Up-regulation of high-affinity dehydroepiandrosterone binding activity by dehydroepiandrosterone in activated human T lymphocytes.
Although evidence indicates that dehydroepiandrosterone (DHEA) exerts direct physiological effects, its mechanism of action remains unknown. DHEA binding sites were examined using a whole-cell binding assay in a human T lymphoid cell line, PEER, revealing that a single class of high-affinity binding sites for DHEA (dissociation constant = 7.4 +/- 0.53 nmol/L, mean +/- SE, n = 4) was greatly increased when treated with DHEA, phorbol-12-myristate-13-acetate, and the Ca2+ ionophore A23187. Bound [3H]DHEA was displaced sensitively by DHEA and secondarily by dihydrotestosterone, but not effectively by other steroids, including DHEA sulfate. These results not only indicate the existence of a DHEA receptor, but also suggest that T cells become susceptible to regulation by DHEA during the process of signal-induced activation.
Okabe
T
T
Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Haji
M
M
Takayanagi
R
R
Adachi
M
M
Imasaki
K
K
Kurimoto
F
F
Watanabe
T
T
Nawata
H
H
D001665:Binding Sites; D000001:Calcimycin / Q000494:pharmacology; D002460:Cell Line; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D007700:Kinetics; D008213:Lymphocyte Activation; D011987:Receptors, Steroid / Q000378:metabolism*; D013256:Steroids / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015854:Up-Regulation
D007476:Ionophores; D011987:Receptors, Steroid; D013256:Steroids; C095972:dehydroepiandrosterone receptor; D000001:Calcimycin; D003687:Dehydroepiandrosterone; D013755:Tetradecanoylphorbol Acetate