Experimental study on intramuscular injection of eukaryotic expression vector pcDNA3- IL-6 on BXSB mice.

OBJECTIVE: To study the role of IL-6 in systemic lupus erythematosis (SLE). METHODS: We constructed eukaryotic expression vector pcDNA3- IL-6 encoding for IL-6 and injected it intramuscularly into BXSB mice. 22 of the 3.5-month-old male BXSB mice were divided into two groups. One group was injected with the pcDNA3-IL-6 100 micrograms per mouse twice at the interval of 20 days. Another group was injected with plasmid pcDNA3 at the same time as control. The ANA and proteinuria were monitored every 10 days, and the IL-6 activity in serum, IgG, C3 deposition and IL-6 expression in kidney detected at the 40th day. RESULTS: IL-6 encoding plasmid had harmful effects on murine SLE with increased ANA level, proteinuria, IgG, C3 deposition and IL-6 expression in kidney, but there was no difference of serum GPT levels between the two groups. CONCLUSION: Excessive production of IL-6 could play an important pathogenic role in SLE. Blocking or reducing IL-6 secretion might be a new therapy for SLE.