An identification and an application of an ALV-J MHC-B2 restrictive epitope peptide are provided, which belong to the field of genetic engineering. An amino acid sequence of the provided ALV-J MHC-B2 restrictive epitope peptide is selected from SEQ ID NO:1, SEQ ID NO:2 and SEQ ID NO:3. An application of the ALV-J MHC-B2 restrictive epitope peptide in preparing an ALV epitope-based vaccine is provided. Restrictive motif of B2-haplotype chicken MHC class I molecule binding peptides is identified by in vitro elution assay. Potential epitopes in four proteins expressed by ALV-J are systematically screened by motif. The immunogenic B2-haplotype chicken ALV-J T-cell epitope peptides are identified by functional validation. It provides a material and theoretical basis for the research and development of ALV epitope-based vaccines.

Disclosed herein include methods, compositions, and systems suitable for use in delivering a polynucleotide to a target cell of a subject in need thereof. In some embodiments, a viral vector comprises a polynucleotide encoding nucleoprotein (N), phosphoprotein (P), matrix protein (M), RNA-dependent RNA polymerase (L), and one or more transgenes. The viral vector can comprise one or more of a conditionally stable fusion protein, a protease fusion protein, a degron fusion protein, and/or a glycoprotein derived of another species than the viral vector polynucleotide to enable control of viral vector transduction and/or replication.

Provided herein are delivery particle systems (XDP) useful for the delivery of payloads of any type. In some embodiments, a XDP particle system with tropism for target cells of interest is used to deliver CRISPR/Cas polypeptides (e.g., CasX proteins) and guide nucleic acids (gNA), for the modification of nucleic acids in target cells. Also provided are methods of making and using such XDP to modify the nucleic acids in such cells.

Disclosed herein include methods, compositions, and systems suitable for use in delivering a polynucleotide to a target cell of a subject in need thereof. In some embodiments, a viral vector comprises a polynucleotide encoding nucleoprotein (N), phosphoprotein (P), matrix protein (M), RNA-dependent RNA polymerase (L), and one or more transgenes. The viral vector can comprise one or more of a conditionally stable fusion protein, a protease fusion protein, a degron fusion protein, and/or a glycoprotein derived of another species than the viral vector polynucleotide to enable control of viral vector transduction and/or replication.

The present invention relates to a cell membrane penetrating peptide and an intracellular delivery carrier including the same. The intracellular delivery carrier of the present invention has an advantage of efficiently transferring substances into cells even at a low concentration thereof compared with the existing cell membrane penetrating peptide derived from the virus.

The invention relates to vectors comprising two or more homologous nucleotide sequences and methods for generating them. The invention concerns substituting bases in the homologous nucleotide sequences with different bases that do not alter the encoded amino acid sequence. The invention allows for the reduction of intramolecular recombination between homologous nucleotide sequences, in particular in mammalian cells. The invention further relates to nucleotide sequences containing substituted bases.

Described herein are compositions relating to alphavirus-based virus-like particles (VLPs) and methods for making and using the described VLPs. The described compositions include VLPs and vectors and cells used to produce the VLPs. Also included are related methods to produce the VLPs, to transduce cells using the VLPs, and to produce a protein or polynucleotide of interest in a target cell using the VLPs. Also described are alphavirus-based replicons that allow for expression of proteins or polynucleotides of interest in a target cell without a cytopathic effect.

Disclosed herein include methods, compositions, and systems suitable for use in delivering a polynucleotide to a target cell of a subject in need thereof. In some embodiments, a viral vector comprises a polynucleotide encoding nucleoprotein (N), phosphoprotein (P), matrix protein (M), RNA-dependent RNA polymerase (L), and one or more transgenes. The viral vector can comprise one or more of a conditionally stable fusion protein, a protease fusion protein, a degron fusion protein, and/or a glycoprotein derived of another species than the viral vector polynucleotide to enable control of viral vector transduction and/or replication.

Described herein are compositions relating to alphavirus-based virus-like particles (VLPs) and methods for making and using the described VLPs. The described compositions include VLPs and vectors and cells used to produce the VLPs. Also included are related methods to produce the VLPs, to transduce cells using the VLPs, and to produce a protein or polynucleotide of interest in a target cell using the VLPs. Also described are alphavirus-based replicons that allow for expression of proteins or polynucleotides of interest in a target cell without a cytopathic effect.

The present invention relates to a cell membrane penetrating peptide and an intracellular delivery carrier including the same. The intracellular delivery carrier of the present invention has an advantage of efficiently transferring substances into cells even at a low concentration thereof compared with the existing cell membrane penetrating peptide derived from the virus.