Br. Lauwerys et al., Cytokine production and killer activity of NK/T-NK cells derived with IL-2, IL-15, or the combination of IL-12 and IL-18, J IMMUNOL, 165(4), 2000, pp. 1847-1853
NK cell populations were derived from murine splenocytes stimulated by IL-2
, IL-15, or the combination of IL-12 and IL-18, Whereas NK cells derived wi
th the latter cytokines consisted of an homogeneous population of NK cells
(DX5(+)CD3(-)), those derived with IL-2 or IL-15 belonged to two different
populations, namely NK cells (DX5(+)CD3(-)) and T-NK cells (DX5(+)CD3(+)).
Among NK cells, only those derived with IL-12/IL-18 produced detectable lev
els of cytokines, namely IFN-gamma, IL-10, and IL-13 (with the exception of
IL-13 production by NK cells derived with IL-2), As for T-NK cells, IL-2-s
timulated cells produced a wide range of cytokines, including IL-4, IL-5, I
L-9, IL-10, and IL-13, but no IFN-gamma, whereas IL-15-derived T-NK cells f
ailed to produce any cytokine, Switch-culture experiments indicated that T-
NK cells derived in IL-2 and further stimulated with IL-12/IL-18 produced I
FN-gamma and higher IL-13 levels. Next, we observed that NWT-NK cell popula
tions exerted distinct effects on Ig production by autologous splenocytes a
ccording to the cytokines with which they were derived. Thus, addition of N
K cells derived in IL-12/IL-18 inhibited Ig production and induced strong c
ytotoxicity against splenocytes, whereas addition of NK or T-NK cells grown
in IL-2 or IL-15 did not. Experiments performed in IFN-gamma R knockout mi
ce demonstrated that IFN-gamma was not involved in the killer activity of I
L-12/IL-18-derived NK cells. The hypothesis that their cytotoxic activity w
as related to the induction of target apoptosis was confirmed on murine A20
lymphoma cells. Experiments performed in MRL/lpr mice indicated that IL-12
/IL-18- derived NK cells displayed their distinct killer activity through a
Fas-independent pathway. Finally, perforin was much more expressed in IL-1
2/IL-18-derived NK cells as compared with IL-2- or IL-15-derived NK cells,
an observation that might explain their unique cytotoxicity.