Efficient mass production of purified recombinant porcine IL-2 with baculovirus/insect cell culture gene expression system

To develop an efficient mass production system of purified cytokines, we attempted to use a bioreactor and produced porcine interleukin-2 (poIL-2). The poIL-2 recombinant baculovirus infected insect cell line SF21AE was incubated in the bioreactor with 6 L of serum free medium for 72 hrs. This culture fluid contained 84 mg/L (purity: 65%) of recombinant poIL-2 (rpoIL-2). Three Litres of the fluid was filtered with 300kDa ultra-filter to remove virus particles etc. and concentrated by 10kDa ultra-filtration. The rpoIL-2 in the concentrate was precipitated between 65% and 90% saturation of ammonium sulfate. The precipitate was dissolved and dialyzed against PBS. Finally, 15.5 ml of the rpoIL-2 containing fraction (5.4 mg/ml, total: 84 mg, recovery: 33%) was prepared. Purity was 94.2%.