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.
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 (rDeltaP1-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 rDeltaP1-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-2D(b) 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.
Vignuzzi
Marco
M
Unité de Génétique Moléculaire des Virus Respiratoires, URA 1966 CNRS, Institut Pasteur, 25 rue du Dr Roux, F-75724 Paris cedex 15, France1.
Gerbaud
Sylvie
S
Unité de Génétique Moléculaire des Virus Respiratoires, URA 1966 CNRS, Institut Pasteur, 25 rue du Dr Roux, F-75724 Paris cedex 15, France1.
van der Werf
Sylvie
S
Unité de Génétique Moléculaire des Virus Respiratoires, URA 1966 CNRS, Institut Pasteur, 25 rue du Dr Roux, F-75724 Paris cedex 15, France1.
Escriou
Nicolas
N
Unité de Génétique Moléculaire des Virus Respiratoires, URA 1966 CNRS, Institut Pasteur, 25 rue du Dr Roux, F-75724 Paris cedex 15, France1.
D000818:Animals; D006183:H-2 Antigens / Q000276:immunology; D064532:Histocompatibility Antigen H-2D; D007111:Immunity, Cellular; D007114:Immunization; D016056:Immunodominant Epitopes / Q000276:immunology; D009980:Influenza A virus / Q000276:immunology* / Q000302:isolation & purification; D008168:Lung / Q000821:virology; D008285:Major Histocompatibility Complex / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009698:Nucleoproteins / Q000235:genetics / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D017955:Poliovirus / Q000235:genetics; D012367:RNA, Viral / Q000008:administration & dosage / Q000276:immunology*; D011995:Recombination, Genetic / Q000276:immunology; D012093:Replicon / Q000276:immunology*; D012672:Semliki forest virus / Q000235:genetics; D016176:T-Lymphocyte Subsets / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage; D019562:Viral Load; D014765:Viral Vaccines / Q000008:administration & dosage
D006183:H-2 Antigens; D064532:Histocompatibility Antigen H-2D; D016056:Immunodominant Epitopes; D009698:Nucleoproteins; D012367:RNA, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines