Fcγ receptors in autoimmunity and end-organ damage

Ernandez, Thomas; Okubo, Koshu; Saggu, Gurpanna; Mayadas, Tanya N.

doi:10.1016/b978-0-12-814551-7.00022-2

Cited by 1 publication

(1 citation statement)

References 192 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Intracellular signaling through the activating receptors triggers activities such as ADCC, ADCP, and inflammation via modulation of the secretion of cytokines (X. Wang et al, 2018). On the contrary, intracellular signaling through the inhibitory FcγRIIb activates Src‐family tyrosine kinases, which downmodulates activating signaling pathways (Ernandez et al, 2016; Tay et al, 2019; Q. Wang et al 2018; X. Wang et al, 2018). ADCC is an adaptive immune response, largely mediated by natural killer (NK) cells, but also by other effector cells such as polymorphonuclear leukocytes (PMNs), and macrophages (Igietseme et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

The interplay of protein engineering and glycoengineering to fine‐tune antibody glycosylation and its impact on effector functions

Wang

Zhang

et al. 2021

Biotech & Bioengineering

View full text Add to dashboard Cite

The N‐glycan pattern of an IgG antibody, attached at a conserved site within the fragment crystallizable (Fc) region, is a critical antibody quality attribute whose structural variability can also impact antibody function. For tailoring the Fc glycoprofile, glycoengineering in cell lines as well as Fc amino acid mutations have been applied. Multiple glycoengineered Chinese hamster ovary cell lines were generated, including defucosylated (FUT8KO), α‐2,6‐sialylated (ST6KI), and defucosylated α‐2,6‐sialylated (FUT8KOST6KI), expressing either a wild‐type anti‐CD20 IgG (WT) or phenylalanine to alanine (F241A) mutant. Matrix‐assisted laser desorption ionization‐time of flight mass spectrometry characterization of antibody N‐glycans revealed that the F241A mutation significantly increased galactosylation and sialylation content and glycan branching. Furthermore, overexpression of recombinant human α‐2,6‐sialyltransferase resulted in a predominance of α‐2,6‐sialylation rather than α‐2,3‐sialylation for both WT and heavily sialylated F241A antibody N‐glycans. Interestingly, knocking out α‐1,6‐fucosyltransferase (FUT8KO), which removed core fucose, lowered the content of N‐glycans with terminal Gal and increased levels of terminal GlcNAc and Man5 groups on WT antibody. Further complement‐dependent cytotoxicity (CDC) analysis revealed that, regardless of the production cells, WT antibody samples have higher cytotoxic CDC activity with more exposed Gal residues compared to their individual F241A mutants. However, the FUT8KO WT antibody, with a large fraction of bi‐GlcNAc structures (G0), displayed the lowest CDC activity of all WT antibody samples. Furthermore, for the F241A mutants, a higher CDC activity was observed for α‐2,6‐ compared to α‐2,3‐sialylation. Antibody‐dependent cellular cytotoxicity (ADCC) analysis revealed that the defucosylated WT and F241A mutants showed enhanced in vitro ADCC performance compared to their fucosylated counterparts, with the defucosylated WT antibodies displaying the highest overall ADCC activity, regardless of sialic acid substitution. Moreover, the FcγRIIIA receptor binding by antibodies did not always correspond directly with ADCC result. This study demonstrates that glycoengineering and protein engineering can both promote and inhibit antibody effector functions and represent practical approaches for varying glycan composition and functionalities during antibody development.

show abstract