Murray K, Gull K, Dickson A J
Biochemistry Research Division, School of Biological Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom.
Biotechnol Bioeng. 1996 Feb 20;49(4):377-82. doi: 10.1002/(SICI)1097-0290(19960220)49:4<377::AID-BIT3>3.0.CO;2-M.
We have studied the effect of the pyruvate dehydrogenase (PDH) activator, dichloroacetate (DCA), on the growth, metabolism, and productivity of the PQXB (1/2) hybridoma cell line. In control batch cultures, cessation of growth and the onset of decline phase coincided with the time at which the media became exhausted of glutamine. Supplementation of the media with DCA (1 mM) extended the growth phase of this cell line by approximately 20 h without affecting its growth rate. This prolonged period of growth resulted in an increased maximum cell density (16%) and final antibody yield (55%). Repeat experiments showed these effects to be reproducible, with the increases in antibody yield being between 50 and 60%. DCA did not affect the specific rates of glucose utilization and lactate production. However, it decreased the specific glutamine consumption rate. This characteristic of DCA action appeared, at least in part, to provide an explanation for the extended growth phase exhibited by DCA-treated cultures, since it delayed the time at which the media became depleted of glutamine. The consumption and production kinetics for various nutrients and their metabolites in both control and DCA-treated cultures suggested that: (1) glutamine catabolism proceeded by a pathway involving conversion to glutamate by glutaminase followed by subsequent transamination by alanine aminotransferase, and (2) DCA decreased the specific glutamine consumption rate by directly or indirectly inhibiting the transamination. It is expected that the routine inclusion of DCA in media used for hybridoma cultivation will be valuable for enhancement of monoclonal antibody (Mab) yields on a laboratory scale. (c) 1996 John Wiley & Sons, Inc.
我们研究了丙酮酸脱氢酶(PDH)激活剂二氯乙酸(DCA)对PQXB(1/2)杂交瘤细胞系生长、代谢及生产力的影响。在对照分批培养中,生长停止和衰退期开始与培养基中谷氨酰胺耗尽的时间一致。向培养基中添加1 mM DCA可使该细胞系的生长阶段延长约20小时,且不影响其生长速率。这种延长的生长阶段导致最大细胞密度增加(16%),最终抗体产量提高(55%)。重复实验表明这些效应具有可重复性,抗体产量的增加在50%至60%之间。DCA不影响葡萄糖利用和乳酸产生的比速率。然而,它降低了谷氨酰胺的比消耗速率。DCA的这一作用特性似乎至少部分地解释了经DCA处理的培养物所表现出的延长生长阶段,因为它延迟了培养基中谷氨酰胺耗尽的时间。对照培养和经DCA处理的培养中各种营养物质及其代谢产物的消耗和产生动力学表明:(1)谷氨酰胺分解代谢通过一条途径进行,该途径包括谷氨酰胺酶将其转化为谷氨酸,随后由丙氨酸转氨酶进行转氨作用;(2)DCA通过直接或间接抑制转氨作用降低了谷氨酰胺的比消耗速率。预计在用于杂交瘤培养的培养基中常规加入DCA对于在实验室规模上提高单克隆抗体(Mab)产量将是有价值的。(c)1996约翰·威利父子公司