Myeloma cell culture in transferrin-free low iron medium

Abstract

The present invention relates to a method for culturing mammalian cells in a culture medium which is transferrin free and which contains no lipophilic or synthetic nitrogen-containing chelators. Also provided is the use of the medium and a process for providing a mammalian product by culturing cells capable of producing the product in the medium.

We claim: 
     
         1 . A method for the in vitro culture of a myeloma cell line which comprises:
 (a) inoculating a culture medium with a myeloma cell line, said medium being capable of supporting the growth of said myeloma cell line and comprising iron at concentrations in the medium of from about 0.03 mg/L to about 3.2 mg/L,   wherein said medium does not contain transferrin, a lipophilic chelator, a   synthetic nitrogen-containing chelator or a lipophilic synthetic nitrogen-containing chelator; and   (b) growth of the inoculated culture medium under appropriate conditions and using agitated suspension culture.   
     
     
         2 . The method of  claim 1  wherein the concentration of iron in the medium is from about 0.03 mg/L to about 2.4 mg/L. 
     
     
         3 . The method of  claim 1  wherein the concentration of iron in the medium is from about 0.064 mg/L to about 1.6 mg/L. 
     
     
         4 . The method of  claim 1  wherein the concentration of iron in the medium is from about 0.16 mg/L to about 0.32 mg/L. 
     
     
         5 . The method of  claim 1  wherein the source of iron is a soluble iron compound. 
     
     
         6 . The method of  claim 5  wherein the soluble iron compound is selected from the group consisting of ferrous or ferric salts or simple chelates thereof. 
     
     
         7 . The method of  claim 6  wherein the soluble iron compound is selected from the group consisting of ferrous sulphate, ferrous citrate, ferric citrate and ferric ammonium compounds. 
     
     
         8 . The method of  claim 7  wherein the ferric ammonium compound is selected from the group consisting of ferric ammonium citrate, ferric ammonium oxalate, ferric ammonium fumarate, ferric ammonium malate and ferric ammonium succinate. 
     
     
         9 . The method of  claim 7  wherein the ferric ammonium compound is ferric ammonium citrate. 
     
     
         10 . A method for the in vitro culture of a myeloma cell line which comprises:
 (a) inoculating a culture medium with a myeloma cell line, said medium being capable of supporting the growth of said myeloma cell line and comprising ferric ammonium citrate at a concentration in the medium of from about 0.2 mg/L to about 20 mg/L, wherein said medium does not contain transferrin, a lipophilic chelator, a synthetic nitrogen-containing chelator or a lipophilic synthetic nitrogen-containing chelator; and   (b) growth of the inoculated culture medium under appropriate conditions and using agitated suspension culture.   
     
     
         11 . The method of  claim 10  wherein the ferric ammonium citrate is present in the medium at a concentration of from about 0.2 mg/L to about 15 mg/L. 
     
     
         12 . The method of  claim 10  wherein the ferric ammonium citrate is present in the medium at a concentration of from about 0.4 mg/L to about 10 mg/L. 
     
     
         13 . The method of  claim 10  wherein the ferric ammonium citrate is present in the medium at a concentration of from about 1 mg/L to about 2 mg/L. 
     
     
         14 . The method of  claim 1  wherein the medium is serum free, protein free, free of components of animal derivation or is chemically defined. 
     
     
         15 . The method of  claim 1  wherein the myeloma cell line is selected from the group consisting of an NSO series, a P3 series, MOPC series, MPC-11, J558L, K6H6/B5, 45.6.TG1.7, Y0, Y3 HTK, RPMI 8226 and U266B1. 
     
     
         16 . The method of  claim 1  wherein the myeloma cell line is an NSO cell line. 
     
     
         17 . A process for obtaining a mammalian cell product comprising culturing a myeloma cell capable of producing said product under agitated suspension culture and in a culture medium capable of supporting the growth of said myeloma cell line, said medium comprising iron at concentrations in the medium of from about 0.03 mg/L to about 3.2 mg/L, or ferric ammonium citrate at a concentration in the medium of from about 0.2 mg/L to about 20 mg/L, wherein said medium does not contain transferrin, a lipophilic chelator, a synthetic nitrogen-containing chelator or a lipophilic synthetic nitrogen-containing chelator; and recovering said mammalian cell product. 
     
     
         18 . The process of  claim 17  wherein the concentration of iron in the medium is from about 0.03 mg/L to about 2.4 mg/L. 
     
     
         19 . The process of  claim 17  wherein the concentration of iron in the medium is from about 0.064 mg/L to about 1.6 mg/L. 
     
     
         20 . The process of  claim 17  wherein the concentration of iron in the medium is from about 0.16 mg/L to about 0.32 mg/L.