Kim Hyun Sung, Lee Gyun Min
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
J Microbiol Biotechnol. 2007 May;17(5):712-20.
To investigate clonal variations of recombinant Chinese hamster ovary (rCHO) clones in response to culture pH and temperature, serum-free suspension cultures of two antibody-producing CHO clones (clones A and B), which were isolated from the same parental clone by the limiting dilution method, were performed in a bioreactor at pH values in the range of 6.8-7.6, and two different temperatures, 33 degrees C and 37 degrees C. In regard to cell growth, clone A and clone B displayed similar responses to temperature, although their degree of response differed. In contrast, clones A and B displayed different responses to temperature in regard to antibody production. In the case of clone A, no significant increase in maximum antibody concentration was achieved by lowering the culture temperature. The maximum antibody concentration obtained at 33 degrees C (pH 7.4) and 37 degrees C (pH 7.0) were 82.0 +/- 2.6 and 73.2 +/- 4.1 microg/ml, respectively. On the other hand, in the case of clone B, an approximately 2.5-fold increase in maximum antibody concentration was achieved by lowering the culture temperature. The enhanced maximum antibody concentration of clone B at 33 degrees C (132.6 +/- 14.9 microg/ml at pH 7.2) was due to not only enhanced specific antibody productivity but also to prolonged culture longevity. At 33 degrees C, the culture longevity of clone A also improved, but not as much as that of clone B. Taken together, CHO clones derived from the same parental clone displayed quite different responses to culture temperature and pH with regards antibody production, suggesting that environmental parameters such as temperature and pH should be optimized for each CHO clone.
为研究重组中国仓鼠卵巢细胞(rCHO)克隆对培养pH值和温度的克隆变异,采用有限稀释法从同一亲本克隆中分离出的两个产生抗体的CHO克隆(克隆A和克隆B),在生物反应器中于pH值6.8 - 7.6范围内以及33℃和37℃这两个不同温度下进行无血清悬浮培养。关于细胞生长,克隆A和克隆B对温度表现出相似的反应,尽管它们的反应程度有所不同。相比之下,克隆A和克隆B在抗体产生方面对温度表现出不同的反应。对于克隆A,降低培养温度未使最大抗体浓度显著增加。在33℃(pH 7.4)和37℃(pH 7.0)下获得的最大抗体浓度分别为82.0±2.6和73.2±4.1μg/ml。另一方面,对于克隆B,通过降低培养温度使最大抗体浓度提高了约2.5倍。克隆B在33℃(pH 7.2时为132.6±14.9μg/ml)下最大抗体浓度的提高不仅归因于特异性抗体生产率的提高,还归因于培养寿命的延长。在33℃时,克隆A的培养寿命也有所改善,但不如克隆B改善得多。综上所述,源自同一亲本克隆的CHO克隆在抗体产生方面对培养温度和pH表现出截然不同的反应,这表明温度和pH等环境参数应针对每个CHO克隆进行优化。