biostudies-literatureMillan AJParker Institute for Cancer ImmunotherapyVirtual CellNIAID NIH HHSNational Institutes of HealthNational Institute for General Medical SciencesNIH HHSNIGMS NIH HHS384-398https://www.ebi.ac.uk/biostudies/studies/S-EPMC11952873biostudies-literatureUnknown214(3)Natural killer (NK) cells express activating receptors that signal through ITAM (immunoreceptor tyrosine-based activation motif)-bearing adapter proteins. The phosphorylation of each ITAM creates binding sites for SYK and ZAP70 protein tyrosine kinases to propagate downstream signaling including the induction of Ca2+ influx. While all immature and mature human NK cells coexpress SYK and ZAP70, clonally driven memory or adaptive NK cells can methylate SYK genes, and signaling is mediated exclusively using ZAP70. Here, we examined the role of SYK and ZAP70 in a clonal human NK cell line KHYG1 by CRISPR-based deletion using a combination of experiments and mechanistic computational modeling. Elimination of SYK resulted in more robust Ca2+ influx after crosslinking of the CD16 and NKp30 receptJournal of immunology (Baltimore, Md. : 1950)SYK negatively regulates ITAM-mediated human NK cell signaling and CD19-CAR NK cell efficacy.PMC11952873R01AI146581R24 GM137787R01 AI146581T32 AI007334Lanier LLMillan AJDas JUreno GLibang JBAguilar OAAllain VRothrock AGShemesh ANayak IQuijada-Madrid LMArakawa-Hoyt JSEyquem JfalseSYK negatively regulates ITAM-mediated human NK cell signaling and CD19-CAR NK cell efficacy.Natural killer (NK) cells express activating receptors that signal through ITAM (immunoreceptor tyrosine-based activation motif)-bearing adapter proteins. The phosphorylation of each ITAM creates binding sites for SYK and ZAP70 protein tyrosine kinases to propagate downstream signaling including the induction of Ca2+ influx. While all immature and mature human NK cells coexpress SYK and ZAP70, clonally driven memory or adaptive NK cells can methylate SYK genes, and signaling is mediated exclusively using ZAP70. Here, we examined the role of SYK and ZAP70 in a clonal human NK cell line KHYG1 by CRISPR-based deletion using a combination of experiments and mechanistic computational modeling. Elimination of SYK resulted in more robust Ca2+ influx after crosslinking of the CD16 and NKp30 recept2025-01-01T00:00:00Z2025 Mar2026-07-16T23:24:40.688Z2026-07-12T03:11:18.063ZS-EPMC119528734007310310.1093/jimmun/vkaf012