Butyrate increases production of human chimeric IgG in CHO-K1 cells whilstmaintaining function and glycoform profile

The influence of sodium butyrate on the production and glycosylation of rec ombinant mouse/human chimeric antibody by transfected CHO-KI cells was inve stigated. We selected cells expressing 'wild-type' antibody with a human Ig G3 heavy chain and a mutant of this molecule in which Phe 243 is replaced b y Ala. These proteins have previously been shown to exhibit very different glycoform profiles with the mutant IgG being comprised of glycoforms having a high galactose and sialic acid content. Cell culture with 0-5 mM butyrat e was shown to effect a 2-4-fold increase in antibody production whilst the induction of apoptosis was observed in a dose-dependent manner. The optima l butyrate concentration was observed to be 2 mM. The glycoform profile of each antibody produced in the presence of butyrate was analyzed by HPAEC-PA D and shown to be unchanged, relative to that produced in the absence of bu tyrate. Biological activity was evaluated by the ability of the antibodies to trigger superoxide generation, through Fc gamma RI, and shown to be inde pendent of production in the presence or absence of butyrate. A similar inc rease in production was observed for a high antibody-producing cell line wh en expanded in a hollow fibre bioreactor under low-serum conditions (1%). T hese results demonstrated that butyrate is of value for increasing the prod uctivity of CHO-KI for recombinant IgG and does not compromise either glyco sylation or biological activity. (C) 2001 Elsevier Science B.V. All rights reserved.