Effect of amino acid addition on cell growth of human hybrid F2N78 cells

초록

A human hybrid cell line named F2N78 was developed by somatic fusion of human embryonic kidney cells (HEK293) and Namalwa (Burkitt’s Lymphoma) cells. F2N78 cell line inherited advantageous phenotypes such as ease to suspension, high transfection efficacy, EBV genome insertion in chromosome, and human-specific glycosylation. For that reason, this cell line can be used for the production of human therapeutic antibody or vaccines. In order to be used in commercial processes, the formulation of the culture medium for F2N78 cell line has been investigated for optimal culture condition. Glucose and glutamine are the most commonly employed carbon and nitrogen sources and directly affect cell growth. However, their rapid depletion was found to cause the accumulation of lactate and ammonia during F2N78 cell culture. To support cell growth with the generation of minimal quantities of lactate and ammonium, amino acids were chosen as the alternatives for glucose and glutamine. Lysine, histidine, valine, cysteine, isoleucine, glycine were found to be critical amino acids for cell growth in previous studies. The objective of this study is to find the best ratio between the selected amino acids which mitigate the negative effects of byproducts and improve cell growth. The concentration range of selected amino acids was set 1-fold, 2-fold, 3-fold and the experiments were designed by using 2-level fractional factorial design. It was confirmed that cysteine and isoleucine were the most significant factors on specific growth rate and maximum viable cell density, and glycine showed the most negative results. Without additional nutrient feeding, maximum viable cell density with fortified amino acids was 1.2-fold higher than that of control cultures.