed for optimizing the activity of the proteins comprised therein, and methods for using the same. The invention further relates to newly designed Cas12a-based cytosine base editors.

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.

A recombinant lentiviral vector containing a gene encoding a TRAIL protein and a CD protein; and a cell that is transfected with the lentivirus produced by using the vector. A host cell transfected with the recombinant lentivirus maintains a high cell proliferation rate and overexpresses a TRAIL protein and a CD protein. Thus, a mesenchymal stem cell transfected with the lentivirus may be usefully employed as a cell therapeutic agent.

The present invention discloses base editing systems for mutating a base C to A and a base C to G and applications thereof. The base editing system for mutating C to A disclosed in the present invention includes cytosine deaminase AID and nCas9 nuclease or includes cytosine deaminase AID, nCas9 nuclease and uracil DNA glycosidase; the base editing system for mutating C to G of the present invention includes cytosine deaminase APOBEC, nCas9 nuclease and uracil DNA glycosidase. The experiments show that a combination of the three base editing systems for mutating C to A, C to T and A to G can realize a mutation of A, T, C or G to any base in both prokaryotes and eukaryotes.

Provided are a fusion protein that improves gene editing efficiency and an application thereof. The fusion protein comprises a single-stranded DNA binding protein functional domain, nucleoside deaminase and nuclease. According to CBEs, when carrying our base conversion from C-G to T-A, nucleoside deaminase such as cytosine deaminase carries out deamination by using single-stranded DNA as a substrate, and by re-fusing the single-stranded DNA binding protein functional domain on the fusion protein of the nucleoside deaminase and nuclease, the chance of single-stranded DNA being exposed to the nucleoside deaminase is greatly increased, thereby significantly improving base editing efficiency. The present disclosure provides a breakthrough improvement of single-base gene editing technology and can greatly promote the application thereof in aspects such as gene editing, gene therapy, cell therapy, animal model making, and crop genetic breeding.

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.

The disclosure is directed to a gene transfer vector which comprises (i) all or part of a viral genome and (ii) a suicide gene flanked by unique cloning sequences. The disclosure also is directed to a system for producing an adenoviral vector comprising a destination vector comprising (i) all or part of an adenoviral genome and (ii) a suicide gene flanked by unique cloning sequences; a transgene flanked by unique cloning sequences; and (c) reagents for Gibson DNA Assembly (GDA). A method of producing an adenoviral vector using the aforementioned system also is provided.

A method is disclosed for decreasing or retarding an increase in the size of a localized or metastatic tumor by using a combination of an immune stimulating cytotoxic gene therapy and immune-checkpoint modulating agent, in conjunction with other therapies, including radiation therapy, chemotherapy, surgery, and immunotherapies.