Influence of stimulatory and suppressive DNA motifs on host susceptibility to inflammatory arthritis.
OBJECTIVE: To examine whether systemic administration of immunostimulatory and immunosuppressive oligodeoxynucleotides (ODNs) alter host susceptibility to inflammatory arthritis. METHODS: Normal BALB/c mice were treated systemically with CpG ODNs or suppressive ODNs, and then challenged intraarticularly with CpG DNA. The onset and magnitude of the resulting inflammatory response was monitored. RESULTS: Systemic delivery of CpG ODNs significantly increased susceptibility to local inflammation, whereas systemic treatment with suppressive ODNs reduced this susceptibility. CD11c+ cells played a key role in mediating host sensitivity to arthritis. These cells were the dominant source of tumor necrosis factor alpha production in CpG-stimulated animals and transferred resistance to arthritis from mice treated with suppressive ODNs. CONCLUSION: Systemic exposure to immunostimulatory and immunosuppressive DNA influences host susceptibility to local inflammatory challenge. Current findings raise the possibility that suppressive ODNs may be useful in the prevention/treatment of proinflammatory diseases.