STABLE TRANSDUCTION OF THE INTERLEUKIN-2 GENE INTO HUMAN NATURAL-KILLER-CELL LINES AND THEIR PHENOTYPIC AND FUNCTIONAL-CHARACTERIZATION IN-VITRO AND IN-VIVO
S. Nagashima et al., STABLE TRANSDUCTION OF THE INTERLEUKIN-2 GENE INTO HUMAN NATURAL-KILLER-CELL LINES AND THEIR PHENOTYPIC AND FUNCTIONAL-CHARACTERIZATION IN-VITRO AND IN-VIVO, Blood, 91(10), 1998, pp. 3850-3861
A variety of strategies have been attempted in the past to stably tran
sduce natural killer (MK) cells with cytokine or other cellular genes.
Here, we demonstrate the successful delivery of the interleukin-2 (IL
-2) gene into two human NK cell lines, IL-2-dependent NK-92 and IL-2-i
ndependent YT, by retroviral transduction, An MuLV-based retroviral ve
ctor expressing human IL-2 and neo(r) markers from a polycistronic mes
sage was constructed and transduced into a GRIP packaging cell line, B
y coincubation of NK cells with monolayers of GRIP cells or by using r
etrovirus-containing supernatants in a flow-through method, 10% to 20%
of NK cells were stably transduced. Upon selection in the presence of
increasing G418 concentrations, transduced NK cells were able to prol
iferate independently of IL-2 for more than 5 months and to secrete up
to 5.5 ng/10(6) cells/24 h of IL-2. IL-2 gene-transduced NK-92 cells
had an in vitro cytotoxicity against tumor targets that was significan
tly higher than that of parental cells and secreted interferon gamma (
IFN gamma) and tumor necrosis factor alpha (TNF alpha) in addition to
IL-2. Moreover, the in vivo antitumor activity of IL-2 gene-transduced
NK-92 cells against established 3-day liver metastases in mice was gr
eater than that of parental nontransduced NK cells. Stable expression
of the IL-2 transgene in NK cells improved their therapeutic potential
in tumor-bearing hosts. Thus, transduced NK cells secreted sufficient
quantities of bioactive IL-2 to proliferate in vitro and mediated the
antitumor effects both in vitro and in vivo in the absence of exogeno
us IL-2. These results suggest that genetic modification of NK cells e
x vivo could be useful for clinical cancer therapy in the future. (C)
1998 by The American Society of Hematology.