© 2003 by European Society of Cardiology
Copyright © 2003, European Society of Cardiology
Carvedilol, a new antioxidative β-blocker, blocks in vitro human peripheral blood T cell activation by downregulating NF-
B activity
aCardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC
bInstitute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC
cRheumatology/Immunology and Allergy, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Cheng-Kung Rd., Neihu 114, Taipei, Taiwan, ROC
haungben{at}tpts5.seed.net.tw
* Corresponding author. Tel.: +886-2-8792-7135; fax: +886-2-8792-7136.
Objective: The activation of T lymphocytes contributes to the inflammatory process of atherosclerosis. Here we examined the effects of carvedilol, a new β-blocker containing an antioxidative property, on the activation of T cells. Methods: Human peripheral blood T cells were negatively selected from whole blood. Cytokines were measured by ELISA. The NF-
B and related protein activity was determined by electrophoretic mobility shift assays, Western blotting, kinase assays and transfection assays. Results: Carvedilol was nontoxic at concentrations
10 µM, however, higher dosages (
20 µM) induced T cell apoptosis. We demonstrated that carvedilol inhibited cytokine production from various stimuli-activated T cells. Carvedilol also suppressed the expression of T cell activation markers, including CD25, CD69 and CD71. Molecular investigation indicated that carvedilol specifically downregulated NF-
B but not activator protein 1 DNA-binding activity in activated T cells. The inhibitory effect was likely due to its antioxidative property. Meanwhile, carvedilol prevented stimuli-induced I
B
degradation. Such an effect was mediated through the inhibition of I
B
kinase activity. The inhibitory specificity on NF-
B by carvedilol was also demonstrated in transfection assays. Conclusions: Our results demonstrated a novel therapeutic mechanism of carvedilol in atherosclerosis, namely the inhibition of T cell activation via downregulating NF-
B activity.
KEYWORDS Carvedilol; Atherosclerosis; T cells; Cytokines; NF-
B