Cell culture method using amino acid-enriched medium

Abstract

Methods of culturing cells capable of producing desired proteins to obtain the proteins by use of a medium from which biological components are excluded as much as possible are provided. Specifically, a culture method characterized by culturing while maintaining a specific amino acid in a culture solution at a high concentration, and a cell culture fed-batch medium for use in the method are provided.

1 . A method of culturing a cell characterized in that a concentration of serine in a culture solution is maintained at 1 mM or higher at least during a certain period after the onset of a cell growth phase, the method used in a process comprising culturing a cell that is capable of producing a desired protein to obtain the desired protein. 
     
     
         2 . The method of  claim 1 , further characterized in that a concentration of tyrosine in the culture solution is maintained at 1 mM or higher, and/or a concentration of cysteine in the culture solution is maintained at a concentration of the cysteine in an initial medium or at 0.4 mM or higher at least during the certain period after the onset of the cell growth phase. 
     
     
         3 . A medium for animal cell culture, comprising at least 1 mM of serine or a salt thereof. 
     
     
         4 . The medium for animal cell culture of  claim 3 , further comprising at least 1 mM of tyrosine and/or at least 0.4 mM of cysteine. 
     
     
         5 . A process of producing a desired protein, comprising culturing a cell that is capable of producing the desired protein, by use of the medium of  claim 3  to obtain the desired protein. 
     
     
         6 . A method of culturing a cell, the method used in a process comprising culturing a cell that is capable of producing a desired protein to obtain the desired protein, the method characterized in that a concentration of serine in a culture solution is maintained at 1 mM or higher at least during a part of or an entire period sufficient to enable the cell that is to be cultured to grow sufficiently, or during a part of or an entire period sufficient to enable adequate production of the desired protein that is to be produced. 
     
     
         7 . The method of  claim 6 , further characterized in that a concentration of tyrosine in the culture solution is maintained at 1 mM or higher, and/or a concentration of cysteine in the culture solution is maintained at a concentration of the cysteine in an initial medium or at 0.4 mM or higher at least during a part of or the entire period sufficient to enable the cell that is to be cultured to grow sufficiently, or during a part of or the entire period sufficient to enable adequate production of the desired protein that is to be produced. 
     
     
         8 . A method of culturing a cell, characterized in that a concentration of serine in a culture solution is maintained at 1 mM or higher at least during a part of or an entire period of an exponential cell growth phase, the method used in a process comprising culturing a cell that is capable of producing a desired protein to obtain the desired protein. 
     
     
         9 . The method of  claim 8 , further characterized in that a concentration of tyrosine in the culture solution is maintained at 1 mM or higher, and/or a concentration of cysteine in the culture solution is maintained at a concentration of the cysteine in an initial medium or higher or at 0.4 mM or higher at least during a part of or an entire period of the exponential cell growth phase. 
     
     
         10 . The method of  claim 8 , wherein the concentration of serine in the culture solution is maintained at 2 mM or higher at least during a part of or an entire period of the exponential cell growth phase. 
     
     
         11 . A method of culturing a cell, characterized in that a concentration of serine in a culture solution is maintained at 1 mM or higher at least during a part of or an entire period from a third day to a tenth day of the culture, the method used in a process comprising culturing a cell that is capable of producing a desired protein to obtain the desired protein. 
     
     
         12 . The method of  claim 11 , further characterized in that a concentration of tyrosine in the culture solution is maintained at 1 mM or higher, and/or a concentration of cysteine in the culture solution is maintained at a concentration of the cysteine in an initial medium or higher or at 0.4 mM or higher at least during a part of or an entire period from the third day to the tenth day of the culture. 
     
     
         13 . The method of  claim 11 , wherein the concentration of serine in the culture solution is maintained at 2 mM or higher at least during a part of or an entire period from the third day to the tenth day of the culture. 
     
     
         14 . The method of  claim 1 , wherein the cell is cultured by batch culture, repeated batch culture, fed-batch culture, repeated fed-batch culture, continuous culture, or perfusion culture. 
     
     
         15 . The method of  claim 1 , wherein the cell is cultured by fed-batch culture. 
     
     
         16 . The method or process according to  claim 15 , wherein the serine and tyrosine and/or cysteine are fed into the culture solution in multiple batches sequentially or continuously. 
     
     
         17 . The method of  claim 1 , wherein the cell is transformed with a gene encoding the desired protein. 
     
     
         18 . The method or process of  claim 17 , wherein the desired protein is an antibody. 
     
     
         19 . The method of  claim 1 , wherein the cell is a mammal cell. 
     
     
         20 . The method of  claim 19 , wherein the mammal cell is a CHO cell. 
     
     
         21 . A fed-batch medium for culturing a cell, comprising serine at a concentration of 10 mM to 1000 mM. 
     
     
         22 . A fed-batch medium for culturing a cell, comprising serine at a concentration of 20 mM to 500 mM. 
     
     
         23 . The fed-batch medium of  claim 21 , further comprising cysteine and/or tyrosine. 
     
     
         24 . The fed-batch medium of  claim 21 , further comprising cysteine and tyrosine. 
     
     
         25 . A method of culturing a cell by fed-batch culture, comprising adding the fed-batch medium of  claim 21 . 
     
     
         26 . A process of producing a desired protein by culturing a cell, comprising culturing a cell using the method of  claim 1 . 
     
     
         27 . A preparation process of a medicament comprising as an active ingredient a protein produced by the process of  claim 5 .