Abstract
Chinese hamster ovary (CHO) cell is the predominant cell factory to
produce biopharmaceuticals such as immunoglobulin G (IgG), but in CHO
cells lactate accumulation and cell death compromise IgG production
while fucosylation mitigates the antibody-dependent cellular
cytotoxicity (ADCC) of IgG. To tackle these problems, we harnessed a
burgeoning gene silencing system, CRISPR-Cas13d, to effectively suppress
the endogenous genes governing lactate production (LDHA), fucosylation
(GFT) and cell death (DDIT3), hence repressing lactate accumulation and
core fucosylation. We further exploited the Sleeping Beauty system to
integrate the CRISPR-Cas13d module co-targeting these 3 genes and
generated a CHO cell platform for IgG production. The new platform
exhibited simultaneous knockdown of LDHA, GFT and DDIT3, accumulated
less lactate, had prolonged longevity, produced more IgG with less
fucosylation and stronger ADCC efficacy. These data collectively warrant
the potentials of CRISPR-Cas13d for CHO cell engineering and improving
antibody production with regard to quantity and quality.