title: Enhancement of natural killer cell effector functions against selected lymphoma and leukemia cell lines by dasatinib.
abstract: As NK cell immunotherapy is still poorly successful, combinations with drugs enhancing NK cell activity are of major interest. NK large granular lymphocyte expansions associated with improved survival have been described under monotherapy with the Bcr-Abl/Src inhibitor dasatinib, which inhibits NK cell functions in vitro. As Src kinases play a major role in inhibitory and activating signaling pathways of NK cells, both outcomes appear plausible. To clarify these contradictory observations and potentially enable the use of dasatinib as adjuvant, we analyzed how clinically relevant doses promote NK cell effector functions. Polyclonal human NK cells were studied ex vivo. Functional outcomes assessed included conjugate formation, calcium flux, receptor regulation, cytokine production, degranulation, cytotoxicity, apoptosis induction and signal transduction. While dasatinib inhibits NK cell effector functions during functional assays, 24 hr pretreatment of NK cells followed by washout of dasatinib, led to dose-dependent enhancement of cytokine production, degranulation marker expression and cytotoxicity against selected lymphoma and leukemia cell lines. Mechanistically, this was neither due to an altered viability of NK cells nor increased NKG2D, LFA-1 or conjugate formation with target cells. Receptor proximal signaling events were inhibited. However, a slight time dependent enhancement of Vav phosphorylation was observed under certain circumstances. The shift in Vav phosphorylation level may be one major mechanism for NK cell activity enhancement induced by dasatinib. Our findings argue for a careful timing and dosing of dasatinib application during leukemia/lymphoma treatment to enhance NK cell immunotherapeutic efforts.
authors.affiliation: Immune Recovery Section, Comprehensive Cancer Center, Department of Internal Medicine II, University of Würzburg, Würzburg, Germany.
authors.forename: Nicole
authors.initials: N
authors.lastname: Hassold
authors.forename: Katharina
authors.initials: K
authors.lastname: Seystahl
authors.forename: Kristina
authors.initials: K
authors.lastname: Kempf
authors.forename: Doris
authors.initials: D
authors.lastname: Urlaub
authors.forename: Michael
authors.initials: M
authors.lastname: Zekl
authors.forename: Hermann
authors.initials: H
authors.lastname: Einsele
authors.forename: Carsten
authors.initials: C
authors.lastname: Watzl
authors.forename: Jörg
authors.initials: J
authors.lastname: Wischhusen
authors.forename: Ruth
authors.initials: R
authors.lastname: Seggewiss-Bernhardt
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D045744:Cell Line, Tumor; D016207:Cytokines / Q000096:biosynthesis; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D000069439:Dasatinib; D058851:GPI-Linked Proteins / Q000032:analysis; D053804:Granzymes / Q000096:biosynthesis; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects* / Q000276:immunology; D007938:Leukemia / Q000276:immunology* / Q000473:pathology; D008223:Lymphoma / Q000276:immunology* / Q000473:pathology; D052118:Lysosomal-Associated Membrane Protein 1 / Q000096:biosynthesis; D052119:Lysosomal-Associated Membrane Protein 2 / Q000096:biosynthesis; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000032:analysis; D009336:Necrosis; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D017452:Receptors, IgG / Q000032:analysis; D013844:Thiazoles / Q000494:pharmacology*; D000097625:HLA-E Antigens
chemical_list: D002118:Calcium; D016207:Cytokines; D000069439:Dasatinib; D058851:GPI-Linked Proteins; D053804:Granzymes; D015395:Histocompatibility Antigens Class I; D052118:Lysosomal-Associated Membrane Protein 1; D052119:Lysosomal-Associated Membrane Protein 2; D055655:NK Cell Lectin-Like Receptor Subfamily K; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D017452:Receptors, IgG; D013844:Thiazoles; D000097625:HLA-E Antigens; C428200:FCGR3B protein, human; C527085:KLRK1 protein, human