title: CD137 induces adhesion and cytokine production in human monocytic THP-1 cells.
abstract: CD137, which is expressed on activated T cells, plays a critical role in inflammatory responses. However, the exact role that CD137 plays in monocytes is not fully known. Here we studied the expression and function of CD137 in human monocytic THP-1 cells, which we found constitutively expresses CD137 at the mRNA and protein level. Cross-linking of CD137 increased the secretion of IL-8 and TNF-alpha, promoted the expression of CD54 and CD11b, and increased adhesion to extracellular matrix (ECM) proteins. In particular CD137-induced adhesion of THP-1 cells was inhibited by an inhibitor of mitogen-activated protein kinase kinase (MEK), but not by a p38 kinase inhibitor. Taken together, these results show that the adhesion and cytokine production of THP-1 cells induced by CD137 occur via activation of MEK, which results in the activation of ERK-1/2 signaling pathways. Therefore, this study suggests that CD137 induces an activating and migrating signal during inflammatory processes.
authors.affiliation: National Genome Research Institute, National Institute of Health, KCDC, 5 Nokbun-dong, Eunpyung-gu, Seoul 122-701, Korea.
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Choi
authors.forename: Hyeon-Woo
authors.initials: HW
authors.lastname: Lee
authors.forename: Gu-Seob
authors.initials: GS
authors.lastname: Roh
authors.forename: Hong-Hee
authors.initials: HH
authors.lastname: Kim
authors.forename: Kyubum
authors.initials: K
authors.lastname: Kwack
mesh_terms: D015703:Antigens, CD / Q000096:biosynthesis / Q000276:immunology*; D018845:CD11 Antigens / Q000096:biosynthesis; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000096:biosynthesis; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis*; D004789:Enzyme Activation; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007113:Immunity, Innate; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D011485:Protein Binding; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis / Q000276:immunology*; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis / Q000276:immunology*; D015398:Signal Transduction; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D015703:Antigens, CD; D018845:CD11 Antigens; D015815:Cell Adhesion Molecules; D016207:Cytokines; D016326:Extracellular Matrix Proteins; D016209:Interleukin-8; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C505714:TNFRSF9 protein, human; D053261:Tumor Necrosis Factor Receptor Superfamily, Member 9; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases