title: Generation of a highly diverse panel of antagonistic chicken monoclonal antibodies against the GIP receptor.
abstract: Raising functional antibodies against G protein-coupled receptors (GPCRs) is challenging due to their low density expression, instability in the absence of the cell membrane's lipid bilayer and frequently short extracellular domains that can serve as antigens. In addition, a particular therapeutic concept may require an antibody to not just bind the receptor, but also act as a functional receptor agonist or antagonist. Antagonizing the glucose-dependent insulinotropic polypeptide (GIP) receptor may open up new therapeutic modalities in the treatment of diabetes and obesity. As such, a panel of monoclonal antagonistic antibodies would be a useful tool for in vitro and in vivo proof of concept studies. The receptor is highly conserved between rodents and humans, which has contributed to previous mouse and rat immunization campaigns generating very few usable antibodies. Switching the immunization host to chicken, which is phylogenetically distant from mammals, enabled the generation of a large and diverse panel of monoclonal antibodies containing 172 unique sequences. Three-quarters of all chicken-derived antibodies were functional antagonists, exhibited high-affinities to the receptor extracellular domain and sampled a broad epitope repertoire. For difficult targets, including GPCRs such as GIPR, chickens are emerging as valuable immunization hosts for therapeutic antibody discovery.
authors.affiliation: a Division Research , Immune Modulation & Biotherapeutics Discovery, Boehringer Ingelheim , Biberach/Riss , Germany.
authors.forename: Jennifer D
authors.initials: JD
authors.lastname: Könitzer
authors.affiliation: b Crystal Bioscience , Emeryville , CA , USA.
authors.forename: Shreya
authors.initials: S
authors.lastname: Pramanick
authors.affiliation: c Division Research , Immune Modulation & Biotherapeutics Discovery, Boehringer Ingelheim , Ridgefield , CT , USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Pan
authors.affiliation: d Novo Nordisk , Måløv , Denmark.
authors.forename: Robert
authors.initials: R
authors.lastname: Augustin
authors.affiliation: e Division Research Germany , Cardio-Metabolic Diseases Research, Boehringer Ingelheim , Biberach/Riss , Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bandholtz
authors.affiliation: b Crystal Bioscience , Emeryville , CA , USA.
authors.forename: William
authors.initials: W
authors.lastname: Harriman
authors.affiliation: b Crystal Bioscience , Emeryville , CA , USA.
authors.forename: Shelley
authors.initials: S
authors.lastname: Izquierdo
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000915:Antibody Affinity; D002645:Chickens; D006801:Humans; D051379:Mice; D051381:Rats; D011964:Receptors, Gastrointestinal Hormone / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D011964:Receptors, Gastrointestinal Hormone; C041086:gastric inhibitory polypeptide receptor
keywords: Antagonist; GIPR; GPCR; chicken-derived antibodies; therapeutic antibodies