Harnessing secretory pathway differences between HEK293 and CHO to rescue production of difficult to express proteins
Magdalena Malm, Chih‐Chung Kuo, Mona Moradi Barzadd, Aman Mebrahtu, Num Wistbacka, Ronia Razavi, Anna-Luisa Volk, Magnus Lundqvist, David Kotol, Hanna Tegel, Sophia Hober, Fredrik Edfors, Torbjörn Gräslund, Véronique Chotteau, Ray Field, Paul Varley, Robert Roth, Nathan E. Lewis, Diane Hatton, Johan Rockberg
Abstract
Biologics represent the fastest growing group of therapeutics, but many advanced recombinant protein moieties remain difficult to produce. Here, we identify metabolic engineering targets limiting expression of recombinant human proteins through a systems biology analysis of the transcriptomes of CHO and HEK293 during recombinant expression. In an expression comparison of 24 difficult to express proteins, one third of the challenging human proteins displayed improved secretion upon host cell swapping from CHO to HEK293. Guided by a comprehensive transcriptomics comparison between cell lines, especially highlighting differences in secretory pathway utilization, a co-expression screening of 21 secretory pathway components validated ATF4, SRP9, JUN, PDIA3 and HSPA8 as productivity boosters in CHO. Moreover, more heavily glycosylated products benefitted more from the elevated activities of the N- and O-glycosyltransferases found in HEK293. Collectively, our results demonstrate the utilization of HEK293 for expression rescue of human proteins and suggest a methodology for identification of secretory pathway components for metabolic engineering of HEK293 and CHO.