Identification of human cytomegalovirus phosphoprotein 65 in C57BL/6 and BXSB mice as a potential trigger of systemic lupus erythematosus related serum markers

Objective:To investigate the potential role of human cytomegalovirus lower matrix phosphoprotein 65(HCMV-pp65) in murine systemic lupus erythematosus(SLE).Methods:The prokaryotic plasmid pET-28b-pp65 was constructed to express the HCMVpp65 protein.BXSB mice and C57BL/6 mice were inoculated with pp65 eukarvotic plasmid pcDNA3.0-pp65 intramuscularly 5 times at 2-week intervals,and then the blood of the mice was subsequently collected via the retro-orbital vein.Indirect ELISAs were used to evaluate the concentration of anti-pp65 immunoglobulin G,anti-double-stranded DNA and antinuclear antibodies.lnterleukin-1β and tumor necrosis factor-α were also determined by competitive ELISA.At the same time,3 major SLE-related circulating microRNAs were examined by quantitative RT-PCR.Results:The early production of autoantibodies was observed in pp65-immunized male BXSB as well as C57BL/6 mice.Overexpression of interleukin-1β and tumor necrosis factor-a were detected in pp65-immunized male BXSB mice.Quantitative RT-PCR analyses showed that three SLE related microRNAs(microRNA-126,microRNA-125 a,and microRKA-146a) were dovvnrcgulatcd in peripheral blood mononuclear cells of pp65-immunizcd mice.Conclusions:Our findings indicate that HCMV-pp65 immunization strongly triggers the development and progression of" SLE-like disease in both BXSB and C57BL/6 mice,which indicates that the immune responses induced by HCMV-pp65 may be involved in the development of SLE.