title: Expression and characterization of human growth hormone-Fc fusion proteins for transcytosis induction.
abstract: The major obstacle for oral delivery of administered therapeutic proteins is malabsorption in the intestine. This malabsorption could be overcome by induction of neonatal FcRn [Fc (CH2 and CH3 domains of human IgG1 antibody) receptor]-mediated transcytosis in the intestine using recombinant fusion of CH2 and CH3 moieties of human IgG to a therapeutic protein. To this end we developed recombinant hGH (human growth hormone) fused to the N-terminus of Fc moieties [CH2-CH3 or h (hinge)-CH2-CH3] from human IgG1. These recombinant proteins secreted by the methylotrophic yeast Pichia pastoris functionally induced secretion of insulin-like growth factor 1 by HepG2 cells in the response to hGH moiety in the fusion proteins. In a transport study using polarized T84 cells, 3.7% of added dimeric hGH-h-Fc was transported in the apical-to-basolateral direction within 1 h by FcRn-mediated transcytosis of 1 cm(2) monolayers. However, transport of monomeric hGH-Fc (only 0.43%) was much less effective, yet its transport was 2.3 times higher than that of hGH. Finally, we concluded that, upon recombinant fusion, maintenance of dimeric structure of Fc moieties is crucial for the induction of FcRn-mediated transcytosis.
authors.affiliation: Laboratory of Animal Cell Biotechnology, Department of Animal Science and Technology, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-742, Korea.
authors.forename: Chang Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Jung Hee
authors.initials: JH
authors.lastname: Woo
authors.forename: Kwang Keun
authors.initials: KK
authors.lastname: Cho
authors.forename: Seung Ha
authors.initials: SH
authors.lastname: Kang
authors.forename: Sang Kee
authors.initials: SK
authors.lastname: Kang
authors.forename: Yun Jaie
authors.initials: YJ
authors.lastname: Choi
mesh_terms: D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D003001:Cloning, Molecular; D015870:Gene Expression; D019382:Human Growth Hormone / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000737:chemistry / Q000378:metabolism*; D010843:Pichia; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism*
chemical_list: D007141:Immunoglobulin Fc Fragments; D011993:Recombinant Fusion Proteins; D019382:Human Growth Hormone