title: Cytokine-facilitated priming of CD8+ T cell responses by DNA vaccination.
abstract: Immune responses elicited by plasmid DNA vaccination can be enhanced and modulated by codelivery of cytokine-encoding plasmids. We studied whether priming of cytotoxic T lymphocyte (CTL) responses against hepatitis B surface antigen (HBsAg) by DNA vaccines injected either intramusculary or intradermally with the gene gun is enhanced by codelivery of cytokine-encoding plasmids. From a panel of tested cytokine plasmids only mouse IFNbeta, IL-15, and GM-CSF encoding plasmids showed an effect. Intradermal gene gun vaccination with 1 micro g plasmid DNA encoding intracellular HBsAg (large LS) showed enhanced CTL priming when IFNbeta, IL15, or GM-CSF encoding plasmids were codelivered; this was not observed when a DNA vaccine encoding secreted HBsAg (small S) was injected. Intramuscular injection of low (5 micro g) doses of a DNA vaccine encoding large HBsAg did not prime CTL when delivered without cytokines, with IFNbeta or IL15-encoding plasmids. However, codelivery with GM-CSF encoding plasmid DNA primed potent, specific CTL immunity detected either in a cytotoxic assay or by determining the frequency of L(d)-restricted CD8(+) T cells specifically inducible to IFNgamma production. The codelivery of GM-CSF encoding plasmids with the DNA vaccine furthermore enhanced CTL priming to a subdominant, D(d)-restricted epitope of HBsAg. The adjuvant effect of cytokine-encoding plasmids on CTL priming by DNA vaccines is thus complex and depends on: (a) the type of cytokine (or combination of cytokines) codelivered, (b) the type (intracellular vs. secreted) and dose (1-50 micro g) of the DNA vaccine, (c) the method of DNA vaccine delivery ("naked" vs. particle-coated DNA), and (d) the (intramuscular vs. intradermal) route of delivery of the DNA vaccine.
authors.affiliation: Institute for Medical Microbiology, University of Ulm, Albert Einstein Allee 11, 89081 Ulm, Germany.
authors.forename: Marcin
authors.initials: M
authors.lastname: Kwissa
authors.forename: Andrea
authors.initials: A
authors.lastname: Kröger
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Hauser
authors.forename: Jörg
authors.initials: J
authors.lastname: Reimann
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schirmbeck
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics* / Q000378:metabolism; D016899:Interferon-beta / Q000235:genetics* / Q000378:metabolism; D019409:Interleukin-15 / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D019444:Vaccines, DNA / Q000276:immunology*
chemical_list: D019409:Interleukin-15; D019444:Vaccines, DNA; D016899:Interferon-beta; D016178:Granulocyte-Macrophage Colony-Stimulating Factor