Estrogen increases CD40 ligand expression in T cells from women with systemic lupus erythematosus.
OBJECTIVE
To examine the in vitro effects of estrogen on CD40 ligand (CD40L) expression in peripheral blood T cells isolated from patients with systemic lupus erythematosus (SLE) and normal controls.


METHODS
T cells from female patients with SLE and controls were cultured in serum-free medium without and with 2-fluoroestradiol. Some T cells were activated by further culture on anti-CD3 coated plates. Calcineurin was activated in some T cells by culture in ionomycin. Cell surface CD40L was quantitated by FACS analysis. mRNA expression was measured using semiquantitative PCR.


RESULTS
Lupus T cells cultured in medium containing 2-fluoroestradiol showed a significant (p = 0.04) increase in the amount of CD40L on the cell surface, but not in the number of positive cells, compared to the same T cells cultured without estradiol. Estradiol did not significantly change CD40L expression on the surface of T cells from normal women. In addition, the difference in cell surface CD40L between T cells cultured without and with estradiol was significantly greater (p = 0.048) on SLE than on normal T cells. Culture of SLE T cells in medium containing 2-fluoroestradiol followed by T cell receptor (TCR) activation for 2 h using anti-CD3 resulted in a significant (p = 0.04) estrogen dependent increase in CD40L mRNA. The estrogen dependent increases in SLE T cell CD40L mRNA and cell surface protein were blocked by the estrogen receptor antagonist ICI 182,780. SLE and normal T cells pretreated with estradiol and cultured with ionomycin for 2 h to activate calcineurin showed no significant differences in CD40L mRNA.


CONCLUSIONS
These results suggest that estradiol, working through the estrogen receptor, stimulates the expression of CD40L in unstimulated and activated SLE T cells. Estradiol effects may be exerted on multiple regulatory steps that control CD40L expression. The estrogen dependent increase in CD40L expression could hyperstimulate SLE T cells and thereby contribute to the pathogenesis of SLE.
Rider
V
V
School of Biological Sciences, University of Missouri-Kansas City, USA. VRider@pittstate.edu
Jones
S
S
Evans
M
M
Bassiri
H
H
Afsar
Z
Z
Abdou
N I
NI
D000328:Adult; D017252:CD3 Complex / Q000276:immunology; D019013:CD40 Antigens / Q000096:biosynthesis* / Q000235:genetics; D002478:Cells, Cultured; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D005434:Flow Cytometry; D000077267:Fulvestrant; D006801:Humans; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008024:Ligands; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism
D017252:CD3 Complex; D019013:CD40 Antigens; D004965:Estrogen Antagonists; D004967:Estrogens; D007476:Ionophores; D008024:Ligands; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell; C037475:2-fluoroestradiol; D000077267:Fulvestrant; D004958:Estradiol; D015759:Ionomycin