Evaluation of immunomodulatory effect of immunace on adjuvanticity of 1,2-dioleoyl-3-trimethylammoniumpropane-based liposomes

Abstract

Purpose: To investigate the antibody effect of immunace on the adjuvanticity of 1,2-dioleoyl-3- trimethylammoniumpropane (DOTAP)- based liposomes. Method: The vesicles of the liposome-based ND vaccine were prepared by lipid film hydration method and physically characterized for shape, particle size and zeta potential. Forty experimental birds were divided into an unvaccinated group, a liposomal Newcastle disease (ND) vaccine group, combined liposomal ND vaccine and immunace group, and a live La Sota® vaccine group. The liposomal ND vaccine, liposomal ND vaccine and immunace and a live La Sota® vaccine groups were vaccinated orally at 3 and 6 weeks of age. Haemagglutination inhibition test was carried out after primary and booster doses. Results: The log2 mean antibody titre induced by the liposomal ND vaccine after secondary immunization of the birds was 9.60 ± 0.95 while that of the combined liposomal ND vaccine and immunace group was 7.00 ±1.71, and that of the live La Sota vaccine® was 6.00 ±0.63. There was no detectable antibody in the unvaccinated group throughout the experiment. At p < 0.05, the liposomal ND vaccine group, after secondary immunization, produced antibodies which were significantly higher than those of the combined immunace-liposomal ND vaccine group. Conclusion: There was a boost in the immune response of the birds immunized with liposomal ND vaccine and immunace after primary immunization only.