Surface-displayed viral antigens on Salmonella carrier vaccine

We have developed a recombinant live oral vaccine using the ice-nucleation protein (Inp) from Pseudomonas syringae to display viral antigens on the su rface of Salmonella spp. Fusion proteins containing viral antigens were exp ressed in the oral vaccine strain, Salmonella typhi Ty21a. Surface localiza tion was verified by immunoblotting and fluorescence-activated cell sorting . The immunogenicity of surface-displayed viral antigens on the recombinant live vaccine strain was assessed in mice inoculated intranasally and intra peritoneally. Inoculation resulted in significantly higher serum antibody l evel than those induced by viral antigens expressed intracellularly. Thus, this multivalent mucosal live vaccine may provide an effective means for in ducing mucosal or systemic immune responses against multiple viral antigens .