Protein secretory factor with high secretory efficiency and an expression vector comprising the same

Abstract

The present invention relates to a novel protein secretion factor, a vector including a nucleic acid sequence encoding the protein secretion factor, and a transformed cell into which the vector is introduced. The invention also relates to a method of producing a target protein using the transformed cell including the vector.

1 - 18 . (canceled) 
     
     
         19 . A method of producing an antibody, comprising:
 i) culturing a transformed cell, into which the vector is introduced, to express an antibody and secrete the antibody to the outside of the cell; and   ii) recovering the antibody from a culture or culture supernatant of the cell of step i),   wherein said vector comprises:   a) i) a first expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 2, which is operably linked to a gene encoding an antibody light chain; and
 ii) a second expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence selected from the group consisting of SEQ ID NOS: 4 and 8, which is operably linked to a gene encoding an antibody heavy chain, or 
   b) i) a first expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 2, which is operably linked to a gene encoding an antibody heavy chain; and
 ii) a second expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence selected from the group consisting of SEQ ID NOS: 4 and 8, which is operably linked to a gene encoding an antibody light chain. 
   
     
     
         20 . The method according to  claim 19 , wherein the protein secretion factor of the first expression cassette has an amino acid sequence of SEQ ID NO: 1, and wherein the protein secretion factor of the second expression cassette has an amino acid sequence selected from the group consisting of SEQ ID NO: 4 or 8. 
     
     
         21 . The method according to  claim 19 , further comprising purifying the recovered antibody. 
     
     
         22 . The method according to  claim 21 , wherein the cell is a Chinese Hamster Ovary (CHO) cell. 
     
     
         23 . A method of producing an antibody, comprising:
 i) culturing a transformed cell, into which a vector is introduced, to express an antibody and secrete the antibody to the outside of the cell; and   ii) recovering the antibody from a culture or culture supernatant of the transformed cell of step i),   wherein the antibody is secreted at a secretion level which increases along with the increase in culture period, and   wherein said vector comprises:   
       a) i) a first expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 2, which is operably linked to a gene encoding an antibody light chain; and
 ii) a second expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence selected from the group consisting of SEQ ID NOS: 1, 3, 4 and 8, which is operably linked to a gene encoding an antibody heavy chain, or 
 
       b) i) a first expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence of SEQ ID NO: 1 or SEQ ID NO: 2, which is operably linked to a gene encoding an antibody heavy chain; and
 ii) a second expression cassette comprising a promoter, which is operably linked to a nucleic acid sequence encoding a protein secretion factor having an amino acid sequence selected from the group consisting of SEQ ID NOS: 1, 3, 4 and 8, which is operably linked to a gene encoding an antibody light chain. 
 
     
     
         24 . The method according to  claim 23 , wherein the antibody light chain has an amino acid sequence of SEQ ID NO: 48, and the antibody heavy chain has an amino acid sequence of SEQ ID NO: 49.