Methods and compositions for production of recombinant protein in hbx-expressing mammalian cells

Abstract

The method of the invention provides for producing a heterologous protein in mammalian host cells having nucleic acid encoding Hepatitis B X protein and the heterologous protein, by growing mammalian host cells selected from the group consistng of HKB11, CHO, BHK21, C2C12, and HEK293 cells, by growing mammalian host cells in non-adherent suspension culture, or by growing mammalian host cells which contain nucleic acid providing exogenous X-box Binding Protein, XBP1s. The conditions should be such that HBx, exogenous XBP1s if present, and the heterologous protein are expressed by the mammalian cells. The invention includes compositions for carrying out the method.

1 - 14 . (canceled) 
     
     
         15 . A composition comprising mammalian host cells containing a nucleic acid encoding a heterologous protein and a nucleic acid encoding HBx, wherein the mammalian host cells are derived from a cell line selected from the group consisting of HKB11 cells, CHO cells, BHK21 cells, C2C12 cells, and HEK293 cells, and wherein the cells express or can be induced to express HBx and the heterologous protein. 
     
     
         16 . A composition comprising a suspension culture of anchorage-independent mammalian host cells, which mammalian host cells contain nucleic acid encoding HBx and nucleic acid encoding a heterologous protein, and which mammalian host cells express or can be induced to express HBx and the heterologous protein. 
     
     
         17 . A composition comprising mammalian host cells, which mammalian host cells contain:
 (a) nucleic acid encoding HBx,   (b) nucleic acid which provides exogenous XBP1s, and   (c) nucleic acid encoding a heterologous protein,   
       wherein the mammalian host cells express or can be induced to express HBx, exogenous XBP1s and the heterologous protein. 
     
     
         18 . The composition of  claim 15 , wherein the mammalian host cells stably express HBx, the heterologous protein, or both. 
     
     
         19 . The composition of  claim 17  wherein the mammalian host cells stably express HBx, XBP1s, and/or the heterologous protein. 
     
     
         20 . The composition of  claim 15 , wherein the mammalian host cells transiently express HBx, the heterologous protein, or both. 
     
     
         21 . The composition of  claim 17 , wherein the mammalian host cells transiently express HBx, XBP1s, and/or the heterologous protein.