title: Identification of antibody-interacting proteins that contribute to the production of recombinant antibody in mammalian cells.
abstract: Protein folding and assembly processes are essential for antibody secretion; however, the endogenous proteins involved in these processes remain largely unknown. Therefore, except for some well-known endoplasmic reticulum (ER) chaperones such as GRP78/Bip and protein disulfide isomerase, enhancement of recombinant antibody expression by co-expression of interacting proteins has been largely elusive. Here, in addition to known ER chaperones, we identified additional endogenous proteins that interact with recombinant antibody in mammalian cells by immunoprecipitation coupled with liquid chromatography-tandem mass spectrometry. Most of our identified proteins enhanced antibody production, and furthermore, some of their combinations resulted in greater enhancement. In particular, eukaryotic initiation factor 4A combined with other proteins had approximately fourfold higher effect on antibody production. Identified proteins that could improve antibody expression contain not only ER-resident proteins like GRP78/Bip but also non-ER-resident proteins. These results suggest that this method could be effective in the investigation of novel proteins that are involved in enhancing recombinant antibody production because immunoprecipitation coupled with mass spectroscopy could identify proteins which directly interact with the antibody.
authors.affiliation: Biologics Research Laboratories, R&D Division, Daiichi Sankyo Co., Ltd., 1-16-13, Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan. nishimiya.daisuke.tc@daiichisankyo.co.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Nishimiya
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ogura
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Sakurai
authors.forename: Tohru
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000235:genetics; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D000091342:Endoplasmic Reticulum Chaperone BiP; D006801:Humans; D008969:Molecular Sequence Data; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000911:Antibodies, Monoclonal; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D011506:Proteins; D011994:Recombinant Proteins; C572208:TRA-8 monoclonal antibody