Whole-cell biopanning with a synthetic phage display library of nanobodies enabled the recovery of follicle-stimulating hormone receptor inhibitors

• DOI: 10.1016/j.bbrc.2017.10.036
• Publication Date: 2017-10-12T14:39:33Z
• Authors: Ronan Crepin; Gianluca Veggiani; Selma Djender; Anne Beugnet; François Planeix; Christophe Pichon; Sandrine Moutel; Sebastian Amigorena; Franck Perez; Nicolae Ghinea; Ario de Marco
• Keywords: Male; 0301 basic medicine; Mice; 03 medical and health sciences; L Cells; FSHR; Protein Domains; Antibody Specificity; Peptide Library; pre-immune antibody library; Cyclic AMP; Animals; Humans; GPCR proteins; Single-Domain Antibodies; nanobodies; Recombinant Proteins; HEK293 Cells; Solubility; Receptors, FSH; Female; Immunization; panning; Follicle Stimulating Hormone; Signal Transduction

Antibodies are essential reagents that are increasingly used in diagnostics and therapy. Their specificity and capacity to recognize their native antigen are critical characteristics for their in vivo application. Follicle-stimulating hormone receptor is a GPCR protein regulating ovarian follicular maturation and spermatogenesis. Recently, its potentiality as a cancer biomarker has been demonstrated but no antibody suitable for in vivo tumor targeting and treatment has been characterized so far. In this paper we describe the first successful attempt to recover recombinant antibodies against the FSHR and that: i) are directly panned from a pre-immune library using whole cells expressing the target receptor at their surface; ii) show inhibitory activity towards the FSH-induced cAMP accumulation; iii) do not share the same epitope with the natural binder FSH; iv) can be produced inexpensively as mono- or bivalent functional molecules in the bacterial cytoplasm. We expect that the proposed biopanning strategy will be profitable to identify useful functional antibodies for further members of the GPCR class.