[Alveolar macrophages and granuloma formation].
We measured intracytoplasmic free calcium ion concentration ([Ca3+]i) of alveolar macrophages (AMs) in order to elucidate the mechanism(s) of lipopolysaccharide (LPS)-hyperresponsiveness of AMs in patients with sarcoidosis at the second messenger level. Resting [Ca2+]i was higher in patients with sarcoidosis than in normal subjects. [Ca2+]i increase responses were also elevated in patients with sarcoidosis when AMs were stimulated with either anti-CD14 (a LPS/LPS-binding protein complex receptor) antibody, anti-CD64 (Fc gamma receptor I), antibody or platelet activating factor. After incubation with interferon-gamma, resting [Ca2+]i and increase in [Ca2+]i induced by anti-CD14 antibody stimulation were higher in patients with sarcoidosis as compared with values before incubation. Thus, these data suggest that activation of AMs at the second messenger level induced by IFN gamma, at least in part, accounts for LPS-hyperresponsiveness in sarcoidosis.
Yamaguchi
E
E
First Department of Medicine, School of Medicine, Hokkaido University, Japan.
Kawakami
Y
Y
D000209:Acute-Phase Proteins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D002118:Calcium / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides / Q000378:metabolism; D008262:Macrophage Activation; D016676:Macrophages, Alveolar / Q000378:metabolism*; D008562:Membrane Glycoproteins; D012507:Sarcoidosis / Q000378:metabolism* / Q000473:pathology; D015290:Second Messenger Systems; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D002118:Calcium; D002352:Carrier Proteins; D007371:Interferon-gamma; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein