Production of Highly Sialylated Monoclonal Antibodies

The first monoclonal antibody (Mab), developed against kidney transplant rejection, was accepted by the FDA in 1986 [1]. Today, Mabs are leading the biotherapeutics market as 28 have been approved in Europe and the USA, and hundreds are in clinical trials [2-4]. Most of them are of IgG1 subtype, developed for cancer and immune disease treatments. Mabs clinical efficacy not only relies on specific target binding provided by their variable region, but also on their ability to trigger defense mechanisms such as antibody-dependent cellular cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC). These effector functions are mediated by the interaction between the antibody Fc fragment and the Fcγ-receptors expressed on immune cell surfaces or the molecules of the complement involved in ADCC and CDC respectively. In the last decade, these interactions were found to be highly dependent on on the presence and structure of the N-glycan linked to the Fc fragment [5, 6].