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1.
Metab Eng ; 79: 108-117, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37473833

RESUMO

Chinese hamster ovary (CHO) cells are used extensively to produce protein therapeutics, such as monoclonal antibodies (mAbs), in the biopharmaceutical industry. MAbs are large proteins that are energetically demanding to synthesize and secrete; therefore, high-producing CHO cell lines that are engineered for maximum metabolic efficiency are needed to meet increasing demands for mAb production. Previous studies have identified that high-producing cell lines possess a distinct metabolic phenotype when compared to low-producing cell lines. In particular, it was found that high mAb production is correlated to lactate consumption and elevated TCA cycle flux. We hypothesized that enhancing flux through the mitochondrial TCA cycle and oxidative phosphorylation would lead to increased mAb productivities and final titers. To test this hypothesis, we overexpressed peroxisome proliferator-activated receptor γ co-activator-1⍺ (PGC-1⍺), a gene that promotes mitochondrial metabolism, in an IgG-producing parental CHO cell line. Stable cell pools overexpressing PGC-1⍺ exhibited increased oxygen consumption, indicating increased mitochondrial metabolism, as well as increased mAb specific productivity compared to the parental line. We also performed 13C metabolic flux analysis (MFA) to quantify how PGC-1⍺ overexpression alters intracellular metabolic fluxes, revealing not only increased TCA cycle flux, but global upregulation of cellular metabolic activity. This study demonstrates the potential of rationally engineering the metabolism of industrial cell lines to improve overall mAb productivity and to increase the abundance of high-producing clones in stable cell pools.


Assuntos
Anticorpos Monoclonais , PPAR gama , Cricetinae , Animais , Cricetulus , Células CHO , PPAR gama/metabolismo , Anticorpos Monoclonais/genética , Estresse Oxidativo , Imunoglobulina G
2.
J Immunol ; 200(11): 3777-3789, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29686054

RESUMO

Monophosphoryl lipid A (MPLA) is a clinically used TLR4 agonist that has been found to drive nonspecific resistance to infection for up to 2 wk. However, the molecular mechanisms conferring protection are not well understood. In this study, we found that MPLA prompts resistance to infection, in part, by inducing a sustained and dynamic metabolic program in macrophages that supports improved pathogen clearance. Mice treated with MPLA had enhanced resistance to infection with Staphylococcus aureus and Candida albicans that was associated with augmented microbial clearance and organ protection. Tissue macrophages, which exhibited augmented phagocytosis and respiratory burst after MPLA treatment, were required for the beneficial effects of MPLA. Further analysis of the macrophage phenotype revealed that early TLR4-driven aerobic glycolysis was later coupled with mitochondrial biogenesis, enhanced malate shuttling, and increased mitochondrial ATP production. This metabolic program was initiated by overlapping and redundant contributions of MyD88- and TRIF-dependent signaling pathways as well as downstream mTOR activation. Blockade of mTOR signaling inhibited the development of the metabolic and functional macrophage phenotype and ablated MPLA-induced resistance to infection in vivo. Our findings reveal that MPLA drives macrophage metabolic reprogramming that evolves over a period of days to support a macrophage phenotype highly effective at mediating microbe clearance and that this results in nonspecific resistance to infection.


Assuntos
Macrófagos/metabolismo , Receptor 4 Toll-Like/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Candidíase/metabolismo , Glicólise/fisiologia , Lipídeo A/análogos & derivados , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais/fisiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo
3.
Metab Eng ; 43(Pt B): 218-225, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28122259

RESUMO

Industrial bioprocesses place high demands on the energy metabolism of host cells to meet biosynthetic requirements for maximal protein expression. Identifying metabolic phenotypes that promote high expression is therefore a major goal of the biotech industry. We conducted a series of 13C flux analysis studies to examine the metabolic response to IgG expression during early stationary phase of CHO cell cultures grown in 3L fed-batch bioreactors. We examined eight clones expressing four different IgGs and compared with three non-expressing host-cell controls. Some clones were genetically manipulated to be apoptosis-resistant by expressing Bcl-2Δ, which correlated with increased IgG production and elevated glucose metabolism. The metabolic phenotypes of the non-expressing, IgG-expressing, and Bcl-2Δ/IgG-expressing clones were fully segregated by hierarchical clustering analysis. Lactate consumption and citric acid cycle fluxes were most strongly associated with specific IgG productivity. These studies indicate that enhanced oxidative metabolism is a characteristic of high-producing CHO cell lines.


Assuntos
Anticorpos Monoclonais/biossíntese , Isótopos de Carbono/química , Ciclo do Ácido Cítrico , Expressão Gênica , Imunoglobulina G/biossíntese , Marcação por Isótopo , Animais , Anticorpos Monoclonais/genética , Células CHO , Cricetulus , Imunoglobulina G/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
4.
Biotechnol J ; 13(10): e1700518, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29405605

RESUMO

13 C metabolic flux analysis (MFA) provides a rigorous approach to quantify intracellular metabolism of industrial cell lines. In this study, 13 C MFA was used to characterize the metabolic response of Chinese hamster ovary (CHO) cells to a novel medium variant designed to reduce ammonia production. Ammonia inhibits growth and viability of CHO cell cultures, alters glycosylation of recombinant proteins, and enhances product degradation. Ammonia production was reduced by manipulating the amino acid composition of the culture medium; specifically, glutamine, glutamate, asparagine, aspartate, and serine levels were adjusted. Parallel 13 C flux analysis experiments determined that, while ammonia production decreased by roughly 40%, CHO cell metabolic phenotype, growth, viability, and monoclonal antibody (mAb) titer were not significantly altered by the changes in media composition. This study illustrates how 13 C flux analysis can be applied to assess the metabolic effects of media manipulations on mammalian cell cultures. The analysis revealed that adjusting the amino acid composition of CHO cell culture media can effectively reduce ammonia production while preserving fluxes throughout central carbon metabolism.


Assuntos
Aminoácidos/química , Amônia , Carbono , Meios de Cultura/química , Amônia/química , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Células CHO , Carbono/química , Cricetulus , Glicosilação , Análise do Fluxo Metabólico/métodos , Proteínas Recombinantes/química
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