Lipopolysaccharide upregulates surface expression of cd14 on human
alveolar macrophages.
Hopkins, Harvey A., Martha M. Monick, and Gary W. Hunninghake.
Division of Pulmonary, Critical Care and Occupational Medicine,
University of Iowa College of Medicine and Veterans Affairs
Administration Medical Center, Iowa City, Iowa 52242
APStracts 2:0125L, 1995.
This study was undertaken to examine the surface expression and
regulation of CD14 on human alveolar macrophages (HAM). HAM obtained
by bronchoalveolar lavage were cultured with or without LPS and with
or without fetal bovine serum (FBS) on plastic or Teflon surfaces.
CD14 expression was assessed by immunofluorescence. The roles of
protein tyrosine kinase, protein kinase A and protein kinase C were
also evaluated utilizing inhibitors of these enzymes. HAM expressed
very low levels of surface CD14 at baseline. CD14 was upregulated on
HAM with time in culture in the presence of FBS and/or
lipopolysaccharide (LPS); adherence did not effect CD14 expression.
Inhibitors of protein kinase C and protein tyrosine kinase prevented
the upregulation of CD14 by LPS but did not effect the upregulation
of CD14 by FBS. These studies show that LPS can upregulate expression
of its receptor on HAM and that this effect is accentuated by serum
-derived factors.
Received 1 August 1994; accepted in final form 17 July 1995.
APS Manuscript Number L212-4.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 August 1995.