Nasal or Oral Immunization with GroEL Attenuates Porphyromonas gingivalis-Induced Atherosclerosis

Abstract

Periodontal disease is one of the most prevalent chronic inflammation of oral cavity, and has been reported to be associated with atherosclerosis. In this study, we assessed the potential of orally or nasally administered recombinant HSP60 from Porphyromonas gingivalis (rGroEL) for prevention of atherosclerosis accelerated by P.gingivalis. Apolipoprotein E deficient spontaneously hyperlipidemic (Apoe^shl) mice were orally or nasally immunized with GroEL and then challenged intravenously with P.gingivalis 381. Atherosclerotic lesions in the proximal aorta of each animal were analyzed histomorphometrically, and the serum concentrations of rGroEL-specific antibodies and cytokines were determined. Although antibody titer sufficient for taking oral or nasal immunity of GroEL under adjuvant-free condition was not obtained, the antibody titers significantly rose by booster effect of P.gingivalis infection. Furthermore, mice given rGroEL orally or nasally followed by P.gingivalis-challenge possessed significant reduction of atherosclerotic plaque accumulation in aortic sinus and lowered the serum MCP-1 and ox-LDL levels compared to nonimmunized, P.gingivalis-challenged mice. These results suggest that oral or nasal immunization with rGroEL could be an effective vaccine for prevention of atherosclerosis accelerated by P.gingivalis.