biostudies-literatureUnknown13Liang Q<i>Listeria monocytogenes</i> (LM) induces efficient and specific T-cell immune responses in the host. Listeriolysin O (LLO) is the main virulence protein of LM. LLO helps LM escape from the lysosome. However, the pronounced pathogenicity of LM limits its practical application as a live bacterial vector. <i>Listeria ivanovii</i> (LI) also displays intracellular parasitic abilities, cell to cell transfer, and other LM properties, with an elevated biosafety relative to LM. We have confirmed that LI can be used as a viable bacterial vaccine vector. However, we have also observed <i>in vivo</i> that LI vector vaccine candidates survive in the immune organ (spleen) for a shorter time compared with the survival time of LM and elicit weaker immune responses compared with LM. Studies have confirmeFrontiers in microbiology962326https://www.ebi.ac.uk/biostudies/studies/S-EPMC9355162biostudies-literatureRecombinant <i>Listeria ivanovii</i> strain expressing listeriolysin O in place of ivanolysin O might be a potential antigen carrier for vaccine construction.PMC9355162Ou QChen ZZhang YWang CTian SLi RLiu SLiang QfalseRecombinant <i>Listeria ivanovii</i> strain expressing listeriolysin O in place of ivanolysin O might be a potential antigen carrier for vaccine construction.<i>Listeria monocytogenes</i> (LM) induces efficient and specific T-cell immune responses in the host. Listeriolysin O (LLO) is the main virulence protein of LM. LLO helps LM escape from the lysosome. However, the pronounced pathogenicity of LM limits its practical application as a live bacterial vector. <i>Listeria ivanovii</i> (LI) also displays intracellular parasitic abilities, cell to cell transfer, and other LM properties, with an elevated biosafety relative to LM. We have confirmed that LI can be used as a viable bacterial vaccine vector. However, we have also observed <i>in vivo</i> that LI vector vaccine candidates survive in the immune organ (spleen) for a shorter time compared with the survival time of LM and elicit weaker immune responses compared with LM. Studies have confirme2022-01-01T00:00:00Z20222025-04-26T14:15:36.502Z2025-02-19T05:05:32.549ZS-EPMC93551623593524410.3389/fmicb.2022.962326