Enhanced sialylation of a human chimeric IgG1 variant produced in human and rodent cell lines

Research output: Contribution to journalArticle


  • Ronan M. Kelly
  • Louise Unwin
  • Simone Albrecht
  • Margaret Goodall
  • Yoichi Mizukami
  • Yuka Mimura-kimura
  • Tsuneo Matsumoto
  • Hiroshi Ueoka
  • Pauline M. Rudd

Colleges, School and Institutes

External organisations

  • NIBRT GlycoScience Group, National Institute for Bioprocessing Research and Training, Mount Merrion, Blackrock, Dublin 4, Ireland
  • Department of Clinical Research, NHO Yamaguchi-Ube Medical Center, 685 Higashi-Kiwa, Ube 755-0241, Japan
  • Center for Gene Research, Yamaguchi University, 1-1-1 Minami-Kogushi, Ube 755-8505, Japan
  • School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, UK


Glycosylation of the IgG-Fc is essential for optimal binding and activation of Fcγ receptors and the C1q component of complement. However, it has been reported that the effector functions are down-regulated when the Fc glycans terminate in sialic acid residues and that sialylated IgG mediates anti-inflammatory effects of intravenous immunoglobulin (IVIG). Although recombinant IgG is hypo-sialylated, Fc sialylation is shown to be markedly increased when a mouse/human chimeric IgG3 Phe243Ala (F243A) variant is expressed in Chinese hamster ovary (CHO)-K1 cells. Here we investigate whether sialylation is increased in IgG1 F243A when expressed in CHO-K1, mouse myeloma J558L and human embryonic kidney (HEK) 293. Although the sialylation level was 2–5% for IgG1 wild type (WT), it was increased to 31%, 10% and 33% for the variant from CHO-K1, J558L and HEK293 cells, respectively. Interestingly, an increased addition of bisecting GlcNAc and α(1-3)-galactose residues to the Fc glycan was observed for HEK293-derived and J558L-derived IgG1 F243A, respectively. Fucosylation of HEK293-derived IgG1 F243A was maintained despite increased bisecting GlcNAc content. Although sialic acid and bisecting GlcNAc residues are reported to have an opposing effect on antibody-dependent cellular cytotoxicity (ADCC), IgG1 F243A showed 7 times lower ADCC activities than IgG1 WT, irrespective of bisecting GlcNAc residue. Thus, highly sialylated, human cell-derived IgG1 F243A with lowered ADCC activity may be of interest for the development of therapeutic antibodies with anti-inflammatory properties as an alternative to IVIG.


Original languageEnglish
Pages (from-to)30-36
JournalJournal of Immunological Methods
Early online date26 Nov 2015
Publication statusPublished - Jan 2016


  • Glycosylation, IgG, Intravenous immunoglobulin, Sialic acid, Therapeutic antibody