Association and function study of tumor necrosis factor receptorⅡ position 196 polymorphism with systemic lupus erythematosus

AIM: To investigate the association of gene polymorphism at position 196 of tumor necrosis factor receptor Ⅱ (TNFRⅡ) with systemic lupus erythematosus (SLE) in Chinese, and establish recombinant retroviral vector to analyze the function of the TNFRⅡ 196M/R. METHODS: The genotype at position 196 of TNFRⅡ was determined by PCR-RFLP in 106 SLE patients and 119 healthy controls in china. Human TNFRⅡ196M cDNA were amplified by PCR and cloned into PMD18-T vector. Then, PMD18-TNFRⅡ196R was induced by site-directed mutagenesis. The recombinant T vector, PMD18-TNFRⅡ196M and PMD18-TNFRⅡ196R, were subcloned into retroviral vector PLXSN. Both normal and variant were transfected into rat mesangial cell. The effects of TNFα on production of sTNFRⅡ and IL-6 were study by ELISA. RESULTS: (1) The frequency of TNFRⅡ196R allele was significantly higher than those in controls (35.2% vs 14.3%, P<0.05); (2) The recombinant retroviral vector (PLXSN-TNFR 196M and PLXSN-TNFR 196R) was constructed successfully; (3) rhTNFα caused a significant increase in IL-6 production by rat mesangial cells transfected with PLXSN-TNFRⅡ196R than that with TNFRⅡ196M. CONCLUSION: These data indicate that TNFRⅡ196R allele is associated with SLE in the Chinese. TNFRⅡ196R transduces the signals of TNFα more effectively than TNFRⅡ196M, which may be involved in the pathogenesis of SLE.