Salmonella Typhimurium, the major causative agent of foodborne illness inactivated by a phage lysis system provides effective protection against lethal challenge by induction of robust cell-mediated immune responses and activation of dendritic cells.

摘要: Salmonella Typhimurium infection via foodborne transmission remains a major public health threat even in developed countries. Vaccines have been to reduce the disease burden at pre-harvest stage, but cell-mediated immune response against intracellular invasion of pathogen is not sufficiently elicited by conventional killed vaccines, which are safer than live vaccines. In this study, we genetically inactivated vaccine candidate introducing lysis plasmid pJHL454 harboring λ phage holin–endolysin system into S. Typhimurium; designated JOL1950. vitro expression endolysin was validated immunoblotting, and complete inactivation JOL1950 cells observed following 36 h lysis. Electron microscopic examinations scanning electron microscopy immunogold labeling EM revealed conserved surface antigenic traits after An vivo immunogenicity study mice immunized with lysed showed significantly increased serum IgG, IgG1, IgG2a levels. Further, markedly cell proliferation upregulation Th1, Th2, Th17 cytokines repulsed splenic T-cells mice. dendritic (DCs) treated JOL1950, significant increase activation, co-stimulatory molecule production, levels immunomodulatory cytokines. addition, Th1 were also released naive CD4+ pulsed primed DCs. Lysed protected lethal challenge Together, these results indicate that our has great potential induce immunity facilitating activation