Human lung fibroblasts release chemokinetic activity for monocytes constitutively.
We determined whether human lung fibroblasts (HLFs) might release mediators that are responsible for monocyte chemokinetic activity (MCA) constitutively. HLF supernatant fluids showed MCA in a time-dependent manner (P < 0.001). Checkerboard analysis of 24- and 72-h supernatant fluids showed that the activity was chemokinetic. Partial characterization of 24- and 72-h supernatant fluids revealed that the mediators released after 24 h were predominantly composed of lipid-soluble activity, and MCA was blocked by lipoxygenase inhibitors. The mediators released after 72 h were predominantly trypsin sensitive and blocked by cycloheximide. Molecular-sieve column chromatography identified four peaks of MCA. A polyclonal antibody to monocyte chemoattractant protein-1 (MCP-1) inhibited MCA by 20% after 24 h and by 40% after 72 h. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and transforming growth factor-beta (TGF-beta) antibodies attenuated MCA released after 72 h by 30 and 10%, respectively. These antibodies inhibited corresponding molecular-weight peaks separated by molecular-sieve column. The concentrations of MCP-1, GM-CSF, and TGF-beta were 4,698 +/- 242, 26.8 +/- 3.8, and 550 +/- 15 pg/ml, respectively. A leukotriene B4 (LTB4)-receptor antagonist attenuated the total MCA and the lowest molecular weight peak of MCA. The concentrations of LTB4 were 153.4 +/- 12.4 (24 h) and 212 +/- 16.6 (72 h) pg/ml. These findings suggest that HLFs may modulate the recruitment of monocytes into the lung by releasing MCP-1, GM-CSF, TGF-beta, and LTB4 constitutively.
Shinshu University School of Medicine, First Department of Internal Medicine, Matsumoto 390, Japan.
S
S
Koyama
E
E
Sato
T
T
Masubuchi
A
A
Takamizawa
H
H
Nomura
K
K
Kubo
S
S
Nagai
T
T
Izumi
D000328:Adult; D000906:Antibodies; D002460:Cell Line; D018932:Chemokine CCL2 / Q000096:biosynthesis / Q000378:metabolism; D018946:Chemokine CCL5 / Q000096:biosynthesis; D002634:Chemotaxis, Leukocyte; D003513:Cycloheximide / Q000494:pharmacology; D004049:Diethylcarbamazine / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000502:physiology; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D008168:Lung / Q000502:physiology*; D009637:Masoprocol / Q000494:pharmacology; D009000:Monocytes / Q000502:physiology*; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors; D018102:Receptors, Leukotriene B4 / Q000037:antagonists & inhibitors; D013601:T-Lymphocytes / Q000276:immunology / Q000502:physiology; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000502:physiology; D014357:Trypsin
D000906:Antibodies; D018932:Chemokine CCL2; D018946:Chemokine CCL5; D016859:Lipoxygenase Inhibitors; D010972:Platelet Activating Factor; D018102:Receptors, Leukotriene B4; D016212:Transforming Growth Factor beta; D009637:Masoprocol; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003513:Cycloheximide; D014357:Trypsin; D004049:Diethylcarbamazine