The present invention relates to a dual
vector system for expressing Otoferlin
protein, comprising a first
nucleic acid vector and a second
nucleic acid vector wherein the first
nucleic acid vector comprises a first
nucleotide sequence; the second nucleic acid vector comprises a second
nucleotide sequence; the first
nucleotide sequence comprises an
expression cassette inserted between two first ITR sequences; the second nucleotide sequence comprises an
expression cassette inserted between two second ITR sequences; the
expression cassette of the first nucleotide sequence comprises a
promoter, an N-terminal coding sequence of Otoferlin, an N-terminal coding sequence of
intein and polyA; the expression cassette of the second nucleotide sequence comprises a
promoter, a C-terminal coding sequence of
intein, a C-terminal coding sequence of Otoferlin and polyA, wherein the first
amino acid of the C-terminal coding sequence of Otoferlin is mutated into
serine (S),
threonine (T) or
cysteine (C). The invention also relates to a packaging
carrier system of the adeno-associated
virus, a packaging method of the adeno-associated
virus and the adeno-associated
virus obtained by the method. The dual
vector system or adeno-associated virus for expressing the Otoferlin
protein of the present invention can be used in
gene therapy, particularly in the treatment of
hearing loss, such as in the treatment of Oof
gene mutation associated autosomal recessive hereditary
hearing loss 9 (DFNB9).