title: NK cell function triggered by multiple activating receptors is negatively regulated by glycogen synthase kinase-3β.
abstract: Activation of NK cells is triggered by combined signals from multiple activating receptors that belong to different families. Several NK cell activating receptors have been identified, but their role in the regulation of effector functions is primarily understood in the context of their individual engagement. Therefore, little is known about the signaling pathways broadly implicated by the multiple NK cell activation cues. Here we provide evidence pointing to glycogen synthase kinase (GSK)-3β as a negative regulator of multiple NK cell activating signals. Using an activation model that combines NKG2D and 2B4 and tests different signaling molecules, we found that GSK-3 undergoes inhibitory phosphorylation at regulatory serine residues by the engagement of NKG2D and 2B4, either individually or in combination. The extent of such phosphorylation was closely correlated with the degree of NK cell activation. NK cell functions, such as cytokine production and cytotoxicity, were consistently enhanced by the knockdown of GSK-3β or its inhibition with different pharmacological inhibitors, whereas inhibition of the GSK-3α isoform had no effect. In addition, NK cell function was augmented by the overexpression of a catalytically inactive form of GSK-3β. Importantly, the regulation of NK cell function by GSK-3β was common to diverse activating receptors that signal through both ITAM and non-ITAM pathways. Thus, our results suggest that GSK-3β negatively regulates NK cell activation and that modulation of GSK-3β function could be used to enhance NK cell activation.
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Hyung-Joon
authors.initials: HJ
authors.lastname: Kwon
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Soon Jae
authors.initials: SJ
authors.lastname: Kwon
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Heejae
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Hye-Ran
authors.initials: HR
authors.lastname: Park
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Go-Eun
authors.initials: GE
authors.lastname: Choi
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea; Cellular Dysfunction Research Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Sang-Wook
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Department of Laboratory Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea.
authors.forename: Seog Woon
authors.initials: SW
authors.lastname: Kwon
authors.affiliation: Medical Research Center for Gene Regulation, Research Institute of Medical Sciences, Chonnam National University Medical School, Gwangju 501-746, South Korea.
authors.forename: Nacksung
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, South Korea; Department of Life Science, Ewha Womans University, Seoul 120-750, South Korea.
authors.forename: Soo Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, South Korea; Center for Food and Bioconvergence, Seoul National University, Seoul 151-921, South Korea.
authors.forename: Sangryeol
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea.
authors.forename: Sun Chang
authors.initials: SC
authors.lastname: Kim
authors.affiliation: Department of Biomedical Sciences, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea; Department of Microbiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea; Cellular Dysfunction Research Center, University of Ulsan College of Medicine, Asan Medical Center, Seoul 138-736, South Korea. Electronic address: hunkim@amc.seoul.kr.
authors.forename: Hun Sik
authors.initials: HS
authors.lastname: Kim
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism*; D008213:Lymphocyte Activation / Q000502:physiology*; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D000071176:Signaling Lymphocytic Activation Molecule Family
chemical_list: D015703:Antigens, CD; C084093:CD244 protein, human; C527085:KLRK1 protein, human; D055655:NK Cell Lectin-Like Receptor Subfamily K; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3
keywords: Activation; GSK-3; Natural killer cell; Receptor; Signaling