title: The CD40-CD40L axis and IFN-γ play critical roles in Langhans giant cell formation.
abstract: The presence of Langhans giant cells (LGCs) is one of the signatures of systemic granulomatous disorders such as tuberculosis and sarcoidosis. However, the pathophysiological mechanism leading to LGC formation, especially the contribution of the T cells abundantly found in granulomas, has not been fully elucidated. To examine the role of T cells in LGC formation, a new in vitro method for the induction of LGCs was developed by co-culturing human monocytes with autologous T cells in the presence of concanavalin A (ConA). This system required close contact between monocytes and T cells, and CD4+ T cells were more potent than CD8+ T cells in inducing LGC formation. Antibody inhibition revealed that a CD40-CD40 ligand (CD40L) interaction and IFN-γ were essential for LGC formation, and the combination of exogenous soluble CD40L (sCD40L) and IFN-γ efficiently replaced the role of T cells. Dendritic cell-specific transmembrane protein (DC-STAMP), a known fusion-related molecule in monocytes, was up-regulated during LGC formation. Moreover, knock-down of DC-STAMP by siRNA inhibited LGC formation, revealing that DC-STAMP was directly involved in LGC formation. Taken together, these results demonstrate that T cells played a pivotal role in a new in vitro LGC formation system, in which DC-STAMP was involved, and occurred via a molecular mechanism that involved CD40-CD40L interaction and IFN-γ secretion.
authors: Department of Pediatrics, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku Kyoto 606-8507, Japan.
authors: Hidemasa
authors: H
authors: Sakai
authors: Ikuo
authors: I
authors: Okafuji
authors: Ryuta
authors: R
authors: Nishikomori
authors: Junya
authors: J
authors: Abe
authors: Kazushi
authors: K
authors: Izawa
authors: Naotomo
authors: N
authors: Kambe
authors: Takahiro
authors: T
authors: Yasumi
authors: Tatsutoshi
authors: T
authors: Nakahata
authors: Toshio
authors: T
authors: Heike
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D019013:CD40 Antigens / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D023201:CD40 Ligand / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D018920:Coculture Techniques; D003208:Concanavalin A / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015744:Giant Cells, Langhans / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D018664:Interleukin-12 / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D034622:RNA Interference; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019013:CD40 Antigens; C501589:DCSTAMP protein, human; D004791:Enzyme Inhibitors; D008565:Membrane Proteins; D011994:Recombinant Proteins; D003208:Concanavalin A; D023201:CD40 Ligand; D018664:Interleukin-12; D007371:Interferon-gamma; D020928:Mitogen-Activated Protein Kinases