title: Lipopolysaccharide preferentially induces 4-1BB ligand expression on human monocyte-derived dendritic cells.
abstract: Dendritic cells (DCs) represent a promising tool for immunotherapy. A key feature in their action is to provide co-stimulatory signals for full activation of T cells. In view of recent studies demonstrating the critical role of 4-1BB co-stimulation in T cell response, it is of importance to optimize 4-1BB ligand (4-1BBL) expression on human monocyte-derived DCs (MDDCs), the DC source of many clinical studies. In this study, two types of MDDCs, generated in granulocyte-macrophage colony-stimulating factor and interleukin-4 (GM-CSF/IL-4-DCs) or in interferon-beta and IL-3 (IFN-beta/IL-3-DCs), were analyzed for 4-1BBL expression in response to several known DC activators. Immature MDDCs expressed 4-1BBLs at very low levels. Lipopolysaccharide (LPS) was the only activator that preferentially triggered 4-1BBL expression on either MDDCs, but 4-1BBL-positive cells were significantly more frequently observed on LPS-activated GM-CSF/IL-4-DCs (30.2+/-2.6% versus 14.3+/-1.2%). Combinations of multiple activating signals did not bring about enhanced 4-1BBL stimulatory capacity. In addition, plasmid DNA transfection and necrotic cell pulsing of GM-CSF/IL-4-DCs for antigen loading also resulted in 4-1BBL up-regulation. However, in all circumstances, the induced 4-1BBL levels were low in comparison with CD80 co-stimulatory molecule. Finally, by demonstrating LPS-matured GM-CSF/IL-4-DCs from sorted 4-1BBL(high) population augmented T cell expansion and survival, we propose that efforts are required to increase 4-1BBL levels on MDDCs achieved by current activation schemes.
authors.affiliation: Department of Microbiology, Soochow University, Wai Shuang Hsi, Shih Lin, Taipei, 11102, Taiwan, ROC.
authors.forename: Pao-Kung
authors.initials: PK
authors.lastname: Lee
authors.forename: Chun-Jung
authors.initials: CJ
authors.lastname: Chang
authors.forename: Chun-Ming
authors.initials: CM
authors.lastname: Lin
mesh_terms: D053330:4-1BB Ligand; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism*; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D016899:Interferon-beta / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D053330:4-1BB Ligand; D008070:Lipopolysaccharides; C505974:TNFSF9 protein, human; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D016899:Interferon-beta; D016178:Granulocyte-Macrophage Colony-Stimulating Factor