Screening of transformed insect cell lines for recombinant protein production.
Nine insect cell lines were evaluated for their potential as host systems for recombinant protein production using a new expression vector permitting the continuous high-level expression of secreted glycoproteins by transformed insect cells (Farrell et al., 1998). As a means of preliminary screening, all nine insect cell lines were transfected with the green fluorescence protein. Growth in static and suspension culture was then examined as a further method of screening. On the basis of their transfection efficiencies and cell growth characteristics, five insect cell lines, Bm5, High Five, IPLB-LdFB, IZD-MB-0503, and Sf-21, were selected for stable transformation to produce granulocyte-macrophage colony-stimulating factor (GM-CSF). These five cell lines were stably transformed using an antibiotic resistance scheme and evaluated as a polyclonal population. Increasing the antibiotic concentration was found to cause not only a decrease in the specific growth rate but also an increase in the specific protein production rate and final GM-CSF concentration. The transformed High Five cells exhibited by far the greatest specific protein production rate of 5.1 x 10(-)(6) microgram/(cell.h), resulting in the highest final GM-CSF concentration of 22.8 mg/L when grown in static culture. One cloned High Five cell line produced a GM-CSF concentration of 46 mg/L in static culture and 27 mg/L in suspension culture.
Keith
M B
MB
Department of Chemical Engineering, The University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
Farrell
P J
PJ
Iatrou
K
K
Behie
L A
LA
D000818:Animals; D001709:Biotechnology / Q000379:methods; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division; D002460:Cell Line; D002461:Cell Line, Transformed; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis* / Q000235:genetics; D049452:Green Fluorescent Proteins; D007313:Insecta; D008164:Luminescent Proteins / Q000096:biosynthesis* / Q000235:genetics; D010957:Plasmids; D011994:Recombinant Proteins / Q000096:biosynthesis*; D014162:Transfection / Q000379:methods*
D008164:Luminescent Proteins; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D016178:Granulocyte-Macrophage Colony-Stimulating Factor