1. Interaction of plant-produced antibodies with neonatal Fc receptor
Szymon Stelter, Muriel Bardor and Julian Ma,
27/05/2016

2. Introduction Neonatal Fc Receptor provides long IgG serum half-life
FcRn in antibody-based therapy
extends therapeutic/protective effect
lower and less frequent dosing
reduced cost of antibody therapy
Roopenian et al. (2007) Nat Rev Immunol

3. Introduction Structural interaction of IgG with FcRn
FcRn – lgG binding is independent of human glycosylation;
Unusual glycoforms on recombinant antibodies might have an indirect impact on the binding
- Jefferis, R. (2009) Nat Rev Drug Discov,
Some plant-made antibodies are cleared out faster than the variants made in mammalian cells (Rosenberg 2015, Triguero 2011, Ko 2003)
Some have similar clearance rate
(Hiatt 2014, Rodriguez 2013, Lee 2013, Gasdanska 2012, Khoudi 1999)
Does plant glycosylation affect binding of IgG to FcRn?
No studies of plant-made IgG interacting with FcRn

4. Results Binding of different plant antibody glycovariants to FcRn
VRC01HEK original VRC01 from HEK cells
VRC01WT plant VRC01
VRC01ΔXF plant VRC01 without fucose and xylose
VRC01Gal VRC01 ΔXF extended with galactose
VRC01aglyco plant VRC01 without Fc glycan

5. Results Affinity of different plant antibody glycovariants to FcRn
VRC01HEK original VRC01 from HEK cells
VRC01WT plant VRC01
VRC01ΔXF plant VRC01 without fucose and xylose
VRC01Gal VRC01 ΔXF extended with galactose
VRC01aglyco plant VRC01 without Fc glycan

6. Discussion Antibody oxidation affects FcRn bindnig
Met252
Met428
we found that substituting a more hydrophobic residue Leu at Met428 position resulted in a mutant that has a stronger binding to FcRn
Met252 oxidation impairs FcRn binding more profoundly than Met428 oxidation
IgG Fc
Gaza-Bulseco (2008) J Chrom B
Gao, X., et al. (2015), J Pharm Sci,

7. Results Oxidation of plant-made VRC01 glycovariants
DTLM252ISR
in collaboration with Prof. Muriel Bardor, Université de Rouen, France

8. Results Oxidation of plant-made VRC01 glycovariants
Oxidation, not glycosylation, affects binding of plant-made antibodies to FcRn

9. ACKNOWLEDGEMENTS St George’s University of London, UK
Prof. Julian Ma Dr Rachel Allen Dr Matthew Paul
Glyco-Mev Laboratory, University of Rouen, France
Prof. Muriel Bardor
Prof. Patrice Lerouge
Jessica Vanier
University of Natural Resources and Life Sciences, Vienna Prof. Herta Steinkellner Dr Alexandra De Vitoria Castilho
Prof. Friedrich Altmann Daniel Marsch