In Vitro Activation of NK Cells From Regional Lymph Nodes of Melanoma Patients With IL-2 and IL-15
2012
Authors:
Vuletić, AnaJovanić, Irena
Nikolić, Srđan S
Tanić, Nikola
Konjević, Gordana
Contributors
Eggermont, Alexander M.M.Document Type:
Conference object (Published version)
Metadata
Show full item recordAbstract:
Introduction: NK cells are subpopulation of innate immunity system and play
an important role in antitumor immune defense. Since regional lymph nodes
(LN) s represent the first barrier to malignant cell invasion, the aim of this study
was to investigate in melanoma (MM) patients, the ability of two cytokines,
IL-2, currently used for MM treatment, and IL-15 which is under intensive
clinical investigation and is essential for NK cell maturation, to modulate NK
cell antitumor activity of scarcely investigated NK cells from regional LNs.
Material and Method: Mononuclear cells were purified from 50 regional LNs
of MM patients and cultured for 72 h and 7 days in cell culture medium RPMI
1640 (CM) alone, CM with 200 IU/ml rhIL-2 and CM with 25 ng IL-15. NK cell
cytotoxicity was determined by standard 4h 51 Cr release assay, while perforine
(PRF) iRNA level was estimated by rt-PCR. Expression of several NK cell
receptors (Rc)s was analyzed after 7 day in vitro treatments on CD3− CD56+
NK cells by flow cytometry.
Results: Both cytokines induced significant in vitro enhancement of NK cell
cytotoxicity against K562 target tumor cell of tumor-infiltrated (LN+) and un-
infiltrated (LN−) LNs after 72 h of cultivation. Alongside with the induction of
NK cell cytotoxicity, the transcription of iRNA for cytotoxic mediator PRF was
significantly induced by each cytokine compared to control CM treatments.
After longer 7 day cultivation, the enhancement of NK cell cytotoxicity persisted
together with significant increase in expression of activating NKG2D and
cytotoxic CD16 Rcs, and CD69 early activation antigen on gated CD3− CD56+
NK cells from LN+ and LN−, induced by both cytokines. The analysis of
inhibitory KIR Rcs showed increase in CD158b KIR expression on NK cells
from LN+ and LN− by both cytokines. The expression of other investigated KIR
CD158a was induced by IL-15 only on NK cells from LN+. The comparison
of the cytokine induced NK cell cytotoxicity with respect to CM after 7 day in
vitro treatments, revealed the significantly lower increase in NK cell activity
obtained with IL-15 in LN+ compared to LN−, which is probably due to IL-15
induction of CD158a KIR that may act suppressive on NK cell cytotoxicity of
LN+.
Conclusion: IL-2 and IL-15 induce in vitro activation of NK cell from LNs
regardless the LN tumor infiltration probably by enhancing PRF transcription
and expression of NKG2D and CD16 activating Rcs on NK cells.
In:
- Eggermont AMM, editor. Proceedings Book: 22nd Biennial Congress of the European Association for Cancer Research; 2012 Jul 7-10; Barcelona, Spain. Oxford: Elsevier; 2012. p. S266. (European Journal of Cancer; Vol. 48; Suppl. 5).