title: Co-expression of miRNA targeting the expression of PERK, but not PKR, enhances cellular immunity from an HIV-1 Env DNA vaccine.
abstract: Small non-coding micro-RNAs (miRNA) are important post-transcriptional regulators of mammalian gene expression that can be used to direct the knockdown of expression from targeted genes. We examined whether DNA vaccine vectors co-expressing miRNA with HIV-1 envelope (Env) antigens could influence the magnitude or quality of the immune responses to Env in mice. Human miR-155 and flanking regions from the non-protein encoding gene mirhg155 were introduced into an artificial intron within an expression vector for HIV-1 Env gp140. Using the miR-155-expressing intron as a scaffold, we developed novel vectors for miRNA-mediated targeting of the cellular antiviral proteins PKR and PERK, which significantly down-modulated target gene expression and led to increased Env expression in vitro. Finally, vaccinating BALB/c mice with a DNA vaccine vector delivering miRNA targeting PERK, but not PKR, was able to augment the generation of Env-specific T-cell immunity. This study provides proof-of-concept evidence that miRNA effectors incorporated into vaccine constructs can positively influence vaccine immunogenicity. Further testing of vaccine-encoded miRNA will determine if such strategies can enhance protective efficacy from vaccines against HIV-1 for eventual human use.
authors.affiliation: Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria, Australia.
authors.forename: Adam K
authors.initials: AK
authors.lastname: Wheatley
authors.forename: Marit
authors.initials: M
authors.lastname: Kramski
authors.forename: Marina R
authors.initials: MR
authors.lastname: Alexander
authors.forename: Jesse G
authors.initials: JG
authors.lastname: Toe
authors.forename: Rob J
authors.initials: RJ
authors.lastname: Center
authors.forename: Damian F J
authors.initials: DF
authors.lastname: Purcell
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology; D000818:Animals; D000998:Antiviral Agents / Q000378:metabolism; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D005799:Genes, Dominant / Q000235:genetics; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000378:metabolism; D015497:HIV-1 / Q000276:immunology*; D006367:HeLa Cells; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D019444:Vaccines, DNA / Q000276:immunology*; D019892:eIF-2 Kinase / Q000378:metabolism*; D054299:env Gene Products, Human Immunodeficiency Virus / Q000235:genetics / Q000378:metabolism*
chemical_list: D016915:AIDS Vaccines; D000998:Antiviral Agents; D049452:Green Fluorescent Proteins; D035683:MicroRNAs; D016601:RNA-Binding Proteins; D019444:Vaccines, DNA; D019892:eIF-2 Kinase; D054299:env Gene Products, Human Immunodeficiency Virus; C524942:MIRN155 microRNA, human; C104647:PRKRA protein, human; C485184:enhanced green fluorescent protein; C097729:gp140 envelope protein, Human immunodeficiency virus 1