Fig. 4

Promoters containing RegCG increase the production levels of an anti human-CD20 antibody in CHO-K1 cells. CHO-K1 cells transfected with pRegCG/GRE/CMV-aCD20, pRegCG/CMV-aCD20 and pCMV-aCD20 vectors and cloned by limiting dilution were cultured for 35 days after removal of the selection antibiotic; supernatants were obtained and the volumetric production of antibodies was measured by ELISA. a Schematic representation of recombinant promoters cloned in biscistronic vectors to express a human anti-CD20 antibody. b Antibody concentration from 39 clones with three different promoters: CMV: 6.2 ng/mL, RegCG/CMV: 25.3 ng/mL and RegCG/GRE/CMV: 24.3 ng/mL (horizontal bar indicates standard error of the mean, (SEM)). Data were analyzed by the Kruskal-Wallis test (ANOVA), followed by the Dunn test. *** p < 0.001, **** p < 0.0001 (n = 39)