title: Autophagy and apoptosis of recombinant Chinese hamster ovary cells during fed-batch culture: effect of nutrient supplementation.
abstract: Upon nutrient depletion during recombinant Chinese hamster ovary (rCHO) cell batch culture, cells are subjected to apoptosis, type I programmed cell death (PCD), and autophagy which can be type II PCD or a cell survival mechanism. To investigate the effect of nutrient supplementation on the two PCDs and protein production in rCHO cells, an antibody-producing rCHO cell line was cultivated in batch and fed-batch modes. The feed medium containing glucose, amino acids, and vitamins was determined through flask culture tests and used in bioreactor cultures. In the bioreactor cultures, the nutrient feedings extended the culture longevity and enhanced antibody production. In addition, cells in the fed-batch culture showed delayed onset of both apoptosis and autophagy, compared with those in the batch culture. The inhibition of apoptosis was demonstrated by a decreased amount of cleaved caspase-7 protein and less fragmentation of chromosomal DNA. Concurrently, reduced LC3 conversion, from LC3-I to LC3-II, was observed in cells that received the feeds. Cultivation with pharmacological autophagy inducer (rapamycin) or inhibitor (bafilomycin A1) indicated that autophagy is necessary for the cells to survive under nutrient depletion. Taken together, the delayed and relieved cell death by nutrient supplementation could improve antibody production.
authors.affiliation: Department of Biological Sciences, Graduate School of Nanoscience & Technology (WCU), KAIST, 373-1 Kusong-Dong, Yusong-gu, Daejon 305-701, Korea.
authors.forename: Young Kue
authors.initials: YK
authors.lastname: Han
authors.forename: Tae Kwang
authors.initials: TK
authors.lastname: Ha
authors.forename: So Jeong
authors.initials: SJ
authors.lastname: Lee
authors.forename: Jae Seong
authors.initials: JS
authors.lastname: Lee
authors.forename: Gyun Min
authors.initials: GM
authors.lastname: Lee
mesh_terms: D000818:Animals; D000906:Antibodies / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D001343:Autophagy / Q000187:drug effects*; D019149:Bioreactors; D016466:CHO Cells / Q000166:cytology / Q000187:drug effects*; D053179:Caspase 7 / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D000906:Antibodies; D003470:Culture Media; D011994:Recombinant Proteins; D053179:Caspase 7