The effects of interferon-gamma and bacterial lipopolysaccharide on CD14 expression in human monocytes.
CD14 has been reported to be the lipopolysaccharide (LPS)-LPS binding protein receptor. The effects of interferon-gamma (IFN-gamma) on CD14 expression have not been clearly established. The purpose of this investigation was to examine the effects of IFN-gamma alone and IFN-gamma followed by bacterial LPS on CD14 expression. Human peripheral blood monocytes were isolated by counterflow centrifugal elutriation (CCE). Monocytes were cultured for 48 h with IFN-gamma alone or for 24 h with IFN-gamma followed by LPS for a second 24 h. IFN-gamma alone caused a down-regulation of CD14 expression, as assessed by flow cytometry, relative to CD14 expression in untreated monocytes. In addition, CD14 expression was even more significantly down-regulated after IFN-gamma pretreatment followed by either Prevotella intermedia or Salmonella typhimurium LPS. Likewise, the percentage of CD14+ monocytes decreased after IFN-gamma alone and even more dramatically after IFN-gamma treatment followed by either LPS. This study clearly demonstrated that IFN-gamma down-regulates CD14 expression and that LPS following IFN-gamma pretreatment potentiates this effect.
Payne
J B
JB
Department of Surgical Specialties, University of Nebraska Medical Center, College of Dentistry, Lincoln 68583-0740.
Nichols
F C
FC
Peluso
J F
JF
D015703:Antigens, CD / Q000097:blood*; D002478:Cells, Cultured; D002498:Centrifugation; D004357:Drug Synergism; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000633:toxicity*; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology; D012486:Salmonella typhimurium
D015703:Antigens, CD; D008070:Lipopolysaccharides; D007371:Interferon-gamma