Abstract: The present disclosure provides a muscle-specific chimeric promoter, including: (1) a hybrid ?-myosin heavy chain enhancer/muscle creatine kinase enhancer-promoter (MHCK7 promoter); and (2) one or more binding sites of a transcription factor, wherein the MHCK7 promoter includes the sequence set forth in SEQ ID NO: 2 or a functional variant thereof having at least 90% sequence identity to SEQ ID NO: 2, and wherein the transcription factor is a member selected from the group consisting of the MyoD family of transcription factors. Compared with the MHCK7 promoter, the specificity and expression ability in muscle tissue of the muscle-specific chimeric promoter provided in the present application are significantly improved. The application of the muscle-specific chimeric promoter in mammals and muscle cells is of great significance for the treatment of muscle diseases.

Abstract: The present application provides virions and uses thereof in the biological field. The present application specifically provides multiple mutants of an adeno-associated virus with high muscle targeting, quite low liver tropism, and better specificity, and applications thereof. Recombinant adeno-associated viral vectors (rAAV) are constructed using the mutants of the AAV capsid protein provided in this application. The rAAV is not only effective in mouse muscles, but also exhibits better muscle targeting and low liver toxicity in non-human primates (NHP), providing better safety and a wide range of applications.

Abstract: The present disclosure provides a mutant of an adeno-associated virus 2 (AAV2) capsid protein, including an amino acid sequence KTINGSGQNQQTLK (SEQ ID NO: 2) or an amino acid sequence having 1, 2, 3, or 4 amino acid changes when compared to SEQ ID NO: 2 in variable region IV; and an amino acid sequence TTVTQ (SEQ ID NO: 3) or an amino acid sequence having 1 or 2 amino acid changes when compared to SEQ ID NO: 3 in variable region V. The mutants of an adeno-associated virus provided herein have low liver tropism and low hepatotoxicity.

Abstract: Provided are a mutant of an adeno-associated virus (AAV) targeting a resting or activated T cell, a use of the mutant of the AAV, and a heterologous peptide targeting a T cell. An amino acid sequence of the heterologous peptide is set forth in any one of SEQ ID NOS: 1-5. The mutant of the AAV exhibits high efficiency in targeting resting or activated T cells, and has advantages such as low dose, strong infectivity, and high safety. A recombinant adeno-associated virus (rAAV) can be constructed from a mutant of an AAV capsid protein of the present application. Nucleic acid sequences carried by rAAV can not be integrated into the genome of the host cell. T he rAAV can be used for the quick infection and reinfusion of activated T cells, which reduces the unnecessary quality control and in vitro dwell time.