Effect of oestrogen on T cell apoptosis in patients with systemic lupus erythematosus

• Published in: Clinical and experimental immunology 2010-09, Vol.161 (3), p.453-458
• Main Authors: Kim, W.-U, Min, S.-Y, Hwang, S.-H, Yoo, S.-A, Kim, K.-J, Cho, C.-S
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Antibodies - pharmacology; Apoptosis; Apoptosis - drug effects; Autoimmune diseases; Biological and medical sciences; Cells, Cultured; DNA Fragmentation - drug effects; Dose-Response Relationship, Drug; Estradiol - pharmacology; estrogen; Estrogens - pharmacology; Fas Ligand Protein - genetics; Fas Ligand Protein - immunology; Fas Ligand Protein - metabolism; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Gene Expression - drug effects; Humans; Lupus; Lupus Erythematosus, Systemic - blood; Lupus Erythematosus, Systemic - immunology; Lymphocytes; Medical sciences; Reverse Transcriptase Polymerase Chain Reaction; Sarcoidosis. Granulomatous diseases of unproved etiology. Connective tissue diseases. Elastic tissue diseases. Vasculitis; T cells; T-lymphocytes; T-Lymphocytes - drug effects; T-Lymphocytes - metabolism; testosterone; Translational Studies
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2010.04194.x

Defective control of T cell apoptosis is considered to be one of the pathogenetic mechanisms in systemic lupus erythematosus (SLE). Oestrogen has been known to predispose women to SLE and also to exacerbate activity of SLE; however, the role of oestrogen in the apoptosis of SLE T cells has not yet been documented. In this study, we investigated the direct effect of oestrogen on the activation-induced cell death of T cells in SLE patients. The results demonstrated that oestradiol decreased the apoptosis of SLE T cells stimulated with phorbol 12-myristate 13-acetate (PMA) plus ionomycin in a dose-dependent manner. In addition, oestradiol down-regulated the expression of Fas ligand (FasL) in activated SLE T cells at the both protein and mRNA levels. In contrast, testosterone increased FasL expression dose-dependently in SLE T cells stimulated with PMA plus ionomycin. The inhibitory effect of oestradiol on FasL expression was mediated through binding to its receptor, as co-treatment of tamoxifen, an oestrogen receptor inhibitor, completely nullified the oestradiol-induced decrease in FasL mRNA expression. Moreover, pre-treatment of FasL-transfected L5178Y cells with either oestradiol or anti-FasL antibody inhibited significantly the apoptosis of Fas-sensitive Hela cells when two types of cells were co-cultured. These data suggest that oestrogen inhibits activation-induced apoptosis of SLE T cells by down-regulating the expression of FasL. Oestrogen inhibition of T cell apoptosis may allow for the persistence of autoreactive T cells, thereby exhibiting the detrimental action of oestrogen on SLE activity.