Effect of dexamethasone on expression of adhesion molecules on CD4+ lymphocytes.
Despite the widespread use of corticosteroids 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 analyze the effects of 1, 10, and 100 nM dexamethasone on expression of markers on resting and phytohemagglutinin (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 70-h 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.
Hughes
J M
JM
Department of Pharmacy, University of Sydney, New South Wales, Australia.
Sewell
W A
WA
Black
J L
JL
Armour
C L
CL
D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D006801:Humans; D039041:Integrin alpha4beta1; D019012:Integrin beta1 / Q000378:metabolism; D016023:Integrins / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism
D015815:Cell Adhesion Molecules; D039041:Integrin alpha4beta1; D019012:Integrin beta1; D016023:Integrins; D016201:Receptors, Lymphocyte Homing; D003907:Dexamethasone; D017493:Leukocyte Common Antigens