The possible role of Epstein–Barr virus latent membrane protein 1 in inducing or promoting systemic lupus erythematosus

Abstract

To investigate the role of latent membrane protein 1 (LMP-1) in the Epstein-Barr virus (EBV) induced systemic lupus erythematosus (SLE) and its possible mechanism, fluorescence quantitative polymerase chain reaction (PCR) was employed to detect the mRNA expressions of LMP1, BcL-2 and Bax in the peripheral blood mononuclear cells (PBMCs) of SLE patients and healthy controls, and ELISA was performed to measure the serum B-cell activating factor (BAFF). Results showed: 1) The positive rate of LMP1 expression in 67 cases of SLE patient was 25.4%, significantly higher than the 10.8% in 65 cases of healthy control (P<0.05). The 2-∆Ct value of LMP1 mRNA expression level of SLE patients was 0.0000008349, 1.59 times to that (0.0000005241) of healthy controls, with statistical significance. 2) The expression of BcL-2 in SLE patients was 1.41 times higher than that in healthy controls with statistical significance. However, there was no significant difference in the Bax expression between two groups; 3) Among these SLE patients, the BcL-2 expression in LMP1 positive patients was 1.98 times higher than that in LMP1 negative patients with statistical significance. While there was no marked difference in the Bax expression between LMP1 positive and LMP1 negative SLE patients. Moreover, the expressions of BcL-2 and Bax were similar between LMP1 positive and LMP1 negative healthy controls; 4) The serum BAFF level in LMP1 positive SLE patients, LMP1 negative SLE patients and healthy controls was 105.50±14.67, 82.42±18.64 and 65.19±17.68 μg/L respectively, showing significant difference between any two groups (P<0.05). EBV can affect the Bcl-2 expression through LMP1 and induce the production of BAFF resulting in prolonged survival of autoreactive B lymphycytes and subsequent occurrence and development of SLE. Key words: Systemic lupus erythem