Intranasal immunization with chitosan/pCETP nanoparticles inhibits atherosclerosis in a rabbit model of atherosclerosis

In search of a convenient and pain-free route of administration of DNA vaccine against atherosclerosis, the plasmid pCR-X8-HBc-CETP (pCETP) encoding B-cell epitope of cholesteryl ester transfer protein C-terminal fragment displayed by Hepatitis B virus core particle was condensed with chitosan to form chitosan/pCETP nanoparticles. Cholesterol-fed rabbits were then intranasally immunized with the chitosan/pCETP nanoparticles to evaluate antiatherogenic effects. The results showed that significant serum antibodies against CETP were detected by enzyme-linked immunosorbent analysis and verified by Western blot analysis. The significant anti-CETP IgG lasted for 21 weeks in the rabbits immunized intranasally. Moreover, the atherogenic index was significantly lower compared with the saline control (5.95 versus 2.39, p < 0.05). In addition, the average percentage of aortic lesions in the entire aorta area in the rabbits intranasally vaccinated with nanoparticles was 59.2% less than those treated with saline (29.0 ± 10.9% versus 71.0 ± 14.4%, p < 0.01) and was similar to those intramuscularly injected with pCETP solution (29.0 ± 10.9% versus 21.2 ± 14.2%, p > 0.05). Thus, chitosan/pCETP nanoparticles could significantly attenuate the progression of atherosclerosis by intranasal immunization. The results suggested that intranasal administration could be potentially developed as a vaccination route against atherosclerosis.