title: Up-regulation of phospholipase Cgamma1 and phospholipase D during the differentiation of human monocytes to dendritic cells.
abstract: Phospholipase C (PLC)gamma and phospholipase D (PLD) play pivotal roles in the signal transduction required for various cellular responses, including cell proliferation and differentiation. Dendritic cells (DCs), which are professional antigen-presenting cells, can be generated from human monocytes by stimulating the cells with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 4 (IL-4). We investigated whether PLCgamma and PLD expression levels can be changed during the differentiation of the human monocytes into DCs. The enzymatic activity and protein level of PLC gamma1 were significantly increased in the human monocyte-derived DCs by GM-CSF/IL-4, but the protein levels of PLC gamma2 were unaltered. Moreover, the enzymatic activity and protein level of PLD1b and PLD2 were up-regulated during the differentiation of human monocytes to DCs, but those of PLD1a were not changed. A higher phagocytic activity of DCs was found to be correlated with the up-regulations of PLCgamma1 and PLD, and the phagocytic activity of DCs was inhibited by a PLC-specific inhibitor (U73122) and by a phosphatidic acid acceptor (n-butanol), but to be increased by phosphatidic acid. Thus, suggesting that PLC and PLD participate in the process. This study suggests that the up-regulations of PLCgamma1 and PLD are accompanied by the differentiation of monocytes into DCs, which results in increased phagocytic activity.
authors.affiliation: Medical Research Center for Cancer Molecular Therapy, Dong-A University, Busan 602-714, South Korea.
authors.forename: Hyun Kyu
authors.initials: HK
authors.lastname: Kang
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Lee
authors.forename: Youl-Nam
authors.initials: YN
authors.lastname: Lee
authors.forename: Eun Jin
authors.initials: EJ
authors.lastname: Jo
authors.forename: Jung Im
authors.initials: JI
authors.lastname: Kim
authors.forename: Gi-Young
authors.initials: GY
authors.lastname: Kim
authors.forename: Yeong Min
authors.initials: YM
authors.lastname: Park
authors.forename: Do Sik
authors.initials: DS
authors.lastname: Min
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yano
authors.forename: Jong-Young
authors.initials: JY
authors.lastname: Kwak
authors.forename: Yoe-Sik
authors.initials: YS
authors.lastname: Bae
mesh_terms: D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects* / Q000201:enzymology; D020404:Glycerophospholipids / Q000096:biosynthesis; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology; D009000:Monocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010587:Phagocytosis / Q000187:drug effects; D051966:Phospholipase C gamma; D010739:Phospholipase D / Q000096:biosynthesis* / Q000276:immunology; D015398:Signal Transduction; D010738:Type C Phospholipases / Q000096:biosynthesis* / Q000276:immunology; D015854:Up-Regulation
chemical_list: D020404:Glycerophospholipids; C068564:phosphatidylbutanol; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D010739:Phospholipase D