title: Comparison of antibody molecules produced from two cell lines with contrasting productivities and aggregate contents.
abstract: Cell culture processes that produce therapeutic antibodies with high productivity (titer) and low aggregate content reduce the risk of adverse effects and expense to patients. To elucidate the mechanism of aggregate formation, we compared trastuzumab samples produced from two contrasting cell lines: cell line A, which exhibits high titer and low aggregate content, and cell line B, which exhibits low titer and high aggregate content. Cell line B produced significantly fewer (approximately 1/3) antibodies compared with cell line A and contained higher (approximately 3-fold) percentages of aggregates. The aggregates of antibodies found in the protein A-purified samples of cell line B were associated mostly with noncovalent interactions. Cell line B exhibited a low content of monomers/dimers of light chains in the medium and within cells. Because light chains are essential for the correct folding of heavy chains and secretion of mature antibodies, the characteristics of cell line B may be attributed to low levels of light chain production. In addition, protein A-purified antibodies from cell line B (but not those from cell line A) contained fragments that are expected to expose the hydrophobic CH3 domain, which may serve as nuclei for aggregation.
authors.affiliation: Bio-process Research and Development Laboratories, Kyowa Hakko Kirin Co., Ltd., 100-1 Hagiwara-machi, Takasaki; Graduate School of Engineering, Gunma University, 1-5-1 Tenjin-cho, Kiryu 376-8515, Japan. yoichi.ishii@kyowa-kirin.co.jp
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ishii
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Imamoto
authors.forename: Rie
authors.initials: R
authors.lastname: Yamamoto
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tsukahara
authors.forename: Kaori
authors.initials: K
authors.lastname: Wakamatsu
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D007143:Immunoglobulin Heavy Chains / Q000737:chemistry; D007147:Immunoglobulin Light Chains / Q000737:chemistry; D008970:Molecular Weight; D000068878:Trastuzumab / Q000096:biosynthesis* / Q000737:chemistry*
chemical_list: D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D000068878:Trastuzumab