title: Characterization of guinea pig T cell responses elicited after EP-assisted delivery of DNA vaccines to the skin.
abstract: The skin is an ideal target tissue for vaccine delivery for a number of reasons. It is highly accessible, and most importantly, enriched in professional antigen presenting cells. Possessing strong similarities to human skin physiology and displaying a defined epidermis, the guinea pig is an appropriate model to study epidermal delivery of vaccine. However, whilst we have characterized the humoral responses in the guinea pig associated with skin vaccine protocols we have yet to investigate the T cell responses. In response to this inadequacy, we developed an IFN-γ ELISpot assay to characterize the cellular immune response in the peripheral blood of guinea pigs. Using a nucleoprotein (NP) influenza pDNA vaccination regimen, we characterized host T cell responses. After delivery of the DNA vaccine to the guinea pig epidermis we detected robust and rapid T cell responses. The levels of IFN-γ spot-forming units averaged approximately 5000 per million cells after two immunizations. These responses were broad in that multiple regions across the NP antigen elicited a T cell response. Interestingly, we identified a number of NP immunodominant T cell epitopes to be conserved across an outbred guinea pig population, a phenomenon which was also observed after immunization with a RSV DNA vaccine. We believe this data enhances our understanding of the cellular immune response elicited to a vaccine in guinea pigs, and globally, will advance the use of this model for vaccine development, especially those targeting skin as a delivery site.
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Schultheis
authors.affiliation: Intracelluar Pathogens, Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany.
authors.forename: Hubert
authors.initials: H
authors.lastname: Schaefer
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA.
authors.forename: Bryan S
authors.initials: BS
authors.lastname: Yung
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA.
authors.forename: Janet
authors.initials: J
authors.lastname: Oh
authors.affiliation: Vaccine Center, The Wistar Institute of Anatomy & Biology, 3601 Spruce St., Philadelphia, PA 19104, USA.
authors.forename: Karuppiah
authors.initials: K
authors.lastname: Muthumani
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA.
authors.forename: Laurent
authors.initials: L
authors.lastname: Humeau
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA.
authors.forename: Kate E
authors.initials: KE
authors.lastname: Broderick
authors.affiliation: Inovio Pharmaceuticals, Inc., 660W. Germantown Pike, Suite 110, Plymouth Meeting, PA 19462, USA. Electronic address: tsmith@inovio.com.
authors.forename: Trevor R F
authors.initials: TR
authors.lastname: Smith
mesh_terms: D000818:Animals; D018274:Electroporation; D058501:Enzyme-Linked Immunospot Assay; D005260:Female; D006168:Guinea Pigs; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000276:immunology*; D007371:Interferon-gamma / Q000378:metabolism; D019590:Nucleocapsid Proteins; D016601:RNA-Binding Proteins / Q000276:immunology*; D012867:Skin / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014758:Viral Core Proteins / Q000276:immunology*
chemical_list: D007252:Influenza Vaccines; C048842:NP protein, Influenza A virus; D019590:Nucleocapsid Proteins; D016601:RNA-Binding Proteins; D019444:Vaccines, DNA; D014758:Viral Core Proteins; D007371:Interferon-gamma
keywords: DNA vaccine; ELISpot; Electroporation; Guinea pig; Skin; T cells