Vaccines containing peptides linked to stress proteins are the most potent known T cell immunogens. However, the precise mechanisms by which they activate immune cells remain unclear. To address this, we will track activated dendritic cells (DCs) and CD8+ T cells in mice immunized with antigens fused to the stress protein hsp70, and determine which cytokines and cell surface receptors are required for their responses. Our preliminary studies reveal hspTO fusion vaccines elicit much more potent and durable specific CD8+ T cell responses than antigen alone or with other adjuvants. Our underlying hypothesis is that antigen/hsp70 fusions are potent vaccines because they stimulate DCs to provide an optimal microenvironment for CD8+ T cell activation. This microenvironment is defined by high antigen density and strong costimulation. To test this, we will track in vivo DC and CD8+ T cell responses in draining lymph nodes, and the resultant effector and memory CD8+ T lymphocytes in the periphery. Novel aspects of our proposal include: 1) quantifying the amount of antigen presented by activated DCs, 2) the effect hsp70 fusion proteins have on DC lifespan, 3) determining which of the several reported hsp70-receptors are necessary or sufficient for delivering activation signals to DCs in vivo, and 4) determining the costimulatory and cytokines required for the profound effect our vaccine has CD8+ T cell memory. The results of these experiments will allow us to manipulate stress protein-induced responses rationally with the ultimate goal of maximizing their use for cancer therapy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA113576-03
Application #
7341718
Study Section
Transplantation, Tolerance, and Tumor Immunology (TTT)
Program Officer
Yovandich, Jason L
Project Start
2006-03-01
Project End
2010-01-31
Budget Start
2008-03-01
Budget End
2009-02-28
Support Year
3
Fiscal Year
2008
Total Cost
$252,477
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Pathology
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Dietz, Wynette M; Skinner, Nicole E B; Hamilton, Sara E et al. (2013) Minicircle DNA is superior to plasmid DNA in eliciting antigen-specific CD8+ T-cell responses. Mol Ther 21:1526-35