Notice of Retraction Construction of an Attenuated Listeria-Based Vaccine Delivery Plasmid

We aimed to construct an effective tumor targeting vaccine delivery plasmid that can express antigen protein in attenuated Listeria monocytogenes (LM). The produced fusion proteins were supposed to induce the antitumor immune response strongly. In our study, the gene of a truncated non-cytolytic form of listeriolysin O (LLO) was cloned in the plasmid pERL3 under the control of a hemolysin promoter (Phly). To check if the genes of interest were successfully inserted into pERL3, recombinant pERL3 was transferred into E. coli strain DH5α, and positive clones were obtained from Luria Bertani agar plate. Here we collected 46 positive clones and analyzed by PCR. Finally, we found a clear electrophoretic band in electrophoregram that was identified as a 726-bp fragment of hly. In conclusion, we've constructed a listeria-based vaccine delivery plasmid: pERL3-Phly-hly (441aa), with which we can express exogenous proteins in host cells, we planned to use it in delivering MIA (melanoma inhibitory activity) antigens to host cells to induce cellular immune response in further research.