CHOZN® ZFN-Modified GS-/- CHO Cell Line GS敲除的CHO悬浮高效表达细胞株 BioVector NTCC质粒载体菌种细胞基因保藏中心

CHOZN® ZFN-Modified GS-/- CHO Cell Line GS敲除的CHO悬浮高效表达细胞株

The CHOZN GS-/- cell line was created using BioVector NTCC Inc. proprietary
CompoZr® Zinc Finger Nuclease (ZFN) technology. ZFNs are
a class of engineered DNA-binding proteins, which facilitate
targeted genome editing by binding to a user-specified locus
and causing a double-strand break (DSB). The cell then
employs endogenous DNA repair processes, either
non-homologous end joining (NHEJ) or homology-directed
repair (HDR), to heal this targeted DSB. These repair processes
can be channeled to generate precisely targeted genomic
edits resulting in an organism or cell line with specific gene
disruptions (knockouts), integrations, or modifications.
Glutamine synthetase (GS) is one of the most commonly used
selectable markers in the biopharmaceutical industry. Glutamine
is an essential amino acid for cellular growth. The GS enzyme
is responsible for the conversion of glutamate into glutamine.
Without this enzymatic activity, cells can no longer synthesize
glutamine endogenously and if glutamine is not supplemented
in the culture media, the cells will die. Cell lines producing
recombinant proteins can be selected for by linking the
expression of gene(s) coding for the recombinant protein(s) to
the expression of an exogenous GS gene. In GS deficient host
lines, only those cells that have been successfully transfected
with an exogenous GS gene will survive when the culture is
grown in the absence of glutamine. In host lines that have a
functional endogenous GS gene, MSX (Methionine
Sulphoximine) can be used to suppress the endogenous
GS activity and enable the use of GS selection in these lines.
However, for biopharmaceutical manufacturing, an MSX-free
process is advantageous. To accomplish this using GS
selection, a GS knock-out host cell line is required. Leveraging
the ZFN technology, SAFC has engineered a novel CHO K1
GS-/- cell line. SAFC’s CHOZN GS-/- cell line has been developed
for use in MSX-free GS selection processes for the development
of recombinant cell lines. This CHOZN GS-/- cell line is adapted
to chemically-defined, suspension growth in EX-CELL® CD CHO
Fusion media (SAFC catalog number 14365C) and maintains
the robust characteristics of wild type CHO K1.

Supplier来源:BioVector NTCC Inc.
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