Induction of Toll-like receptor 4 in granulocytic and monocytic cells differentiated from HL-60 cells.
Toll-like receptor 4 (TLR4) is the main protein expressed on the cell surface and is an essential receptor for lipopolysaccharide (LPS) signalling in human peripheral blood leucocytes. We examined TLR4 expression and the functional response to LPS in retinoic acid-treated HL-60 cells (HL-60-derived granulocytic cells) and interferon-gamma-treated HL-60 cells (HL-60-derived monocytic cells). Slight TLR4 expression was induced in HL-60-derived granulocytic cells, while strong induction was seen in HL-60-derived monocytic cells. LPS induced interleukin 1beta (IL-1beta) production and TLR4 expression in HL-60-derived monocytic cells, but not HL-60-derived granulocytic cells. These data indicate different responses to LPS in the cells. TLR4 surface expression paralleled LPS-induced phagocytosis and TLR4-neutralizing antibody partially inhibited LPS-induced IL-8 production in HL-60-derived monocytic cells, but not in HL-60-derived granulocytic cells. These results suggest that HL-60-derived monocytic cells are partially activated via TLR4, but that HL-60-derived granulocytic cells are not activated via TLR4.
Mita
Y
Y
First Department of Internal Medicine, Gunma University Faculty of Medicine, 3-39-15, Showa-machi, Maebashi, Gunma 371-8511, Japan. ymita@pop.showa.gunma-u.ac.jp
Dobashi
K
K
Nakazawa
T
T
Mori
M
M
D002454:Cell Differentiation; D029721:Drosophila Proteins; D005434:Flow Cytometry; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D010587:Phagocytosis / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000378:metabolism*; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014212:Tretinoin / Q000494:pharmacology
D029721:Drosophila Proteins; D007375:Interleukin-1; D016209:Interleukin-8; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D014212:Tretinoin; D007371:Interferon-gamma