title: Enhanced FcRn-dependent transepithelial delivery of IgG by Fc-engineering and polymerization.
abstract: Monoclonal IgG antibodies (Abs) are used extensively in the clinic to treat cancer and autoimmune diseases. In addition, therapeutic proteins are genetically fused to the constant Fc part of IgG. In both cases, the Fc secures a long serum half-life and favourable pharmacokinetics due to its pH-dependent interaction with the neonatal Fc receptor (FcRn). FcRn also mediates transport of intact IgG across polarized epithelial barriers, a pathway that is attractive for delivery of Fc-containing therapeutics. So far, no study has thoroughly compared side-by-side how IgG and different Fc-fusion formats are transported across human polarizing epithelial cells. Here, we used an in vitro cellular transport assay based on the human polarizing epithelial cell line (T84) in which both IgG1 and Fc-fusions were transported in an FcRn-dependent manner. Furthermore, we found that the efficacy of transport was dependent on the format. We demonstrate that transepithelial delivery could be enhanced by Fc-engineering for improved FcRn binding as well as by Fc-polymerization. In both cases, transport was driven by pH-dependent binding kinetics and the pH at the luminal side. Hence, efficient transcellular delivery of IgG-based drugs across human epithelial cells requires optimal pH-dependent FcRn binding that can be manipulated by avidity and Fc-engineering, factors that should inspire the design of future therapeutics targeted for transmucosal delivery.
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway.
authors.forename: Stian
authors.initials: S
authors.lastname: Foss
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway.
authors.forename: Algirdas
authors.initials: A
authors.lastname: Grevys
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway.
authors.forename: Kine Marita Knudsen
authors.initials: KMK
authors.lastname: Sand
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway.
authors.forename: Malin
authors.initials: M
authors.lastname: Bern
authors.affiliation: Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
authors.forename: Pat
authors.initials: P
authors.lastname: Blundell
authors.affiliation: Department of Bacteriology and Immunology, Norwegian Institute of Public Health, Oslo, Norway; Department of Chemical Pharmacy, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Terje E
authors.initials: TE
authors.lastname: Michaelsen
authors.affiliation: Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Pleass
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway.
authors.forename: Inger
authors.initials: I
authors.lastname: Sandlie
authors.affiliation: Centre for Immune Regulation (CIR), Department of Biosciences, University of Oslo, N-0316, Oslo, Norway; Department of Immunology and CIR, Oslo University Hospital, Rikshospitalet, University of Oslo, N-0372, Oslo, Norway. Electronic address: j.t.andersen@medisin.uio.no.
authors.forename: Jan Terje
authors.initials: JT
authors.lastname: Andersen
mesh_terms: D000911:Antibodies, Monoclonal / Q000378:metabolism; D045744:Cell Line, Tumor; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism*; D007074:Immunoglobulin G / Q000235:genetics / Q000378:metabolism*; D058105:Polymerization; D015202:Protein Engineering; D011961:Receptors, Fc / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015395:Histocompatibility Antigens Class I; D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins; C100688:Fc receptor, neonatal
keywords: Epithelial; Fc-fusion; FcRn; IgG; Mucosal barrier; Transcytosis; pH-dependent binding