title: IL-4 inhibits the LPS-induced expression of CD14 and monocyte-specific esterase mRNA in MONO-MAC-6 cells.
abstract: The human MONO-MAC-6 cell line expresses the monocyte-associated differentiation markers CD14 and monocyte-specific esterase (MSE) and can be stimulated by lipopolysaccharide (LPS) to produce high mRNA levels of monocyte-related cytokines. This similarity to human peripheral blood monocytes (PBMo) renders this cell line a promising model for studies of monocyte activation and differentiation. Interleukin-4 (IL-4) is known to act antagonistically to LPS during the activation process of PBMo, inhibiting the production of cytokines. Therefore, this study was designed to compare the effects of IL-4 and LPS on the expression of monocytic markers and tumor necrosis factor alpha (TNF alpha) mRNA on PBMo and the MONO-MAC-6 cell line. IL-4 inhibited the LPS-induced expression of TNF alpha mRNA in PBMo and downregulated the LPS receptor CD14 but it had no influence on MONO-MAC-6 cells regarding these parameters. However, upregulation of CD14 and MSE mRNA expression in the cell line by a 2-day incubation with LPS were inhibited by IL-4. This response to IL-4 after long-term treatment with LPS was seemingly contradictory to the missing reduction of TNF alpha mRNA expression after short-term incubation with LPS. Obviously long-term treatment with LPS made the cells responsive to IL-4. The increase in responsiveness was not due to IL-4 receptor (IL-4R) upregulation, as LPS did not influence the constitutive expression of the IL-4R.
authors.affiliation: DSM-German Collection of Microorganisms and Cell Cultures, Department of Human and Animal Cell Cultures, Braunschweig.
authors.forename: H
authors.initials: H
authors.lastname: Quentmeier
authors.forename: K
authors.initials: K
authors.lastname: Kolsdorf
authors.forename: M
authors.initials: M
authors.lastname: Zaborski
authors.forename: H G
authors.initials: HG
authors.lastname: Drexler
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics*; D015536:Down-Regulation; D006801:Humans; D015847:Interleukin-4 / Q000494:pharmacology*; D007948:Leukemia, Monocytic, Acute / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors*; D009000:Monocytes / Q000201:enzymology* / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D015854:Up-Regulation
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D012333:RNA, Messenger; D019948:Receptors, Interleukin-4; D011975:Receptors, Mitogen; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D002265:Carboxylic Ester Hydrolases