・Yosuke Shimizu1／Shinobu Watarai1／Tadashi Iwasaki1／Tomoko Tajima1／Eiji Yuba2／Kenji Kono2
1 Osaka Prefecture University School of Life and Environmental Sciences／2 Osaka Prefecture University Graduated School of Engineering
”Development of liposomal intraocular vaccine for canine periodontitis”
Porphyromonas gingivalis is suspected to be one of the most important causative agents of canine periodontitis. Adhesion of P. gingivalis to the surface of the periodontal epithelium is a necessary first step in the infection. So, an effective strategy for the protection against P. gingivalis infection would be to induce anti-P. gingivalis local immunity in the oral cavity in addition to systemic immune responses following immunization. In this study, we examined the induction of oral mucosal immune responses against P. gingivalis by immunizing dogs with liposome-associated antigen. Intraocular immunization induced serum IgG and IgA responses. Also, significant IgA antibodies were detected in the saliva. However, immunization with liposome-unassociated antigen didn’t induce both systemic and local antibody responses. Furthermore, the aggregation effect of salivary antibodies against P. gingivalis was tested. The aggregation of P. gingivalis was observed by the addition of saliva from dogs intraocularly immunized with liposome-associated P. gingivalis antigen. These results suggest that liposome-associated antigen would serve effectively as a vaccine for inducing oral mucosal immune responses against P. gingivalis, and also that this liposomal vaccine has potential in stimulating oral antibody responses that may be helpful in the protection of dog against infection from P. gingivalis.