Imatinib and nilotinib off-target effects on human NK cells, monocytes, and M2 macrophages

Francesca Bellora, Alessandra Dondero, Maria Valeria Corrias, Beatrice Casu, Stefano Regis, Fabio Caliendo, Alessandro Moretta, Mario Cazzola, Chiara Elena, Luciana Vinti, Franco Locatelli, Cristina Bottino, Roberta Castriconi

Research output: Contribution to journalArticlepeer-review


Tyrosine kinase inhibitors (TKIs) are used in the clinical management of hematological neoplasms. Moreover, in solid tumors such as stage 4 neuroblastomas (NB), imatinib showed benefits that might depend on both on-target and immunological off-target effects. We investigated the effects of imatinib and nilotinib on human NK cells, monocytes, and macrophages. High numbers of monocytes died upon exposure to TKI concentrations similar to those achieved in patients. Conversely,NKcells were highly resistant to the TKI cytotoxic effect, were properly activated by immunostimulatory cytokines, and degranulated in the presence of NB cells. In NB, neither drug reduced the expression of ligands for activating NK receptors or upregulated that of HLA class I, B7-H3, PD-L1, and PD-L2, molecules that might limit NK cell function. Interestingly, TKIs modulated the chemokine receptor repertoire of immune cells. Acting at the transcriptional level, they increased the surface expression of CXCR4, an effect observed also in NK cells and monocytes of patients receiving imatinib for chronic myeloid leukemia. Moreover, TKIs reduced the expression of CXCR3 (in NK cells) and CCR1 (in monocytes). Monocytes also decreased the expression of M-CSFR, and low numbers of cells underwent differentiation toward macrophages. M0 and M2 macrophages were highly resistant to TKIs and maintained their phenotypic and functional characteristics. Importantly, also in the presence of TKIs, the M2 immunosuppressive polarization was reverted by TLR engagement, and M1-oriented macrophages fully activated autologous NK cells. Our results contribute to better interpreting the offtarget efficacy of TKIs in tumors and to envisaging strategies aimed at facilitating antitumor immune responses.

Original languageEnglish
Pages (from-to)1516-1525
Number of pages10
JournalJournal of Immunology
Issue number4
Publication statusPublished - Aug 15 2017

ASJC Scopus subject areas

  • Immunology


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