An extraordinarily high level of IL-15 expression by a cell line transduced with a modified BMGneo vector displays hypoxic upregulation.
Interleukin (IL)-15 expression level is tightly controlled in mammalian cells by various mechanisms. In order to achieve higher expression levels of IL-15, many attempts have been made, but the highest expression rate among those reported is still only 13.3 ng/106 cells/24 h. Here we report that a selected human embryonic kidney 293 (HEK293) cell line, denoted 293HAN cells, which can survive and proliferate under conditions of hypoxia, acidity, and nutritional depletion (HAN), after transduction -- with a modified BMGneo vector -- can produce functional human IL-15 at the extremely high rate of 890 ng/106 cells/24 h under normoxic conditions -- a 67-fold increase. This is as a result of multiple episomally based vector copy numbers per cell. An extra benefit was that the BMGneo vector was found to be inducible in hypoxia and allowed a further approximately threefold upregulation of the human IL-15 level which made these 293HAN cells, transduced with the modified BMGneo vector, a very promising tool for high IL-15 production (approximately 200-fold increase above that of baseline normoxia). The mechanism of hypoxic upregulation was found to be related to the mouse MT-1 promoter present in the vector.
Huang
Xiang Q
XQ
Cancer Immunotherapy Department, Queensland Institute of Medical Research, Post Office Royal Brisbane Hospital, Qld 4029, Australia. Quan.Huang@qimr.edu.au
Hamilton
Michael J
MJ
Li
Chung L
CL
Schmidt
Chris
C
Ellem
Kay A
KA
D000818:Animals; D002417:Cattle; D015687:Cell Hypoxia / Q000502:physiology; D002460:Cell Line; D017077:Culture Media, Conditioned; D015870:Gene Expression; D005822:Genetic Vectors / Q000235:genetics*; D006801:Humans; D019409:Interleukin-15 / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic / Q000235:genetics; D014161:Transduction, Genetic / Q000379:methods*; D015854:Up-Regulation
D017077:Culture Media, Conditioned; D019409:Interleukin-15