IgE-dependent expression of interleukin-5 mRNA and protein in human lung: modulation by dexamethasone.
mRNA and protein expression of the Th2 cytokines IL-4 and IL-5 from human lung were examined during the first 4 hr following IgE-mediated triggering, a time representative of the evolving late-phase reaction (LPR). Lung explants were incubated for 16 hr at 37 degrees C in culture media alone or with added dexamethasone (10(-6) M), washed, and then challenged with buffer or anti-IgE (3 micrograms/ml). Using RNase protection assays, in 16/16 individual lungs IL-5 mRNA expression was observed at 4 hr following anti-IgE and at no points following buffer challenge. Fragments released 1129 +/- 499 ng of IL-5/g wet wt over a 24-hr period (mean +/- SEM, n = 5). Neither IL-4 transcripts nor protein were detected in any anti-IgE challenges. Both the IgE-mediated IL-5 mRNA and protein responses were below the limits of detection following dexamethasone preincubation, suggesting a mechanism for the potent inhibitory effects of these agents observed in the LPR.
Glaum
M C
MC
Department of Medicine, Hahnemann University, Philadelphia, Pennsylvania 19102, USA.
Jaffe
J S
JS
Gillespie
D H
DH
Raible
D G
DG
Post
T J
TJ
Wang
Y
Y
Dimitry
E
E
Schulman
E S
ES
D003907:Dexamethasone / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007073:Immunoglobulin E / Q000494:pharmacology*; D015848:Interleukin-5 / Q000235:genetics*; D008168:Lung / Q000737:chemistry*; D012333:RNA, Messenger / Q000032:analysis
D015848:Interleukin-5; D012333:RNA, Messenger; D007073:Immunoglobulin E; D003907:Dexamethasone