Fu Yan, Chen Yuying, Xie Zhepei, Huang Huimin, Tan Wen-Song, Cai Haibo
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, P. O. Box 309#, Shanghai, 200237, People's Republic of China.
Bioresour Bioprocess. 2022 Aug 26;9(1):87. doi: 10.1186/s40643-022-00578-4.
Robust ex vivo expansion of NK-92 cells is essential for clinical immunotherapy. The vitamin B group is critical for the expansion and function of immune cells. This study optimized a vitamin combination by response surface methodology based on an in-house designed chemically defined serum-free medium EM. The serum-free medium EM-V4 with an optimal vitamin combination favoured ex vivo expansion of NK-92 cells. The characteristics of glucose metabolism of NK-92 cells in EM-V4 and the relationships between cell expansion and metabolism were investigated. NK-92 cells in EM-V4 underwent metabolic reprogramming. An elevated ratio of glucose-6-phosphate dehydrogenase/phosphofructokinase (G6PDH/PFK) indicated that NK-92 cells shifted towards the pentose phosphate pathway (PPP). An increase in the ratio of pyruvate dehydrogenase/lactate dehydrogenase (PDH/LDH) suggested that the cells shifted towards the Krebs (TCA) cycle, i.e., from glycolysis to aerobic metabolism. The enhanced ratio of oxygen consumption rate/extracellular acidification rate (OCR/ECAR) indicated that NK-92 cells were more reliant on mitochondrial respiration than on glycolysis. This shift provided more intermediate metabolites and energy for biosynthesis. Thus, EM-V4 accelerated biomass accumulation and energy production to promote NK-92 cell expansion by regulating the metabolic distribution. Our results provide valuable insight for the large-scale ex vivo expansion of clinically available NK-92 cells.
NK-92细胞强大的体外扩增对临床免疫治疗至关重要。维生素B族对免疫细胞的扩增和功能至关重要。本研究基于内部设计的化学成分明确的无血清培养基EM，采用响应面法优化了维生素组合。具有最佳维生素组合的无血清培养基EM-V4有利于NK-92细胞的体外扩增。研究了EM-V4中NK-92细胞的葡萄糖代谢特征以及细胞扩增与代谢之间的关系。EM-V4中的NK-92细胞发生了代谢重编程。葡萄糖-6-磷酸脱氢酶/磷酸果糖激酶（G6PDH/PFK）比值升高表明NK-92细胞向磷酸戊糖途径（PPP）转变。丙酮酸脱氢酶/乳酸脱氢酶（PDH/LDH）比值增加表明细胞向三羧酸（TCA）循环转变，即从糖酵解转向有氧代谢。耗氧率/细胞外酸化率（OCR/ECAR）比值升高表明NK-92细胞比糖酵解更依赖线粒体呼吸。这种转变为生物合成提供了更多的中间代谢产物和能量。因此，EM-V4通过调节代谢分布加速生物量积累和能量产生，以促进NK-92细胞扩增。我们的结果为临床可用NK-92细胞的大规模体外扩增提供了有价值的见解。
