Abstract: Objective To investigate the effect of CpG sequences on the induction of anti-dsDNA antibodies and the possible mechanism.Methods Using a synthetic oligodeoxynucleotide (CpG-ODN) containing CpG as an adjuvant, native calf thymus DNA (nCTDNA) was used as the mimic self antigen to immunize normal BALB/c mice.About one week after immunization, anti-dsDNA antibodies were tes ted by ELISA using nCTDNA and native Escherichia coli DNA (nECDNA) as test antigens.Results The levels of anti-dsDNA antibodies and cytokines including IL-6, IL-12, IFN-γ in the sera from the mice immunized with CpGODN plus nCTDNA were signigicantly higher than those of othet immunization groups (P<0.01).These induced antibodied could bind both nCTDNA and nECDNA, but the binding abilities were different significantly.Conclusion The CpG motif can promote the production of cross-reactive anti-dsDNA antibodies in normal mice.

Key words: Lupus erythematosus,systemic, Antibodies,antinuclear, Oligonucleotide array sequence analysis