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Silkworm Thioredoxin Peroxidase Is Induced by External Temperature Stimulus and Viral Infection
Lee Kwang-Sik,Kim Seong-Ryul,Park Nam-Sook,Kim Ik-Soo,Kang Pil-Dong,Sohn Bong-Hee,Choi Kwang-Ho,Kang Seok-Woo,Je Yeon-Ho,Lee Sang-Mong,Sohn Hung-Dae,Jin Byung-Rae 한국응용곤충학회 2004 한국응용곤충학회 학술대회논문집 Vol.2004 No.1
Improving Culture Performance and Antibody Titer in CHO Cell Fed-batch Culture by Controlling pH
Sang Yeop LEE,Seungjib JEON,Mi Rae KIM,Hyejeong HEO,Byung Cheon LEE,Joon-Chul LEE 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
Mammalian cell culture is most common industrial process for the production of recombinant proteins. However, higher cell density and titer are still limited due to factors such as excessive metabolites production, nutrients limitation, and high osmolality. Lactate is the major product from glucose metabolism, and lactate accumulation has been demonstrated to inhibit growth rate and negatively affect antibody production in mammalian cells. To partly overcome this factor, we investigated a simple method using pH control in Chinese hamster ovary (CHO) cells. We performed CHO-DG44 fed-batch cultures under pH conditions (6.9 and 7.0) using rocking bioreactor. As a result, cells grown under low pH condition produced lactate approximately 70% lower than cells grown under high pH condition. We also found that peak viable cell density (PVCD) and final antibody titer were increased in fed-batch culture under low pH condition. Taken together, our results demonstrate that fed-batch culture under pH of 6.9 improves the PVCD and titer in CHO cell culture.Mammalian cell culture is most common industrial process for the production of recombinant proteins. However, higher cell density and titer are still limited due to factors such as excessive metabolites production, nutrients limitation, and high osmolality. Lactate is the major product from glucose metabolism, and lactate accumulation has been demonstrated to inhibit growth rate and negatively affect antibody production in mammalian cells. To partly overcome this factor, we investigated a simple method using pH control in Chinese hamster ovary (CHO) cells. We performed CHO-DG44 fed-batch cultures under pH conditions (6.9 and 7.0) using rocking bioreactor. As a result, cells grown under low pH condition produced lactate approximately 70% lower than cells grown under high pH condition. We also found that peak viable cell density (PVCD) and final antibody titer were increased in fed-batch culture under low pH condition. Taken together, our results demonstrate that fed-batch culture under pH of 6.9 improves the PVCD and titer in CHO cell culture.
Lee, Sang-Hoon,Park, Seok-Rae 한국조명·전기설비학회 2018 한국조명·전기설비학회 학술대회논문집 Vol. No.
<P>Interaction between pathogen-associated molecular patterns and pattern recognition receptors triggers innate and adaptive immune responses. Several studies have reported that toll-like receptors (TLRs) are involved in B cell proliferation, differentiation, and Ig class switch recombination (CSR). However, roles of TLRs in B cell activation and differentiation are not completely understood. In this study, we investigated the direct effect of stimulation of TLR1/2 agonist Pam3CSK4 on mouse B cell viability, proliferation, activation, Ig production, and Ig CSR <I>in vitro</I>. Treatment with 0.5 µg/ml of Pam3CSK4 only barely induced IgG1 production although it enhanced B cell viability. In addition, high-dosage Pam3CSK4 diminished IgG1 production in a dose-dependent manner, whereas the production of other Igs, cell viability, and proliferation increased. Pam3CSK4 additively increased TLR4 agonist lipopolysaccharide (LPS)-induced mouse B cell growth and activation. However, interestingly, Pam3CSK4 abrogated LPS-induced IgG1 production but enhanced LPS-induced IgG2a production. Further, Pam3CSK4 decreased LPS-induced germline γ1 transcripts (GLTγ1)/GLTε expression but increased GLTγ2a expression. On the other hand, Pam3CSK4 had no effect on LPS-induced plasma cell differentiation. Taken together, these results suggest that TLR1/2 agonist Pam3CSK4 acts as a potent mouse B cell mitogen in combination with TLR4 agonist LPS, but these 2 different TLR agonists play diverse roles in regulating the Ig CSR of each isotype, particularly IgG1/IgE and IgG2a.</P>