TY - JOUR
T1 - TLR activation of tumor-associated macrophages from ovarian cancer patients triggers cytolytic activity of NK cells
AU - Bellora, Francesca
AU - Castriconi, Roberta
AU - Dondero, Alessandra
AU - Pessino, Anna
AU - Nencioni, Alessio
AU - Liggieri, Giovanni
AU - Moretta, Lorenzo
AU - Mantovani, Alberto
AU - Moretta, Alessandro
AU - Bottino, Cristina
PY - 2014
Y1 - 2014
N2 - We analyzed the functional outcome of the interaction between tumor-associated macrophages (TAMs) and natural killer (NK) cells. TAMs from ascites of ovarian cancer patients displayed an alternatively activated functional phenotype (M2) characterized by a remarkably high frequency and surface density of membrane-bound IL-18. Upon TLR engagement, TAMs acquired a classically activated functional phenotype (M1), released immunostimulatory cytokines (IL-12, soluble IL-18), and efficiently triggered the cytolytic activity of NK cells. TAMs also induced the release of IFN-γ from NK cells, which however was significantly lower compared with that induced by in vitro-polarized M2 cells. Most tumor-associated NK cells displayed a CD56bright, CD16neg or CD56bright, CD16dim phenotype, and very poor cytolytic activities, despite an increased expression of the activation marker CD69. They also showed downregulation of DNAM-1, 2B4, and NTB-A activating receptors, and an altered chemokine receptor repertoire. Importantly however, when appropriately stimulated, NK cells from the patients, including those cells isolated from ascites, efficiently killed autologous TAMs that expressed low, "nonprotective" levels of HLA class I molecules. Overall, our data show the existence of a complex tumor microenvironment in which poorly cytolytic/immature NK cells deal with immunosuppressive tumor-educated macrophages.
AB - We analyzed the functional outcome of the interaction between tumor-associated macrophages (TAMs) and natural killer (NK) cells. TAMs from ascites of ovarian cancer patients displayed an alternatively activated functional phenotype (M2) characterized by a remarkably high frequency and surface density of membrane-bound IL-18. Upon TLR engagement, TAMs acquired a classically activated functional phenotype (M1), released immunostimulatory cytokines (IL-12, soluble IL-18), and efficiently triggered the cytolytic activity of NK cells. TAMs also induced the release of IFN-γ from NK cells, which however was significantly lower compared with that induced by in vitro-polarized M2 cells. Most tumor-associated NK cells displayed a CD56bright, CD16neg or CD56bright, CD16dim phenotype, and very poor cytolytic activities, despite an increased expression of the activation marker CD69. They also showed downregulation of DNAM-1, 2B4, and NTB-A activating receptors, and an altered chemokine receptor repertoire. Importantly however, when appropriately stimulated, NK cells from the patients, including those cells isolated from ascites, efficiently killed autologous TAMs that expressed low, "nonprotective" levels of HLA class I molecules. Overall, our data show the existence of a complex tumor microenvironment in which poorly cytolytic/immature NK cells deal with immunosuppressive tumor-educated macrophages.
KW - Human
KW - Natural killer cells
KW - Ovarian cancer
KW - Tumor-associated macrophages
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U2 - 10.1002/eji.201344130
DO - 10.1002/eji.201344130
M3 - Article
C2 - 24510590
AN - SCOPUS:84901832190
VL - 44
SP - 1814
EP - 1822
JO - European Journal of Immunology
JF - European Journal of Immunology
SN - 0014-2980
IS - 6
ER -