title: Selection of Antibodies Interfering with Cell Surface Receptor Signaling Using Embryonic Stem Cell Differentiation.
abstract: Antibodies able to bind and modify the function of cell surface signaling components in vivo are increasingly being used as therapeutic drugs. The identification of such "functional" antibodies from within large antibody pools is, therefore, the subject of intense research. Here we describe a novel cell-based expression and reporting system for the identification of functional antibodies from antigen-binding populations preselected with phage display. The system involves inducible expression of the antibody gene population from the Rosa-26 locus of embryonic stem (ES) cells, followed by secretion of the antibodies during ES cell differentiation. Target antigens are cell-surface signaling components (receptors or ligands) with a known effect on the direction of cell differentiation (FGFR1 mediating ES cell exit from self renewal in this particular protocol). Therefore, inhibition or activation of these components by functional antibodies in a few elite clones causes a shift in the differentiation outcomes of these clones, leading to their phenotypic selection. Functional antibody genes are then recovered from positive clones and used to produce the purified antibodies, which can be tested for their ability to affect cell fates exogenously. Identified functional antibody genes can be further introduced in different stem cell types. Inducible expression of functional antibodies has a temporally controlled protein-knockdown capability, which can be used to study the unknown role of the signaling pathway in different developmental contexts. Moreover, it provides a means for control of stem cell differentiation with potential in vivo applications.
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Rd, Cambridge, CB2 1QW, UK. amelidon@ebi.ac.uk.|European Molecular Biology Laboratory-European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SD, UK. amelidon@ebi.ac.uk.
authors.forename: Anna N
authors.initials: AN
authors.lastname: Melidoni
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Rd, Cambridge, CB2 1QW, UK.|IONTAS Ltd., Babraham Research Campus, Babraham, Cambridge, CB22 3AT, UK.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Dyson
authors.affiliation: Department of Biochemistry, University of Cambridge, Tennis Court Rd, Cambridge, CB2 1QW, UK.|IONTAS Ltd., Babraham Research Campus, Babraham, Cambridge, CB22 3AT, UK.
authors.forename: John
authors.initials: J
authors.lastname: McCafferty
mesh_terms: D000818:Animals; D000906:Antibodies / Q000235:genetics / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D003001:Cloning, Molecular / Q000379:methods; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D051379:Mice; D019151:Peptide Library; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection / Q000379:methods
chemical_list: D000906:Antibodies; D019151:Peptide Library; D011956:Receptors, Cell Surface
keywords: Cell surface receptor signaling; ES cell differentiation; FGF4; FGFR1; Functional antibody; Phage display; Phenotypic selection; Protein knockdown