DNA vaccines offer many advantages over more traditional approaches to immunization, but the levels of immunity induced by this new approach tend to be rather low. In several studies, protection against viral challenge has been conferred by DNA immunization, but levels of induced immunity were low or undetectable by standard in vitro methods. This proposal focuses on improving the immunogenicity of DNA vaccination, by optimizing several criteria (aims 1-3), and by specifically enhancing immunogenicity by co- administration of immunomodulatory molecules (aim 4).
The specific aims are: l. Evaluate different delivery vehicles for DNA. Efficiency of DNA delivery will be assessed when delivered """"""""naked', complexed with cationic lipid. or enclosed in liposomes. The evaluations will employ both marker genes, and immunogenic viral sequences, and both in vitro and in vivo experiments will be undertaken. 2. Evaluate different routes of inoculation. DNA will be administered by several routes, and its expression and immunogenicity determined. Additionally, the laboratory has access to a """"""""gene gun"""""""", which allows transdermal DNA delivery. The efficiency of this process will be compared to simple inoculations. 3. Evaluate different promoters. In concert with aims 1 & 2, I will attempt to optimize DNA expression and immunogenicity by using different transcriptional promoters. Three promoters will be employed; one to give general expression, one to direct transcription to muscle, and one to direct transcription to monocyte/macrophages. 4.Improve the immunogenicity of current DNA vaccines by co-expression of immunomodulatory molecules. Enhancement of immunogenicity will be attempted by co-inoculation of immunogenic DNA sequences and immunomodulatory molecules. Two classes of immunomodulator will be used; adhesion molecules, important in the close apposition of, and signaling between, T cells and antigen presenting cells: and cytokines, which may enhance T cell responses. 5.Evaluate the relative efficiency of DNA vaccines in generation of MHC class I-restricted immune responses, compared to generation of MHC class Il-restricted responses. By their nature, DNA vaccines may favor antigen presentation by the MHC class I path way, and disfavor presentation by MHC class II; this may lead to skewing in favor of CTL responses (and against antibody responses). Experiments will be carried out to address this concern. These experiments will be carried out using the LCMV model system. We have extensively characterized the immune response to this agent. and have identified sequences which confer immunity when employed as vaccines. DNA immunization in this system confers protection, though at a level lower than that conferred by more traditional vaccination. Thus we are ideally placed to optimize this DNA vaccine-induced antiviral protective immunity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI037186-01
Application #
2073830
Study Section
Special Emphasis Panel (SRC (58))
Project Start
1994-09-30
Project End
1997-08-31
Budget Start
1994-09-30
Budget End
1995-08-31
Support Year
1
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Scripps Research Institute
Department
Type
DUNS #
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Leifert, Jens A; Rodriguez-Carreno, Maria P; Rodriguez, Fernando et al. (2004) Targeting plasmid-encoded proteins to the antigen presentation pathways. Immunol Rev 199:40-53
Benning, Nicola; Hassett, Daniel E (2004) Vaccinia virus infection during murine pregnancy: a new pathogenesis model for vaccinia fetalis. J Virol 78:3133-9
Leifert, J A; Holler, P D; Harkins, S et al. (2003) The cationic region from HIV tat enhances the cell-surface expression of epitope/MHC class I complexes. Gene Ther 10:2067-73
Leifert, Jens A; Whitton, J Lindsay (2003) ""Translocatory proteins"" and ""protein transduction domains"": a critical analysis of their biological effects and the underlying mechanisms. Mol Ther 8:13-20
Leifert, J A; Harkins, S; Whitton, J L (2002) Full-length proteins attached to the HIV tat protein transduction domain are neither transduced between cells, nor exhibit enhanced immunogenicity. Gene Ther 9:1422-8
Zhang, Jie; Silvestri, Nicole; Whitton, J Lindsay et al. (2002) Neonates mount robust and protective adult-like CD8(+)-T-cell responses to DNA vaccines. J Virol 76:11911-9
Whitton, J L (2002) Designing arenaviral vaccines. Curr Top Microbiol Immunol 263:221-38
Theil, D J; Tsunoda, I; Rodriguez, F et al. (2001) Viruses can silently prime for and trigger central nervous system autoimmune disease. J Neurovirol 7:220-7
Whitton, J L; Fujinami, R S (2001) DNA immunization and central nervous system viral infection. Adv Virus Res 56:243-73
Leifert, J A; Lindencrona, J A; Charo, J et al. (2001) Enhancing T cell activation and antiviral protection by introducing the HIV-1 protein transduction domain into a DNA vaccine. Hum Gene Ther 12:1881-92

Showing the most recent 10 out of 27 publications