@article{mbs:/content/journal/jgv/10.1099/0022-1317-82-7-1737, author = "Vignuzzi, Marco and Gerbaud, Sylvie and van der Werf, Sylvie and Escriou, Nicolas", title = "Naked RNA immunization with replicons derived from poliovirus and Semliki Forest virus genomes for the generation of a cytotoxic T cell response against the influenza A virus nucleoprotein", journal= "Journal of General Virology", year = "2001", volume = "82", number = "7", pages = "1737-1747", doi = "https://doi.org/10.1099/0022-1317-82-7-1737", url = "https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-82-7-1737", publisher = "Microbiology Society", issn = "1465-2099", type = "Journal Article", abstract = "The potential of RNA-based vaccines was evaluated for the generation of a protective immune response in the mouse model of influenza type A virus infection using the internal nucleoprotein (NP) as antigen. This antigen is of particular interest, since it has the potential to elicit protective cytotoxic T lymphocytes (CTL) against heterologous strains of influenza A virus. In view of the short half-life of RNA, self-replicating RNAs or replicons of the positive-stranded genomes of Semliki Forest virus (SFV) and poliovirus were engineered to synthesize the influenza A virus NP in place of their structural proteins. NP expression was demonstrated by immunoprecipitation after transfection of cells with RNA from the SFV (rSFV-NP) and poliovirus (rΔP1-E-NP) genome-derived replicons transcribed in vitro. C57BL/6 mice were injected intramuscularly with these synthetic RNAs in naked form. Both replicons, rSFV-NP and rΔP1-E-NP, induced antibodies against the influenza virus NP, but only mice immunized with the rSFV-NP replicon developed a CTL response against the immunodominant H-2Db epitope NP366. Finally, the protective potential of the CTL response induced by immunization of mice with rSFV-NP RNA was demonstrated by the reduction of virus load in the lungs after challenge infection with mouse-adapted influenza A/PR/8/34 virus and was comparable to the protective potential of the response induced by plasmid DNA immunization. These results demonstrate that naked RNA immunization with self-replicating molecules can effectively induce both humoral and cellular immune responses and constitutes an alternative strategy to DNA immunization.", }