Intracytoplasmic delivery of listeriolysin O by a vaccinal strain of Bacillus anthracis induces CD8-mediated protection against Listeria monocytogenes.

摘要: The facultative intracellular pathogen Listeria monocytogenes secretes a 58-kDa hemolysin, listeriolysin O (LLO), that allows bacteria to access the cytoplasm and multiply inside infected cells. LLO is also protective Ag required for development of specific immunity. We studied capacity new bacterial vector, derived from an attenuated strain Bacillus anthracis, deliver in vivo induce protection against L. infection. hly gene encoding was fused B. anthracis regulatory region induced integrated into resident plasmid this bacterium. This recombinant secreted functional vitro phagosomes bone marrow macrophages. production enabled conversion extracellular replicating intracytoplasmic LLO+ thus mimicked behavior Specific mice lethal doses by immunization with anthracis. immunity mediated CD8+ T lymphocytes associated activation LLO-specific MHC class I-restricted CTL, able recognize immunodominant H-2d-restricted epitope 91-99 LLO. study, therefore, suggests delivery sufficient CD8-mediated monocytogenes. represents potential vector delivering foreign Ags involved responses.