Generation and comparative characterization of glycosylated and aglycosylated human IgG1 antibodies

Monoclonal antibodies (mAbs) are the fastest growing class of biopharmaceuticals reflecting their diverse applications in research and the clinic. The correct glycosylation of mAbs is required to elicit effector functions such as complement-dependent and antibody-dependent cell-mediated cytotoxicity, although these may be undesirable for the treatment of certain chronic diseases. To gain insight into the properties of glycan-deficient mAbs, we generated and characterized six different aglycosylated human IgG1 mAbs (carrying the N297A mutation) and compared them to their glycosylated counterparts. We found no differences in solubility or heterogeneity, and all mAbs the remained stable in stress tests at 4 and 37 °C. Surface plasmon resonance spectroscopy showed no differences in binding affinity, and the in vivo terminal serum half-life and plasma clearance were similar in rats. However, differential scanning calorimetry revealed that the aglycosylated mAbs contained a less stable CH2 domain and they were also significantly more susceptible to pH-induced aggregation. We conclude that aglycosylated mAbs are functionally equivalent to their glycosylated counterparts and could be particularly suitable for certain therapeutic applications, such as the treatment of chronic diseases.