Organic compounds
AssigneeNovartis AG
InventorsYehuda G. Assaraf, Thomas Jostock, Hans-Peter Knopf
Life of this patent
Estimating the term…
Abstract
The present invention relates to a novel selection system for use in a eukaryotic cell culture process and for expression of a recombinant product of interest. The selection system is based on the introduction of an exogenous functional membrane-bound folate receptor gene together with the polynucleotide or gene encoding the product of interest into a eukaryotic cell and can be widely utilized with eukaryotic cells for which cellular viability is dependent upon folic acid uptake.
Claims17
A method for selection of a CHO cell capable of stably expressing a product of interest encoded by an expression vector which has been introduced into the cell, comprising
- (i) providing a plurality of CHO cells for which cellular viability is dependent upon folate uptake, and into which cells a first polynucleotide located on an expression vector and encoding a functional membrane-bound folate receptor alpha as selection marker and a second polynucleotide located on an expression vector and encoding the product of interest have been introduced, wherein the first polynucleotide and the second polynucleotide are located on the same expression vector or on separate expression vectors,
- (ii) culturing said plurality of CHO cells in a cell culture medium having a limiting concentration of a folic acid, wherein the concentration in the cell culture medium is from 0.001 nM to 100 nM, thereby obtaining a CHO cell wherein stable expression of the product of interest is achieved, and
- (iii) identifying and isolating a CHO cell wherein stable expression of the product of interest is achieved.
Dependencies are inferred from the claim text.