Synthetic CpG oligodeoxynucleotides accelerate the development of lupus nephritis during preactive phase in NZB × NZWF1 mice

The effect of synthetic CpG-oligodeoxynucleotides (CpG-ODN) on the development of lupus nephritis during preactive phase (within seven months of age) in autoimmune lupus NZB ×NZWF1(B/WF1) mice was examined. Treatment of CpG-ODN was started at the age of 2.75 months and continued until 6.25 months. Overt disease began at the age of six months and progressed linearly at the age of 6.75 months in CpG-ODN-treated, but not control ODN-treated (control) groups. Also compared to control group, CpG-ODN-treated mice exhibited a severe glomerulonephritis(GN), with prominent deposits of IgG2a and C3, which paralleled increased titre of IgG2a type anti-nuclear antibody in the blood. Among several cytokines (interleukin, IL-6, IL-4, IL-1a, IL-10, interferon-g and tumor necrosis factor-a) in blood, IL-6 production paralleled the developmentof lupus nephritis. The present study suggests that CpG-ODN may enhance IL-6 production. The role of IL-6 in the development of GN will be discussed.