Background Patients with systemic lupus erythematosus often have various autoantibodies. The relationship between these antibodies is still poorly understood. The aim of the present study was to observe the anti-SSB antibody and anti-dsDNA antibody production profiles following immunization with synthetic SSB peptide alone, DNA alone or co-immunization with these two antigens. Methods SSB 214-225 aa peptide was synthesized by organic chemistry solid-phase peptide synthesis. Rabbits were immunized with the following antigens： synthetic SSB peptide linked with keyhole limpet hemocyanin （KLH）, DNA, SSB plus dsDNA, KLH and PBS. Antibodies were measured by ELISA. Histopathology and direct immufluorescence assays were also applied. Results Anti-SSB and anti-dsDNA antibodies were produced following immunization with SSB peptide and DNA respectively. The level of SSB antibody in the co-immunization group was higher than that of the SSB peptide immunization group. The level of anti-dsDNA antibody in the co-immunization group was, however, lower than that in the DNA immunization group. Meanwhile, the level of anti-SSB antibody was higher than that of anti-DNA antibody in the co-immunization group. No morphological or immunological abnormalities were found in the heart, liver, kidney, spleen or skin tissues. Conclusion Inhibition of anti-dsDNA-antibody was induced by co-immunization with synthesized SSB peptide and DNA, which might explain, at least partly, the mild disease in some LE subsets associated with SSB antibody.
