title: Internalizing cancer antibodies from phage libraries selected on tumor cells and yeast-displayed tumor antigens.
abstract: A number of approaches have been utilized to generate antibodies to cancer cell surface receptors that can be used as potential therapeutics. A number of these therapeutic approaches, including antibody-drug conjugates, immunotoxins, and targeted nucleic acid delivery, require antibodies that not only bind receptor but also undergo internalization into the cell upon binding. We previously reported on the ability to generate cancer cell binding and internalizing antibodies directly from human phage antibody libraries selected for internalization into cancer cell lines. While a number of useful antibodies have been generated using this approach, limitations include the inability to direct the selections to specific antigens and to identify the antigen bound by the antibodies. Here we show that these limitations can be overcome by using yeast-displayed antigens known to be associated with a cell type to select the phage antibody output after several rounds of selection on a mammalian cell line. We used this approach to generate several human phage antibodies to yeast-displayed EphA2 and CD44. The antibodies bound both yeast-displayed and mammalian cell surface antigens, and were endocytosed upon binding to mammalian cells. This approach is generalizable to many mammalian cell surface proteins, results in the generation of functional internalizing antibodies, and does not require antigen expression and purification for antibody generation.
authors.affiliation: Department of Anesthesia and Pharmaceutical Chemistry, University of California, San Francisco, Room 3C-38,San Francisco General Hospital, 1001 Potrero Avenue, San Francisco, CA 94110, USA.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.forename: Hao
authors.initials: H
authors.lastname: Zou
authors.forename: Shaoyi
authors.initials: S
authors.lastname: Zhang
authors.forename: James D
authors.initials: JD
authors.lastname: Marks
mesh_terms: D000912:Antibodies, Neoplasm / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004353:Drug Evaluation, Preclinical / Q000379:methods*; D004705:Endocytosis; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D036104:Receptor, EphA2 / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
chemical_list: D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; C497483:CD44 protein, human; D018960:Hyaluronan Receptors; D011994:Recombinant Proteins; D036104:Receptor, EphA2