Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.

Fc fusion proteins, formed by fusing an active protein to the Fc region of immunoglobulin G, are a validated strategy for extending the half-life of therapeutic proteins. Human growth hormone (hGH) Fc fusion proteins exhibit longer circulation half-lives than hGH, reducing injection frequency and im...

Full description

Saved in:
Bibliographic Details
Main Authors: Taekyeol Lee, Dongsop Lee, Eunee Jung, Mikyung Son, Kyohwan Koo, Jaehoon Choi
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0323791
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850128305168056320
author Taekyeol Lee
Dongsop Lee
Eunee Jung
Mikyung Son
Kyohwan Koo
Jaehoon Choi
author_facet Taekyeol Lee
Dongsop Lee
Eunee Jung
Mikyung Son
Kyohwan Koo
Jaehoon Choi
author_sort Taekyeol Lee
collection DOAJ
description Fc fusion proteins, formed by fusing an active protein to the Fc region of immunoglobulin G, are a validated strategy for extending the half-life of therapeutic proteins. Human growth hormone (hGH) Fc fusion proteins exhibit longer circulation half-lives than hGH, reducing injection frequency and improving convenience for hGH replacement therapy. Most approved Fc fusion proteins involve directly attaching the active protein to the hinge region of IgG Fc; however, few reports have described the effects of structural variations on these characteristics in detail. We analyzed pharmacokinetic and pharmacodynamic properties of various hGH-Fc fusion constructs differing in linker type, hGH valency, and fusion position to investigate the structure-function relationships of these proteins in cell-based assays and animal models, including normal and hypophysectomized rats. Monovalent hGH-Fc fusion variants and those with hGH fused to the C-terminal of IgG Fc exhibited higher in vitro and in vivo activity than bivalent hGH-Fc. However, these variants also exhibited accelerated clearance in rat pharmacokinetic experiments. The linker connecting the hGH moiety to the Fc domain significantly influenced in vitro activity and pharmacokinetics. Constructs with a rigid alpha-helical A(EAAAK)5A linker showed greater in vitro activity than those with a flexible (GGGGS)3 linker but exhibited accelerated clearance in rats. To a lesser extent, linker length influenced activity and pharmacokinetics. Bivalent hGH-Fc constructs with shorter linkers (0-1 GGGGS repeats) exhibited higher in vivo exposure (AUC) but lower in vitro activity than those with longer linkers (2-3 repeats). In vitro activity did not correlate linearly with linker length, as constructs with no linker (n = 0) showed reduced activity, while no consistent trend was observed for n = 1-3. These findings provide valuable insights into the design of hGH-Fc fusion proteins, offering a framework for systematically improving their potency and longevity and supporting the development of long-acting hGH therapies.
format Article
id doaj-art-a51497d9b1cb4e749969a3ac4e356212
institution OA Journals
issn 1932-6203
language English
publishDate 2025-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS ONE
spelling doaj-art-a51497d9b1cb4e749969a3ac4e3562122025-08-20T02:33:23ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01205e032379110.1371/journal.pone.0323791Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.Taekyeol LeeDongsop LeeEunee JungMikyung SonKyohwan KooJaehoon ChoiFc fusion proteins, formed by fusing an active protein to the Fc region of immunoglobulin G, are a validated strategy for extending the half-life of therapeutic proteins. Human growth hormone (hGH) Fc fusion proteins exhibit longer circulation half-lives than hGH, reducing injection frequency and improving convenience for hGH replacement therapy. Most approved Fc fusion proteins involve directly attaching the active protein to the hinge region of IgG Fc; however, few reports have described the effects of structural variations on these characteristics in detail. We analyzed pharmacokinetic and pharmacodynamic properties of various hGH-Fc fusion constructs differing in linker type, hGH valency, and fusion position to investigate the structure-function relationships of these proteins in cell-based assays and animal models, including normal and hypophysectomized rats. Monovalent hGH-Fc fusion variants and those with hGH fused to the C-terminal of IgG Fc exhibited higher in vitro and in vivo activity than bivalent hGH-Fc. However, these variants also exhibited accelerated clearance in rat pharmacokinetic experiments. The linker connecting the hGH moiety to the Fc domain significantly influenced in vitro activity and pharmacokinetics. Constructs with a rigid alpha-helical A(EAAAK)5A linker showed greater in vitro activity than those with a flexible (GGGGS)3 linker but exhibited accelerated clearance in rats. To a lesser extent, linker length influenced activity and pharmacokinetics. Bivalent hGH-Fc constructs with shorter linkers (0-1 GGGGS repeats) exhibited higher in vivo exposure (AUC) but lower in vitro activity than those with longer linkers (2-3 repeats). In vitro activity did not correlate linearly with linker length, as constructs with no linker (n = 0) showed reduced activity, while no consistent trend was observed for n = 1-3. These findings provide valuable insights into the design of hGH-Fc fusion proteins, offering a framework for systematically improving their potency and longevity and supporting the development of long-acting hGH therapies.https://doi.org/10.1371/journal.pone.0323791
spellingShingle Taekyeol Lee
Dongsop Lee
Eunee Jung
Mikyung Son
Kyohwan Koo
Jaehoon Choi
Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
PLoS ONE
title Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
title_full Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
title_fullStr Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
title_full_unstemmed Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
title_short Engineering of long-acting human growth hormone-Fc fusion proteins: Effects of valency, fusion position, and linker design on pharmacokinetics and efficacy.
title_sort engineering of long acting human growth hormone fc fusion proteins effects of valency fusion position and linker design on pharmacokinetics and efficacy
url https://doi.org/10.1371/journal.pone.0323791
work_keys_str_mv AT taekyeollee engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy
AT dongsoplee engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy
AT euneejung engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy
AT mikyungson engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy
AT kyohwankoo engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy
AT jaehoonchoi engineeringoflongactinghumangrowthhormonefcfusionproteinseffectsofvalencyfusionpositionandlinkerdesignonpharmacokineticsandefficacy