Abstract
Previously we reported the preparation and characterization of fusogenic liposomes (FL) which have highly immunogenic envelope glycoprotcins derived from Sendai virus on their surface. In this report, we investigated the ability of antigen-encapsulated FL to stimulate antigen-specific humoral immunity in mice. Anti-OVA antibody production was markedly increased in serum from mice subcutaneously immunized with ovalbumin (OVA) in FL compared to OVA alone or OVA in simple liposomes. However, these enhancements were not observed in mice immunized with OVA simply mixed with empty-FL. Moreover, consistent with mitogenic effects of Sendai virus' envelope glycoprotein, empty-FL were mitogenic for cultured murine splenocytes and B cells were especially proliferated. And this stimulation depended on protein concentration derived from Sendai virus. These results indicate that fusogenic liposome functions as an efficient immunoadjuvants in inducing antigen-specific antibody production and that for efficient adjuvancy it is necessary to encapulate antigens into FL. Moreover it was speculated that B cell stimulation which was given by glycoprotein derived from Sendai virus participated in adjuvancy of FL.
