The effect of dexamethasone on expression of adhesion molecules on
cd4+ lymphocytes.
Hughes, Jm, W A Sewell, Jl Black, and Cl Armour.
Departments of Pharmacy and Pharmacology, University of Sydney and
Centre for Immunology, St Vincent's Hospital, Sydney, Australia
APStracts 3:0028L, 1996.
Despite wide usage in asthma therapy, little is known of the effects
of corticosteroids on cell surface markers involved in T-lymphocyte
activation and adhesion. We used flow cytometry to analyse the
effects of 1, 10 and 100nM dexamethasone on expression of markers on
resting and phytohaemagglutinin (PHA)-stimulated peripheral blood
CD4+ T-lymphocytes. Expression of the leukocyte common antigen CD45
was significantly (p=0.016, n=3) increased from an average mean
fluorescence intensity of 215.8 (95% confidence intervals (CI):
100.5, 463.5) on cells from unstimulated cultures to 334.2 (CI:
167.9, 663.7) on cells from PHA-stimulated cultures after 70h
incubation. At the same time, the percentage of cells also expressing
the CD45RO isoform, a marker of memory T-lymphocytes, increased
significantly (p=0.0006, n=3) from 54.4 +/- 1.3% (unstimulated) to
92.8+/-0.6% (stimulated). Dexamethasone had no significant effect on
expression of CD45, or CD45RO, including the observed changes.
Dexamethasone also did not affect expression of the [beta]1 integrin
VLA-4. These results suggest that corticosteroids do not modulate the
cell surface expression of these molecules involved in CD4+ T
-lymphocyte activation, adhesion and recirculation.
Received 7 August 1995; accepted in final form 26 January 1996.
APS Manuscript Number L245-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 February 96