title: Interleukin-15 improves cytotoxicity of natural killer cells via up-regulating NKG2D and cytotoxic effector molecule expression as well as STAT1 and ERK1/2 phosphorylation.
abstract: NK cells are crucial components of the innate immune system, providing a first line of defense against infectious pathogens and tumors. IL-15 is the major physiologic growth factor responsible for NK cell differentiation, survival and cytolytic activity of mature NK cells. However, the exact regulatory mechanism of IL-15 on NK cell function is still unclear. In this study, we try to investigate the mechanism of IL-15 on NK cytolysis. Our results demonstrate that IL-15 treatment increased NKG2D transcripts and surface expression in NK cells. NKG2D or MICA blockade attenuated the up-regulation of IL-15 on NK cytolysis, demonstrating that the up-regulatory effect of IL-15 on NK cytolysis is at least partly dependent of the interaction of NKG2D and MICA. Furthermore, IL-15 augmented the expression of cytotoxic effector molecules (TRAIL and Perforin) and the phosphorylation of STAT1 and ERK1/2, which may also contribute the NK lysis. These results may have therapeutic implications when designing cytokine immunotherapy against cancer.
authors.affiliation: Institute of Immunopharmacology & Immunotherapy, School of Pharmaceutical Sciences, Shandong University, 44 Wenhua West Road, Jinan 250012, China. caizhangsd@yahoo.com.cn
authors.forename: Cai
authors.initials: C
authors.lastname: Zhang
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhang
authors.forename: Jiafeng
authors.initials: J
authors.lastname: Niu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Tian
mesh_terms: D000818:Animals; D002460:Cell Line; D018920:Coculture Techniques; D003602:Cytotoxicity, Immunologic; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000276:immunology; D019409:Interleukin-15 / Q000276:immunology*; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism*; D055655:NK Cell Lectin-Like Receptor Subfamily K; D010766:Phosphorylation; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D055607:Receptors, Natural Killer Cell; D050794:STAT1 Transcription Factor / Q000235:genetics / Q000378:metabolism*
chemical_list: D015395:Histocompatibility Antigens Class I; D019409:Interleukin-15; C527085:KLRK1 protein, human; C099187:MHC class I-related chain A; D055655:NK Cell Lectin-Like Receptor Subfamily K; D011971:Receptors, Immunologic; D055607:Receptors, Natural Killer Cell; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D007371:Interferon-gamma; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3